Introduction: Atypical Hemolytic Uremic Syndrome (aHUS) represents a rare yet severe medical condition characterized by the trifecta of hemolytic anemia, thrombocytopenia, and acute kidney injury. While typical HUS is commonly linked to infections by specific strains of Escherichia coli (E. coli), particularly the O157:H7 strain, atypical HUS is distinguished by its non-bacterial etiology, stemming from dysregulation within the complement system—a pivotal component of the immune response.

Case Report: This case pertains to a 41-year-old woman who had previously undergone a renal transplant at our medical facility. Historically, she had experienced an uncomplicated pregnancy but encountered significant health challenges during her second conception at the 26th week of gestation. Upon presentation at the referring hospital, she complained of severe abdominal pain, followed by a seizure episode and subsequent loss of consciousness. Diagnostic evaluations revealed concurrent complications including Abruptio Placentae, Postpartum Haemorrhage (PPH), Pre-eclampsia, and Acute Kidney Injury (AKI). Prompt medical intervention led to a prophylactic hysterectomy, accompanied by transfusions of 2 units of blood and fresh frozen plasma (FFP), as her haemoglobin levels plummeted to 6.5 gm/dl and serum creatinine rose to 2.04 mg/dl during the procedure. The following day witnessed a precipitous drop in haemoglobin levels to 2.9 gm/dl, concomitant with a diagnosis of rectus sheath hematoma and bilateral pleural oedema. Urgent surgical intervention ensued, with the administration of 4 units of blood transfusion. Despite these efforts, her renal function continued to deteriorate, necessitating haemodialysis. A kidney biopsy confirmed the presence of Thrombotic Microangiopathy (TMA), indicative of HUS. Subsequent genetic testing unveiled a heterozygous deletion involving CFH, CFHR1, 2, 4, and 5 genes, thus confirming the diagnosis of Atypical Haemolytic Uremic Syndrome. Persistent renal insufficiency mandated thrice-weekly haemodialysis sessions until February 2024, when she underwent renal transplantation at our institution. The donor was a female with ABO compatibility and negative CDC crossmatch for B and T cells. Post-transplant, her haemoglobin levels rose to 7.4 gm/dl. Furthermore, she received Eculizumab infusions (100mg for 4 cycles) post-transplantation, resulting in a gradual improvement in renal function, with serum creatinine levels dropping to 1.20 and haemoglobin levels stabilizing at 13.8 gm/dl.

Conclusion: Despite the challenges posed by aHUS, timely intervention, including renal transplantation and targeted therapy with Eculizumab, resulted in a significant improvement in renal function and overall clinical status.