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Introduction: Anti-Compliment Factor H antibody hemolytic uremic syndrome (AFH-HUS) is a common cause of paediatric atypical HUS in India. We wanted to study the outcome of patients receiving less than recommended plasma exchange (PLEX) but adequate immunosuppression, with respect to hypertension, preservation of renal function and proteinuria., Methods: A retrospective study was performed in 15 children admitted from 2016 to 2018 with AFH-HUS. Follow up details including physical examination, hematological parameters, renal function test and urine examination performed at 3, 6, and 12 months were noted. Risk stratification and staging for chronic kidney disease (CKD) were done according to the Kidney Disease Improving Global Outcomes (KDOQI) guidelines. Standard statistical tests which were appropriate were used., Results: Mean age of our study cohort was 7.8 ± 1.9 years. 14 children had hypertension. Mean nadir hemoglobin was 5.8 ± 1.0 g/dL and platelet = 58 ± 37.7 × 109 cells/L. Median anti factor H (AFH) level was 316 AU/mL (150 to 452). Hemodialysis was required in 7 children. Fourteen children received PLEX with a mean of 11 ± 6 cycles. Thirteen children received 6 cycles of intravenous cyclophosphamide. After six months, therapy was switched to mycophenolate mofetil in 4 children, steroids alone in 2 children and 9 children with azathioprine. On follow-up, risk of CKD reduced from 80% at 3 months to 26% at 12 months (P = .01). Only 40% patients had CKD stage 2 at the end of 12 months (mean eGFR = 95.0 ± 19.4 mL/min/1.73m2)., Conclusion: The adequate number of PLEX needed in AFH-HUS needs further studies. Till such reports come, PLEX in recommended strategies or lesser, if not available, with immunosuppression in AFH-HUS can decrease progression to CKD. DOI: 10.52547/ijkd.6507.

Hemolytic uremic syndrome (HUS), a cause of pediatric acute kidney injury (AKI), has a spectrum of extra-renal manifestations. While neurological and gastrointestinal system involvement is common, cardiac involvement is rare. This is more so with pericardial involvement, though it has been reported in a handful of HUS cases associated with shiga toxin-producing Escherichia coli (STEC HUS). However, this complication has scarcely been reported in atypical HUS (aHUS) where there is alternate complement abnormality or DKGE (diacylglycerol kinase epsilon) mutation. We describe two children diagnosed with anti-complement factor H (CFH) antibody-associated aHUS who had pericardial involvement. Two boys, one 10-year-old and another 8-year-old, presented with pallor, oliguria and hypertension. They both had microangiopathic haemolytic anemia, thrombocytopenia and AKI suggestive of HUS. Complement workup revealed elevated anti-CFH antibody titres. With a diagnosis of anti-CFH antibody aHUS, they were started on plasmapheresis, pulse methylprednisolone and cyclophosphamide. The first case developed cardiac tamponade during the second week of hospital stay for which he needed pigtail drainage and further immunosuppression with rituximab. He gradually improved and pigtail was removed. The second case presented with pericardial effusion which subsequently resolved during the course of treatment. Thus, our patients developed pericardial effusion, with one of them progressing to life-threatening cardiac tamponade. Therefore, it is prudent that we are aware of this complication while treating children with aHUS.

Acute kidney injury (AKI) occurs in about 1% of cases of malaria; however, in these cases, the mortality rate can be as high as 45%. Thrombotic microangiopathy (TMA) as a cause of AKI in malaria is rare with only a handful cases documented in literature so far. Alternate complement pathway (ACP) dysregulation as a major mechanism of injury in the development of thrombotic microangiopathies is well known. It is proposed that patients with preexisting defects in ACP are usually clinically silent, until stress condition such as infections help manifest them. Herein, we describe the presence of two complement factor H (CFH) variants in an 8-year-old female with vivax malaria associated TMA. The complement workup confirmed dysregulated ACP and revealed two single-nucleotide polymorphisms in CFH gene, i.e. exon-7 rs1061147 (p.Ala243Ala) and exon-9 rs1061170 (p.His402Tyr) which predisposed this patient to develop TMA precipitated by vivax malaria.