Search

Following primary infection, the polyomavirus BK remains latent in the urinary tract e peripheral blood cells. Reactivation may occur spontaneously in healthy subjects and in immunocompromised conditions. BKV reactivation may determine urinary shedding of infected urothelial cells, hemorrhagic cystitis (particularly in bone marrow transplant recipients), and nephropathy in kidney graft recipients. Moreover, a possible role for BKV in the pathogenesis of systemic lupus erythematosus (SLE) has been hypothesised. SLE is characterised by production of autoantibodies, in particular anti-double stranded (ds)-DNA antibodies. The induction of anti-dsDNA antibodies by BKV has been described in experimental animals and during naturally acquired infection in man. Therefore, it has been proposed that the BKV large T-antigen-chromatin complex may function as a hapten-carrier model with subsequent production of anti-dsDNA antibodies.Aim of this study was to evaluate the relation between BKV and autoimmunity in renal transplant recipients by determining the prevalence of non-organ-specific antibodies (NOSA) by indirect immunofluorescence on serum samples obtained from 95 renal transplant recipients during post-transplantation follow-up. BKV infection was evaluated by competitive-quantitative PCR. NOSA were present in 25/95 patients: 18 ANA and 6 SMA, one patient both ANA and SMA. BKV-DNA was positive in 16/95 patients: 3 NOSA-positive and 13 negative. BKV-DNA was negative in 79/95 patients: 22 NOSApositive and 57 negative. The prevalence of NOSA did not differ between BKV-DNA positive and negative patients. It does not seem to exist a relation between BKV and NOSA in renal transplant recipients.

The widespread worldwide implementation of ABO-incompatible kidney transplantation (ABOi KT) programs have increased the chances of gaining access to kidney transplantation. In Italy the practice of ABOi KT has somewhat lagged behind that practiced in many other European Countries. Even though some Italian Transplant Centers have recently started ABOi KT programs, most of them appear still reluctant in adopting this procedure. In this paper, nephrologists from two different Italian Transplant Centers express their contrasting point of view concerning specific issues related to ABOi KT. The first issue concerns the safety and efficacy of ABOi KT and how it compares with HLA-incompatible kidney transplantation. The second concerns to what extent does ABOi KT be adopted, whenever a paired kidney exchange program is available. The third issue regards the indications or contraindications of ABOi KT in specific patient categories. The last issue is about the economical sustainability of ABOi KT programs nowadays. The different point of views of the discussants are summarized in the context of the most recent available evidence.

Introduction: Polyomavirus BK nephropathy is emerging as a significant cause of interstitial nephritis and allograft dysfunction (1-2)., Case Report: Two patients with renal transplants from cadaveric kidneys were treated with Tacrolimus plus Mycophenolate Mofetil (MMF) and Cyclosporine plus MMF, respectively. Their renal function gradually deteriorated eight to twelve months after the transplant. The renal biopsy of the first patient showed signs of significant interstitial tubulite, which necessitated the anti-rejection therapy with intravenous steroid pulses. After the pulses there was an additional dramatic increase in plasmatic creatinine, which suggested a revaluation of the kidney biopsy because of suspected Polyomavirus BK (BKV) nephropathy. In fact, after a more careful review, the suspicion of BKV infection was confirmed by the presence of intranuclear inclusions of tubular epithelium cells and marked denudation of the tubular basal membrane. The subsequent screening in both cases confirmed the presence of decoy cells in the urine, while the immunohistochemical analysis of the renal biopsy was strongly positive for the SV40 antigen. Our diagnosis was that of interstitial nephritis due to Polyomavirus BK that, in the first patient, was expressed by more aggressive clinical progress, probably due to enhanced immunosuppression from incorrect diagnosis of the interstitial rejection. The pre-transplant clinical outcome of the first patient was characterised by proteinuric nephropathy without any histological confirmation. Furthermore, we observed abundant pre-transplant residual diuresis and glucose intolerance. All these elements led us to hypothesise that native kidneys could have a fundamental role as viral reservoirs., Conclusion: Even though we reconfirm the decisive role of the immunosuppressive therapy and of the donor s kidney as the fundamental causes of Polyomavirus reactivation, we believe that it cannot be the result of a possible active role by the native kidney. In fact, as already noted, the SV40 genome is important in the pathogenesis of focal gomerulosclerosis. Furthermore, reports of polyoma nephropathy in not-yet-transplanted patients could accredit the role of the native kidneys as important viral reservoirs capable of inducing nephropathy in renal transplant patients.

The occurrence of infections in organ transplantation is one of the most significant determinants of transplant outcome, because it is the most common life-threatening complication of long-term immunosuppressive therapy. Recently, besides the well-known direct effect of infections, other relevant biochemical factors such as cytokines, chemokines and growth factors have been considered. Aim of this review is to deal with the infections by mainly considering the unusual consequences of several infectious diseases like malignancies, graft loss and atherosclerosis. The number of patients affected by malignancies is increasing in all registries. Viral pathogens play a pathophysiological role in the development of the most frequent malignancies after solid organ transplantation. In some cases viruses act by altering cell transformation. Moreover, some pathogens may contribute to global immunosuppression and work together to promote oncogenesis. The viral load surveillance is recommended in the prevention of malignancies. The BK virus nephropathy in renal transplant recipients is emerging as an unusual consequence of graft loss. In this paper we examine the risk factors, the clinical characteristics and especially the diagnostic tools and treatments actually available. The third unusual consequence is the transplant vascular sclerosis, a multifactorial late complication of solid organ transplantation. The transplant vascular sclerosis has emerged as an important limitation in long-term graft survival. Several epidemiological, clinical and therapeutic interventional studies have shown how several potential contributing etiologic factors, such as Chlamydia and CMV infection, have been identified as being definitely associated with the development of transplant vascular sclerosis.

The BK virus (BKV) belongs to the family of the polyoma group. Although up to 60% of AIDS patients excrete BKV in the urine, there have been few reports of infection of kidney, lung, retina, brain and peripheral blood mononuclear cells. We report the case of a 37 year-old male HIV positive patient with BKV encephalitis. This diagnosis should be considered in AIDS patients with signs of cerebral disease.