Clinical course and outcome after kidney transplantation in patients with C3 glomerulonephritis due to CFHR5 nephropathy.

BACKGROUND: Complement factor H-related protein 5 (CFHR5) nephropathy is an inherited renal disease characterized by microscopic and synpharyngitic macroscopic haematuria, C3 glomerulonephritis and renal failure. It is caused by an internal duplication of exons 2-3 within the CFHR5 gene resulting in dysregulation of the alternative complement pathway. The clinical characteristics and outcomes of transplanted patients with this rare familial nephropathy remain unknown. METHODS: This is a retrospective case series study of 17 kidney transplant patients with the established founder mutation, followed-up over a span of 30 years. RESULTS: The mean (±SD) age of patients at the time of the study and at transplantation was 58.6 ± 9.9 and 46.7 ± 8.8 years, respectively. The 10- and 15-year patient survival rates were 100 and 77.8%, respectively. Proteinuria was present in 33.3% and microscopic haematuria in 58.3% of patients with a functional graft. Serum complement levels were normal in all. 'Confirmed' and 'likely' recurrence of CFHR5 nephropathy were 16.6 and 52.9%, respectively; however, 76.5% of patients had a functional graft after a median of 120 months post-transplantation. Total recurrence was not associated with graft loss (P = 0.171), but was associated with the presence of microscopic haematuria (P = 0.001) and proteinuria (P = 0.018). Graft loss was associated with the presence of proteinuria (P = 0.025). CONCLUSIONS: We describe for the first time the clinical characteristics and outcome of patients with CFHR5 nephropathy post-transplantation. Despite the recurrence of CFHR5 nephropathy, we provide evidence for a long-term favourable outcome and support the continued provision of kidney transplantation as a renal replacement option in patients with CFHR5 nephropathy.

Frequency of COL4A3/COL4A4 mutations amongst families segregating glomerular microscopic hematuria and evidence for activation of the unfolded protein response. Focal and segmental glomerulosclerosis is a frequent development during ageing.

Familial glomerular hematuria(s) comprise a genetically heterogeneous group of conditions which include Alport Syndrome (AS) and thin basement membrane nephropathy (TBMN). Here we investigated 57 Greek-Cypriot families presenting glomerular microscopic hematuria (GMH), with or without proteinuria or chronic kidney function decline, but excluded classical AS. We specifically searched the COL4A3/A4 genes and identified 8 heterozygous mutations in 16 families (28,1%). Eight non-related families featured the founder mutation COL4A3-p.(G1334E). Renal biopsies from 8 patients showed TBMN and focal segmental glomerulosclerosis (FSGS). Ten patients (11.5%) reached end-stage kidney disease (ESKD) at ages ranging from 37-69-yo (mean 50,1-yo). Next generation sequencing of the patients who progressed to ESKD failed to reveal a second mutation in any of the COL4A3/A4/A5 genes, supporting that true heterozygosity for COL4A3/A4 mutations predisposes to CRF/ESKD. Although this could be viewed as a milder and late-onset form of autosomal dominant AS, we had no evidence of ultrastructural features or extrarenal manifestations that would justify this diagnosis. Functional studies in cultured podocytes transfected with wild type or mutant COL4A3 chains showed retention of mutant collagens and differential activation of the unfolded protein response (UPR) cascade. This signifies the potential role of the UPR cascade in modulating the final phenotype in patients with collagen IV nephropathies.

Renal graft outcome in autosomal dominant medullary cystic kidney disease type 1.

BACKGROUND: Medullary cystic kidney disease (MCKD) is an inherited interstitial nephritis, leading to end-stage renal disease (ESRD) between the fourth and seventh decade of life. MCKD shares clinical and morphological features with nephronophthisis, although advances in molecular genetics have distinguished these 2 entities. Data regarding graft survival after kidney transplantation in MCKD patients are extremely limited. The aim of this study was to compare renal graft survival in transplanted MCKD1 and non-MCKD1 patients, to discover whether renal transplantation can be considered as an acceptable treatment for MCKD. METHODS: Thirty-three transplanted patients with MCKD1 and 33 controls (transplanted due to other causes) were included in the study. Graft losses were considered censored for death. Graft survival was evaluated with the Kaplan-Meier method, and comparisons between groups were made by log-rank test. Cox regression analysis was used to estimate the effect of several variables on graft survival, and the chi-square test was used to compare groups of categorical data. RESULTS: The 1-year cumulative graft survival rate for the MCKD1 group was 97%, while at 5 and 10 years it was 94% and 86%, respectively. For the control group, the respective values at years 1, 5 and 10 were 97%, 97% and 90%. Comparisons of graft survival rates between the 2 groups revealed no significant differences. CONCLUSIONS: Renal graft survival of transplanted MCKD1 patients was not shown to be inferior in comparison with that for patients undergoing transplants due to other causes. Therefore, it may represent a treatment of choice in MCKD1 patients with ESRD.

A fatal case of paraquat poisoning following minimal dermal exposure.

Paraquat is a pesticide widely used in agriculture. Numerous cases of paraquat intoxication have been reported either accidentally or intentionally as a suicidal attempt. The most severe cases of paraquat poisoning refer to oral ingestion. Complications include respiratory, hepatic, and renal failure, and are usually fatal. Dermal exposure is less frequent and rarely fatal. This article reports a case of an 81-year-old man with minimal skin burn after accidental paraquat exposure. The patient developed acute renal and respiratory failure and, despite aggressive treatment with hemodialysis, hemoperfusion, and mechanical ventilation, died two days later.