Hemolytic-uremic syndrome, malignant hypertension and IgA nephropathy: successful treatment with plasma exchange therapy

Efficacy and Safety of Plasma Exchange as an Adjunctive Therapy for Rapidly Progressive IgA Nephropathy and Henoch-Schönlein Purpura Nephritis: A Systematic Review

Patients with IgA nephropathy (IgAN), including Henoch-Schönlein purpura nephritis (HSP), who present with rapidly progressive glomerulonephritis (RPGN) have a poor prognosis despite aggressive immunosuppressive therapy. The utility of plasmapheresis/plasma exchange (PLEX) for IgAN/HSP is not well established. This systematic review aims to assess the efficacy of PLEX for IgAN and HSP patients with RPGN. A literature search was conducted using MEDLINE, EMBASE, and through Cochrane Database from inception through September 2022. Studies that reported outcomes of PLEX in IgAN or HSP patients with RPGN were enrolled. The protocol for this systematic review is registered with PROSPERO (no. CRD42022356411). The researchers systematically reviewed 38 articles (29 case reports and 9 case series articles) with a total of 102 RPGN patients (64 (62.8%) had IgAN and 38 (37.2%) had HSP). The mean age was 25 years and 69% were males. There was no specific PLEX regimen utilized in these studies, but most patients received at least 3 PLEX sessions that were titrated based on the patient's response/kidney recovery. The number of PLEX sessions ranged from 3 to 18, and patients additionally received steroids and immunosuppressive treatment (61.6% of patients received cyclophosphamide). Follow-up time ranged from 1 to 120 months, with the majority being followed for at least 2 months after PLEX. Among IgAN patients treated with PLEX, 42.1% (n = 27/64) achieved remission; 20.3% (n = 13/64) achieved complete remission (CR) and 18.7% (n = 12/64) partial remission (PR). 60.9% (n = 39/64) progressed to end-stage kidney disease (ESKD). Among HSP patients treated with PLEX, 76.3% (n = 29/38) achieved remission; of these, 68.4% (n = 26/38) achieved CR and 7.8% achieved (n = 3/38) PR. 23.6% (n = 9/38) progressed to ESKD. Among kidney transplant patients, 20% (n = 1/5) achieved remission and 80% (n = 4/5) progressed to ESKD. Adjunctive plasmapheresis/plasma exchange with immunosuppressive therapy showed benefits in some HSP patients with RPGN and possible benefits in IgAN patients with RPGN. Future prospective, multi-center, randomized clinical studies are needed to corroborate this systematic review's findings.

IgA nephropathy and atypical hemolytic uremic syndrome: a case series and a literature review

BACKGROUND

IgA nephropathy (IgAN) has been anecdotally reported in association with atypical hemolytic uremic syndrome (aHUS). The association likely portends poor renal outcome, and the possible relationship with complement overactivation has yet to be elucidated. We evaluated a series of IgAN patients with aHUS and reviewed the available literature.

METHODS

Adult patients who received a diagnosis of IgAN and developed aHUS between January 2009 and December 2019 were included in this retrospective review.

RESULTS

We identified six IgAN-aHUS patients, all of whom developed end-stage kidney disease. At aHUS presentation all patients had decreased serum C3 levels. Predisposing pathogenetic variants and risk haplotypes for aHUS in CFH gene heterozygosity were documented in four out of six patients. Anti-CFH antibodies were found to be negative in the five tested patients. In the literature we identified 21 case reports involving aHUS-IgAN and six retrospective studies evaluating the presence of TMA at the time of renal biopsy. Hypertension, severe proteinuria, reduced sC3 and a worse renal prognosis were the common features of most cases.

CONCLUSION

Our case series and literature review show that the onset of either aHUS or renal TMA in the course of IgAN are associated with very poor renal outcome. Activation of the alternative pathway revealed by consumption of serum C3 seems to play a major role. Our hypothesis is that the presence of a predisposing factor (e.g. dysregualtion of complement alternative pathway and/or other intrarenal precipitating factors) might be at the heart of aHUS-IgAN pathophysiology.

C3 mesangial proliferative glomerulonephritis initially presenting with atypical hemolytic uremic syndrome: a case report

BACKGROUND

Hemolytic uremic syndrome is characterized by acute renal failure, thrombocytopenia, and Coombs-negative hemolytic anemia. In C3 mesangial proliferative glomerulonephritis, an increase in mesangial cell proliferation without thickening in the glomerular capillary wall can be seen under light microscopy, but the definitive diagnosis is made with the immunohistologic demonstration of isolated C3 deposits in the mesangium. C3 glomerulonephritis may be detected in childhood; however, in this case report we describe the first case of isolated C3 glomerulonephritis together with atypical hemolytic uremic syndrome in an adult patient.

CASE PRESENTATION

Here we present a case of a 27-year-old white man with anuria who was hospitalized after being diagnosed as having hemolytic uremic syndrome accompanied by acute renal failure. Renal biopsy results revealed C3 glomerulonephritis. There was a complete recovery of renal function after hemodialysis, and prednisolone and plasma exchange treatment.

CONCLUSIONS

C3 glomerulopathy is distinct from atypical hemolytic uremic syndrome although both diseases are due to abnormal control of the alternative complement pathway. In atypical hemolytic uremic syndrome activation of complement occurs on glomerular or microvascular endothelium causing a thrombotic microangiopathy; in most cases, no electron-dense deposits are seen on electron microscopy and glomerular C3 is not detected on immunofluorescence.