Validation of distinct pathogenic patterns in a cohort of membranoproliferative glomerulonephritis patients by cluster analysis

Background: A novel data-driven cluster analysis identified distinct pathogenic patterns in C3-glomerulopathies and immune complex-mediated membranoproliferative glomerulonephritis. Our aim was to replicate these observations in an independent cohort and elucidate disease pathophysiology with detailed analysis of functional complement markers. ----- Methods: A total of 92 patients with clinical, histological, complement and genetic data were involved in the study, and hierarchical cluster analysis was done by Ward method, where four clusters were generated. ----- Results: High levels of sC5b-9 (soluble membrane attack complex), low serum C3 levels and young age at onset (13 years) were characteristic for Cluster 1 with a high prevalence of likely pathogenic variations (LPVs) and C3 nephritic factor, whereas for Cluster 2-which is not reliable because of the small number of cases-strong immunoglobulin G staining, low C3 levels and high prevalence of nephritic syndrome at disease onset were observed. Low plasma sC5b-9 levels, decreased C3 levels and high prevalence of LPV and sclerotic glomeruli were present in Cluster 3, and patients with late onset of the disease (median: 39.5 years) and near-normal C3 levels in Cluster 4. A significant difference was observed in the incidence of end-stage renal disease during follow-up between the different clusters. Patients in Clusters 3-4 had worse renal survival than patients in Clusters 1-2. ----- Conclusions: Our results confirm the main findings of the original cluster analysis and indicate that the observed, distinct pathogenic patterns are replicated in our cohort. Further investigations are necessary to analyse the distinct biological and pathogenic processes in these patient groups

C4 nephritic factor in patients with immune-complex-mediated membranoproliferative glomerulonephritis and C3-glomerulopathy

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Surgical versus Medical Management of Progressive Familial Intrahepatic Cholestasis—Case Compilation and Review of the Literature

(1) Background: Progressive familial intrahepatic cholestasis (PFIC) is a rare cause of liver failure. Surgical biliary diversion (SBD) and ileal bile salt inhibitors (IBAT) can delay or prevent liver transplantation (LTX). A comparison of the two methodologies in the literature is lacking. The combination has not been investigated. (2) Methods: We performed a literature survey on medical and surgical treatments for PFIC and reviewed the charts of our patients with PFIC of a tertiary hospital. The end points of our analysis were a decrease in serum bile acid (sBA) levels, reduction of pruritus and delay or avoidance of (LTX). (3) Results: We included 17 case series on SBD with more than 5 patients and a total of 536 patients. External or internal SBD, either conventional or minimally invasive, can reduce pruritus and sBA, but not all PFIC types are suitable for SBD. Six publications described the use of two types of IBAT in PFIC with a total of 118 patients. Treatment response was dependent on genetic type and subtype. Patients with PFIC 2 (nt-BSEP) showed the best response to treatment. Four out of eleven PFIC patients underwent SBD at our centre, with two currently receiving IBAT. (4) Conclusions: Limited data on IBAT in selected patients with PFIC show safety and effectiveness, although surgical methods should still be considered as a successful bridging procedure. Further studies to evaluate a possible combination of IBAT and SBD in PFIC are warranted and treatment decision should be discussed in an interdisciplinary board