A case report of atypical hemolytic uremic syndrome with a CFH mutation complicated by recurrent posterior reversible encephalopathy syndrome.

rationaleAtypical hemolytic uremic syndrome (aHUS) is a rare thrombotic microangiopathy (TMA) characterized by microangiopathic hemolytic anemia, thrombocytopenia, and organ dysfunction, particularly affecting the kidneys and the central nervous system. It is caused by genetic variants or autoantibodies involved in dysregulation of the complement system. Pathogenic variants of the complement factor H (CFH) gene are associated with severe disease and may lead to life-threatening multiorgan failure during the acute phase. We report a case of CFH mutation-positive aHUS complicated by recurrent posterior reversible encephalopathy syndrome (PRES) during the course of treatment. PATIENT CONCERNS: A 32-year-old woman presented with progressive fatigue and acute dyspnea. Laboratory tests revealed hemolytic anemia, thrombocytopenia, and severe acute kidney injury. DIAGNOSES: A peripheral blood smear revealed schistocytes, consistent with TMA. On hospital day 1, she developed generalized tonic-clonic seizures followed by respiratory arrest that required mechanical ventilation. Continuous hemodialysis was initiated for severe renal failure. After the exclusion of thrombotic thrombocytopenic purpura, typical hemolytic uremic syndrome, and secondary causes of TMA, a clinical diagnosis of aHUS was made. Genetic testing later revealed a pathogenic heterozygous CFH variant (c.3572C>T, p.Ser1191Leu), confirming the diagnosis of aHUS.

interventionsAnti-C5 monoclonal antibody (eculizumab) was initiated based on the clinical diagnosis of aHUS. Intensive care management, including mechanical ventilation, renal replacement therapy, plasma exchange, and strict blood pressure control, was also provided. OUTCOMES: During the course of the disease, she developed severe cardiomyopathy and recurrent PRES. Early initiation of complement inhibition combined with intensive care management resulted in complete neurological recovery, and the patient was discharged home without any sequelae. LESSONS: This case highlights that CFH mutation-positive aHUS can be complicated by severe multiorgan dysfunction, including cardiomyopathy and recurrent PRES. Early clinical recognition and prompt initiation of complement inhibition were central to the favorable outcome, while intensive blood pressure control and comprehensive supportive care may have contributed to neurological recovery.