Hyperuricemia in renal disease patients.

Hyperuricemia is a common laboratory finding in different types of patients. Except of those with acute or chronic gout, it is frequently found in patients with metabolic syndrome, patients with malignancies or renal impairment - acute kidney injury (AKI) and chronic kidney disease (CKD). Hyperuricemia might cause renal dysfunction or might be a part of laboratory abnormalities associated with loss of renal function as well. There is also large body of evidence of hyperuricemia as a potential cardiovascular (CV) risk factor, which might even more increase CV risk in CKD patients. Association of asymptomatic hyperuricemia and progression of CKD remaines controversial, as well as indication for hypouricemic treatment in this clinical setting.

A prospective longitudinal study of BK virus infection in 120 Czech renal transplant recipients.

Polyomavirus BK (BKV) is a common human polyomavirus that rarely causes clinical symptoms in immunocompetent individuals. However, BK virus reactivation occurs in 20-40% of kidney transplant patients and 1-10% of cases present with BK virus-associated nephropathy (BKVN) and reduced kidney allograft survival. In this study, 120 consecutive renal allograft recipients were monitored for BK virus replication by real-time PCR (qPCR) in the blood and urine during the first year post-transplantation and risk factors for BK viremia, viruria, and polyoma BKV-associated nephropathy were evaluated. Receiver operating characteristic curve analysis was used to determine the cutoff points for assessing the risk of developing BKVN. In total, 1,243 samples were tested. BK-DNAuria >10(7) copies/ml and BK-DNAemia >10(4) copies/ml were found in 25.8% and 5% of the samples screened, respectively, during the 12 month follow-up period. BKVN was confirmed histologically in 3/120 patients and viremic patients were treated with dialysis for longer time periods and had higher levels of panel [corrected] reactive antibodies. Patients with viruria were also treated longer with dialysis and had impaired graft function 12 months post-transplantation. Patients with sustained viruria exhibited more acute rejection episodes than patients with transient viruria. Using receiver operating characteristic curve analysis, the cutoff point for viremia and viruria was redefined to 10(3) copies/ml serum for BK viremia and a cutoff point of 6.7 × 10(7) copies/ml in urine. In conclusion, polyoma BK viremia and viruria are frequent findings in kidney transplant recipients that warrant intensive monitoring as a means of preventing graft failure [corrected].

Molecular phenotypes of acute rejection predict kidney graft prognosis.

Earlier detection of antibody-mediated rejection of kidney allografts may improve graft outcomes. Profiling of gene expression holds promise for the diagnosis and prognosis of antibody-mediated rejection. Here, we identified 730 patients who received kidney transplants during 2002-2005, including 21 patients (2.9%) who experienced early acute antibody-mediated rejection. We also identified a matched group of 43 patients with early acute T cell-mediated rejection to serve as controls. Compared with patients with T cell-mediated rejection, those with antibody-mediated rejection had significantly higher intrarenal mRNA expression of the cytoprotective heme oxygenase-1 but had lower expression of the regulatory T cell marker forkhead box P3 (FoxP3), the B cell marker CD20, and the chemokine regulated upon activation, normal T cell expressed and secreted (RANTES). T cell infiltration was similar in both groups of patients. Compared with grafts that had a favorable course, those that failed as a result of antibody-mediated rejection had expression profiles suggesting a lack of regulation (less FoxP3, TGF-beta1, RANTES, and CD20). Grafts that failed as a result of T cell-mediated rejection only revealed lower expression of CD20 mRNA. In summary, these data suggest that severe antibody-mediated rejection and T cell-mediated rejection result in graft loss by distinct mechanisms. Molecular phenotypes of early acute rejection might help to identify grafts with poor prognosis, allowing earlier application of additional therapies.

[Kidney transplantation at the Institute for Clinical and Experimental Medicine]. / Transplantace ledviny v IKEM.

BACKGROUND: Kidney transplantation represents the method of choice of end stage renal disease. METHODS AND RESULTS: The program of kidney transplantation was established in 1966 in our centre. In recent years, roughly 200 patients have undergone kidney transplantation annually, and 20-30 of them have received a graft from the living donor. Triple immunosuppressive regimen based on tacrolimus, MMF and steroids is given to majority of patients, in a case of high rejection risk; patients have received the induction protocols with polyclonal or monoclonal antilymphocyte globulins. Acute rejection is not a frequent finding in recent years and has occurred in 15% of cases in the first 3 months, the use of induction immunosuppression has decreased the rejection risk. Valgancyclovir has been used as prophylactic agent to prevent and treat cytomegalovirus infection. The usage of this strategy reduced the incidence of CMV infection below 10%. Kidney transplant recipients suffer from similar comorbidities as other renal patients in the long term, as cardiovascular complications, infections and malignancies. Anemia is a frequent complication in patients with graft dysfunction and erythropoesis stimulating agents have been used in its therapy. The median kidney graft survival is 8 years. CONCLUSIONS: Kidney transplantation is associated with better long-term results when compared with dialysis therapy and thus this method should be offered to all of suitable end stage renal disease patients.

RAGE polymorphisms, renal function and histological finding at 12 months after renal transplantation.

OBJECTIVES: Rage (receptor for advanced glycation end products) is involved in pathogenesis of many diseases. The aim of the study was to test whether polymorphisms of RAGE gene are associated with the outcome of kidney transplantation. DESIGN AND METHODS: Four polymorphisms of the RAGE gene (-429T/C, -374T/A, Gly82Ser and 2184A/G) were assessed in 145 renal transplant recipients and their relationship to histological changes in 12 months protocol kidney graft biopsy and renal function was examined. RESULTS: Genotype frequencies of each polymorphism corresponded to expected frequencies according to Hardy-Weinberg equilibrium. No differences between allelic and genotype frequencies among patients with normal histological findings, chronic allograft nephropathy and subclinical rejection were observed. CONCLUSION: This is the first study on polymorphisms of the RAGE gene in patients with the transplanted kidney. No association of RAGE selected gene polymorphisms with 12-months outcome of renal transplants was shown in study.

Haplotypic structure of ABCB1/MDR1 gene modifies the risk of the acute allograft rejection in renal transplant recipients.

BACKGROUND: Bioavailability of tacrolimus (Tac) and cyclosporine is determined by cytochrome P450IIIA and by P-glycoprotein encoded by the CYP3A4/CYP3A5 and ABCB1 genes. Polymorphisms in these genes have been suggested to influence acute rejection and pharmacokinetics in renal transplantation. We aimed to validate these findings in a haplotype analysis. METHODS: A total of 832 renal transplant recipients were genotyped for the CYP3A4 -288A>G, CYP3A5 +6986G>A, ABCB1 +1236C>T, +2677G>T>A, and +3435C>T polymorphisms. Their association with acute rejection and with pharmacokinetic parameters was analyzed in haplotype models. RESULTS: Apart from human leukocyte antigen-DR mismatches, delayed graft function and age at renal transplantation, acute rejection was also predicted by the [ABCB1 +1236C; +2677G; +3435T] haplotype. Allograft survival was determined by donor age, age at renal transplantation, delayed graft function, cold ischemia, and history of more than two acute rejections. Homozygotes for the [CYP3A4 -288A; CYP3A5 +6986G] haplotype achieved earlier therapeutic concentrations of Tac and a higher concentration to dose ratio at week 1. ABCB1 haplotypes did not influence pharmacokinetic parameters. CONCLUSIONS: ABCB1 haplotypes modify the risk of acute rejection, suggesting that ABCB1 allelic arrangement is a stronger regulator of P-glycoprotein activity than single polymorphisms. The risk of acute rejection determined by ABCB1 is independent of pharmacokinetic parameters. CYP3A haplotypes control the bioavailability of Tac, but do not modify the risk of acute rejection.