First epidemiologic study in Argentina of the prevalence of BK viruria in kidney transplant patients.

BACKGROUND: The worldwide seroprevalence of human BK polyomavirus (BKV) in adults is 80%. About 10%-60% of renal transplant recipients experience BKV infection, nephropathy of the graft may occur in 5% of the cases, and up to 45% lose the graft. The aim of this work was to describe the prevalence of BK viruria during the 1st year after transplantation. METHODS: An epidemiologic multicenter cross-sectional study was carried out in consecutive patients at each site with kidney transplantation from August 2011 to July 2012. Clinically significant viruria was defined as >10(7) copies/mL. Viral DNA was extracted with the use of silica columns. Quantification was performed with the use of real-time polymerase chain reaction with primers that amplify a fragment of the large T-antigen gene and with a specific Taqman-MGB probe for BKV. For each assay, a standard curve with a quantified plasmid was included. RESULTS: Of 402 renal transplant recipients at 18 renal transplant sites, we analyzed 382; median age was 46.33 years, and 46.40% were female. The median of the temporal distribution for urine samples was 153 days. BK virus was detected in 50/382 samples (13%), 18 with values >10(7) copies/mL (4.7%). The median of the distribution of positive values was 123 days and the highest frequency of positive values was in months 3-7. The conditions of recipient older than 34 years and donor older than 41 years were the only ones that showed statistically significant association with BK viruria. No association with any specific immunosuppressive drug was observed. CONCLUSIONS: This is the first multicenter study conducted in Argentina to determine the prevalence of BK viruria in renal transplant recipients. Because of the growing number of the population susceptible to this infection, it is important to register and describe data about its epidemiology and associated risk factors.

Results of a calcineurin-inhibitor-free immunosuppressive protocol in renal transplant recipients of expanded criteria deceased donors.

The increasing number of patients on waiting lists and the relatively stable organ procurement rate provide the groundwork for the use of expanded criteria deceased donors. While calcineurin-inhibitors (CNI) are excellent immunosuppressive drugs, their nephrotoxicity is largely responsible for the lack of improvement in long-term graft survival. The objective of this study was to analyze the results obtained with the use of a calcineurin inhibitor-free immunosuppressive protocol (polyclonal antibody induction, plus sirolimus, mycophenolate mofetil, and low doses of steroids) in terms of graft and patient survival as well as posttransplant clinical complications over 2 years. Under this immunosuppressive protocol, 78.04% of the patients completed the follow-up. A protocol biopsy was performed on 17 patients (53.1%) within 2 years posttransplant of which 82.31% were diagnosed as chronic allograph nephropathy grade I. The incidence of clinical complications was low and not significantly different from that reported with other immunosuppressive schemes. Death-censored graft survival was 95.12%. In conclusion, the use of a calcineurin inhibitor-free protocol in renal-transplant recipients of expanded criteria deceased donors was associated with excellent graft and patient survival rates and a low incidence of adverse events.

Comparison between clinical and histopathological scoring in cadaveric kidney transplantation and its correlation with posttransplant evolution.

INTRODUCTION: There are several scoring systems, both clinical (Deceased Donor Score [DDS]) and histopathological (Remuzzi [REM]), that attempt to determine acceptability criteria for deceased donor kidney transplant. A retrospective study was performed among a group of kidney transplant recipients to evaluate posttransplant evolution with clinical and histopathological scores. MATERIALS AND METHODS: Among 107 first deceased donor kidney transplant patients, 95 had undergone a pretransplant biopsy. Donor age was 38.46 +/- 16.9 years; recipient age: 49.2 +/- 16.3 years; DDS was 15.58 +/- 7.29. REM was 2.89 +/- 1.7. Delayed graft function was 64.2%. Induction therapy was administered to 49.5%. Cold ischemia time (CIT) was 1364 +/- 348 minute. Time on dialysis was 2275 +/- 1501 days. Induction therapy, immunosuppressive regimens, CIT, and time on dialysis were not significantly different among the groups. One-year patient and graft survival were 94.5% and 86%, respectively and 2-year values, 92.6% and 81%, respectively. CONCLUSION: DDS showed a significant correlation with serum creatinine values over 1 and 2 years. REM did not show a significant association with any events. The differences were sustained after adjusting for other variables. Graft survival maintained a strong correlation with DDS categories and no association with REM. The clinical characteristics of a deceased donor appeared to be of greater importance than the biopsy findings in terms of posttransplant events.

Efficacy of conversion to sirolimus in posttransplantation Kaposi's sarcoma.

UNLABELLED: The increased incidence of Kaposi's sarcoma (KS) in organ transplantation has been related to the KS herpes virus and the permissive effect of immunosuppressive therapy. We postulated that conversion to SRL in renal recipients with KS favored regression of KS lesions without increasing the risk of graft rejection. METHODS: In this study we performed a retrospective chart review of 7 caucasian renal transplant recipients affected by KS to determine demographic data, etiology of ESRD, immunologic risk factors, immunosuppressive treatment, KS disease follow-up, and renal function before and after SRL conversion. RESULTS: All seven patients were under calcineurin inhibitor treatment at the onset of KS which was limited to the skin, without regression despite attempts to minimize immunosuppression. After conversion to SRL, six patients showed progressive regression of KS lesions, with only hyperpigmented atrophic cutaneous lesions remaining after a mean time of 8.1 months (2-18 months). The seventh patient has completed 9 months follow-up with a near complete regression of KS lesions. One patient returned to hemodialysis after 13 months following irreversible acute renal failure not directly related to SRL conversion; in the other six, renal function was stable. The mean serum creatinine was 1.87 +/- 0.64 versus 1.74 +/- 0.68 mg/dL, pre-conversion versus the end of follow up, respectively. Mean SRL blood level was 9.2 +/- 2.0 ng/mL. CONCLUSION: After SRL conversion, patients with KS showed progressive regression without an increased risk of acute rejection. SRL offers a promising approach to the management of posttransplantation KS and probably other malignancies in organ transplant recipients.