Background: Atypical hemolytic-uremic syndrome is caused by a thrombotic microangiopathy and manifests itself with hemolytic anemia, thrombocytopenia, and organ ischemia. Its etiology is a mutation affecting the genes encoding for proteins of the complement system. Early treatment with eculizumab (8.6 months from the moment of presentation), a humanized monoclonal antibody against complement, is shown to be effective in controlling symptoms and reversing organ damage. We present a patient with a mutation not previously described in the literature. Late treatment with eculizumab resulted in a good therapeutic response, eliminating the need for peritoneal dialysis.
Case presentation: A 34-year-old woman showed symptoms and laboratory findings consistent with atypical hemolytic-uremic syndrome. Genetic analysis revealed an unusual mutation of the complement regulatory gene not seen previously. Due to unavailability of eculizumab at the time of presentation, conventional treatment was started with poor response. Late initiation of eculizumab resulted in discontinuation of peritoneal dialysis and yielded a good and sustained clinical response.
Conclusions: This case shows that eculizumab treatment for patients with atypical hemolytic-uremic syndrome, even when initiated many months after beginning on dialysis, might offer substantial benefits and improve the patients' quality of life.
Keywords: Atypical hemolytic-uremic syndrome; Complement inactivating agents; Eculizumab; Mutation.