Miliarial-type gout in association with chronic use of glucocorticoids

A 59-year-old male patient with long-standing tophaceous gout (more than 30 years) characterized by polyarticular involvement and recurrent disseminated tophi formation; his past medical history is relevant for poor adherence to urate-lowering medications, as well as persistent use of self-prescribed systemic glucocorticoids. Despite achieving therapeutic goals for serum uric acid levels, new tophi formation with an intradermal location in the form of "miliarial-type gout" was documented. Due to functional limitations, the patient underwent surgical resection of the olecranon bursa. This case illustrates a widespread and recurrent tophi formation associated with long-standing gout and regular and sustained glucocorticoid use, despite an adequate disease control based on serum urate levels and involving an intradermal location of tophi presenting as "miliarial-type" lesions. In addition, the coexistence of urate and cholesterol crystal deposition disease in olecranon gouty bursitis is presented. Finally, a sonographic extended field of view of lesions distributed along the patient's extremities is presented as a novel characterization of this condition.

Rapamycin downregulates α-klotho in the kidneys of female rats with normal and reduced renal function

Both mTOR and α-klotho play a role in the pathophysiology of renal disease, influence mineral metabolism and participate in the aging process. The influence of mTOR inhibition by rapamycin on renal α-klotho expression is unknown. Rats with normal (controls) and reduced (Nx) renal function were treated with rapamycin, 1.3 mg/kg/day, for 22 days. The experiments were conducted with rats fed 0.6% P diet (NP) and 0.2% P diet (LP). Treatment with rapamycin promoted phosphaturia in control and Nx rats fed NP and LP. A decrease in FGF23 was identified in controls after treatment with rapamycin. In rats fed NP, rapamycin decreased mRNA α-klotho/GADPH ratio both in controls, 0.6±0.1 vs 1.1±0.1, p = 0.001, and Nx, 0.3±0.1 vs 0.7±0.1, p = 0.01. At the protein level, a significant reduction in α-klotho was evidenced after treatment with rapamycin both by Western Blot: 0.6±0.1 vs 1.0±0.1, p = 0.01, in controls, 0.7±0.1 vs 1.1±0.1, p = 0.02, in Nx; and by immunohistochemistry staining. Renal α-klotho was inversely correlated with urinary P excretion (r = -0.525, p = 0.0002). The decrease in α-klotho after treatment with rapamycin was also observed in rats fed LP. In conclusion, rapamycin increases phosphaturia and down-regulates α-klotho expression in rats with normal and decreased renal function. These effects can be observed in animals ingesting normal and low P diet.

Comparison of the efficacy of two alveolar recruitment manoeuvres in improving the lung mechanics and the degree of atelectasis in anaesthetized healthy sheep

The aim of the present study was to evaluate whether the application of two types of alveolar recruitment manoeuvres (ARMs) followed by a positive end-expiratory pressure (PEEP) improved lung mechanics and the degree of atelectasis caused by general anaesthesia. Twenty-one female Merino sheep were divided into three groups: sustained inflation ARM (ARMsust), stepwise ARM (AMRstep), and control (without ARM). Sheep received detomidine-morphine for premedication, propofol for induction, and isoflurane during general anaesthesia in a volume-controlled mode with 100% oxygen during the first 15 min of anaesthesia and 40% the rest of the study. The right jugular vein and metacarpal artery were catheterised for mixed venous and arterial blood sample collection, respectively. The quasistatic compliance (Cqst), oxygenation parameters, and shunt fraction (Qs/Qt) were monitored before ARM application (TpreARM), and at 10 (T10) and 60 min (T60) after ARM application. A pulmonary histopathological study was conducted on five animals from each group. A significant increase in Cqst was observed in both ARM groups at T10 compared to TpreARM (ARMsust: P = 0.001; ARMstep: P = 0.002), although only the ARMsust group showed significant differences compared to the control group. The ARMstep group presented a significant improvement in oxygenation parameters and Qs/Qt fraction (T10: 4.84 (3.26-16.48)%, P = 0.048; T60: 4.40 (4.31-14.16)%, P = 0.004) compared with TpreARM (21.48 (20.61-28.32)%). The ARMstep group had the highest percentage of alveolar area and the most homogeneous values. In conclusion, the application of a stepwise ARM followed by PEEP improved atelectasis caused by isoflurane anaesthesia in healthy sheep.

OP0168 DEVELOPMENT OF AN ULTRASOUND SCORING SYSTEM FOR CPPD EXTENT: RESULTS FROM A DELPHI PROCESS AND WEB-RELIABILITY EXERCISE BY THE OMERACT US WORKING GROUP

Background

Ultrasound (US) has proven to be an excellent imaging technique for detecting calcium pyrophosphate (CPP) deposition disease (CPPD); it is also widely available and inexpensive and can be performed during the clinic visit making it the preferred imaging modality for many rheumatologists. However, no validated grading systems have yet been developed allowing for a quantification of the extent of crystal deposition in CPPD.

Objectives

The aim of this study was to develop a scoring system for the quantification of CPP deposition at a patient level according to the OMERACT framework.

Methods

As part of the OMERACT methodology, we performed a systematic literature review (SLR) and meta-analysis aimed to estimate the prevalence of CPP deposition in peripheral joints by imaging, in order to identify relevant joints for CPPD monitoring. A preliminary survey was also circulated among the members of the OMERACT US – CPPD working group to collect their own suggestions according to their personal experience. Subsequently, a Delphi survey was prepared and circulated between members of the group, including statements that reflected both the results of the SLR and of the preliminary survey. In total, 32 statements were generated regarding the type of scoring for single structures, the sites to be included, the final scoring at patient level, and the scanning technique. Participants were asked to reply on a 5-point Likert scale (1, strongly disagree to 5, strongly agree) and agreement was achieved when 4 and 5 grades reached 75% or more of concordance. In case of disagreement, new statements were proposed according to the members’ suggestions and circulated for voting in a subsequent round. After agreement of a scoring system, the validation process began. Two rounds of a web-based exercise on static images were conducted on 120 images representing equally all sites under investigation and all degrees of crystal deposition, to assess the intra- and inter-reader reliability of the new scoring system. Representative images of the scoring system were visible throughout the entire exercise in order to facilitate the scoring of the lesions.

Results

Three Delphi rounds were needed to reach agreement on all items. 32/41 members of the OMERACT US-CPPD working group replied in the first round, 26/32 in the second, and 25/26 in the third round. Twenty statements were approved in the first round, 3 in the second, and 3 in the third round. Only the knees (menisci and hyaline cartilage) and the triangular fibrocartilage of the wrist were included in the final score, using a four-grade system (0-3). It was decided that each anatomical structure should be scored separately and then also summed in order to define the joint score. The sum of the assessed joints was the total score at patient level. The final scoring system with the definitions and the relative technical notes is represented in Figure 1. 33/41 members participated to the reliability exercise. The inter-reader reliability of the scoring was substantial (kappa of 0.72), and the intra-reader reliability was almost perfect (kappa of 0.82).

Conclusion

This is the first study for developing a scoring system for the extent of CPP crystal deposition in patients with CPPD. The scoring system demonstrated to be reliable in static images. The next step of the validation process is to assess the reliability of the scoring system in a patient-based exercise. This study represents a fundamental step in the OMERACT process of validating US as an outcome measure instrument, and above proposed scoring system will hopefully provide a useful tool for clinical practice and research.

Disclosure of Interests

None declared

POS0276 TRADITION VS INNOVATION! CONVENTIONAL RADIOGRAPHY AND ULTRASOUND IN THE DIAGNOSIS OF CPPD: INSTRUCTIONS FOR USE

Background

Conventional radiography (CR) is widely used as the first-line investigation for calcium pyrophosphate deposition (CPPD) disease, given its widespread use and the low cost. Next to it a series of advanced imaging techniques have been evaluated for accuracy and reliability. Among them, ultrasound (US) has been thoroughly tested and demonstrated to be accurate and reliable for CPPD diagnosis. However, even if there are data on the diagnostic accuracy of US and CR alone, it is not clear if performing both diagnostic tests and in which sequential order provides an added value for the diagnosis of CPPD.

Objectives

The aim of this study was to assess which diagnostic test performs better for the diagnosis of CPPD and if a combination of the two exams provides an additional value.

Methods

This is an ancillary study of the criterion validity of US in CPPD study1. Consecutive patients with knee osteoarthritis requiring total joint replacement were enrolled in 8 centres. Participants underwent US and CR of the affected knee prior to surgery. US was performed by experienced sonographers following the same scanning protocol described in the main study, while CR were performed in weight bearing AP and lateral views and were read by 2 experienced radiologists that reached a consensus on the presence/absence of CPPD. The evaluation of CPPD at the level of menisci and hyaline cartilage (HC) was based on the OMERACT definitions for US and on the new definitions developed by the ACR/EULAR CPPD classification criteria working group for CR [paper under submission]. Patients were classified as having CPPD considering histological examination as reference standard. Diagnostic indexes were calculated for US and CR alone and combined. Poisson models with robust estimation were used to estimate the best sequence of these diagnostic methods for a more accurate diagnosis of CPPD.

Results

51 pts were enrolled (63% F, mean age 74y ± 8). Diagnostic indexes of US and CR alone and combined are indicated in Table 1. Compared to histology, US demonstrated to be a sensitive tool for identification of CPPD at the knee, with a good sensitivity in all sites and in the overall evaluation. Instead, CR was less sensitive, but it was a highly specific exam for CPPD identification. Combining US and CR led to a higher sensitivity compared with CR alone, but a lower specificity compared to both CR and US alone, and it offered no additional increase in diagnostic accuracy. The Figure 1 shows the results of the appropriate sequence of use of US and CR in patients with suspected CPPD: in case of a positive CR at any of the 3 sites (menisci and HC) no additional exam is necessary, and the same in case of a positive US in at least two sites; however in case of a negative CR, US could help in a statistically significant way to identify CPPD patients, and further in case of a positive US in a single site CR can offer additional information.

Table 1.

diagnostic indexes of US, CR and US + CR in the identification of CPPD. MM: medial meniscus, LM: lateral meniscus, HC: hyaline cartilage, SN: sensitivity, SP: specificity, PPV: positive predictive value, NPV: negative predictive value, ACC: accuracy.

USSNSPPPVNPVACCMM0.880.810.820.880.84LM0.880.730.760.860.80HC0.780.860.820.830.82Overall0.920.640.730.890.78CRMM0.32110.610.67LM0.400.960.910.630.69HC0.480.930.850.680.73Overall0.540.920.880.660.73US + CRMM0.880.810.820.880.84LM0.920.690.740.900.80HC0.870.820.800.890.84Overall0.920.560.670.880.75Figure 1.

evaluation of sequence of US and CR

Conclusion

US confirmed a high diagnostic accuracy in identifying patients affected by CPPD at knee level, while CR demonstrated a high specificity but a low sensitivity. Performing both diagnostic tests could make sense in case of a negative CR or in case of an inconclusive US (only one positive site). To our knowledge, this is the first study that investigates the role of the combination of the two exams in CPPD. Further studies in a large number of patients and in different joints would be helpful to address this point.

References

[1]Filippou G. et al, Ann Rheum Dis, 2020

Disclosure of Interests

None declared

OP0291 SCORING STRUCTURAL DAMAGE IN RHEUMATOID ARTHRITIS BY ULTRASOUND: RESULTS FROM A DELPHI PROCESS AND WEB-RELIABILITY EXERCISE BY THE OMERACT US WORKING GROUP

Background

Structural damage in rheumatoid arthritis (RA) includes bone erosion, cartilage change, and joint malalignment; historically evaluated with conventional radiography. Ultrasound (US) has been shown to be a valid tool for evaluating both cartilage change and bone erosion.

Objectives

To obtain agreement on definitions and develop semiquantitative scoring systems for assessing structural damage by US and to validate these in a web-based reliability exercise.

Methods

A Delphi survey of statements was prepared by an OMERACT US Working Group task force (USWG) based on a previously published systematic literature review (1) and circulated between group members, including definitions on normal US appearance of joint components, definitions of elementary lesions and scoring systems for bone erosions and joint malalignment. Definitions and a US scoring system for scoring cartilage change were recently developed and validated by the USWG (2) After agreement was achieved (≥75% of grades 4-5 on 1-5 Likert scale) on the statements, still images of metacarpophalangeal and proximal interphalangeal joints 2-5 in healthy controls and in RA patients with varying degrees of pathology were acquired by the USWG members. A dataset of 100 anonymized images, representing various grades of the 3 components of structural damage was created and utilized in 2 rounds of a web-based exercise. Intra- and inter-reader reliability of the scoring systems was assessed by kappa statistics.

Results

19 USWG members needed 4 Delphi rounds to reach agreement on a total of 9 statements. 4/12 statements were approved in the first, 2/6 in the second, 1/5 in the third and 2/2 in the fourth round. Final scoring systems and representative images are shown in Table 1 & Figure 1. 22 members participated in the web-based reliability exercise. The intra-reader reliability was almost perfect for bone erosion (kappa: 0.87) and cartilage change (kappa: 0.83) and substantial for malalignment (kappa of 0.72). The inter-reader reliability was almost perfect for bone erosion (kappa: 0.85), and substantial for cartilage change (kappa: 0.79) and malalignment (0.62).

Table 1.

Final definitions of scoring systems of elementary lesions of structural damage in rheumatoid arthritis

AgreementBone erosionA 4-grade semiquantitative scoring system can be used to score erosions as follows: grade 0. intact cortical bone; grade 1. single small erosion (diameter: ≤2mm); grade 2. single large erosion (diameter: >2mm) or 2 small erosions; grade 3. 2 large erosions or ≥3 erosions, regardless of size. Both longitudinal and transverse scans should be considered, and the largest measure chosen for each erosion.100%Cartilage changeA 3-grade semiquantitative scoring system can be used to grade hyaline cartilage change as follows: grade 0. normal cartilage; grade 1. minimal change: focal thinning or incomplete loss of cartilage; grade 2. severe change: diffuse thinning or complete loss of cartilage.80% (2)MalalignmentA 3-grade semiquantitative scoring system can be used to grade malalignment as follows: 0. normal alignment; 1. subluxation or partial dislocation, where the two bone endings are malaligned so that one bone ending is dislocated from its normal position, but still within the articulation; 2. luxation or total dislocation, where the luxated bone ending moves beyond the articulation and the opposing bone ending. Bone position may be compared with a contralateral or similar intact joint if available.94%Figure 1.

Representative images of the scoring systems for bone erosion (A), cartilage change (B) and malalignment (C)

Conclusion

This first attempt to create a composite US instrument based on scoring systems encompassing all aspects of structural damage, demonstrates that US is a reliable tool for evaluating and scoring bone erosion, cartilage change and malalignment in the finger joints of RA patients.

References

[1]Gessl I, et al. Semin Arthritis Rheum. 2021 Jun;51(3):627-39.

[2]Mandl P, et al. Rheumatology (Oxford). 2019 Oct 1;58(10):1802-11.

Disclosure of Interests

Peter Mandl Speakers bureau: AbbVie, Janssen, Lilly, Novartis, Consultant of: AbbVie, Janssen, Lilly, Novartis, Grant/research support from: AbbVie, BMS, Novartis, Janssen, Lilly, MSD, UCB, Irina Gessl: None declared, Georgios Filippou: None declared, Silvia Sirotti: None declared, Lene Terslev Speakers bureau: Novartis, Pfizer, UCB, Janssen, GE, Carlos Pineda: None declared, Helen Keen Speakers bureau: Roche, AbbVie, Janssen, Consultant of: Sanofi, Marina Backhaus: None declared, David Andrew Bong: None declared, Edoardo Cipolletta: None declared, PAZ COLLADO: None declared, Christian Dejaco Speakers bureau: Roche, AbbVie, Sanofi, Lilly, Pfizer, Novartis, Janssen, Galapagos, Consultant of: Roche, AbbVie, Sanofi, Lilly, Pfizer, Novartis, Janssen, Galapagos, Andrea Delle Sedie Speakers bureau: Abbvie, Amgen, Lilly, MSD, Novartis, UCB, Paid instructor for: Abbvie, Amgen, Lilly, MSD, Novartis, UCB, Consultant of: Abbvie, Amgen, Lilly, MSD, Novartis, UCB, Christina Duftner: None declared, Hilde Berner Hammer: None declared, Annamaria Iagnocco: None declared, Zunaid Karim: None declared, Ingrid Möller Speakers bureau: Bristol-Myers Squibb, Ibsa, Pfizer, Galapagos, Esperanza Naredo Speakers bureau: Abbvie, Pfizer, Lilly, Novartis, Janssen, Celgene GmbH, Paid instructor for: Novartis, Consultant of: Novartis, Lilly, Grant/research support from: Lilly, Pfizer, Wolfgang A. Schmidt: None declared, Marcin Szkudlarek: None declared, Giorgio Tamborrini: None declared, Priscilla C Wong: None declared, Emilio Filippucci Speakers bureau: AbbVie, Amgen, Bristol -Myers Squibb, Janssen-Cilag, Lilly, Novartis, Pfizer, Roche, Union Chimique Belge Pharma, Peter Balint Speakers bureau: Abbvie, Janssen, Lilly, Novartis, Maria-Antonietta D’Agostino: None declared

Accuracy of synovial fluid analysis compared to histology for the identification of calcium pyrophosphate crystals: an ancillary study of the OMERACT US Working Group - CPPD subgroup

The aim of this study was to evaluate the accuracy of synovial fluid analysis in the identification of calcium pyrophosphate dihydrate crystals compared to microscopic analysis of joint tissues as the reference standard. This is an ancillary study of an international, multicentre cross-sectional study performed by the calcium pyrophosphate deposition disease (CPPD) subgroup of the OMERACT Ultrasound working group. Consecutive patients with knee osteoarthritis (OA) waiting for total knee replacement surgery were enrolled in the study from 2 participating centres in Mexico and Romania. During the surgical procedures, synovial fluid, menisci and hyaline cartilage were collected and analysed within 48 hours from surgery under transmitted light microscopy and compensated polarised light microscopy for the presence/absence of calcium pyrophosphate crystals. All slides were analysed by expert examiners on site, blinded to other findings. A dichotomic score (absence/ presence) was used for scoring both synovial fluid and tissues. Microscopic analysis of knee tissues was considered the gold standard. Sensitivity, specificity, accuracy, positive and negative predictive values of synovial fluid analysis in the identification of calcium pyrophosphate crystals were calculated. 15 patients (53% female, mean age 68 yo ± 8.4) with OA of grade 3 or 4 according to Kellgren-Lawrence scoring were enrolled. 12 patients (80%) were positive for calcium pyrophosphate crystals at the synovial fluid analysis and 14 (93%) at the tissue microscopic analysis. The overall diagnostic accuracy of synovial fluid analysis compared with histology for CPPD was 87%, with a sensitivity of 86% and a specificity of 100%, the positive predictive value was 100% and the negative predictive value was 33%. In conclusion synovial fluid analysis proved to be an accurate test for the identification of calcium pyrophosphate dihydrate crystals in patients with advanced OA.

AB0531 THERAPIES FOR PERIPHERAL JOINT INVOLVEMENT IN PSORIATIC ARTHRITIS: A SYSTEMATIC LITERATURE REVIEW

Background:

Much new information has been reported since the last evidence-based GRAPPA recommendations for the treatment of psoriasis and psoriatic arthritis (PsA).

Objectives:

We aimed to compile the evidence for the efficacy and safety of established and newly developed drugs targeting the peripheral arthritis domain in PsA so as to provide information for the revised GRAPPA treatment recommendations.

Methods:

A working group consisting of clinicians and patient research partners (PRPs) was convened. We performed an updated systematic literature review (SLR) of randomized controlled trials (RCTs) for the treatment of PsA, including peripheral arthritis, from the date of the last GRAPPA SLR, from February 19, 2013 to August 28, 2020. The working group reviewed the evidence supporting the efficacy on peripheral arthritis for each class of drug, according to the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach, for three patients groups: 1) naïve to treatment; 2) refractory to conventional (-c)DMARDs; and 3) with prior biological (-b)DMARD experience. We also evaluated the evidence for non-pharmacological treatments. A set of important outcomes for the peripheral arthritis domain was assessed for each class of medication. The certainty of evidence supporting each class of drugs for each patient group was evaluated. Recommendations were derived through consensus meetings.

Results:

87 articles from 52 RCTs were included. For patients with mild disease who are naïve to treatment, the working group strongly recommends csDMARDs (methotrexate, sulfasalazine, leflunomide) and PDE4i, and weakly recommends them for severe disease, where TNFi are preferred over csDMARDs. Other bDMARDs (IL-17i, IL-12/23i, IL-23i) and JAKi are strongly recommended to treat peripheral arthritis for treatment naïve patients. For patients with inadequate response to csDMARDs, we strongly recommend TNFi, IL-17i, IL-12/23i, IL-23i and JAKi. For those who had prior experience with bDMARDs, we strongly recommend a second TNFi, IL-17i, IL-23i and JAKi. Certainty of evidence (GRADE) and recommendations for peripheral arthritis domain of PsA for different population groups are shown in Table 1. While the evidence supporting non-pharmacological treatments was low, we derived the recommendations from clinician/PRP expert opinion, included advocating an increase in physical activity, smoking cessation and a healthy diet to control weight gain.

Conclusion:

Evidence supporting drug treatment for the peripheral arthritis domain of PsA was compiled, providing required information for the revised GRAPPA treatment recommendations. Further work seeking agreement from a broader group of stakeholders is in progress.

Table 1.

Certainty of evidence (GRADE) and Recommendation for peripheral arthritis of PsA

Treatment naivecsDMARD inadequate responsebDMARD inadequate responseDrug classevidence (GRADE)Recom-mendationevidence (GRADE)Recom-mendationevidence (GRADE)Recom-mendationPDE-4iMod to highStrong for(mild/ mod disease)Conditional for(severe disease)Mod to HighStrong forbDMARD exp: ModbDMARD IR: Mod (NS)Conditional for (bDMARD exp)Conditional against (bDMARD IR)TNFiHighStrong forHighStrong forModStrong fora 2ndTNFiTNFiVs. MTXHighStrong for TNFi as 1st line for severe disease----IL-17iHighStrong forHighStrong forMod to highStrong forIL-12/23iMod to highStrong forMod to HighStrong forLowConditional forIL-23iHighStrong forHighStrong forModStrong forJAKiMod*Strong forHighStrong forMod to HighStrong forCTLA4iVery LowConditional for†LowConditional for†Mod (NS)Conditional for†Dual TNFi/ IL17iModerateNA¥ModNA¥NANA¥IL-6iVery LowConditional againstVery low to lowConditional againstNAConditional against

NS: not statistically significant; *included data from abstract; ¥ not making recommendation due to not approved and not available in market; †reserve for no alternatives. Mod: Moderate; exp: experienced; IR: inadequate response.

Acknowledgements:

We are grateful to the contribution of our patient research partner, Rodrigo Firmino.

Disclosure of Interests:

None declared.

AB0629 ACCURACY OF SYNOVIAL FLUID ANALYSIS FOR THE IDENTIFICATION OF CALCIUM PYROPHOSPHATE CRYSTALS: AN ANCILLARY STUDY OF OMERACT CRITERION VALIDITY STUDY FOR ULTRASOUND IN CPPD

Background:

Synovial fluid analysis (SFA) via compensated polarized light microscopy is still considered the gold standard for the identification and diagnosis of Calcium Pyrophosphate Deposition disease (CPPD)-related arthropathies[1], but very few studies have been published about its diagnostic accuracy.

Objectives:

The aim of this study was to evaluate the accuracy of SFA in the identification of calcium pyrophosphate dihydrate (CPP) crystals compared to microscopic analysis of joint tissues as the reference standard.

Methods:

This is an ancillary study of an international, multicentre cross-sectional study performed by the CPPD subgroup of the OMERACT Ultrasound working group[2]. Consecutive patients with knee osteoarthritis (OA) waiting for total knee replacement surgery were enrolled in the study from 2 participating centres, Mexico and Romania. During surgical procedures synovial fluid (SF), menisci and hyaline cartilage were collected and analysed within 48 hours after surgery under transmitted light microscopy and compensated polarised light microscopy for the presence/absence of CPP crystals. All slides were analysed by expert examiners on site, blinded to other findings. A dichotomic score (absence/presence) was used for scoring both SF and tissues. Microscopic analysis of knee tissues was considered the gold standard. Sensitivity, specificity, accuracy, positive and negative predictive values (PPV and NPV) of SFA in the identification of CPP crystals were calculated.

Results:

15 patients (53% female, mean age 68yo ± 8.4) with OA of grade 3 or 4 according to Kellgren-Lawrence scoring were enrolled. 12 patients (80%) were positive for CPP crystals at SFA and 14 (93%) at tissues microscopic analysis. Among 12 SFA positive patients, all were positive for CPP crystals in either medial or lateral meniscus, and 11 were positive in both; 10 patients were positive at the hyaline cartilage, and all 10 were also positive for at least one meniscus. Regarding the 3 SFA negative patients, only one had no crystals in the examined tissues, while the other 2 patients had CPP crystals in both menisci and hyaline cartilage. The overall diagnostic accuracy of SFA compared to histology analysis for CPPD was 87%, with a sensitivity of 86% and a specificity of 100%, the PPV was 100% and the NPV was 33% (Table 1).

Table 1.

sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and diagnostic accuracy of synovial fluid analysis compared to the reference standard. CI: Confidential Interval. SF: synovial fluid, in parentheses: numerators and denominators for all percentages provided.

SensitivitySpecificityPPVNPVAccuracySF analysis86% (12/14)100% (1/1)100% (12/12)33% (1/3)87% (13/15)(0.65-0.99) CI 95%(0.0-0.25) CI 95%(0.65-0.99) CI 95%(0.0-0.25) CI 95%

Conclusion:

SFA demonstrated to be an accurate test for the identification of CPP crystals in patients with advanced OA. However, is not always feasible and carries some risks for the patient. Considering the availability of validated imaging techniques for the detection of CPPD, such as US, SFA could be used in those patients where imaging and clinical data are not definitely confirmatory of the disease.

References:

[1]W. Zhang et al., ‘European League Against Rheumatism recommendations for calcium pyrophosphate deposition. Part I: terminology and diagnosis’, Ann Rheum Dis, vol. 70, no. 4, pp. 563–570, Apr. 2011, doi: 10.1136/ard.2010.139105.

[2]G. Filippou et al., ‘Criterion validity of ultrasound in the identification of calcium pyrophosphate crystal deposits at the knee: an OMERACT ultrasound study’, Ann Rheum Dis, p. annrheumdis-2020-217998, Sep. 2020, doi: 10.1136/annrheumdis-2020-217998.

Disclosure of Interests:

None declared.

POS1132 DIAGNOSTIC ACCURACY OF CONVENTIONAL RADIOGRAPHY OF THE KNEE FOR CALCIUM PYROPHOSPHATE DEPOSITION DISEASE: AN ANCILLARY STUDY OF THE OMERACT ULTRASOUND – CPPD GROUP

Background:

Conventional Radiography (CR) has been widely used in the assessment of knee chondrocalcinosis (CC) and is still considered one of the most important diagnostic methods for the diagnosis. However, there are very few studies that examine the diagnostic accuracy of CR compared to histology of the knee tissues.

Objectives:

To assess the diagnostic accuracy of CR of the knee in Calcium Pyrophosphate Deposition Disease (CPPD) by using the recently created definitions for CPPD in CR of the ACR/EULAR taskforce for the new classification criteria for CPPD.

Methods:

This is an ancillary study of the Criterion Validity of Ultrasound in CPPD study [1]. Consecutive patients with osteoarthritis (OA) awaiting total knee replacement were enrolled in 4 centres from Romania, Italy, USA and Mexico. All patients underwent CR of the knees taken maximum 6 months before surgery, in posterior-anterior weight baring and lateral projections. DICOM files of the radiographs were anonymised and read independently by two musculoskeletal radiologists with experience in microcrystalline arthropathies. For each patient, a dichotomic score was used (absence/presence of CC) at the level of the menisci and tibiofemoral hyaline cartilage by each reader. The definitions of the ACR/EULAR taskforce for identification of CPPD in CR were used in this study [paper in preparation]. According to these definitions CPPD in CR appears as “linear or punctate opacities in the region of fibro- or hyaline articular cartilage/synovial membrane or joint capsule/within tendons or entheses that are distinct from denser, nummular radio-opaque deposits due to basic calcium phosphate deposition”. In case of disagreement a consensus decision was taken by both radiologists after discussion of the case. Menisci and the hyaline cartilage were analysed using compensated polarized light microscopy as described previously [1], patients were considered positive for CPPD if at least one of their tissue specimens revealed the presence of calcium pyrophosphate crystals. All examiners were blind to each other’s findings.

Results:

We enrolled 33 patients with OA (61% female, mean age 69yo). The accuracy values of CR in the various sites of the knee are indicated in Table 1. CR demonstrated to be a specific exam for identification of CPPD at the knee, but sensitivity remains low in all sites and in the overall evaluation. Identification of CPPD appears challenging and this could be due to the advanced grade of OA in our cohort of patients. Advanced degeneration, dislocation of the menisci and thinning of the hyaline cartilage in these patients is frequent and the eventual presence of calcific deposits in one of these structures could overlap with other anatomical structures making the exact localisation difficult. According to the results of the predictive values, the presence of typical deposition on CR allows a definite confirmation of the diagnosis, but a negative radiography does not exclude CPPD as testified by the low negative predictive value.

Table 1.

Sensitivity, specificity, PPV, NPV, accuracy and AUC of CR for identification of CPPD by using the new ACR/EULAR taskforce definitions.

Medial meniscusLateral meniscusHyaline cartilageOverallSensitivity22%33%31%42%Specificity100%100%85%90%Positive predictive value100%100%67%80%Negative predictive value56%60%55%61%Accuracy61%68%58%66%AUC0.60.70.60.7

Conclusion:

CR has been extensively used for the diagnosis of OA and CPPD and has been tested previously for diagnostic accuracy. The results of our study confirm that the presence of typical CPPD calcifications, as defined by the ACR/EULAR task force, are highly specific but have low sensitivity for disease identification when using CR. Absence of CPPD on CR does not exclude the diagnosis.

References:

[1]Filippou G, et al. Criterion validity of ultrasound in the identification of calcium pyrophosphate crystal deposits at the knee: an OMERACT ultrasound study. Ann Rheum Dis 2020. doi:10.1136/annrheumdis-2020-217998

Disclosure of Interests:

None declared.

POS1141 ASSESSING RELEVANT JOINTS FOR MONITORING CPPD DISEASE: A SYSTEMATIC LITERATURE REVIEW OF IMAGING TECHNIQUES BY THE OMERACT ULTRASOUND – CPPD SUBGROUP

Background:

Imaging has been extensively used for the Calcium Pyrophosphate Deposition Disease (CPPD) diagnosis but the prevalence of joint calcifications at imaging in CPPD patients has not been thoroughly assessed.

Objectives:

This systematic literature review (SLR) is aimed to estimate the prevalence of calcium crystal deposition in peripheral joints by imaging in suspected or definite CPPD patients to establish relevant joints for CPPD monitoring

Methods:

After defining PICOs, Pubmed and Embase were searched from inception to October 2020 for identifying studies that evaluated the use of Conventional Radiography (CR), Ultrasound (US), Computed Tomography (CT) and Dual Energy Computed Tomography (DECT) in detecting calcifications at peripheral joints in patients with defined or probable CPPD. Search strategies based on MeSH terms and free text were applied. Six reviewers independently screened titles and abstracts, eligible article full texts were evaluated for inclusion and data extraction.

Results:

The SLR identified 1149 manuscripts. 524 papers entered in the full text evaluation and 181 articles were finally included. Considering excluded abstracts and full texts, 23 and 17 were excluded as duplicate, 156 and 9 for language, 171 and 48 for population, 171 and 20 for intervention, 57 and 117 for outcome, 47 and 70 for study type and 76 for full text unavailability. Among included, 41 papers considered patients with definite CPPD with a total population of 1239 patients, 908 cases and 331 controls and 140 papers referred to patients with suspected CPPD with a total population of 26785 patients, 2896 affected by CPPD and 23889 controls. The results about all joints are summarized in the Table 1. In patients with definite diagnosis, knee and wrist are the joints with the highest prevalence of calcifications at all imaging types, followed by hip and acromion-clavicular joint while in patients with suspected CPPD, the knee is the most prevalent followed by the wrist, hip and ankle (only sites with more than 50 patients assessed considered). The hand joints are characterized by CPPD lowest prevalence at imaging. Bilateral imaging findings varies depending on the technique used, the site and the patient’s type.

Table 1.

Definite CPPD Diagnosis

KNEEWRISTHANDELBOWSHOULDERACHIPANKLEFOOTTMXRImaging positive cases/all cases330/584 57%214/409 52%43/158 27%54/212 25%65/249 26%37/84 44%140/293 48%30/255 12%15/59 25%0Cases positivebilaterally99/146 68%30/79 38%0/104/12 33%2/2 100%9/17 53%7/10 70%7/10 70%00USImaging positive cases/all cases155/252 62%86/118 75%4/42 9%2/2 100%0/304/30 13%47/80 59%30/255 12%15/59 25%0Cases positivebilaterally83/96 86%33/47 70%1/ 4 25%003/ 4 75%29/47 62%7/10 70%00CTImaging positive cases/all cases41/50 82%22/28 78%00000000Cases positivebilaterally27/30 90%000000000DECTImaging positive cases/all cases8/10 80%9/10 90%1/1 100%0000000Cases positivebilaterally001/1 100%0000000Suspected CPPD diagnosisKNEEWRISTHANDELBOWSHOULDERACHIPANKLEFOOTTMXRImaging positive cases/all cases1989/2442 81%549/1024 54%98/602 16%29/72 40%75/185 41%27/31 87%322/887 36%56/116 48%24/42 57%0Cases positive bilaterally611/1068 57%209/334 63%64/85 75%22/23 96%41/46 89%0/294/196 48%44/53 83%18/19 95%0USImaging positive cases/all cases241/261 93%125/185 68%2/39 5%1/1 100%4/12 33%02/2 100%27/78 35%8/37 22%0Cases positivebilaterally4/9 44%74/93 80%00000000CTImaging positive cases/all cases019/23 83%002/2 100%02/2 100%001/1 100%Cases positivebilaterally0000000001/1 100%DECTImaging positive cases/all cases1/1 100%2/2 100%00000000Cases positivebilaterally1/1 100%000000000

Table 1 For each joint, are summarized the ratio between positive joints and overall evaluated joints and the ratio between the joints positive bilaterally and overall joints evaluated bilaterally.

AC Acromion Clavicular, TM temporo mandibular

Conclusion:

According to the results of this SLR, knees and wrists could be the sentinel joints for CPPD detection by imaging.

Disclosure of Interests:

None declared.

POS1133 RELIABILITY OF CONVENTIONAL RADIOGRAPHY OF THE KNEE FOR THE ASSESSMENT OF CHONDROCALCINOSIS: AN ANCILLARY STUDY OF THE OMERACT ULTRASOUND – CPPD GROUP

Background:

Conventional Radiography (CR) has been widely used in the assessment of knee chondrocalcinosis (CC) and is still considered one of the most important diagnostic methods for the diagnosis. However, there are no studies on the reliability of CR for CC.

Objectives:

To assess the reliability of CR of the knee in the assessment of chondrocalcinosis (CC).

Methods:

This is an ancillary study of the Criterion Validity of Ultrasound in Calcium Pyrophosphate Deposition Disease (CPPD) study [1]. Consecutive patients with knee osteoarthritis (OA) that were planned for total knee replacement surgery were enrolled in 4 centres from Romania, Italy, USA and Mexico. All patients underwent CR of the knees taken maximum 6 months before surgery, in posterior-anterior weight baring and lateral projections. DICOM files of the radiographs were retrieved, anonymised and read independently by two musculoskeletal radiologists with experience in microcrystalline arthropathies. Each reader performed a second evaluation 3 weeks after the first one to calculate the inter- and intra-reader agreement. For each patient a dichotomic score was assigned (absence/presence of CC) at the level of the medial and lateral menisci, tibiofemoral hyaline cartilage, quadriceps and patella tendons, synovial membrane/joint capsule. The definitions of the ACR/EULAR taskforce for identification of CPPD in conventional radiography were used in this study [paper in preparation]. According to these definitions CPPD in CR appears as “linear or punctate opacities in the region of fibro- or hyaline articular cartilage/synovial membrane or joint capsule/within tendons or entheses that are distinct from denser, nummular radio-opaque deposits due to basic calcium phosphate deposition”. Cohen’s kappa was used to calculate the agreement between the two readers.

Results:

We enrolled 33 patients with knee OA (60.6% female, mean age 69yo ± 8). The kappa values of the inter-reader and intra-reader agreement in the various sites of the knee are indicated in Table 1. Inter-reader agreement was substantial at the level of both menisci but only moderate or fair at the other sites of assessment. This had a negative impact on the overall evaluation of the knee joint that proved to be unreliable (k of 0.16 – none to slight agreement) if all anatomical structures are included for assessment, and moderately reliable (kappa 0.41) when both menisci and hyaline cartilage are considered. On the other hand, intra-reader kappa values were substantial or higher in all sites (except for synovial membrane/joint capsule for one reader). The striking difference of the intra-reader compared to the inter-reader kappa values, highlight a different interpretation and application of the definitions used for most of the sites with the exception of the menisci.

Table 1.

kappa values for intra- and inter-reader agreement. Values from 0.01–0.20 are considered as none to slight agreement, 0.21–0.40 as fair, 0.41– 0.60 as moderate, 0.61–0.80 as substantial, and 0.81–1.00 as almost perfect agreement.

Medial meniscusLateral meniscusHyaline cartilageQuadriceps tendonPatellar tendonCapsule/ synoviaMenisci + cartilageEntire jointInter-reader0.670.710.340.47NA0.370.400.17Intra-reader 1st assessor0.670.900.840.65NA(insufficient number of categories)0.530.710.76Intra-reader 2nd assessor10.801110.910.860.94

Conclusion:

CR has been extensively used for diagnosis of OA and CPPD. The results of our study raise some concerns on the reliability of CR in identification of CPPD. Assessment of calcium crystals at the menisci level should be used for identification of CC as other sites of the knee seem to present low reliability.

References:

[1]Filippou G et al. Criterion validity of ultrasound in the identification of calcium pyrophosphate crystal deposits at the knee: an OMERACT ultrasound study. Ann Rheum Dis 2020. doi:10.1136/annrheumdis-2020-217998

Disclosure of Interests:

None declared.

Cost of tuberculosis treatment in low- and middle-income countries: systematic review and meta-regression

BACKGROUND: Despite a scarcity of tuberculosis (TB) cost data, a substantial body of evidence has been accumulating for drug-susceptible TB (DS-TB) treatment. In this study, we review unit costs for DS-TB treatment from a provider´s perspective. We also examine factors driving cost variations and extrapolate unit costs across low- and middle-income countries (LMICs).METHODS: We searched published and grey literature for any empirically collected TB cost estimates. We selected a subgroup of estimates looking at DS-TB treatment. We extracted information on activities and inputs included. We standardised costs into an average per person-month, fitted a multi-level regression model and cross-validated country-level predictions. We then extrapolated estimates for facility-based, directly observed DS-TB treatment across countries.RESULTS: We included 95 cost estimates from 28 studies across 17 countries. Costs predictions were sensitive to characteristics such as delivery mode, whether hospitalisation was included, and inputs accounted for, as well as gross domestic product per capita. Extrapolation results are presented with uncertainty intervals (UIs) for LMICs. Predicted median costs per 6 months of treatment were US$315.30 (95% CI US$222.60-US$417.20) for low-income, US$527.10 (95% CI US$395.70-US$743.70) for lower middle-income and US$896.40 (95% CI US$654.00-US$1214.40) for upper middle-income countries.CONCLUSIONS: Our study provides country-level DS-TB treatment cost estimates suitable for priority setting. These estimates, while not standing as a substitute for local high-quality primary data, can inform global, regional and national exercises.

Structural damage in rheumatoid arthritis assessed by musculoskeletal ultrasound: A systematic literature review by the Structural Joint Damage Task Force of the OMERACT Ultrasound Working Group

OBJECTIVES

To identify and synthesize the evidence for the use and measurement properties of musculoskeletal ultrasound in assessing structural joint damage in patients with rheumatoid arthritis (RA).

METHODS

A systematic literature search (SLR) of the PubMed, Embase and Cochrane Library was performed. Original articles were included published in English reporting on ultrasound of bone erosion, cartilage damage and the measurement properties of ultrasound according to the OMERACT filter 2.1.

RESULTS

Of the 1.495 identified articles 149 were included in the final review, most of which reported on cross-sectional studies and used the OMERACT definitions for ultrasonographic pathology. Among these, bone erosions were assessed in 139 (93.3%), cartilage damage in 24 (16.1%), enthesophytes in 8 (5.4%), osteophytes in 15 (10.1%) and malalignment and ankylosis in a single (0.9%) study, respectively. Most studies (126/149, 84.6%) assessed the joints of the hands. The overwhelming majority of studies (127/149, 85.2%) assessed structural joint damage bilaterally. Validity, reliability and responsiveness were assessed in 21 (14.1%), 34 (22.8%) and 17 (11.4%) studies, respectively.

CONCLUSION

While the results of this SLR suggest that ultrasound is a sensitive, reliable and feasible tool to detect damage in RA, they also highlight the need for further research and validation. Findings of this SLR will inform the next steps of the OMERACT Ultrasound Working Group in developing an ultrasound score for assessing structural joint damage in patients with RA.

Increased 1,25(OH)2-Vitamin D Concentrations after Energy Restriction Are Associated with Changes in Skeletal Muscle Phenotype

The influence of energy restriction (ER) on muscle is controversial, and the mechanisms are not well understood. To study the effect of ER on skeletal muscle phenotype and the influence of vitamin D, rats (n = 34) were fed a control diet or an ER diet. Muscle mass, muscle somatic index (MSI), fiber-type composition, fiber size, and metabolic activity were studied in tibialis cranialis (TC) and soleus (SOL) muscles. Plasma vitamin D metabolites and renal expression of enzymes involved in vitamin D metabolism were measured. In the ER group, muscle weight was unchanged in TC and decreased by 12% in SOL, but MSI increased in both muscles (p < 0.0001) by 55% and 36%, respectively. Histomorphometric studies showed 14% increase in the percentage of type IIA fibers and 13% reduction in type IIX fibers in TC of ER rats. Decreased size of type I fibers and reduced oxidative activity was identified in SOL of ER rats. An increase in plasma 1,25(OH)₂-vitamin D (169.7 ± 6.8 vs. 85.4 ± 11.5 pg/mL, p < 0.0001) with kidney up-regulation of CYP27b1 and down-regulation of CYP24a1 was observed in ER rats. Plasma vitamin D correlated with MSI in both muscles (p < 0.001), with the percentages of type IIA and type IIX fibers in TC and with the oxidative profile in SOL. In conclusion, ER preserves skeletal muscle mass, improves contractile phenotype in phasic muscles (TC), and reduces energy expenditure in antigravity muscles (SOL). These beneficial effects are closely related to the increases in vitamin D secondary to ER.

Nociceptive related microRNAs and their role in rheumatoid arthritis

Rheumatoid Arthritis (RA) is an autoimmune disease with unknown etiology and a global incidence around 1%, a positive family history increases the risk of RA roughly three to five times. Pain is one of the first symptoms to appear in this disease. MicroRNAs (miRNAs) belong to the class of small non-coding RNAs; they regulate multiple cellular processes including embryonic development, cellular proliferation, differentiation and apoptosis among others. A great deal of evidence points to the employment of miRNAs as therapeutic targets and biomarkers for several pathologies. The main objective of this Review is to assess how miRNAs participate in the pathogenesis of RA. Two advanced searches were conducted in databases, one using "micro-RNA" and "rheumatoid arthritis" as key words, and another one with "micro-RNA", "pain" and "nociception". In this Review, we describe how six miRNAs: miR-16-5p, miR-23b-3b, miR-124-3p, miR-146a-5p, miR-155-5p and miR-223-3p, involved in the modulation and transmission of the nociceptive input are unregulated in RA patients. Key molecular pathways involved in nociception, inflammation and autoimmune responses, are regulated by these miRNAs; the NF-κB, TNF-α, interleukins and TLR4. By means of gene repression, the miRNAs here described modulate the nociceptive process as well as the autoimmune response that characterize this disease.

OP0317 ACCURACY OF THE OMERACT DEFINITIONS FOR IDENTIFICATION OF CALCIUM PYROPHOSPHATE CRYSTALS WITH ULTRASOUND: FINAL RESULTS OF THE OMERACT US IN CPPD SUB-TASK FORCE STUDY

Background:

The OMERACT Ultrasound (US) in calcium pyrophosphate deposition disease (CPPD) sub-task force has been working on the use of US in CPPD since 2014 first creating definitions for CPPD identification and then assessing the reliability[1].

Objectives:

Objective of this study is to assess the diagnostic accuracy (truth) of US in CPPD.

Methods:

Consecutive patients waiting to undergo knee replacement surgery due to osteoarthritis were enrolled in 12 centres from 6 countries. Each patient underwent US examination of the knee, focusing on the menisci and the hyaline cartilage, the day prior to surgery, scoring each site for presence/absence of CPP as defined previously[1]. After surgery, the menisci and the condyles were retrieved and examined microscopically. Six samples were collected, both from the surface and from the internal part of menisci and cartilage trying to cover a large part of it. All slides were observed under transmitted light microscopy and by compensated polarised microscopy. A dichotomous score was given for the presence/absence of CPP. US and microscopic analysis were performed by different operators, blind to each other’s findings. Sensitivity and specificity of US were calculated using microscopic findings as the gold standard.

Results:

101 patients have been enrolled in the study. 33 patients have been excluded due to loss of anatomical pieces at surgery. The mean age of the remaining 68 pts was 71yo (±8), 44 women, 34 were affected by CPPD according to microscopy. Overall and per site diagnostic US accuracy results are presented in table 1

Diagnostic accuracySensitivitySpecificityPositive Predictive valueNegative Predictive valueGlobal0.750.910.590.690.87Medial meniscus0.820.870.770.770.87Lateral meniscus0.750.830.680.680.83Medial cartilage0.860.790.920.880.85Lateral cartilage0.820.710.880.770.84Medial side (combined cartilage and meniscus)0.820.880.760.790.87Lateral side (combined cartilage and meniscus)0.780.880.690.730.86

Conclusion:

Our results demonstrate that US is an accurate exam for identification of CPPD. The best combination of sensitivity and specificity is achieved by examining the medial aspect of the knee.

References:

[1]Filippou G, Scirè CA, Adinolfi A,et al.Identification of calcium pyrophosphate deposition disease (CPPD) by ultrasound: reliability of the OMERACT definitions in an extended set of joints—an international multiobserver study by the OMERACT Calcium Pyrophosphate Deposition Disease Ultrasound Subtask Force.Ann Rheum Dis2018;:annrheumdis-2017-212542. doi:10.1136/annrheumdis-2017-212542

Disclosure of Interests:

Georgios Filippou: None declared, Anna Scanu: None declared, Antonella Adinolfi: None declared, Carmela Toscano: None declared, Dario Gambera: None declared, Raquel Largo: None declared, Esperanza Naredo: None declared, Emilio Calvo: None declared, Gabriel Herrero-Beaumont: None declared, Pascal Zufferey: None declared, Christel Madelaine-Bonjour: None declared, Daryl MacCarter: None declared, Stanley Makman: None declared, Zachary Weber: None declared, Fabiana Figus: None declared, Ingrid Möller: None declared, Marwin Gutierrez: None declared, Carlos Pineda: None declared, Denise Clavijo Cornejo: None declared, Héctor García: None declared, Victor Ilizaliturri: None declared, Jaime Mendoza Torres: None declared, Raul Pichardo: None declared, Luis Carlos Rodriguez Delgado: None declared, Emilio Filippucci Speakers bureau: Dr. Filippucci reports personal fees from AbbVie, personal fees from Bristol-Myers Squibb, personal fees from Celgene, personal fees from Roche, personal fees from Union Chimique Belge Pharma, personal fees from Pfizer, outside the submitted work., Edoardo Cipolletta: None declared, Teodora Serban: None declared, Catalin Cirstoiu: None declared, Florentin Ananu Vreju: None declared, Dun Grecu: None declared, Gael Mouterde: None declared, Marcello Govoni: None declared, Leonardo Punzi: None declared, Nemanja Damjanov Grant/research support from: from AbbVie, Pfizer, and Roche, Consultant of: AbbVie, Gedeon Richter, Merck, Novartis, Pfizer, and Roche, Speakers bureau: AbbVie, Gedeon Richter, Merck, Novartis, Pfizer, and Roche, Lene Terslev Speakers bureau: LT declares speakers fees from Roche, MSD, BMS, Pfizer, AbbVie, Novartis, and Janssen., Carlo Alberto Scirè: None declared, Annamaria Iagnocco Grant/research support from: Abbvie, MSD and Alfasigma, Consultant of: AbbVie, Abiogen, Alfasigma, Biogen, BMS, Celgene, Eli-Lilly, Janssen, MSD, Novartis, Sanofi and Sanofi Genzyme, Speakers bureau: AbbVie, Alfasigma, BMS, Eli-Lilly, Janssen, MSD, Novartis, Sanofi

P0919CALORIC RESTRICTION DOES NOT PROTECT AGAINST THE DEVELOPMENT OF VASCULAR CALCIFICATION

Background and Aims

Vascular calcification (VC) is an important contributor to the high rate of cardiovascular mortality associated to chronic kidney disease.

The inability to eliminate phosphorus (P) and the subsequent P retention promotes CV. P metabolism and uremic VC are influenced by obesity and by the caloric content of the diet.

Caloric restriction (CR) has been shown to have multiple beneficial effects on health, for example, CR has been reported to improve vascular health and retard vascular ageing. However, to our knowledge the effect of CR on the development of uremic VC has not been explored.

We hypothesize that CR may be beneficial to prevent the development of uremic VCs. Thus, the objective of the present study was to determine if rats subjected to CR were protected against VC.

Method

48 Wistar rats were divided in four groups. The control diet provided Metabolizable Energy = 3.528 kcal/g and contained 0.6% Calcium (Ca) and 0.6% P. Additional diets of identical composition to the control diet but containing varying levels of Ca and P: 0.9% Ca, 0.9% P; 0.6% Ca, 1.2% P; and 0.9% Ca, 1.8% P, were also used in the experiments.

Rats in Group 1 and 3 were fed 15 g/day of the control diet. Rats in Group 2 and 4 were calorie restricted and fed 10 g/day of diet with Ca/P = 0.9%/0.9%. Thus the daily P intake should be identical in the four groups.

Uremia was induced by 5/6 nephrectomy (Nx). After Nx rats in Group 1 and 2 were fed ad libitum a diet with 0.6% Ca and 1.2% P. While rats in Group 3 and 4 were fed ad libitum a diet with 0.9% Ca and 1.8% P. Rats were supplemented with calcitriol.

At the end of the experiment, rats were sacrificed to obtain blood samples and tissue samples (thoracic and abdominal aortas).

After blood collection, plasma was separated by centrifugation and stored at –20° C until assayed. Plasma creatinine, Ca and P were measured by spectrophotometry. Energy intake was calculated based on food intake. VC was studied by histology and by measuring the tissue Ca content.

Values are expressed as mean ± standard error (SE), the difference between groups was assessed by ANOVA. Fisher LSD test was used as a post-hoc procedure. p&lt;0.05 was considered significant.

Results

Before Nx, caloric intake was significantly lower in calorie restricted rats (35.4 ± 0.1 and 35.8 ± 0.1 kcal/day) than in rats eating normal calories (52.7 ± 0.1 and 52.8 ± 0.2 kcal/day); however, P intake was almost identical in the four groups and ranged between 89.8 and 91.6 mg/day.

After Nx, rats in all groups reduced food intake and, consequently, caloric intake. Thus, although the P content of the diet was increased after Nx, daily P intake was not increased in Groups 1 and 2; however, P intake was significantly increased in Groups 3 and 4 (120.9 ± 4.6 and 122.2 ± 6.2 mg/day, respectively).

In all groups, rats had high plasma concentrations of creatinine and P, and low plasma concentrations of Ca. Also, all rats had elevated Ca content in the aorta. No significant differences between the study groups were found in any of these parameters (Table 1).

Von Kossa staining of the aortas showed abundant mineral deposition in the four groups.

Conclusion

This study shows that, contrary to what was expected, CR did not prevent or ameliorate uremic calcifications.

Effect of caloric restriction on phosphate metabolism and uremic vascular calcification

Caloric restriction (CR) is known to have multiple beneficial effects on health and longevity. To study the effect of CR on phosphorus metabolism and vascular calcification (VC), rats were fed normal or restricted calories (67% of normal). The phosphorus content of the diets was adjusted to provide equal phosphorus intake independent of the calories ingested. After 50 days of CR, rats had negative phosphorus balance, lower plasma phosphorus, glucose, triglycerides, and leptin, and higher adiponectin than rats fed normal calories. Uremia was induced by 5/6 nephrectomy (Nx). After Nx, rats were treated with calcitriol (80 ng/kg ip every other day) and high-phosphorus diets (1.2% and 1.8%). No differences in aortic calcium content were observed between rats that ate normal or restricted calories before Nx in either rats that received 1.2% phosphorus (11.5 ± 1.7 vs. 10.9 ± 2.1 mg/g tissue) or in rats that received 1.8% phosphorus (12.5 ± 2.3 vs. 12.0 ± 2.9 mg/g of tissue). However, mortality was significantly increased in rats subjected to CR before Nx in both the 1.2% phosphorus groups (75% vs. 25%, P = 0.019) and 1.8% phosphorus groups (100% vs. 45%, P < 0.001). After calcitriol administration was stopped and phosphorus intake was normalized, VC regressed rapidly, but no significant differences in aortic calcium were detected between rats that ate normal or restricted calories during the regression phase (5.7 ± 2.7 and 5.2 ± 1.5 mg/g tissue). In conclusion, CR did not prevent or ameliorate VC and increased mortality in uremic rats.

Structural and ultrastructural renal lesions in rats fed high-fat and high-phosphorus diets

Background

Foods prone to deteriorate renal function are rich in fat and in phosphorus (P), but the interaction between these two factors is not well studied.

Method

Detailed structural and ultrastructural histopathological studies were performed on the kidneys of rats fed different amounts of fat and P: low (4%) fat (LF) and normal (0.6%) P (NP), LF and high (1.2%) P (HP), high (35%) fat (HF) and NP, HF and HP, and HF with low (0.2%) P (LP) for 28 weeks.

Results

Glomeruli of the HF groups showed segmental areas of retraction, sclerosis and thickening of the Bowman’s capsule and basal membranes, which were more accentuated in the HF–HP group. Ultrastructural lesions in the glomeruli also were prominent in rats fed HF, particularly in the HF–HP group, and included thickening of the capillary membrane, endothelial damage, mesangial matrix hypercellularity and podocyte effacement. P restriction reduced the severity of endothelial damage, mesangial matrix hypercellularity, thickening of capillary basement membrane and podocyte effacement. The kidneys of rats fed HP showed significant tubular atrophy and dilatation, focal tubular hyperplasia, thickening of the tubular basal membrane, interstitial edema, inflammation and calcification. All groups fed HF also showed tubular lesions that were more prominent in the HF–HP group. P restriction had a beneficial effect on inflammation and calcification.

Conclusions

Intake of both HF and HP damages the kidneys and their noxious effects are additive. HF intake was preferentially associated with glomerular lesions, while lesions related to HP intake were located mainly in the tubuli and in the interstitium.

Hypervitaminosis D has no positive effects on goat tuberculosis and may cause chronic renal lesions

BACKGROUND

There is evidence for a link between vitamin D deficiency and active tuberculosis (TB). In human beings, several trials have evaluated the role of vitamin D supplementation in TB treatment with conflicting results. However, the role of vitamin D supplementation in animal TB control has received less attention. The authors evaluated the benefit of vitamin D supplementation for preventing mycobacterial infection or reducing TB lesions (TBL) in a controlled trial with goats naturally exposed to Mycobacterium caprae.

METHODS

Two groups of goats, a vitamin D-supplemented group and a non-supplemented control group, were housed for 10 months in direct contact with M caprae-infected adult goats. Upon contact with the infected adult goats, all animals were TB-tested every two months.

RESULTS

No experimental evidence of a protective effect of vitamin D supplementation based on M caprae culture prevalence, TBL prevalence, median TBL score or the proportion of single versus multiple organs presenting TBL was observed.

CONCLUSION

The results indicate that, in the conditions used in this study, vitamin D supplementation in goats does not reduce TB infection risk nor the diffusion and severity of TBL. In addition, vitamin D-supplemented goats presented hyperphosphataemia and renal injury with calcifications suggestive of vitamin D intoxication.

Calcimimetics maintain bone turnover in uremic rats despite the concomitant decrease in parathyroid hormone concentration

Calcimimetics decrease parathyroid hormone (PTH) secretion in patients with secondary hyperparathyroidism. The decrease in PTH should cause a reduction in bone turnover; however, the direct effect of calcimimetics on bone cells, which express the calcium-sensing receptor (CaSR), has not been defined. In this study, we evaluated the direct bone effects of CaSR activation by a calcimimetic (AMG 641) in vitro and in vivo. To create a PTH "clamp," total parathyroidectomy was performed in rats with and without uremia induced by 5/6 nephrectomy, followed by a continuous subcutaneous infusion of PTH. Animals were then treated with either the calcimimetic or vehicle. Calcimimetic administration increased osteoblast number and osteoid volume in normal rats under a PTH clamp. In uremic rats, the elevated PTH concentration led to reduced bone volume and increased bone turnover, and calcimimetic administration decreased plasma PTH. In uremic rats exposed to PTH at 6-fold the usual replacement dose, calcimimetic administration increased osteoblast number, osteoid surface, and bone formation. A 9-fold higher dose of PTH caused an increase in bone turnover that was not altered by the administration of calcimimetic. In an osteosarcoma cell line, the calcimimetic induced Erk1/2 phosphorylation and the expression of osteoblast genes. The addition of a calcilytic resulted in the opposite effect. Moreover, the calcimimetic promoted the osteogenic differentiation and mineralization of human bone marrow mesenchymal stem cells in vitro. Thus, calcimimetic administration has a direct anabolic effect on bone that counteracts the decrease in PTH levels.

Abstract P1-11-17: Effects of depression, anxiety, and sexual functioning on quality of life among young breast cancer patients in Mexico

Background: Despite the disproportionately high-rates of breast cancer (BC) in young women in Mexico, cancer-control efforts have been predominantly aimed at improving oncological treatment, bypassing survivorship issues and supportive care for this group. The “Joven & Fuerte” cohort, the first supportive care and research program for young BC patients in Latin America, aims to describe and assess the burden of BC in young Mexican women. In this study, we focused on evaluating the association between quality of life (QoL) and anxiety, depression, and sexual functioning in young women with BC (≤ 40 years).

Methods: This study included non-metastatic and non-recurrent patients belonging to the cohort's pilot phase. QoL was assessed with the EORTC QLQ-C30 global score. Patients were classified in the domains of anxiety and depression with the Hospital Anxiety and Depression Scale (HADS) as either probable case, doubtful case, or not a case. Sexual functioning was assessed with the Female Sexual Function Index (FSFI) and the sexual functioning and enjoyment domains of the EORTC QLQ-BR23. Assessments were performed at baseline, 6 months, 1 year, and 2 years. Pearson chi-square and analysis of variance (ANOVA) were used for analysis. Nominal unadjusted significance is reported with p&lt;0.05.

Results: 73 out of 96 (76%) pilot phase patients met the inclusion criteria and had complete assessments up to 2 years follow-up. Global QoL was significantly worse for cases with anxiety and depression at baseline (means for non-cases, doubtful cases and cases, respectively: for anxiety, 81.09, 69.54, and 61.54, p&lt;.001; and for depression, 75.63, 64.17, and 55.00, p=0.01) and depression at 6 months (76.55, 66.67, and 35.42, respectively, p&lt;.001). Classification of case level anxiety was associated with FSFI morbidity during the first year (baseline, p=0.03; 6 months, p=0.09; 1 year, p=0.04). There was no significant association between case level depression and FSFI morbidity in the first 2 years. Neither anxiety nor depression was generally associated with significantly different BR23 sexual functioning or sexual enjoyment; however, a sporadic association was observed between anxiety and BR23 sexual functioning at 6 months (p=0.04).

Conclusion: This study confirmed an association between anxiety and/or depression and worse QoL at diagnosis of BC and after 6 months. Additionally, worse sexual function was significantly associated with the classification of case level anxiety. These findings support the current recommendation that physicians should regularly assess patients' psychosocial health and sexual functioning and provide prompt referral to corresponding supportive care services. Additional efforts must be conducted in low-resource settings, where sexual health and psychosocial care are not considered routine cancer treatment. Dedicated programs that promote multidisciplinary and supportive care services, such as “Joven & Fuerte”, should be incorporated into institutional health-care protocols to systematically address patients' emerging needs and improve QoL.

Citation Format: Villarreal-Garza C, Platas A, Miaja M, Lopez-Martinez EA, Muñoz-Lozano JF, Fonseca A, Pineda C, Barragan-Carrillo R, Martinez-Cannon BA, Chapman J-AW, Goss PE, Bargallo-Rocha JE, Mohar A, Castro-Sanchez A. Effects of depression, anxiety, and sexual functioning on quality of life among young breast cancer patients in Mexico [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P1-11-17.

Hypocaloric Diet Prevents the Decrease in FGF21 Elicited by High Phosphorus Intake

The effect of dietary phosphorus (P) on fibroblast growth factor 21 (FGF21)/β-klotho axis was investigated in rats that were fed diets with: Normal (NP) or high P (HP) and either normal (NC), high (HC) or low calories (LC). Sampling was performed at 1, 4 and 7 months. Plasma FGF21 concentrations were higher (p < 0.05) in NC and HC than in LC groups. Increasing P intake had differing effects on plasma FGF21 in rats fed NC and HC vs. rats fed LC at the three sampling times. When compared with the NP groups, FGF21 concentrations decreased at the three sampling points in rats fed NC-HP (80 vs. 194, 185 vs. 382, 145 vs. 403 pg/mL) and HC-HP (90 vs. 190, 173 vs. 353, 94 vs. 434 pg/mL). However, FGF21 did not decrease in rats fed LC-HP (34 vs. 20, 332 vs. 164 and 155 vs. 81 pg/mL). In addition, LC groups had a much lower liver FGF21 messenger ribonucleic acid/glyceraldehyde 3-phosphate dehydrogenase (mRNA/GAPDH) ratio (0.51 ± 0.08 and 0.56 ± 0.07) than the NC-NP (0.97 ± 0.14) and HC-NP (0.97 ± 0.22) groups. Increasing P intake reduced liver FGF21 mRNA/GAPDH in rats fed NC and HC to 0.42 ± 0.05 and 0.37 ± 0.04. Liver β-klotho mRNA/GAPDH ratio was lower (p < 0.05) in LC groups (0.66 ± 0.06 and 0.59 ± 0.10) than in NC (1.09 ± 0.17 and 1.03 ± 0.14) and HC (1.19 ± 0.12 and 1.34 ± 0.19) groups. A reduction (p < 0.05) in β-klotho protein/α-tubulin ratio was also observed in LC groups (0.65 ± 0.05 and 0.49 ± 0.08) when compared with NC (1.12 ± 0.11 and 0.91 ± 0.11) and HC (0.93 ± 0.17 and 0.87 ± 0.09) groups. In conclusion β-klotho is potently regulated by caloric restriction but not by increasing P intake while FGF21 is regulated by both caloric restriction and increased P intake. Moreover, increased P intake has a differential effect on FGF21 in calorie repleted and calorie depleted rats.

Phosphorus restriction does not prevent the increase in fibroblast growth factor 23 elicited by high fat diet

This study was designed to evaluate the influence of phosphorus (P) restriction on the deleterious effects of high fat diets on mineral metabolism. Twenty-four rats were allotted to 3 groups (n = 8 each) that were fed different diets for 7 months. Rats in group 1 were fed normal fat-normal P (0.6%) diet (NF-NP), rats in group 2 were fed high fat- normal P diet (HF-NP) and rats in group 3 were fed high fat-low P (0.2%) diet (HF-LP). Blood, urine and tissues were collected at the end of the experiments. When compared with the control group (NF-NP), rats fed HF diets showed increases in body weight, and in plasma concentrations of triglycerides and leptin, and decreased plasma calcitriol concentrations. In rats fed HF-NP plasma fibroblast growth factor 23 (FGF23) was higher (279.6±39.4 pg/ml vs 160.6±25.0 pg/ml, p = 0.018) and renal klotho (ratio klotho/GAPDH) was lower (0.75±0.06 vs 1.06±0.08, p<0.01) than in rats fed NF-NP. Phosphorus restriction did not normalize plasma FGF23 or renal klotho; in fact, rats fed HF-LP, that only ingested an average of 22.9 mg/day of P, had higher FGF23 (214.7±32.4 pg/ml) concentrations than rats fed NF-NP (160.6±25.0 pg/ml), that ingested and average of 74.4 mg/day of P over a 7 month period. In conclusion, our results demonstrate that severe P restriction over a prolonged period of time (7 months) does not normalize the increase in circulating FGF23 induced by HF diets. These data indicate that the deleterious effects of high fat diet on the FGF23/klotho axis are not eliminated by reduced P intake.

Vitamin E protects against extraskeletal calcification in uremic rats fed high fat diets

Background

High fat diets are implicated in the pathogenesis of metabolic syndrome, obesity and renal disease. Previous studies have revealed that high fat diets promote vascular calcification in uremic rats. Moreover, vitamin E has been shown to prevent uremic calcifications in genetically obese Zucker rats fed standard diet. The objective of this study was to investigate the influence of vitamin E supplementation on the development of extraskeletal calcifications in non-obese (wild type) uremic rats fed high fat diets.

Methods

Wistar rats (n = 32) were preconditioned by feeding either a normal (NF) or high fat (HF) diet for 45 days and subsequently were subjected to 5/6 nephrectomy (Nx). Just before performing the first Nx step, a blood sample (Pre-Nx) was obtained. After Nx rats were switched to a diet with 0.9% phosphorus and supplemented with calcitriol. Also, after Nx, half of the rats from each group (NF and HF) were treated with vitamin E (VitE) in the diet (30,000 mg/kg) and the other half were maintained on basic VitE requirements (27 mg/kg). Thus, rats were allotted to four experimental groups: Nx-NF (n = 8), Nx-NF-VitE (n = 8), Nx-HF (n = 8) and Nx-HF-VitE (n = 8). At the time of sacrifice (day 66), blood and tissue samples were obtained.

Results

Feeding a HF diet for 45 days did not increase body weight but elicited hyperglycemia, hypertriglyceridemia, an increase in plasma fibroblast growth factor 23 and a reduction in plasma calcitriol concentrations. After Nx, rats fed HF diet showed substantial extraskeletal calcification with aortic calcium content that was higher than in rats fed NF diet. Supplementation with VitE significantly (p < 0.05) reduced aortic (from 38.4 ± 8.8 to 16.5 ± 1.4 mg/g), gastric (from 5.6 ± 2.7 to 1.2 ± 0.4 mg/g) and pulmonary (from 1.8 ± 0.3 to 0.3 ± 0.2 mg/g) calcium content in rats on HF diets.

Conclusions

Uremic rats fed HF diets developed more severe extraosseous calcifications than their normocaloric-fed counterparts and dietary VitE supplementation protected against uremic calcifications in rats fed HF diets. Thus, eating energy-rich foods should be discouraged in patients with renal disease and their deleterious effect may be ameliorated with adequate antioxidant supply.

Vitamin D toxicity of dietary origin in cats fed a natural complementary kitten food

Case series summary

This case series describes two young sibling cats and an additional unrelated cat, from two separate households, that developed hypercalcaemia associated with hypervitaminosis D. Excessive vitamin D concentrations were identified in a natural complementary tinned kitten food that was fed to all three cats as part of their diet. In one of the cases, there was clinical evidence of soft tissue mineralisation. The hypercalcaemia and soft tissue mineralisation resolved following withdrawal of the affected food and medical management of the hypercalcaemia.

Relevance and novel information

This case series demonstrates the importance of obtaining a thorough dietary history in patients presenting with hypercalcaemia and the measurement of vitamin D metabolites when investigating such cases. Complementary foods may have the potential to induce nutritional toxicity even when fed with complete, nutritionally balanced diets.

Vitamin D receptor expression in canine mammary gland and relationship with clinicopathological parameters and progesterone/oestrogen receptors

The vitamin D receptor (VDR) belongs to the nuclear class II receptor family. VDR is a ligand transcription factor and mediates the actions of calcitriol, the active product of vitamin D synthesis. Nowadays, it is known that the biological actions of calcitriol include the capacity to modulate cancer features, such as proliferation and differentiation, apoptosis, angiogenesis, invasion and metastasis. VDR expression has been demonstrated in human breast cancer and vitamin D has emerged as a promising targeted therapy. We analyse the VDR expression in normal and neoplastic canine mammary tissue samples and its relationship with clinicopathological parameters and progesterone/oestrogens receptors (PR/ER). Expression of VDR, Ki67 (to evaluate the proliferation index, PI), PR and ER was assessed in 50 mammary gland tissue samples from 41 female dogs by immunohistochemistry. VDR-positive staining was found in the nuclei of both myoepithelial and luminal epithelial cell layers. VDR expression was higher in normal mammary tissue (37/37 cases, 100%) then followed by benign tumours (6/15 cases, 40%) and malignant tumours (9/34 cases, 26.5%) (P = .001). Female dogs aged ≥10 years had lower VDR expression compared with dogs younger (P = .017). Relationship between VDR and breed, number of tumours, tumour size, histologic subtype, histologic grade of malignancy, PI and PR and ER expression was not observed. Studies with more samples are necessary to further evaluate the possible role of VDR in the biological behaviour of canine mammary tumours, and to corroborate the possibility to use the dog as model for human breast cancer.

Treatment of canine leishmaniasis with marbofloxacin in dogs with renal disease

Treatment of canine leishmaniasis (CanL) represents a challenge. Due to the high prevalence of renal disease associated to CanL, it is important to find an effective drug that does not damage the kidneys. Marbofloxacin has been shown to be effective and well tolerated in non-azotemic dogs with leishmaniasis. To evaluate the safety and efficacy of marbofloxacin in dogs with leishmaniasis and decreased renal function, 28 dogs suffering from leishmaniasis and chronic kidney disease (CKD) were treated with oral marbofloxacin at 2 mg/Kg/day for 28 days. During treatment dogs were assessed by performing weekly physical exams, measuring blood pressure and evaluating blood and urine parameters. Lymph node aspirations were also obtained at days 0 and 28. The global clinical score decreased significantly, from 6.2±3.4 to 4.7±3.1 (p = 0.0001), after treatment. Marbofloxacin also decreased parasitic load in 72% of the dogs. No significant differences in plasma creatinine, urine specific gravity, urinary concentrations of cystatin C, ferritin and urinary protein loss were detected during treatment. A transient but significant decrease in blood pressure was detected up to day 14 (from 180.1±36.6 to 166.0±32.7 mmHg; p = 0.016). Moreover, dogs showed a significant increase in plasma albumin concentration (from 15.0±5.2 to 16.6±3.9 g/L; p = 0.014) and a significant decrease in globulin concentration (from 59.0±18.1 to 54.1±18.0 g/L; p = 0.005). The results demonstrate that, in addition to being effective for treatment of CanL, marbofloxacin is a very safe drug in dogs with CKD and leishmaniasis.

High-phosphorus diet maximizes and low-dose calcitriol attenuates skeletal muscle changes in long-term uremic rats

Although disorders of mineral metabolism and skeletal muscle are common in chronic kidney disease (CKD), their potential relationship remains unexplored. Elevations in plasma phosphate, parathyroid hormone, and fibroblastic growth factor 23 together with decreased calcitriol levels are common features of CKD. High-phosphate intake is a major contributor to progression of CKD. This study was primarily aimed to determine the influence of high-phosphate intake on muscle and to investigate whether calcitriol supplementation counteracts negative skeletal muscle changes associated with long-term uremia. Proportions and metabolic and morphological features of myosin-based muscle fiber types were assessed in the slow-twitch soleus and the fast-twitch tibialis cranialis muscles of uremic rats (5/6 nephrectomy, Nx) and compared with sham-operated (So) controls. Three groups of Nx rats received either a standard diet (0.6% phosphorus, Nx-Sd), or a high-phosphorus diet (0.9% phosphorus, Nx-Pho), or a high-phosphorus diet plus calcitriol (10 ng/kg 3 day/wk ip, Nx-Pho + Cal) for 12 wk. Two groups of So rats received either a standard diet or a high-phosphorus diet (So-Pho) over the same period. A multivariate analysis encompassing all fiber-type characteristics indicated that Nx-Pho + Cal rats displayed skeletal muscle phenotypes intermediate between Nx-Pho and So-Pho rats and that uremia-induced skeletal muscle changes were of greater magnitude in Nx-Pho than in Nx-Sd rats. In uremic rats, treatment with calcitriol preserved fiber-type composition, cross-sectional size, myonuclear domain size, oxidative capacity, and capillarity of muscle fibers. These data demonstrate that a high-phosphorus diet potentiates and low-dose calcitriol attenuates adverse skeletal muscle changes in long-term uremic rats.

Slow- and fast-twitch hindlimb skeletal muscle phenotypes 12 wk after ⅚ nephrectomy in Wistar rats of both sexes

This study describes fiber-type adaptations in hindlimb muscles, the interaction of sex, and the role of hypoxia on this response in 12-wk ⅚ nephrectomized rats (Nx). Contractile, metabolic, and morphological features of muscle fiber types were assessed in the slow-twitch soleus and the fast-twitch tibialis cranialis muscles of Nx rats, and compared with sham-operated controls. Rats of both sexes were considered in both groups. A slow-to-fast fiber-type transformation occurred in the tibialis cranialis of Nx rats, particularly in males. This adaptation was accomplished by impaired oxidative capacity and capillarity, increased glycolytic capacity, and no changes in size and nuclear density of muscle fiber types. An oxidative-to-glycolytic metabolic transformation was also found in the soleus muscle of Nx rats. However, a modest fast-to-slow fiber-type transformation, fiber hypertrophy, and nuclear proliferation were observed in soleus muscle fibers of male, but not of female, Nx rats. Serum testosterone levels decreased by 50% in male but not in female Nx rats. Hypoxia-inducible factor-1α protein level decreased by 42% in the tibialis cranialis muscle of male Nx rats. These data demonstrate that 12 wk of Nx induces a muscle-specific adaptive response in which myofibers do not change (or enlarge minimally) in size and nuclear density, but acquire markedly different contractile and metabolic characteristics, which are accompanied by capillary rarefaction. Muscle function and sex play relevant roles in these adaptations.

The use of renal replacement therapy in critically ill pediatric small bowel transplantation candidates and recipients: Experience from one center

Outcomes for pediatric SBT patients requiring perioperative RRT in the PICU remain unknown. The objectives were to document our center's experience with PICU SBT patients receiving perioperative RRT and to identify variables predictive of survival to discharge. A retrospective chart review of patients (ages, 0-18 yr) between January 1, 2000 and December 31, 2011 that received RRT within a SBT perioperative period and were transplanted at our university-affiliated, tertiary care children's hospital was performed. Six SBT patients received perioperative RRT (ages, 5-12 yr). Three patients (50%) survived to hospital discharge. Among survivors, RRT was required for a total of 1-112 days (mean, 49.7 days). All three survivors survived to hospital discharge without renal transplantation and free of RRT. There was a trend toward increased survival among older patients receiving RRT (p = 0.05). Survivors had a higher I-125 GFR prior to PICU admission (p = 0.045). A higher I-125 GFR prior to PICU admission among survivors may support this test's utility during SBT evaluation. In our experience, a high survival rate and freedom from RRT at the time of discharge support RRT use in the SBT population.

Effects of two calculolytic diets on parameters of feline mineral metabolism

OBJECTIVES

To evaluate the influence of two feline calculolytic diets on selected parameters of mineral metabolism.

MATERIALS AND METHODS

Two dry commercial diets designed for struvite urolith dissolution were evaluated in 14 cats. The study was designed as a two-sequence, four-period crossover protocol with a baseline period, two 60-day "run-in" periods in which calculolytic diets (Diet 1 and Diet 2) were fed and one 30-day "wash-out" period. Data are expressed as median (range).

RESULTS

Feeding the calculolytic diets for two months did not alter plasma concentrations of calcium, phosphorus, magnesium and parathyroid hormone. A significant (P < 0.05 in each case) decline in calcitriol was observed after administering both diets from 236.4 (122.4-429.6) to 170.4 (108.0-394.3) pmol/L (Diet 1) and from 278.4 (153.6-492.0) to 177.1 (87.6-392.4) pmol/L (Diet 2). Cats fed Diet 1 showed a significant increase in urine calcium concentration (from 0.3 (0.2-0.5) to 0.4 (0.3-0.7) mmol/L). Magnesium concentration in urine was significantly increased with both diets, from 1.4 (0.1-1.7) to 1.5 (1.3-2.4) mmol/L (Diet 1) and from 1.1 (0.4-1.9) to 2.0 (0.1-3.1) mmol/L (Diet 2).

CLINICAL SIGNIFICANCE

Both diets resulted in an increased urinary concentration of magnesium, through different mechanisms: urine acidification (Diet 1) and increased sodium load (Diet 2).

Acid-base balance in uremic rats with vascular calcification

Background/Aims

Vascular calcification (VC), a major complication in humans and animals with chronic kidney disease (CKD), is influenced by changes in acid-base balance. The purpose of this study was to describe the acid-base balance in uremic rats with VC and to correlate the parameters that define acid-base equilibrium with VC.

Methods

Twenty-two rats with CKD induced by 5/6 nephrectomy (5/6 Nx) and 10 nonuremic control rats were studied.

Results

The 5/6 Nx rats showed extensive VC as evidenced by a high aortic calcium (9.2 ± 1.7 mg/g of tissue) and phosphorus (20.6 ± 4.9 mg/g of tissue) content. Uremic rats had an increased pH level (7.57 ± 0.03) as a consequence of both respiratory (PaCO₂ = 28.4 ± 2.1 mm Hg) and, to a lesser degree, metabolic (base excess = 4.1 ± 1 mmol/l) derangements. A high positive correlation between both anion gap (AG) and strong ion difference (SID) with aortic calcium (AG: r = 0.604, p = 0.02; SID: r = 0.647, p = 0.01) and with aortic phosphorus (AG: r = 0.684, p = 0.007; SID: r = 0.785, p = 0.01) was detected.

Conclusions

In an experimental model of uremic rats, VC showed high positive correlation with AG and SID.

Influence of feeding status, time of the day, and season on baseline adrenocorticotropic hormone and the response to thyrotropin releasing hormone-stimulation test in healthy horses

Equine pituitary pars intermedia function can be assessed by the measurement of baseline and thyrotropin releasing hormone (TRH)-induced concentrations of adrenocorticotropic hormone (ACTH); however, these measurements may be affected by the environment. Therefore, a prospective observational study evaluated the influence of feeding, time of the day, and season on baseline and TRH-induced concentrations of ACTH in healthy horses. Baseline ACTH was measured in 50 horses before and 2 h after feeding. Six research horses were subjected to a crossover study in which 6 TRH tests were performed in 2 different seasons, March-April (MA) and July-September (JS), at 2 different times of the day, 8 AM and 8 PM, and, under 2 different conditions relative to feeding status, fasted and 2 h after feeding. Differences between fasted and fed horses were found in baseline ACTH, 17.1 ± 1.8 versus 46.1 ± 7.6 pg/mL (P = 0.003) and TRH-stimulated ACTH: 124.1 ± 21.3 versus 192.6 ± 33.1 pg/mL (P = 0.029) at 10 min, and 40.1 ± 4.9 versus 73.2 ± 13.4 pg/mL (P = 0.018) at 30 min post TRH injection. No differences were found between tests performed at different times of the day. Basal ACTH concentrations were greater in JS than in MA, 17.1 ± 1.8 versus 11.9 ± 0.6 pg/mL (P = 0.006). A seasonal influence was also found in stimulated ACTH values, which were much greater in JS 122.7 ± 36.7 versus 31.2 ± 7.4 pg/mL, at 10 min (P = 0.03) and 39.0 ± 7.2 versus 19.8 ± 3.1 pg/mL, at 30 min (P = 0.03). In addition to season, feeding is a potential confounding factor when measuring baseline or stimulated ACTH in horses. In conclusion, feeding status should be standardized for the diagnosis of equine pituitary pars intermedia dysfunction.

Defining enthesitis in spondyloarthritis by ultrasound: results of a Delphi process and of a reliability reading exercise

OBJECTIVE

To standardize ultrasound (US) in enthesitis.

METHODS

An initial Delphi exercise was undertaken to define US-detected enthesitis and its core components. These definitions were subsequently tested on static images taken from spondyloarthritis patients in order to evaluate their reliability.

RESULTS

Excellent agreement (>80%) was obtained for including hypoechogenicity, increased thickness of the tendon insertion, calcifications, enthesophytes, erosions, and Doppler activity as core elementary lesions of US-detected enthesitis. US definitions were subsequently obtained for each elementary component. On static images, the intraobserver reliability showed a high degree of variability for the detection of elementary lesions, with kappa coefficients ranging from 0.13-1. The interobserver kappa values were variable, with the lowest kappa coefficient for enthesophytes (0.24) and the highest coefficient for Doppler activity at the enthesis (0.63).

CONCLUSION

This is the first consensus-based US definition of enthesitis and its elementary components and the first step performed to ensure a higher degree of homogeneity and comparability of results between studies and in daily clinical work.