Evaluating Truncated Plasma Exchange in Anti-Complement Factor H Autoantibody-Associated Hemolytic Uremic Syndrome as a Viable Strategy in Resource-Limited Settings: Evidence from a Clinical Cohort

Background: Anti-complement factor H autoantibody-associated hemolytic uremic syndrome (anti-CFH HUS) accounts for >50% of atypical HUS cases in Indian children. The recommended regimen of 20-22 sessions of plasma exchange (PLEX) combined with immunosuppression is expert-based, however, it imposes severe financial burden in low-resource settings. Thus, we investigated the utility of a truncated PLEX regimen of 5-7 sessions in inducing remission. Methods: Hospital records of children ≤18years with anti-CFH HUS (KDIGO 2021 guidelines; anti-CFH antibody titer>150AU/mL) treated at a tertiary center in a low-resource setting between Jan 2017-Apr 2025, were reviewed following ethical approval. PLEX data, clinical and laboratory parameters at baseline and follow-up were noted. Outcome measures were number of PLEX sessions for hematological remission (platelets>105/mm3 for 2 days) and kidney outcome at 1year. Results: Analysis included 28 episodes in 24 patients with median[IQR] age of 8.4[5.8,9.5]years. The median[IQR] anti-CFH antibody (AU/mL) was 4600[342,10816] and 130[78,220] at onset and last follow-up respectively. The median(range) PLEX sessions were 5(3-20). Patients received immunosuppression with steroids (85.7%), mycophenolate (32.1%), and cyclophosphamide (17.9%). Remission was achieved in 89.3% with truncated PLEX regimen (Figure1). In the median(range) follow-up of 24(1-96)months, only 2(8%) relapsed (both received truncated regimen; 2 episodes each), following an average interval of 9.5 and 44.5months between episodes. At 1year follow-up (N=21), eGFR<60 in 4.7%, hypertension in 57%, and proteinuria in 19% was noted. Conclusion: Truncated PLEX regimen with appropriate immunosuppression achieved remission in a majority of pediatric anti-CFH HUS cases. This is a viable, cost-effective strategy to manage HUS in low-resource settings, where eculizumab is inaccessible.Figure1: Kaplan-Meier Plot for Number of PLEX Sessions to Reach Remission