Background: Polyomavirus BK virus infection is a significant complication of renal transplantation and is an important cause of allograft loss. Today, despite the innovations in the pharmaceutical industry, a curative treatment against the BK virus has not been developed. The management is not standardized and is generally based on reported experience from transplantation centers. However, the literature on the subject with large samples is limited. Therefore, we designed a study to present our countrywide experience with BK virus nephropathy (BKVN) in renal transplant recipients. Methods: Our study was conducted with thirty kidney transplant centers from all provinces of Turkey. Only cases with BKVN proven by allograft biopsy were included in our study. Demographic characteristics and laboratory values of the patients were obtained from the archives and electronic databases of the centers. Results: A total of 13.857 patients from 30 transplantation centers were screened. 207 BKVN cases proven by allograft biopsy were identified and included in the study. The mean age was 46.4±13.1, and 146 (70.5%) patients were male. Twenty-six patients did not receive any induction therapy, 144 patients received anti-T lymphocyte globulin (ATLG), and 37 patients received basiliximab after transplantation. 23.6% of the patients had acute rejection history in the first six months of renal transplantation. all were treated with pulse steroids, and 46 were also treated with ATLG. The mean time to diagnosis of BKVN was 15.8±22.2 months after transplantation. At the time of diagnosis, the patients’ mean creatinine level was 1.8±0.7 mg/dl, and the mean estimated glomerular filtration rate was 45.8±19.6 ml/min. While BKVN was solely reported in 181 cases, there were cellular rejection findings in 21 biopsy specimens and humoral rejection in 4 biopsy specimens. In addition of dose reduction or discontinuation of immunosuppressive drugs, eighteen patients were treated with cidofovir, 11 patients with leflunomide, 17 patients with quinolones, 15 patients with intravenous immunoglobulin (IVIG), five patients with cidofovir+IVIG, and 12 patients with leflunomide+IVIG. None of the patients who received leflunomide and leflunomide+IVIG had allograft loss. Allograft loss was observed in 12 (15%) of 78 patients treated with antivirals or immunomodulators. Allograft loss occurred in 32 patients (15%) during follow-up out of 207 patients with BKVN. Five patients were retransplanted, and none developed BKVN during the follow-up. Conclusions: BKVN is still a significant cause of allograft loss in kidney transplantation, which has not been fully elucidated. Leflunomide appears to be an effective treatment in these patients.

Background Right ventricular dysfunction is a major cause of heart failure and mortality in end-stage renal disease patients. Scarce data is available regarding the comparison of echocardiographic right ventricular function in end-stage renal disease patients on hemodialysis (HD) and peritoneal dialysis (PD). The aim of the study was to evaluate the long-term impacts of different dialysis modalities on right ventricular function assessed by conventional echocardiography, in end-stage renal disease patients with preserved left ventricular function. Methods The study included 120 patients grouped as follows: PD(n=40), HD with arterio-venous fistula (n=40) and healthy control subjects (n=40). Conventional echocardiography was performed in all patients. A classification of right ventricular function was defined in HD patients by using tricuspid annular plane systolic excursion (TAPSE), right ventricular myocardial performance index (RV-MPI), fractional area change (FAC) and tricuspid lateral annulus systolic velocity (Sa) values. Correlation analysis was performed by using right ventricular dysfunction score, clinical and echocardiographic parameters. Results The mean age of the study population was 51.9±13.1 years and 47.5% were females. TAPSE and Sa velocity were found to be significantly lower and RV-MPI was significantly higher in patients undergoing HD, compared with control and PD patients. Logistic regression analysis showed that HD treatment was an independent risk factor for developing right ventricular dysfunction. Conclusion RV function was impaired in patients undergoing HD compared with patients on PD.