135. Successfully treated postpartum atypical hemolytic uremic syndrome: A case report in a woman with a gene mutation encoding complement

Abstract

Introduction Pregnancy-associated atypical hemolytic uremic syndrome (P-aHUS) and HELLP syndrome are induced by thrombotic microangiopathies in the kidney and in the liver, respectively. Both clinical entities are characterized by microvascular endothelial activation, cellular damage and thrombosis following the complement dysregulation during pregnancy or postpartum. Same complement mutations are identified in women with P-aHUS and in women with HELLP syndrome; however, a risk of women with a complement mutation during the subsequent pregnancy remains unknown. Case A 24-year-old pregnant woman underwent caesarean section because of cephalopelvic disproportion at a private clinic. Her prenatal course was uneventful. Progressive anemia, thrombocytopenia, and elevated creatinine value were detected until the postpartum day 5, and she was therefore referred to Kumamoto University Hospital. Blood examination on admission revealed thrombocytopenia, hemolytic anemia and renal failure. ADAMTS-13 was not decreased and Shiga toxin-producing Escherichia coli was not detected on culture of stool. Therefore, she was diagnosed as P-aHUS. Plasma exchange therapy was performed a total of five times and hemolytic anemia, thrombocytopenia and creatinine value were improved gradually. Her serum creatine levels were improved and remained normal levels. Her genetic analysis showed a mutation of the gene encoding C3 (p.Ser562Leu). She was conceived two years after the delivery, and her pregnancy course currently remains uneventful. Conclusion Prompt diagnosis and the initiation of plasma exchange therapy is required for the treatment of P-aHUS because some P-aHUS patients reached end-stage renal disease. It is also important to manage women with a complement mutation during the subsequent pregnancy with the possibility of P-aHUS or HEELP syndrome.