Background: Acquired or genetic abnormalities of the complement alternative pathway are the primary cause of C3glomerulopathy(C3G) but may occur in immune-complex-mediated membranoproliferative glomerulonephritis (IC-MPGN) as well. Less is known about the presence and role of C4nephritic factor(C4NeF) which may stabilize the classical pathway C3-convertase. Our aim was to examine the presence of C4NeF and its connection with clinical features and with other pathogenic factors. Results: One hunfe IC-MPGN/C3G patients were enrolled in the study. C4NeF activity was determined by hemolytic assay utilizing sensitized sheep erythrocytes. Seventeen patients were positive for C4NeF with lower prevalence of renal impairment and lower C4d level, and higher C3 nephritic factor (C3NeF) prevalence at time of diagnosis compared to C4NeF negative patients. Patients positive for both C3NeF and C4NeF had the lowest C3 levels and highest terminal pathway activation. End-stage renal disease did not develop in any of the C4NeF positive patients during follow-up period. Positivity to other complement autoantibodies (anti-C1q, anti-C3) was also linked to the presence of nephritic factors. Unsupervised, data-driven cluster analysis identified a group of patients with high prevalence of multiple complement autoantibodies, including C4NeF.

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.

BackgroundFactor H-related protein 5 (FHR-5) is a member of the complement Factor H protein family. Due to the homology to Factor H, the main complement regulator of the alternative pathway, it may also be implicated in the pathomechanism of kidney diseases where Factor H and alternative pathway dysregulation play a role. Here, we report the first observational study on CFHR5 variations along with serum FHR-5 levels in immune complex-mediated membranoproliferative glomerulonephritis (IC-MPGN) and C3 glomerulopathy (C3G) patients together with the clinical, genetic, complement, and follow-up data.MethodsA total of 120 patients with a histologically proven diagnosis of IC-MPGN/C3G were enrolled in the study. FHR-5 serum levels were measured in ELISA, the CFHR5 gene was analyzed by Sanger sequencing, and selected variants were studied as recombinant proteins in ELISA and surface plasmon resonance (SPR).ResultsEight exonic CFHR5 variations in 14 patients (12.6%) were observed. Serum FHR-5 levels were lower in patients compared to controls. Low serum FHR-5 concentration at presentation associated with better renal survival during the follow-up period; furthermore, it showed clear association with signs of complement overactivation and clinically meaningful clusters.ConclusionsOur observations raise the possibility that the FHR-5 protein plays a fine-tuning role in the pathogenesis of IC-MPGN/C3G.

Background/Aims: In cases of severe primary hypertension not responding to conventional medical therapy, neurovascular pulsatile compression of the rostral ventrolateral medulla on the left side may be considered as an etiological factor in the hypertension. Through neurosurgical decompression, the blood pressure can be reduced in these cases, and the conventional medication can also become more effective. Methods:The authors retrospectively analysed the changes in the blood pressure and therapy of patients with or without neurosurgical decompression over a 2-year period. The 2-year data were available for 9 operated and 7 non-operated patients with neurovascular compression. The data of control examinations performed 1, 3, 6, 12 and 24 months after the intervention (or after MR-angiography in the non-operated cases) were analysed. Results: After the decompression, both the systolic and diastolic blood pressure decreased significantly and permanently in all cases, and there was an improved response to the medication. In the non-operated group, the blood pressure did not change significantly during the 2 years. Conclusion: In severe hypertension that does not respond to conventional therapy, neurosurgical decompression of the brain stem on the left side can guarantee a long-lasting blood pressure reduction and a better response to antihypertensive medication.

OBJECTIVE Finerenone significantly improved cardiorenal outcomes in patients with chronic kidney disease (CKD) and type 2 diabetes (T2D) in the Finerenone in Reducing Kidney Failure and Disease Progression in Diabetic Kidney Disease trial. We explored whether baseline HbA1c level and insulin treatment influenced outcomes. RESEARCH DESIGN AND METHODS Patients with T2D, urine albumin-to-creatinine ratio (UACR) of 30–5,000 mg/g, estimated glomerular filtration rate (eGFR) of 25 to <75 mL/min/1.73 m2, and treated with optimized renin–angiotensin system blockade were randomly assigned to receive finerenone or placebo. Efficacy outcomes included kidney (kidney failure, sustained decrease ≥40% in eGFR from baseline, or renal death) and cardiovascular (cardiovascular death, nonfatal myocardial infarction, nonfatal stroke, or hospitalization for heart failure) composite endpoints. Patients were analyzed by baseline insulin use and by baseline HbA1c <7.5% (58 mmol/mol) or ≥7.5%. RESULTS Of 5,674 patients, 3,637 (64.1%) received insulin at baseline. Overall, 5,663 patients were included in the analysis for HbA1c; 2,794 (49.3%) had baseline HbA1c <7.5% (58 mmol/mol). Finerenone significantly reduced risk of the kidney composite outcome independent of baseline HbA1c level and insulin use (Pinteraction = 0.41 and 0.56, respectively). Cardiovascular composite outcome incidence was reduced with finerenone irrespective of baseline HbA1c level and insulin use (Pinteraction = 0.70 and 0.33, respectively). Although baseline HbA1c level did not affect kidney event risk, cardiovascular risk increased with higher HbA1c level. UACR reduction was consistent across subgroups. Adverse events were similar between groups regardless of baseline HbA1c level and insulin use; few finerenone-treated patients discontinued treatment because of hyperkalemia. CONCLUSIONS Finerenone reduces kidney and cardiovascular outcome risk in patients with CKD and T2D, and risks appear consistent irrespective of HbA1c levels or insulin use.