A consensus conference to define the utility of advanced infectious disease diagnostics in solid organ transplant recipients

The last decade has seen an explosion of advanced assays for the diagnosis of infectious diseases, yet evidence-based recommendations to inform their optimal use in the care of transplant recipients are lacking. A consensus conference sponsored by the American Society of Transplantation (AST) was convened on December 7, 2021, to define the utility of novel infectious disease diagnostics in organ transplant recipients. The conference represented a collaborative effort by experts in transplant infectious diseases, diagnostic stewardship, and clinical microbiology from centers across North America to evaluate current uses, unmet needs, and future directions for assays in 5 categories including (1) multiplex molecular assays, (2) rapid antimicrobial resistance detection methods, (3) pathogen-specific T-cell reactivity assays, (4) next-generation sequencing assays, and (5) mass spectrometry-based assays. Participants reviewed and appraised available literature, determined assay advantages and limitations, developed best practice guidance largely based on expert opinion for clinical use, and identified areas of future investigation in the setting of transplantation. In addition, attendees emphasized the need for well-designed studies to generate high-quality evidence needed to guide care, identified regulatory and financial barriers, and discussed the role of regulatory agencies in facilitating research and implementation of these assays. Findings and consensus statements are presented.

User involvement throughout development of technology to support diabetes foot care: a case illustration of the devices for dignity PPIE model

The successful development and implementation of any healthcare technology requires input from multiple stakeholders including clinical leads, trust information technology directorates as well as project management and procurement. In this process however, a key stakeholder that is often overlooked is the patient.This paper illustrates the crucial importance of patient involvement to avoid poor design and poor uptake of technology and subsequently poor health outcomes.To highlight this, we share a case example evidencing involvement of people with lived experience of foot ulcers resulting from Diabetic foot neuropathy throughout identification of unmet technology needs, design requirements for the device and iterative device development and evaluation.

Scintillation light detection in the 6-m drift-length ProtoDUNE Dual Phase liquid argon TPC

DUNE is a dual-site experiment for long-baseline neutrino oscillation studies, neutrino astrophysics and nucleon decay searches. ProtoDUNE Dual Phase (DP) is a 6  ×  6  ×  6 m 3 liquid argon time-projection-chamber (LArTPC) that recorded cosmic-muon data at the CERN Neutrino Platform in 2019-2020 as a prototype of the DUNE Far Detector. Charged particles propagating through the LArTPC produce ionization and scintillation light. The scintillation light signal in these detectors can provide the trigger for non-beam events. In addition, it adds precise timing capabilities and improves the calorimetry measurements. In ProtoDUNE-DP, scintillation and electroluminescence light produced by cosmic muons in the LArTPC is collected by photomultiplier tubes placed up to 7 m away from the ionizing track. In this paper, the ProtoDUNE-DP photon detection system performance is evaluated with a particular focus on the different wavelength shifters, such as PEN and TPB, and the use of Xe-doped LAr, considering its future use in giant LArTPCs. The scintillation light production and propagation processes are analyzed and a comparison of simulation to data is performed, improving understanding of the liquid argon properties.

Renal Crisis as the Initial Manifestation of Scleroderma

We report the case of a young Hispanic woman who was originally admitted to the emergency department following hypertensive urgency and right-sided blurry vision. The patient did not carry a diagnosis of scleroderma at the time of the visit. However, upon further evaluation, the patient was found to have a scleroderma renal crisis. An angiotensin-converting enzyme (ACE) inhibitor was initiated promptly with subsequent normalization of the blood pressure and creatinine level. Scleroderma renal crisis is a rare, highly feared complication of scleroderma that if left untreated can be life-threatening. Therefore, it is important to identify this condition early and initiate therapy without delay.

POS0230 THE miR-320 FAMILY IS UPREGULATED IN FAST-PROGRESSING RADIOGRAPHIC KNEE OSTEOARTHRITIS: DATA FROM THE OSTEOARTHRITIS INITIATIVE

Background

There is an outstanding need for prognostic biomarkers to reliably detect fast-progressing knee osteoarthritis (OA) such that preventative interventions can be targeted to this patient population. MicroRNA-sequencing is an unbiased approach for comprehensive profiling of circulating microRNAs in liquid biopsies to discover novel biomarkers of disease. As negative regulators of gene expression, microRNAs hold potential not only as biomarkers, but also as mechanistic drivers of knee OA.

Objectives

To apply microRNA-sequencing to identify unique circulating microRNAs as potential biomarkers that distinguish fast-progressing radiographic knee OA from both slow- and non-progressing radiographic knee OA.

Methods

Leveraging the Osteoarthritis Initiative (OAI) longitudinal cohort, we applied our customized microRNA-sequencing pipeline [1] to blood plasma samples collected at both baseline and 4-year follow-up from 106 participants. The disease trajectory for each participant was constructed by plotting their Kellgren-Lawrence (KL) grades over an 8-year follow-up period. Based on these trajectories, we defined fast-progression as an increase from KL 0/1 at baseline to KL 3/4 by 4-year follow-up, slow-progression as an increase from KL 0/1 at baseline to KL 2/3/4 by 8-year follow-up, and non-progression as no increase from KL0/1 at baseline throughout the 8-year follow-up. Following differential expression analysis, we assessed predictive performance and identified putative gene targets for prioritized microRNAs.

Results

Comparing fast-progressors to both slow-progressors and non-progressors, we identified differentially expressed microRNAs within timepoints (i.e., 48 microRNAs at baseline and 2 microRNAs at 4-year follow-up) and across timepoints. Among these microRNAs were four members of the miR-320 family, with miR-320d showing an increase in fast-progressors at both timepoints, compared to both slow- and non-progressors. The predictive models we constructed included miR-320 members and had good accuracy (area under the receiver operating characteristic curves ranging from 82.6 to 91.9) in distinguishing fast-progressors. Putative gene targets of the miR-320 family included members of the 14-3-3 gene family (Table 1), including YWHAE, whose downregulation in OA cartilage was reported to promote deterioration [2].

Table 1.

Predicted gene targets of the miR-320 family include members of the 14-3-3 gene family.

14-3-3 gene family memberhsa-miR-320bhsa-miR-320chsa-miR-320dhsa-miR-320eSFNMMMLYWHABMMMMYWHAEVVVHYWHAGVVVMYWHAHVVVMYWHAQVVVMYWHAZVVVM

All mirDIP results with bold text indicating the prediction was among the top 1% for that microRNA/gene target pair. Letters denote the mirDIP score class with V=very high, H=high, M=medium, and L=low.

Conclusion

This microRNA-sequencing study is the first of its kind, profiling circulating microRNAs at two timepoints in 106 participants with data-driven construction of knee OA trajectories. We identify the miR-320 family of microRNAs to be associated with fast-progressing radiographic knee OA over time. While our data suggest this microRNA family could have applications as prognostic biomarkers for knee OA, and could be regulating gene targets to impact OA severity, validation of these findings in independent longitudinal cohorts is required.

References

[1]Potla P, Ali SA, Kapoor M. A bioinformatics approach to microRNA-sequencing analysis. Osteoarthritis and Cartilage Open. 2021;3(1):100131. doi: https://doi.org/10.1016/j.ocarto.2020.100131.

[2]Fu W, Hettinghouse A, Chen Y, Hu W, Ding X, Chen M, Ding Y, Mundra J, Song W, Liu R, Yi YS, Attur M, Samuels J, Strauss E, Leucht P, Schwarzkopf R, Liu CJ. 14-3-3 epsilon is an intracellular component of TNFR2 receptor complex and its activation protects against osteoarthritis. Ann Rheum Dis. 2021 Dec;80(12):1615-1627. doi: 10.1136/annrheumdis-2021-220000.

Disclosure of Interests

None declared

POS0319 DISEASE BURDEN OF PRIMARY SJOGREN SYNDROME: A RETROSPECTIVE UNITED STATES CLAIMS DATABASE STUDY

Background

Primary Sjögren’s syndrome (pSjS) is a chronic and complex systemic autoimmune disease, primarily characterised by inflammation and progressive destruction of the exocrine glands (ie, autoimmune epithelitis) [1].

Objectives

We evaluated disease progression, treatment patterns, mortality, and healthcare resource utilization (HCRU) of pSjS patients in the United States (US) to understand the real-world experiences of patients with pSjS.

Methods

This retrospective cohort study utilised data from US Optum Clinformatics claims between 01 May 2000 and 31 December 2020. The study included pSjS patient cohort and general population cohort, matched (1:1) on age, sex, and index date. Baseline period of 365 days prior to the index date was used for assessment of baseline comorbidities. Descriptive statistics were used to describe baseline characteristics, HCRU, and treatment pattern while multivariable models were used to assess hazard ratios (HRs) and risk factors.

Results

Overall, 23,168 patients with pSjS (ICD-9 710.2 Sicca syndrome and ICD-10 M 35.0 Sjogren Syndrome and excluding patients with Rheumatoid arthritis [RA], Systemic sclerosis [SS] and Systemic lupus erythematosus [SLE] diagnoses codes) were included in the cohort (mean [SD] age: 61.5 [15.3] years; females: 85%). At baseline, 79.4% and 8.2% of pSjS patients had systemic complications and organ-specific autoimmune comorbidities, respectively. In a sub-set of the cohort including patients with at least 5 years of follow-up, by the end of 5 years 96.8% and 16.5% of patients developed systemic complications and organ-specific autoimmune comorbidities, respectively (Table 1). The most frequently occurring organ-specific autoimmune comorbidities over the 5-year follow-up included Graves disease (5.4%), Hashimoto disease (3.7%), and discoid/subacute cutaneous lupus erythematosus (3.5%). Mortality was reported in 7.4% of the patients during 5-year follow-up. Risk factors associated with higher mortality included systemic complications in renal (HR [95% CI]: 2.29 [2.09–2.52]), cardiovascular (HR [95% CI]: 2.42 [2.19–2.67]), lungs (HR [95% CI]: 3.73 [3.41–4.09]) and haematological domains (HR [95% CI]: 2.83 [2.56–3.13]), non-Hodgkin’s lymphoma (HR [95% CI]: 2.58 [2.12–3.14]), and primary biliary cirrhosis (HR [95% CI]: 2.17 [1.60–2.96]). Corticosteroids (28.2%), hydroxychloroquine (15.7%), and cyclosporine (10.9%) were most frequently used medications. During the year following the first pSjS diagnosis, defined as the first claim with the Sjogren Syndrome ICD code (index date), the mean all-cause healthcare costs have increased by 27% from $21,634 to $27,526 per patient per year.

Table 1.

Occurrence of systemic complications and organ-specific autoimmune comorbidities over follow-up of 5 years

Variable, n (%)Baseline (N=6000)Within 5 years (N=6000)Any systemic complication4,555 (75.9%)5,806 (96.8%)Articular involvement3,176 (52.9%)5,026 (83.8%)Renal involvement352 (5.9%)1,185 (19.8%)Cardiovascular complications342 (5.7%)826 (13.8%)Muscles1,390 (23.2%)2,732 (45.5%)Pancreatic31 (0.5%)88 (1.5%)Lungs373 (6.2%)1,383 (23.1%)Peripheral nervous system766 (12.8%)2,109 (35.2%)Haematological1,016 (16.9%)2,507 (41.8%)Glandular542 (9.0%)2,274 (37.9%)Central nervous system212 (3.5%)556 (9.3%)Biological153 (2.6%)408 (6.8%)Skin517 (8.6%)1,327 (22.1%)Lymphadenopathy374 (6.2%959 (16.0%) Non-Hodgkin’s lymphoma59 (1.0%)131 (2.2%)Any organ-specific autoimmune disease464 (7.7%)992 (16.5%)

Conclusion

These results provide additional evidence that pSjS is associated with substantial morbidity and clinical burden supporting the need for safe and efficacious disease modifying treatment options in this patient population.

References

[1]Mariette X, Criswell LA. N Engl J Med. 2018;378(10): 931-939.

Acknowledgements

Medical writing and editorial assistance were provided by Sanjeev Kallapari and Chiranjit Ghosh, PhD of Sanofi. This study was funded by Sanofi.

Disclosure of Interests

LAMA KALOUCHE-KHALIL Shareholder of: May hold stock/stock options in Sanofi., Employee of: Employee of Sanofi., Roopali Gandhi Shareholder of: May hold stock/stock options in Sanofi., Employee of: Employee of Sanofi., Lichen Hao Shareholder of: May hold stock/stock options in Sanofi., Employee of: Employee of Sanofi., Ekaterina Smolkina Shareholder of: May hold stock/stock options in Sanofi., Employee of: Employee of Sanofi., Fabienne Schumacher Shareholder of: May hold stock/stock options in Sanofi., Employee of: Employee of Sanofi.

A218 THE RISK OF RECURRENT HEPATOCELLULAR CARDINOMA IN POST-LIVER TRANSPLANT PATIENTS RECEIVING CAPECITABINE TREATMENT

Background

Little is known on how to reduce the risk of hepatocellular carcinoma (HCC) recurrence post liver transplantation (LT). We examined if adjuvant oral Capecitabine reduces the risk of recurrent HCC in a high-risk group post-LT.

Aims

To examine if adjuvant oral Capecitabine reduces the risk of recurrent HCC in a high-risk group post-LT.

Methods

A retrospective study was performed from a pre-existing liver transplant database from the Liver Transplant Unit at London Health Sciences Center, London; Canada. This database contains demographic, clinical parameters and follow-up of all patients transplanted for HCC. Data was extracted for patients who underwent LT between January 2000 – April 2018 and included follow up until May 31^st, 2020. High-risk of tumor recurrence was defined as a RETREAT score ≥5 or PARFITT score ≥10.5. Log rank test compared the recurrence of HCC or death among patients who were and were not prescribed Capecitabine.

Results

Out of 168 LT for HCC, 25 patients were identified as high-risk group for recurrence. The median age was 63 years (IQR=60–65). 19 (76%) patients had viral hepatitis including Hepatitis B and Hepatitis C as their primary disease while 4 (16%) patients had NASH. The remaining 2 (8%) patients had Autoimmune Hepatitis. 7 (28%) patients received Capecitabine while 18 (72%) did not. All patients were followed for a median of 22 months (IQR=8.9–57.5). No statistical significance difference was found between the two groups with respect to HCC recurrence or death (p=0.56).

Conclusions

Among patients with high risk features for recurrence of HCC, adding Capecitabine therapy added to conventional immunosuppression had no overall effect on reducing overall tumor recurrence or survival.

Funding Agencies

None

A tool for evaluating novel osteoarthritis therapies using multivariate analyses of human cartilage-synovium explant co-culture

OBJECTIVE

There is a need to incorporate multiple tissues into in vitro OA models to evaluate novel therapeutics. This approach is limited by inherent donor variability. We present an optimized research tool: a human OA cartilage-synovium explant co-culture model (OA-EXM) that employs donor-matched lower and upper limit response controls combined with statistical approaches to address variability. Multiple rapid read-outs allow for evaluation of therapeutics while cataloguing cartilage-synovium interactions.

DESIGN

48-h human explant cultures were sourced from OA knee arthroplasties. An OA-like cartilage-synovium co-culture baseline was established relative to donor-matched upper limit supraphysiological pro-inflammatory cytokine and lower limit OA cartilage or synovium alone controls. 100 nM dexamethasone treatment validated possible "rescue effects" within the OA-EXM dual tissue environment. Gene expression, proteoglycan loss, MMP activity, and soluble protein concentrations were analyzed using blocking and clustering methods.

RESULTS

The OA-EXM demonstrates the value of the co-culture approach as the addition of OA synovium increases OA cartilage proteoglycan loss and expression of MMP1, MMP3, MMP13, CXCL8, CCL2, IL6, and PTGS2, but not to the extent of supraphysiological stimulation. Conversely, OA cartilage does not affect gene expression or MMP activity of OA synovium. Dexamethasone shows dual treatment effects on synovium (pro-resolving macrophage upregulation, protease downregulation) and cartilage (pro-inflammatory, catabolic, and anabolic downregulation), and decreases soluble CCL2 levels in co-culture, thereby validating OA-EXM utility.

CONCLUSIONS

The OA-EXM is representative of late-stage OA pathology, captures dual interactions between cartilage and synovium, and combined with statistical strategies provides a rapid, sensitive research tool for evaluating OA therapeutics.

Role of Serum Irisin During Early Pregnancy to Predict The Development of Gestational Diabetes Mellitus at 24-28 Weeks of Pregnancy in high-risk patients

AIMS

The aim of this prospective study was to investigate the role of serum irisin during early pregnancy to predict the development of GDM at 24-28 weeks in high-risk patients.

METHODOLOGY

This study was conducted among the pregnant women attending the Department of Endocrinology and antenatal clinic of Department of Obstetrics and Gynecology of MKCG Medical College for a period of one year with at least one risk factor for the development of gestational diabetes mellitus (GDM). Blood samples were collected for measurement of fasting plasma glucose, serum insulin, serum irisin, lipids (TC, LDL, HDL, TG), and HbA1c. Oral glucose tolerance test was performed using 75 g of glucose during the first trimester and between 24-28 weeks of pregnancy. Patients were diagnosed as GDM based upon IADPSG criteria at 24-28 weeks. Serum irisin, glycemic parameters, and homeostatic model assessment of insulin resistance during first trimester were analyzed for predicting GDM between 24-28 weeks.

RESULTS

Sixty-five patients were included in the study, out of which 20 (30.8%) patients developed GDM and the rest 45 patients had normal glucose tolerance (NGT). The first trimester mean serum irisin concentration was significantly lower in women who later developed GDM compared with women who had NGT (111.65 ± 25.43 μg/L vs 185.89 ± 28.89 μg/L). Serum irisin concentration was the best predictor with an optimal threshold value of 149 μg/L, which had sensitivity, specificity, positive predictive value, and negative predictive value of 90%, 91.1%, 81.8%, 95.3%, respectively, for predicting GDM at 24-28 weeks of pregnancy.

CONCLUSION

We suggest the utility of serum irisin as an early biomarker to predict the development of GDM later in pregnancy in high-risk patients.

'Your mascara is running'

Chromhidrosis is a rare disorder, which can have significant psychosocial consequences for patients, particularly when it affects the face, as it can be mistaken for scarring, dirt or erroneous make-up application. Chromhidrosis can be divided into apocrine, eccrine and pseudo subtypes. We present a case of apocrine chromhidrosis localized to the bilateral cheek area.

Factors associated with unsuccessful return-to-work following work-related upper extremity injury

BACKGROUND

Returning to work following occupational injury is a key outcome for both workers' compensation boards and injured workers. Predictive factors for returning remain unclear.

AIMS

To describe factors associated with unsuccessful return-to-work (RTW) in a hand injury population to identify target areas through which occupational rehabilitation programmes can help injured workers achieve successful RTW outcomes.

METHODS

Demographic data, functional, pain and psychosocial scores were recorded for injured workers discharged between April 2011 and September 2015 from a multidisciplinary upper extremity treatment programme. The primary outcome of RTW status was assessed at programme discharge. Bivariate analyses and multivariable logistic regression were used to identify factors associated with being unable to RTW.

RESULTS

Of 872 participants who met the inclusion criteria, 65% were male and the mean age was 46 (standard deviation [SD] 11) years. In unadjusted bivariate analyses, the group with an unsuccessful RTW outcome had higher mean baseline pain, catastrophizing and QuickDASH scores; a higher baseline prevalence of depression, and reported a high level of pain more frequently than those who were working at discharge. In the adjusted logistic regression model, not working at baseline, higher QuickDASH score and presence of depression at baseline were independently associated with unsuccessful work status outcome.

CONCLUSIONS

Negative baseline work status, greater self-reported functional disability and presence of depression were associated with greater odds of unsuccessful RTW following a workplace upper extremity injury. Integrating mental healthcare provision with occupational rehabilitation is a potential programmatic approach to improve RTW.

National disparities in colorectal cancer screening in patients with comorbid conditions: an analysis of the Behavioral Risk Factor Surveillance System

CONTEXT

Each year, approximately 53,200 people die in the U.S. from colorectal cancer (CRC), indicating a need to increase screening efforts. Some studies have suggested mammography use is higher in patients with comorbid conditions, a reflection of increased follow up. Another study found that patients with obesity were less likely to be screened for CRC than nonobese patients. However, no study has assessed the impact of multiple comorbidities on CRC screening.

OBJECTIVES

To analyze CRC screening rates in patients with comorbidities compared with healthy patients, and to assess whether the number of comorbid diagnoses impacted screening rates.

METHODS

A cross sectional analysis of patients who received CRC screening was performed using the 2018 and 2019 Behavioral Risk Factor Surveillance System (BRFSS). Respondents were classified as having had CRC screening if they answered "yes" to either of the following: "Have you ever had a blood stool test?" or "Have you ever had a sigmoidoscopy/colonoscopy?" Respondents younger than age 50 were excluded. A weighted multivariate logistic regression model was constructed to determine adjusted risk ratios (ARR). Confidence intervals (CI) were reported at 95%.

RESULTS

We identified 279,784 respondents who met inclusion criteria. Of those, 79.7% (sample n=222,879; population N=46,304,360) of respondents had received CRC screening. Patients with diabetes, hypertension, skin cancer, chronic obstructive pulmonary disease (COPD), arthritis, depression, and chronic kidney disease were significantly more likely to be screened than those without comorbidities. There was no statistically significant difference in screening rates between patients with and without cardiovascular disease. Compared with patients with zero comorbidities, those with one were significantly more likely to receive screening (ARR, 1.11; CI, 1.09-1.12) as were those with two to four (ARR, 1.2; CI, 1.18-1.22). Patients with five or more comorbidities were significantly less likely to be screened than those with two to four (ARR, 1.12; CI, 1.1-1.14).

CONCLUSIONS

Patients with one or more comorbidities were more likely to be screened than those without comorbidities, but those with five or more conditions were less likely to be screened than patients with two to four conditions. This indicates that physicians may be more fatigued and less likely to recommend CRC screening to patients with many comorbidities compared with patients diagnosed with only a few conditions. The results of this study add to the literature by identifying an interaction between the number of comorbidities and likelihood of being screened for CRC.

Prospects for beyond the Standard Model physics searches at the Deep Underground Neutrino Experiment: DUNE Collaboration

The Deep Underground Neutrino Experiment (DUNE) will be a powerful tool for a variety of physics topics. The high-intensity proton beams provide a large neutrino flux, sampled by a near detector system consisting of a combination of capable precision detectors, and by the massive far detector system located deep underground. This configuration sets up DUNE as a machine for discovery, as it enables opportunities not only to perform precision neutrino measurements that may uncover deviations from the present three-flavor mixing paradigm, but also to discover new particles and unveil new interactions and symmetries beyond those predicted in the Standard Model (SM). Of the many potential beyond the Standard Model (BSM) topics DUNE will probe, this paper presents a selection of studies quantifying DUNE's sensitivities to sterile neutrino mixing, heavy neutral leptons, non-standard interactions, CPT symmetry violation, Lorentz invariance violation, neutrino trident production, dark matter from both beam induced and cosmogenic sources, baryon number violation, and other new physics topics that complement those at high-energy colliders and significantly extend the present reach.

Zinc finger protein-440 promotes cartilage degenerative mechanisms in human facet and knee osteoarthritis chondrocytes

OBJECTIVES

To investigate the role of zinc finger protein 440 (ZNF440) in the pathophysiology of cartilage degeneration during facet joint (FJ) and knee osteoarthritis (OA).

METHODS

Expression of ZNF440 in FJ and knee cartilage was determined by immunohistochemistry, quantitative (q)PCR, and Western blotting (WB). Human chondrocytes isolated from FJ and knee OA cartilage were cultured and transduced with ZNF440 or control plasmid, or transfected with ZNF440 or control small interfering RNA (siRNA), with/without interleukin (IL)-1β. Gene and protein levels of catabolic, anabolic and apoptosis markers were determined by qPCR or WB, respectively. In silico analyses were performed to determine compounds with potential to inhibit expression of ZNF440.

RESULTS

ZNF440 expression was increased in both FJ and knee OA cartilage compared to control cartilage. In vitro, overexpression of ZNF440 significantly increased expression of MMP13 and PARP p85, and decreased expression of COL2A1. Knockdown of ZNF440 with siRNA partially reversed the catabolic and cell death phenotype of human knee and FJ OA chondrocytes stimulated with IL-1β. In silico analysis followed by validation assays identified scriptaid as a compound with potential to downregulate the expression of ZNF440. Validation experiments showed that scriptaid reduced the expression of ZNF440 in OA chondrocytes and concomitantly reduced the expression of MMP13 and PARP p85 in human knee OA chondrocytes overexpressing ZNF440.

CONCLUSIONS

The expression of ZNF440 is significantly increased in human FJ and knee OA cartilage and may regulate cartilage degenerative mechanisms. Furthermore, scriptaid reduces the expression of ZNF440 and inhibits its destructive effects in OA chondrocytes.

Sequencing identifies a distinct signature of circulating microRNAs in early radiographic knee osteoarthritis

OBJECTIVE

MicroRNAs act locally and systemically to impact osteoarthritis (OA) pathophysiology, but comprehensive profiling of the circulating miRNome in early vs late stages of OA has yet to be conducted. Sequencing has emerged as the preferred method for microRNA profiling since it offers high sensitivity and specificity. Our objective was to sequence the miRNome in plasma from 91 patients with early [Kellgren-Lawrence (KL) grade 0 or 1 (n = 41)] or late [KL grade 3 or 4 (n = 50)] symptomatic radiographic knee OA to identify unique microRNA signatures in each disease state.

DESIGN

MicroRNA libraries were prepared using the QIAseq miRNA Library Kit and sequenced on the Illumina NextSeq 550. Counts were produced for microRNAs captured in miRBase and for novel microRNAs. Statistical, bioinformatics, and computational biology approaches were used to refine and interpret the final list of microRNAs.

RESULTS

From 215 differentially expressed microRNAs (FDR < 0.01), 97 microRNAs showed an increase or decrease in expression in ≥85% of samples in the early OA group as compared to the median expression in the late OA group. Increasing this threshold to ≥95%, seven microRNAs were identified: hsa-miR-335-3p, hsa-miR-199a-5p, hsa-miR-671-3p, hsa-miR-1260b, hsa-miR-191-3p, hsa-miR-335-5p, and hsa-miR-543. Four novel microRNAs were present in ≥50% of early OA samples and had 27 predicted gene targets in common with the prioritized set of predicted gene targets from the 97 microRNAs, suggesting common underlying mechanisms.

CONCLUSION

Sequencing of well-characterized patient cohorts produced unbiased profiling of the circulating miRNome and identified a unique panel of 11 microRNAs in early radiographic knee OA.

TAT-Beclin-1 induces severe synovial hyperplasia and does not protect from injury-induced osteoarthritis in mice

OBJECT

Autophagy maintains cartilage homeostasis and is compromised during osteoarthritis (OA), contributing to cartilage degeneration. We sought to determine if D-isomer TAT-Beclin-1, a potent inducer of autophagy, could attenuate post-traumatic OA in mice.

METHODS

10-week-old mice underwent destabilization of the medial meniscus (DMM) surgery to induce post-traumatic OA, or sham surgery (control), and injected intra-articularly with D-isomer TAT-Beclin-1 (0.5-2 mg/kg) or PBS 1 week post-surgery for up to 9 weeks. Mice were sacrificed at 2 or 10 weeks post-surgery. Knee joint sections were evaluated by histopathology for cartilage degeneration and synovitis, and immunostaining for key markers of autophagy (LC3B), cell proliferation (nuclear Ki67), activated fibroblasts (αSMA), and cells of hematopoietic origin (CD45).

RESULTS

All D-isomer TAT-Beclin-1-treated DMM mice had no difference in the degree of cartilage degeneration compared to PBS-injected DMM mice. Surprisingly, all D-isomer TAT-Beclin-1-treated mice exhibited substantial synovial hyperplasia, with increased cellularity and ECM deposition (fibrosis-like phenotype), as compared to PBS-injected mice. Synovial effects of D-isomer TAT-Beclin-1 were dose- and injection frequency-dependent. An increased percentage of cells positive for LC3B and nuclear Ki67 were found in the synovial intima early after injection, which persisted after frequent injections.

CONCLUSIONS

D-isomer TAT-Beclin-1 did not attenuate cartilage degeneration, but rather induced synovial hyperplasia associated with increased expression of key markers of autophagy and cell proliferation and a fibrosis-like phenotype, independent of markers of fibroblast activation or persistent hematopoietic-origin cell infiltration. These data suggest that, if not tissue-targeted, caution should be taken using autophagy activators due to diverse cellular responses in the joint.

Reduced vitamin D levels in painful diabetic peripheral neuropathy

AIM

Recent studies have reported an association between low vitamin D levels and diabetic peripheral neuropathy. However, many of these did not differentiate between people with painful diabetic peripheral neuropathy and those with painless diabetic peripheral neuropathy, or assess major confounding factors including sunlight exposure and daily activity. Our study addressed these limitations and evaluated vitamin D levels in people with carefully phenotyped diabetic peripheral neuropathy and controls.

METHODS

Forty-five white Europeans with Type 2 diabetes and 14 healthy volunteers underwent clinical and neurophysiological assessments. People with Type 2 diabetes were then divided into three groups (17 with painful diabetic peripheral neuropathy, 14 with painless diabetic peripheral neuropathy and 14 with no diabetic peripheral neuropathy). All had seasonal sunlight exposure and daily activity measured, underwent a lower limb skin biopsy and had 25-hydroxyvitamin D measured during the summer months, July to September.

RESULTS

After adjusting for age, BMI, activity score and sunlight exposure, 25-hydroxyvitamin D levels (nmol/l) (se) were significantly lower in people with painful diabetic peripheral neuropathy [painful diabetic peripheral neuropathy 34.9 (5.8), healthy volunteers 62.05 (6.7), no diabetic peripheral neuropathy 49.6 (6.1), painless diabetic peripheral neuropathy 53.1 (6.2); ANCOVAP = 0.03]. Direct logistic regression was used to assess the impact of seven independent variables on painful diabetic peripheral neuropathy. Vitamin D was the only independent variable to make a statistically significant contribution to the model with an inverted odds ratio of 1.11. Lower 25-hydroxyvitamin D levels also correlated with lower cold detection thresholds (r = 0.39, P = 0.02) and subepidermal nerve fibre densities (r = 0.42, P = 0.01).

CONCLUSIONS

We have demonstrated a significant difference in 25-hydroxyvitamin D levels in well-characterized people with painful diabetic peripheral neuropathy, while accounting for the main confounding factors. This suggests a possible role for vitamin D in the pathogenesis of painful diabetic peripheral neuropathy. Further prospective and intervention trials are required to prove causality between low vitamin D levels and painful diabetic peripheral neuropathy.