Background: Atypical hemolytic uremic syndrome (HUS) is a thrombotic microangiopathy often caused by mutations in complement genes. During pregnancy, disease outcome is poor both for mother and fetus. Since 2009, the humanized monoclonal antibody eculizumab has been successfully used in the treatment of atypical HUS in nonpregnant patients.
Case: A 26-year-old woman with a homozygous mutation in complement factor H developed a relapse of atypical HUS at 17 weeks of gestation in her first pregnancy. Because the disease remained active despite multiple plasma exchanges, eculizumab was started at 26 weeks of gestation. It was well tolerated and has led to remission and to the delivery of a healthy neonate.
Conclusion: Eculizumab may be useful for the treatment of atypical HUS during pregnancy.