Anti-factor H Autoantibody-Associated Hemolytic Uremic Syndrome: A Rare Entity in a Pediatric Patient

Abstract

An 11-year-old patient presented with the primary complaint of hematuria and vomiting. On further investigation and a series of diagnostic tests, including a biopsy and thrombotic microangiopathy (TMA) profile, the patient was diagnosed with thrombotic microangiopathy. TMA is a pathological process involving endothelial cell injury, leading to thrombocytopenia and microangiopathic hemolytic anemia. This case highlights the importance of considering TMA in pediatric patients presenting with nonspecific symptoms, such as loss of appetite. Further research is needed to understand the pathophysiology and optimal management strategies for pediatric TMA. This case adds to the growing body of literature on pediatric TMA and underscores the need for a high index of suspicion in similar clinical scenarios.

Keywords: ahus; anti-factor h antibody; atypical hemolytic uremic syndrome; complement mediated hus; thrombotic microangiopathies; thrombotic thrombocytopenic purpura.

Figure 1. Light microscopy of renal biopsy specimen at 20×10 magnification showing subendothelial edema, ectatic capillary loops, focal mesangiolysis, and RBC fragmentation with capillary tuft retraction.

Figure 2. Electron microscopy of renal biopsy specimen showing foot process flattening with vacuolization of the lamina densa.