Kidney transplants from elderly donors: what we have learned 20 years after the Crystal City consensus criteria meeting

Based on the current projection of the general population and the combined increase in end-stage kidney disease with age, the number of elderly donors and recipients is increasing, raising crucial questions about how to minimize the discard rate of organs from elderly donors and improve graft and patient outcomes. In 2002, extended criteria donors were the focus of a meeting in Crystal City (VA, USA), with a goal of maximizing the use of organs from deceased donors. Since then, extended criteria donors have progressively contributed to a large number of transplanted grafts worldwide, posing specific issues for allocation systems, recipient management, and therapeutic approaches. This review analyzes what we have learned in the last 20 years about extended criteria donor utilization, the promising innovations in immunosuppressive management, and the molecular pathways involved in the aging process, which constitute potential targets for novel therapies.

CytoSorb® in burn patients with septic shock and Acute Kidney Injury on Continuous Kidney Replacement Therapy is associated with improved clinical outcome and survival

BACKGROUND

In burn patients, septic shock and acute kidney injury (AKI) with use of continuous renal replacement therapy (CRRT) severely increase morbidity and mortality. Sorbent therapies could be an adjunctive therapy to address the underlying metabolic changes in inflammatory and anti-inflammatory cytokines dysregulated production.

METHODS

A retrospectively observational study of 35 severe burn patients admitted to the Burn Center (Turin, Italy, from January 2017 to December 2022), who underwent CRRT for AKI-associated septic shock. Out of 35 patients, 11 were treated with CytoSorb® as adjunctive therapy to CRRT (Sorbent group) and 24 patients only with CRRT (Control group).

RESULTS

The application of CytoSorb® took place in a very dispersed way. Out of 11 patients, 7 started the CRRT together with the sorbent application. The patients of the sorbent group exhibited a significant reduction in norepinephrine use compared to that of the control group. A clinical improvement over the first 4 days of Cytosorb® was observed in both survivors and no survivors of the sorbent group, with significant norepinephrine decreased use on day 4 compared to day 1. In-hospital mortality was 45.4% and 70.8% in the sorbent and control group, respectively, and significantly better at Kaplan-Meier survival analysis at 270 days (p = 0.0445). In both groups, all survivor patients recovered renal function at discharge, whereas no survivors did not.

CONCLUSIONS

Adjunctive treatment with CytoSorb® for burn patients with AKI-CRRT and septic shock poorly responsive to standard therapy led to a significant clinical improvement, and was associated with a lower mortality rate compared to CRRT alone.

Safety and Metabolic Tolerance of Citrate Anticoagulation in Critically Ill Polytrauma Patients with Acute Kidney Injury Requiring an Early Continuous Kidney Replacement Therapy

For severe polytrauma patients with an early AKI requiring renal replacement therapy, anticoagulation remains a great challenge. Due to a high bleeding risk, hemodynamic instability, and increased lactate levels, continuous modality (CKRT) and citrate anticoagulation seem to be the most appropriate. However, their safety with regard to the potential risk of impaired citrate metabolism is not documented. A retrospective study of 60 severe polytrauma patients admitted to the emergency department between January 2000 and December 2021 was conducted; the patients requiring CKRT during the first 72 h were treated with citrate (n. 46, group Citrate) or with heparin (n. 14, group Heparin). Out of 60 patients, 31 survived (51.7%). According to logistic regression analysis, age and SOFA score were significant predictors of mortality. The incidence of rhabdomyolysis was more common in the survivors (77.4 vs. 51.7%), and Kaplan-Meyer analysis showed a better trend towards survival at 90 days for the group Citrate than the group Heparin (p 0.0956). In the group Citrate, hemorrhagic episodes were significantly less common (0.045 vs. 0.273 episodes/day, p < 0.001); the effective duration (h/day) of CKRT was longer; and the effective net ultrafiltration rate (mL/kg/h) and blood flow rate were lower. For severe polytrauma patients, early, soft CKRT with citrate anticoagulation at a low blood flow rate and circuit citratemia showed a better safety and hemodynamic stability, suggesting that citrate should be the first choice anticoagulant in this subset of patients.

Clearance of NT-proBNP and Procalcitonin during Continuous Venovenous Hemodialysis with the Medium Cutoff Filter in Patients with Rhabdomyolysis-Associated Early Acute Kidney Injury

INTRODUCTION

In polytrauma patients with AKI continuous venovenous hemodialysis (CVVHD) with medium cutoff membrane filters is commonly adopted to increase the removal of both myoglobin and inflammatory mediators, but its impact on increasing molecular weight markers of inflammation and cardiac damage is debated.

METHODS

Twelve critically ill patients with rhabdomyolysis (4 burns and 8 polytrauma patients) and early AKI requiring CVVHD with EMIc2 filter were tested for 72 h on serum and effluent levels for NT-proBNP, procalcitonin (PCT), myoglobin, C-reactive protein (CRP), alpha1-glycoprotein, albumin, and total protein.

RESULTS

The sieving coefficients (SCs) for proBNP and myoglobin were as higher as 0.5 at the start, decreased to 0.3 at the 2nd h, and then slowly declined to the final value of 0.25 and 0.20 at the 72nd h, respectively. PCT showed a negligible SC at the 1st h, a peak of 0.4 at the 12th h, and a final value of 0.3. SCs for albumin, alpha1-glycoprotein, and total protein were negligible. A similar trend was observed for the clearances (17-25 mL/min for proBNP and myoglobin; 12 mL/for PCT; <2 mL/min for albumin, alpha1-glycoprotein, and total protein). No correlation was found between systemic determinations and filter clearances of proBNP, PCT, and myoglobin. Net fluid loss/hour during CVVHD positively correlated with systemic myoglobin for all patients and NT-proBNP in the burn patients.

CONCLUSION

CVVHD with EMiC2 filter showed low clearances for NT-proBNP and procalcitonin. CVVHD did not significantly affect the serum levels of these biomarkers, which could be adopted in the clinical management of early CVVHD patients.

Relationship between Cytomegalovirus Viremia and Long-Term Outcomes in Kidney Transplant Recipients with Different Donor Ages

OBJECTIVES

To explore the Cytomegalovirus (CMV) burden on the long-term post-transplant course in different donor ages, we evaluated the incidence and risk factors for CMV in our kidney-transplanted patients (KTs) with extensive adoption of expanded-criteria donors (ECDs).

METHODS

Retrospective evaluation of 929 consecutive first KTs (49.5% receiving an organ from a donor ≥ 60 years) performed between 01-2003 and 12-2013. Overall survival was estimated using Kaplan-Meier curves; cumulative incidence function was additionally analyzed to consider the potential role of death with a functioning graft as a competitive event with graft dysfunction and to avoid overestimation. Apart from regular DNAemia monitoring in all patients, prophylaxis was adopted in high-risk groups (D+/R- or recipients of anti-thymocyte globulin induction), with pre-emptive therapy in the remaining groups.

RESULTS

CMV incidence was 19.5% (4-34.9% according to serostatus combination: D-/R-, D-/R+, D+/R+, D+/R-). Donor and recipient age, recipient pre-transplant hypertension, DR antigen compatibility, cold ischemia time, and post-transplant early complications, including rejection, urologic and renal artery stenosis, and lower renal function and proteinuria ≥ 0.5 g/day at one year after KT were associated with CMV. CMV determined lower death-censored graft survival (DCGS) (p < 0.01), with a prominent effect in R+ (p < 0.01) and without impact in R- (p = 0.32 in D-/R- and p = 0.006 in D+/R-). Interestingly, CMV occurrence influenced DCGS only in KTs who received grafts from donors < 50 or 50-69 years old (p < 0.01), while it was not significant with older donors (p = 0.07). The analysis of the cumulative incidence of graft loss accounting for death as a competing risk confirmed all these findings. In multivariate analysis, CMV replication/disease in the first year was an independent predictor for DCGS (HR 1.73 [1.3-2.3]).

CONCLUSIONS

In a large population with extensive ECD adoption, CMV viremia in the first year demonstrates its harmful effect with an independent role for graft loss and significant impact among R+ recipients and KTs with donors < 70 years.

Non-adherence assessment to immunosuppressant therapy with a self-report questionnaire and intra-patient variability in renal transplantation: risk factors and clinical correlations

BACKGROUND

Non-adherence (NA) to immunosuppressive drugs is to date considered a crucial issue in kidney transplanted patients (KTRs), leading to de-novo donor-specific anti-HLA antibodies (dnDSA) development, acute and chronic rejection, and at least graft loss. However, NA assessment is challenging, often leading to underestimation in real-life settings.

METHODS

NA evaluation in all KTRs referred to our post-transplantation clinic in the period between 01/01-15/07/2018 with self-report questionnaire combined to intra-patient variability (IPV) of the pivotal immunosuppressive drug (based on trough levels of tacrolimus/mTOR inhibitor).

RESULTS

Based on both questionnaire and IPV, 86 out of the 504 tested KTRs (17%) were classified as NA. Male gender (OR, 2.0; 95% confidence interval [CI], 1.2 to 3.4), high educational level (OR for KTRs with a degree, 1.8 [95% CI, 1.0 to 3.1]), employment (OR, 2.0 [95% CI, 1.2 to 3.3]), young age at transplantation (P=0.017), longer time on the waiting list and after transplantation (P=0.027 and 0.049 respectively) were all associated with NA. High IPV was mostly documented in KTRs treated with the twice-daily formulation of the immunosuppressive drug (OR, 1.5 [95% CI, 1.0 to 2.1]) and better associated with dnDSA appearance (OR, 2.1 [95% CI, 1.1 to 3.9]).

CONCLUSIONS

NA is a significant problem, difficult to assess, and can lead to dnDSA development also in our population. Identifying risk factors for NA might be an underestimated tool to improve graft and patient outcome in KTRs.

First test-day postcalving risk factors for clinical mastitis in southern Chile dairy farms: A retrospective cohort study

We conducted a retrospective cohort study to evaluate risk factors associated with clinical mastitis in dairy cows in southern Chile between the first milk test after calving to 200 d in milk (DIM). Data from 8,772 cows were collected from June 2017 to November 2019 on 10 dairy farms selected by convenience in southern Chile. Data were analyzed using a multivariable mixed logistic regression using a manual backward selection process with logit link function and farm as a random effect. The dependent variable was clinical mastitis between the first milking sample collected by monthly milk sampling program up to 200 DIM. Days in milk, fat, urea, parity, season, and somatic cell counts were statistically associated with clinical mastitis in the first 200 d in milk. Cows with higher than average milk yield, parity, urea, and somatic cell count were at greater odds of being diagnosed with clinical mastitis compared with their respective referents. In contrast, higher milk fat was associated with lower odds of clinical mastitis. Significant interactions between days in milk with season and parity were observed, where for every 5-d increase in DIM, the odds of clinical mastitis decreased by different proportions depending on the interaction. Identified risk factors for clinical mastitis using first monthly milk sampling data can help dairy farmers in Chile implement herd-level mastitis prevention and control measures.

Increase of continuous treatments and regional citrate anticoagulation during renal replacement therapy in the ICUs of the north-west of Italy from 2007 to 2015

BACKGROUND

Few reports have addressed the change in Renal Replacement Therapy (RRT) management in the ICUs over the years in western countries. This study aims to assess the trend of dialytic practice in a 4.5-million population-based study of the northwest of Italy.

METHODS

A nine-year survey covering all the RRT provided in the ICUs. Consultant nephrologists of the 26 Nephrology and Dialysis centers reported their activities in the years 2007, 2009, 2012, and 2015.

RESULTS

From 2007 to 2015 the patients treated increased from 1042 to 1139, and the incidence of RRT from 254 to 263 cases/10^6 inhabitants. The workload for Dialysis Center was higher in the larger hub hospitals. RRT for Acute Kidney Injury (AKI), continuation of treatment in chronically dialyzed patients, or extrarenal indications accounted for about the stable rate of 70, 25 and 5% of all RRT sessions, respectively. Continuous modality days increased from 2731 days (39.5%) in 2007 to 5076 (70.6%) in 2015, when the continuous+prolonged treatment days were 6880/7196 (95.6% of total days). As to RRT timing, in 2015 only the classical clinical criteria, and no K-DIGO stage were adopted by most Centers. As to RRT interruption, in 2015 urine volume was the first criterion. Implementation of citrate anticoagulation (RCA) for RRT patients significantly increased from 2.8% in 2007 to 30.9% in 2015, when it was applied in all 26 Centers.

CONCLUSIONS

From 2007 to 2015, current practice has changed towards shared protocols, with increasing continuous modality and RCA implementation.

Long-Term Preservation of Renal Function in Septic Shock Burn Patients Requiring Renal Replacement Therapy for Acute Kidney Injury

BACKGROUND

The real impact of septic shock-associated acute kidney injury (AKI) on the long-term renal outcome is still debated, and little is known about AKI-burn patients. In a cohort of burn survivors treated by continuous renal replacement therapy (CRRT) and sorbent technology (CPFA-CRRT), we investigated the long-term outcome of glomerular and tubular function.

METHODS

Out of 211 burn patients undergoing CRRT from 2001 to 2017, 45 survived, 40 completed the clinical follow-up (cumulative observation period 4067 months, median 84 months, IR 44-173), and 30 were alive on 31 December 2020. Besides creatinine and urine albumin, in the 19 patients treated with CPFA-CRRT, we determined the normalized GFR by 99mTc-DTPA (NRI-GFR) and studied glomerular and tubular urine protein markers.

RESULTS

At the follow-up endpoint, the median plasma creatinine and urine albumin were 0.99 (0.72-1.19) and 0.0 mg/dL (0.0-0.0), respectively. NRI-GFR was 103.0 mL/min (93.4-115). Four patients were diabetic, and 22/30 presented at least one risk factor for chronic disease (hypertension, dyslipidemia, and overweight). Proteinuria decreased over time, from 0.47 g/day (0.42-0.52) at 6 months to 0.134 g/day (0.09-0.17) at follow-up endpoint. Proteinuria positively correlated with the peak of plasma creatinine (r 0.6953, p 0.006) and the number of CRRT days (r 0.5650, p 0.035) during AKI course, and negatively with NRI-GFR (r -0.5545, p 0.049). In seven patients, urine protein profile showed a significant increase of glomerular marker albumin and glomerular/tubular index.

CONCLUSIONS

Burn patients who experienced septic shock and AKI treated with CRRT had a long-term expectation of preserved renal function. However, these patients were more predisposed to microalbuminuria, diabetes, and the presence of risk factors for intercurrent comorbidities and chronic renal disease.

Nephrotoxicity in advanced thyroid cancer treated with tyrosine kinase inhibitors: An update

Over the past decade, the prognosis of advanced thyroid cancer (TC) patients has dramatically improved thanks to the introduction of tyrosine kinase inhibitors (TKIs). Despite their effectiveness, these drugs are burdened with several side effects that can negatively affect quality of life and compromise therapy continuation. Among renal adverse events (RAEs), proteinuria is the most frequently reported in clinical trials and real-life experiences, especially during treatment with lenvatinib or cabozantinib. This peculiar toxicity is commonly associated with targeted therapies with anti-angiogenic activity, even if the mechanisms underlying its onset and progression are not entirely clear. RAEs should be early recognized and properly managed to avoid renal function worsening and life-threatening consequences. Aiming at providing a comprehensive summary that can help clinicians to identify and manage TKIs-related RAEs in TC patients, we reviewed the current evidence about this topic, from pathogenesis and potential risk factors to diagnosis and treatment.

Clinical outcomes and temporal trends of immunological and non-immunological rare diseases in adult kidney transplant

BACKGROUND

Rare diseases (RDs) encompass many difficult-to-treat conditions with different characteristics often associated with end-stage renal disease (ESRD). However, data about transplant outcomes in adult patients are still lacking and limited to case reports/case series without differentiation between immunological/non-immunological RDs.

METHODS

Retrospective analysis among all adult kidney transplanted patients (KTs) with RDs (RDsKT group) performed in our high-volume transplantation center between 2005 and 2016. RDs were classified according to the Orphanet code system differentiating between immunological and non-immunological diseases, also comparing clinical outcomes and temporal trends to a control population without RDs (nRDsKT).

RESULTS

Among 1381 KTs, 350 patients (25.3%) were affected by RDs (RDsKTs). During a f/up > 5 years [median 7.9 years (4.8-11.1)], kidney function and graft/patient survival did not differ from nRDsKTs. Considering all post-transplant complications, RDsKTs (including, by definition, patients with primary glomerulopathy except on IgA nephropathy) have more recurrent and de-novo glomerulonephritis (14.6% vs. 9.6% in nRDsKTs; p = 0.05), similar rates of de-novo cancers, post-transplant diabetes, dysmetabolism, hematologic disorders, urologic/vascular problems, and lower infectious episodes than nRDsKTs (63.7% vs 72.7%; p = 0.013). Additional stratification for immunological and non-immunological RDsKTs or transplantation periods (before/after 2010) showed no differences or temporal trends between groups.

CONCLUSIONS

Kidney transplant centers are deeply involved in RDs management. Despite their high-complex profile, both immunological and non-immunological RDsKTs experienced favorable patients' and graft survival.

Recipient pre-existing chronic hypotension is associated with delayed graft function and inferior graft survival in kidney transplantation from elderly donors

Background

Pre-existing chronic hypotension affects a percentage of kidney transplanted patients (KTs). Although a relationship with delayed graft function (DGF) has been hypothesized, available data are still scarce and inconclusive.

Methods

A monocentric retrospective observational study was performed on 1127 consecutive KTs from brain death donors over 11 years (2003–2013), classified according to their pre-transplant Mean Blood Pressure (MBP) as hypotensive (MBP < 80 mmHg) or normal-hypertensive (MBP ≥ 80 mmHg, with or without effective antihypertensive therapy).

Results

Univariate analysis showed that a pre-existing hypotension is associated to DGF occurrence (p<0.01; OR for KTs with MBP < 80 mmHg, 4.5; 95% confidence interval [CI], 2.7 to 7.5). Chronic hypotension remained a major predictive factor for DGF development in the logistic regression model adjusted for all DGF determinants. Adjunctive evaluations on paired grafts performed in two different recipients (one hypotensive and the other one normal-hypertensive) confirmed this assumption. Although graft survival was only associated with DGF but not with chronic hypotension in the overall population, stratification according to donor age revealed that death-censored graft survival was significantly lower in hypotensive patients who received a KT from >50 years old donor.

Conclusions

Our findings suggest that pre-existing recipient hypotension, and the subsequent hypotension-related DGF, could be considered a significant detrimental factor, especially when elderly donors are involved in the transplant procedure.

Antimicrobial resistance and virulence genes profiles of Arcobacter butzleri strains isolated from back yard chickens and retail poultry meat in Chile

This research aims to investigate the presence and pathogenic potential of Arcobacter in poultry meat samples purchased in the retail market of Valdivia (South of Chile) as well as in faecal samples from backyard chickens from rural areas around this city. The isolates obtained were identified by molecular methods. Furthermore, putative virulence genes were assessed by PCR and the antimicrobial resistance was tested by phenotypic methods. Arcobacter was present in 41·6% of the samples, with the highest value in retail poultry meat (55·7%) followed by backyard production (28·0%). Arcobacter butzleri was the most prevalent species (75·6%) followed by Arcobacter skirrowii (14·8%) and Arcobacter cryaerophilus (9·6%). An 8·5% of A. butzleri strains from meat were resistant to both ciprofloxacin and tetracycline and 6·1% were resistant to erythromycin, while none was resistant to gentamycin, unlike strains from domestic chickens, which showed no resistance. Furthermore, A. butzleri strains from chicken meat presented a higher prevalence of virulence genes than strains from domestic chickens. In fact, in this last group, some genes (hecA, hecB and irgA) were completely absent. Therefore, this study provides insight on the epidemiology of Arcobacter in Chilean poultry and suggests that under traditional breeding conditions strains are, apparently, less pathogenic and drug resistant.

Detection of urinary podocytes by flow cytometry in idiopathic membranous nephropathy

Idiopathic membranous nephropathy (iMN) is considered an immune-mediated disease where circulating autoantibodies against podocyte targets (mainly the PLA₂R) cause the deposition of in-situ subepithelial immune-complexes. The consequent podocyte damage may cause cell detachment in urine (Podocyturia-PdoU). PdoU has been assessed in different kidney diseases, but limited data are available in iMN. In this study all patients with a diagnosis of iMN between 15/12/1999-16/07/2014 were tested for PLA₂R antibodies (Ab anti-PLA₂R, ELISA kit) and PdoU by flow cytometry with anti-podocalyxin antibody. A semi-quantitative PdoU score was defined according to the percentage of podocalyxin positive cells normalized to the total volume of sample and set relative to the urine creatinine measured in the supernatant. PdoU was positive in 17/27 patients (63%; 1+ score in 6/27-22.2%, 2+ in 4/27-14.8%, 3+ in 2/27-7.4%, 4+ in 5/27-18.5%). Only 2/7 patients with complete remission showed a positive PdoU (1+) while all six patients without remission have significant PdoU. PdoU+ was statistically correlated with the absence of remission and Ab anti-PLA₂R + (p < 0.05) but PdoU, analysed as a continuous variable, showed a non-linear correlation with proteinuria or PLA₂R antibody levels also in the cohort of patients with two available PdoU tests. In conclusion, PdoU could be detected in iMN and seems to be associated with commonly considered markers of disease activity (proteinuria and Ab anti-PLA₂R) with a non-linear correlation. Despite data should be confirmed in large and prospective cohorts, according to the podocyte depletion hypothesis PdoU may represent an early marker of immunological activation with potential prognostic utility.

Monoclonal gammopathy of undetermined significance coexisting in patients undergoing kidney transplantation does not adversely influence post-graft clinical outcome

Background

Management of patients with oncohaematological disorders such as monoclonal gammopathy of undetermined significance (MGUS) is a frequent problem in pre-transplant work-up. Insights on disease progression and long-term functional outcomes are still lacking in this setting.

Methods

This was a retrospective analysis on all patients with MGUS who underwent kidney transplant (KT) at our centre between 1 January 2000 and 31 December 2017 (cases, n = 65). Patients were matched with a control group (KTs with similar characteristics but without history of haematological disease, controls, n = 1079). Primary endpoints were graft and patient survival; secondary endpoints were causes of graft failure, patient death, occurrence of allograft rejection, post-transplant neoplasia (not correlated to previous disorder) and/or infectious episodes.

Results

The MGUS and control groups had a similar mean age [60 (29–79) versus 55.2 (19.3–79.5) years, respectively] and percentage of males (69.2% versus 64.6%, respectively). Median follow-up time since KT was 3.5 years (0–14) in cases and 8.3 years (0–14.9) in controls. All MGUS patients underwent KT following extensive multidiscliplinary investigations. No differences were found between cases and controls regarding patient and graft survival or post-transplant complications except for lower incidence of infections (58.7% versus 69.8%, P = 0.019) and increased use of mTOR inhbitors (30.3% versus 14.7%, P = 0.001) in MGUS. MGUS isotype did not influence graft and patient survival. The absence of difference in patients and graft survival was also confirmed in an adjunctive analysis where MGUS were compared with controls (ratio 1:2) matched for recipient age, gender, number of transplantations and transplant period.

Conclusion

Patients with MGUS may undergo KT without significantly increased risks of complications, provided that appropriate diagnostic procedures are carefully followed. Multidiscipline-based studies are crucial for establishing well designed pre- and post-transplant protocols for the best management of patients with coexisting MGUS and end-stage renal disease.

Case series of six kidney transplanted patients with COVID-19 pneumonia treated with tocilizumab

Few reports described the outcome of kidney transplanted patients (KTs) affected by COVID‐19 treated with interleukin‐6 receptor inhibitor tocilizumab (TCZ). We report our case series of 6 KTs with COVID‐19 pneumonia who received TCZ: All were of male gender, with a mean age of 55.5 ± 8.4 years, a median time from transplantation of 3611 days (1465‐5757); 5/6 had cardiovascular comorbidities, 1/6 had diabetes, and 3/6 have one or more previous KTs. Four out of six patients died, at an average time of 9.75 ± 2.4 days after tocilizumab administration, 3/6 due to a coexistent septic shock. Two patients improved after TCZ and were discharged at 20 and 21 days, respectively; in both patient, a significant increase of total lymphocyte count was observed. In conclusion, KTs, where the role of peculiar factors such as chronic immunosuppression is still undetermined, represent a high‐risk group with significant COVID‐19‐associated mortality. The evaluation of the TCZ effect in COVID‐19 pneumonia requires controlled studies (ideally RCTs) in this specific population.

Early effects of first-line treatment with anti-interleukin-6 receptor antibody tocilizumab for chronic active antibody-mediated rejection in kidney transplantation

INTRODUCTION

Chronic active antibody-mediated rejection (cAMR) is a major determinant of late allograft failure. Rituximab/immunoglobulins (IVIg) + plasma exchange (PLEX) showed controversial results in cAMR treatment. Tocilizumab (TCZ), a humanized anti-interleukin 6 receptor antibody, has been recently used as rescue therapy in patients non-responsive to rituximab/IVIg/PLEX with favorable outcomes. Whether TCZ acts "per se" or requires a priming effect from previous treatments is currently unknown.

METHODS

Fifteen patients with cAMR were treated with TCZ as a first-line therapy and followed for a median time of 20.7 months.

RESULTS

Despite the majority of patients experiencing advanced transplant glomerulopathy (TG) at diagnosis (60% with cg3), glomerular filtration rate and proteinuria stabilized during the follow-up, with a significant reduction in donor-specific antibodies. Protocol biopsies after 6 months demonstrated significant amelioration of microvascular inflammation and no TG, C4d deposition, or IF/TA progression. Gene-expression and immunofluorescence analysis showed upregulation of three genes (TJP-1, AKR1C3, and CASK) involved in podocyte, mesangial, and tubular restoration.

CONCLUSION

Tocilizumab adopted as a first-line approach in cAMR was associated with early serological and histological improvements and functional stabilization even in advanced TG, suggesting a role for the use of TCZ alone with the avoidance of unnecessary previous immunosuppressants.

Safety and efficacy of a mesenchymal stem cell intramammary therapy in dairy cows with experimentally induced Staphylococcus aureus clinical mastitis

Although, antibiotics are effective in the treatment of bovine mastitis, they do not address the regeneration of mammary glandular tissue and have been associated to the increment in antimicrobial resistance worldwide. Considering the necessity of alternative therapies for this disease of high economic impact and the reported regenerative and antibacterial effects of mesenchymal stem cell (MSCs), we evaluated the safety and efficacy of an allogenic MSC-based intramammary therapy in dairy cows with experimentally induced Staphylococcus aureus clinical mastitis. In a safety trial, heifers were inoculated intramammarily with a 2.5 × 10⁷-suspension of bovine fetal AT-MSCs on experimental days 1 and 10. Animals were evaluated clinically on a daily basis during a 20-day experimental period and blood samples were collected for hemogram determination and peripheral blood leukocytes (PBLs) isolation. In an efficacy trial, Holstein Friesian cows were inoculated with S. aureus and treated intramammarily with vehicle (NEG; days 4 and 10), antibiotics (ATB; days 4 and 5) or a suspension of 2.5 × 10⁷ AT-MSCs (MSC; days 4 and 5). Cows were clinically evaluated daily and milk samples were collected for somatic cell count (SCC) and colony forming units (CFU). Blood samples were collected for serum haptoglobin and amyloid A determination. Intramammary administration of two doses of bovine fetal AT-MSCs in healthy cows did not induce changes in clinical or hematological variables, and gene expression profiles in PBLs associated to activation (CD4, CD8, CD25, CD62L and CD69) and proinflammatory cytokines (CCL2, CCL5, IL2, CXCL3, IFNγ, and TNFα). Quarters of MSC group of cows had similar SCC log/mL in milk compared to infected quarters of ATB or NEG cows. However, quarters of MSC cows had lower CFU log/mL in milk compared to quarters of NEG cows. Intramammarily inoculation of repeated doses of 2.5 × 10⁷ allogenic AT-MSCs did not induce clinical or immunological response in healthy cows. Moreover, MSC-intramammary treatment reduced bacterial count in milk of cows with S. aureus clinical mastitis compared to untreated cows. This work provides initial evidence for the safety and efficacy of an allogenic MSC-based intramammary therapy for the treatment of bovine mastitis.

Furosemide as a functional marker of acute kidney injury in ICU patients: a new role for an old drug

New pharmacokinetics insight suggests that the furosemide pharmacology occurring in ICU patients with AKI is similar, but not equal to that described in chronic stable renal patients. Even if the diuretic response to furosemide is expressed by a steep dose-response curve positively correlated with renal function, pharmacodynamic limitations occur when creatinine clearance is < 20 ml/min or urine output is < 500 ml/12 h. In such cases, other factors specifically due to acute tubular injury can interfere with the furosemide-induced diuretic output. As modality of administration recent reports and metanalysis, even if not conclusive, suggest that for the same given dose a continuous infusion of furosemide was superior in diuretic response. For septic shock patients on CVVHDF where treatment adds an additional clearance of furosemide the maximum diuretic response is achieved by a continuous infusion of 20 mg/h of furosemide. At this infusion rate the reached plasma level was < 20 mg/L, a range considered safe and not ototoxic. Therefore, the severity of AKI establishes whether a patient will respond to furosemide. In this review we summarized all these recent updates, also suggesting that the diuretic response under continuous infusion may allow assessing glomerular and tubular functions with increased reliability than a bolus dose. However, validation studies are still needed to support continuous infusion as a stress test.

In vitro inactivation of Mycobacterium avium subsp. paratuberculosis (MAP) by use of copper ions

Background

Mycobacterium avium subsp. paratuberculosis (MAP) is the causative agent of paratuberculosis, a contagious infectious disease that affects domestic and wild ruminants causing chronic inflammation of the intestine. MAP has proven to be very resistant to both physical and chemical processes, making it difficult to control this pathogen. Based on the recognized antimicrobial properties of copper, the objective of this study was to evaluate the effectiveness of copper ions to reduce MAP numbers and/or MAP viability in a fluid matrix. Besides, methicillin-resistant Staphylococcus aureus (MRSA), and Escherichia coli were used as controls of the effectiveness of copper ions. MAP-spiked PBS was subjected to copper ions treatment at 24 V for 5 min and the PBS suspensions were sampled before and after treatment. MAP viability and quantification were determined using three complementary techniques: a phage amplification assay, MGIT culture and qPCR.

Results

Moderate numbers (10³ CFU ml⁻¹) of the two control bacteria were completely eliminated by treatment with copper ions. For MAP, copper ions treatment reduced both the viability and numbers of this pathogen. Phage assay information quickly showed that copper ions (24 V for 5 min) resulted in a significant reduction in viable MAP. MGIT culture results over time showed statistically significant differences in time-to-detection (TTD) values between PRE and POST treatment. MAP genome equivalent estimates for PBS suspensions indicated that MAP numbers were lower in samples POST-treatment with copper ions than PRE-treatment.

Conclusions

The use of copper ions resulted in a significant reduction of MAP in a liquid matrix, although some MAP survival on some occasions was observed.

Treatment with plasmapheresis, immunoglobulins and rituximab for chronic-active antibody-mediated rejection in kidney transplantation: Clinical, immunological and pathological results

AIM

To evaluate the role of a therapeutic regimen with plasma exchange, intravenous immunoglobulins and rituximab in chronic-active antibody-mediated rejection (cAMR) settings.

METHODS

We compared 21 kidney transplant recipients (KTRs) with a diagnosis of cAMR in a retrospective case-control analysis: nine KTRs treated with plasmapheresis, intravenous immunoglobulins and rituximab (PE-IVIG-RTX group) vs 12 patients (control group) not treated with antibody-targeted therapies. We examined kidney survival and functional outcomes 24 mo after diagnosis. Histological features and donor-specific antibody (DSA) characteristics (MFI and C1q-fixing ability) were also investigated.

RESULTS

No difference in graft survival between the two groups was noted: three out of nine patients in the PE-IVIG-RTX group (33.3%) and 4/12 in the control group (33.3%) experienced loss of allograft function at a median time after diagnosis of 14 mo (min 12-max 18) and 15 mo (min 7-max 22), respectively. Kidney functional tests and proteinuria 24 mo after cAMR diagnosis were also similar in both groups. Only microvascular inflammation (glomerulitis + peritubular capillaritis score) was significantly reduced after PE-IVIG-RTX in seven out of eight patients (87.5%) in the PE-IVIG-RTX group (median score 3 in pre-treatment biopsy vs 1.5 in post-treatment biopsy; P = 0.047), without any impact on kidney survival and/or DSA characteristics. No functional or histological parameter at diagnosis was predictive of clinical outcome.

CONCLUSION

Our data showed no difference in the two year post-treatment outcome of kidney grafts treated with PE-IVIG-RTX for cAMR diagnosis, however there were notable improvements in microvascular inflammation in post-therapy protocol biopsies. Further studies, especially involving innovative therapeutic approaches, are required to improve the management and long-term results of this severe condition.

Update on the treatment of focal segmental glomerulosclerosis in renal transplantation

Focal segmental glomerulosclerosis (FSGS) represents one of the most severe glomerular diseases, with frequent progression to end-stage renal disease and a high rate of recurrence in renal allografts (30%-50%). Recurrent FSGS portends a negative outcome, with the hazard ratio of graft failure being two-fold higher then that of other glomerulonephritis. Two patterns of clinical presentations are observed: Early recurrence, which is characterized by massive proteinuria within hours to days after implantation of the renal graft, and late recurrence, which occurs several months or years after the transplantation. Many clinical conditions have been recognized as risk factors for recurrence, including younger age, rapid progression of the disease to end-stage renal disease on native kidneys, and loss of previous renal allografts due to recurrence. However, much less is known about the incidence and risk factors of the so-called “de novo” type of FSGS, for which sufferers are transplanted patients without disease on native kidneys; but, rapid development of allograft failure is frequently observed. Management of both forms is challenging, and none of the approaches proposed to date have been demonstrated as consistently beneficial or effective. In the present review we report an update on the available therapeutic strategies for FSGS in renal transplantation within the context of a critical overview of the current literature.

mTOR inhibitors for medical treatment of post-transplantation encapsulating peritoneal sclerosis: a favourable single center experience

BACKGROUND

Encapsulating peritoneal sclerosis (EPS) is a serious complication in patients on peritoneal dialysis (PD) causing intestinal obstruction. Two different forms of EPS are reported: the classical one observed in patients on PD, and post-transplantation EPS (PostTx-EPS). The first-line therapy of classical and PostTx-EPS remains surgical treatment, but for both the complication rate and mortality are high. Recently, a few cases of EPS were successfully treated with inhibitors of mammalian target of rapamycin (mTORi). The aim of this study was to evaluate PostTx-EPS outcome in our patients, focusing on the potential benefit of mTORi treatment.

METHODS

We performed a retrospective analysis on 1,048 kidney transplanted patients at our center between 11/2001 and 12/2011.

RESULTS

In the 226 patients treated with PD at any time before grafting, we found 10 cases of PostTx-EPS (prevalence 4.4%). The mean age was 54.9 years (26-69), with a mean time on PD of 83.1 months (33-156). The interval between kidney transplant and EPS diagnosis was 10.5 months (4-18.9). Five of the ten patients were treated after the diagnosis with mTORi, with a favorable outcome in 4/5 cases. This result was substantially independent of surgical and steroid therapy, performed in 9/10 and 10/10 patients respectively.

CONCLUSION

EPS is a serious complication but susceptible to improvement if early diagnosed. mTORi represent a useful option for EPS treatment. We too suggest adopting an immunosuppressive protocol based on mTORi, mycophenolate mofetil and steroids in order to prevent PostTx-EPS in transplanted patients at high risk.

Complement cascade and kidney transplantation: The rediscovery of an ancient enemy

The identification of complement activity in serum and immunohistochemical samples represents a core element of nephropathology. On the basis of this observation, different experimental models and molecular studies have shown the role of this cascade in glomerular disease etiology, but the absence of inhibiting drugs have limited its importance. Since 2006, the availability of target-therapies re-defined this ancient pathway, and its blockage, as the new challenging frontier in renal disease treatment. In the graft, the complement cascade is able to initiate and propagate the damage in ischemia-reperfusion injury, C3 glomerulopathy, acute and chronic rejection, atypical hemolytic uremic syndrome and, probably, in many other conditions. The importance of complement-focused research is revealed by the evidence that eculizumab, the first complement-targeting drug, is now considered a valid option in atypical hemolytic uremic syndrome treatment but it is also under investigation in all the aforementioned conditions. In this review we evaluate the importance of complement cascade in renal transplantation diseases, focusing on available treatments, and we propose a speculative identification of areas where complement inhibition may be a promising strategy.

Pulmonary toxicity in a renal transplant recipient treated with amiodarone and everolimus: a case of hypothetical synergy and a proposal for a screening protocol

Pneumotoxic drugs like amiodarone and m-TOR inhibitors (m-TORi) may be administered contemporaneously in therapy for patients who had renal transplants. We present a case of amiodarone pulmonary toxicity (APT) in a patient treated with amiodarone and everolimus. A 57-year-old Caucasian male, under treatment with both everolimus (for 3 years) and amiodarone (for 2 months), presented with fever, dyspnoea and a negative chest X-ray after his second kidney transplant with suboptimal serum creatinine (3 mg/dl). A non-contrastive high-resolution CT scan showed bilateral interstitial lung disease with an associated reduction in carbon monoxide diffusing capacity. Bronchoalveolar lavage (BAL) was negative for an infection, but BAL cytology was suitable for APT (50% of ‘foamy’ macrophages). A complete recovery was achieved after amiodarone interruption and an oral steroid therapy increase. Everolimus was continued. His kidney function remained unchanged in the upcoming months. In conclusion, we suggest a possible synergistic effect between m-TORi and amiodarone. Furthermore, we propose a diagnostic algorithm that can be used as a surveillance tool to identify a potential initial lung damage in patients treated with 1 or more pneumotoxic drugs.

Somatic cell count in milk of selenium-supplemented dairy cows after an intramammary challenge with Staphylococcus aureus

The objective of this study was to evaluate the effect of selenium (Se) supplementation on milk somatic cell count (SCC) in dairy cows. Twelve multiparous Holstein-Friesian cows were fed a diet containing a suboptimal Se concentration (<0.05 ppm, dry basis) starting 2 months before calving. Supplemented cows (n=6) received a single s.c. injection of barium selenate (1 ml/50 kg BW) 45 days prior to calving, whereas control group was kept unsupplemented. Twenty weeks after calving, two mammary quarters (right side) of each cow were challenged with 205,000 cfu/ml of Staphylococcus aureus (strain Newbould 305). Blood was collected bi-weekly until day 150 of lactation for the analysis of blood glutathione peroxidase (GPx1; EC 1.11.1.9) activity. To re-isolate the challenging pathogen and to evaluate SCC, aseptic milk samples were collected daily starting on the day of challenge, and finishing 7 days after inoculation. Unsupplemented cows had a lower activity of GPx1 through the experiment (P<0.001). Natural log SCC (lnSCC) was higher in unsupplemented than Se-supplemented cows (P=0.04), showing evidence of significance after 5 days. Selenium supplementation of dairy cows fed a diet containing a suboptimal Se concentration, resulted in higher blood activity of GPx1, and lower mean lnSCC after an intramammary challenge with Staph. aureus.

Bayesian analysis to validate a commercial ELISA to detect paratuberculosis in dairy herds of southern Chile

In Chile, Mycobacterium avium subsp. paratuberculosis (Map) has been isolated on several occasions and clinical cases have been reported. Nevertheless, diagnostic tests have not yet been validated for this agent in the Chilean setting. The objective of the study was to validate a commercial ELISA to detect Map shedding dairy cows in management conditions, prevalence and stages of infection existing in Southern Chile, utilising different statistical approaches. Blood and faeces were collected from 1333 lactating cows in 27 dairy herds (both large commercial and smallholder dairy farms) between September 2003 and August 2004. Within the herds up to a maximum of 100 dairy cows were selected based on age (>or=3 years old) and, if present, clinical signs of a Map infection. In herds with less than 100 cows, all cows >or=3 years old were sampled. Blood samples were tested using a commercial ELISA kit (IDEXX Laboratories, Inc.). Faecal samples were cultured on Herrold's Egg Yolk Medium (HEYM). Latent class models (i.e. maximum likelihood (ML) methods and Bayesian inference) were used to determine the validity of the ELISA. Map was cultured from 54 (4.1%) cows and 10 (37.0%) herds, which were all large, commercial dairy herds. As a result of empty cells in the cross-tabulations, the ML model provided the same results as the validation with faecal culture as the gold-standard. In the Bayesian model, the Se and Sp of the ELISA were estimated to be 26% (95% CI: 18-35%) and 98.5% (95% CI: 97.4-99.4%), respectively. For faecal culture, the Se was 54% (95% CI: 46-62%) and the Sp was 100% (95% CI: 99.9-100%). Interestingly, the prevalence in the smallholder dairy farms was estimated to be 8% even though there were no faecal culture positive cows detected in those herds. There was no significant correlation between the two tests. The advantage of Bayesian inference is that the Se and Sp of both tests are obtained in one model relative to the (latent) true disease status, the model can handle small datasets and empty cells and the estimates can be corrected for the correlation between tests when the tests are not conditionally independent. Therefore, Bayesian analysis was the preferred method for Map that lacks a gold-standard and usually has low cow-level prevalence.

Evaluation of disease activity by IGF-I and IGF binding protein-3 (IGFBP3) in acromegaly patients distributed according to a clinical score

To facilitate the estimation of acromegalic activity a prospective study was done comparing, against a clinical score, the effectiveness of serum IGF-I, IGFBP3 and the IGF-I/IGFBP3 molar ratio. Sixty nine observations were distributed in three groups: Group I=patients before surgery; group II=patients improved but still clinically active; group III=patients clinically inactive. Suppression of serum GH levels one hour after an oral glucose load was in agreement with the clinical score in 21/22 observations. Increases in serum IGF-I and IGFBP3 levels were similarly frequent: both 100% in group I, 80% and 95% in group II, 9% and 36% in group III, respectively. The frequency of abnormal molar ratios was 95%, 40% and 0% in the same groups. Log IGF-I, log IGFBP3, and log molar ratio correlated significantly with the clinical scores (r=0.873, r=0.692, and r=0.829, respectively).

CONCLUSIONS

The IGF-I/IGFBP3 molar ratio was not better than either IGF-I or IGFBP3 in detecting activity in the three groups of patients studied. Both IGF-I and IGFBP3 appear comparably useful for the diagnosis and follow-up of acromegalic patients. Since IGF-I is a more biologically meaningful parameter it might be preferable.

Human serotonectin: a blood glycoprotein that binds serotonin. Chemical and physiological characterization

A glycoprotein that circulates in human blood, binds to the surface of platelets and white cells and also binds serotonin with high affinity and specificity has previously been purified and partially characterized. This glycoprotein has been called serotonectin. Antibodies raised against serotonectin inhibited the uptake of [3H]serotonin by platelets. We now report on the amino acid and carbohydrate composition of this protein as well as on some of the properties of the protein from which the carbohydrate moiety was removed. Serotonectin (apparent molecular weight 200 000; as judged by SDS-polyacrylamide gel electrophoresis) is an acidic protein that contains about 13% carbohydrate (w/w) consisting of mannose, galactose, glucosamine and sialic acid in a molar ratio of 2:1:4:0.8. Initial characterization suggests that serotonectin is a sialoglycoprotein of complex-type oligosaccharide N-linked to asparagine through N-acetylglucosamine. Treatment of serotonectin with neuraminidase resulted in a quantitative release of sialic acid without loss of antigenicity or binding capacity for [3H]serotonin. Treatment of desialylated serotonectin under non-denaturing conditions with almond glycopeptidase A resulted in 60-80% release of sugar. The protein moiety of the glycopeptidase-digested material showed no change in the capacity to bind [3H]serotonin and exhibited the same antigenic properties as untreated serotonectin. These data show the non-involvement of the carbohydrate moiety of human serotonectin in the mechanism of binding serotonin but the possible contribution of this moiety to a tighter interaction with the serotonectin receptor.