Rituximab as successful therapy in a patient with refractory paroxysmal cold hemoglobinuria.

Background: Paroxysmal cold hemoglobinuria (PCH) is a rare autoimmune hemolytic anemia (AIHA) attributed to a biphasic hemolysin known as the Donath-Landsteiner (DL) antibody. It is most commonly encountered as an acute transient AIHA after a viral infection in children; the disease resolves after cessation of the infection. The rarest form of PCH is a chronic form in adults that is not (nowadays) associated with infection and is not responsive to conventional therapies. Rituximab has been found to be effective therapy in other forms of AIHA, such as cold agglutinin syndrome, that are refractory to conventional therapies. We describe a case of PCH refractory to steroids that responded to rituximab therapy on two separate occasions.

Case Report: A 64-year-old woman with fatigue was found to be profoundly anemic with laboratory findings consistent with AIHA. She was admitted for the workup and management of her disease after she failed to respond to a course of oral steroids. Laboratory evaluation demonstrated a positive DL test suggesting PCH. She was given a course of rituximab that resulted in normalization of her hemoglobin concentration. She presented 9 months later with recurrent hemolysis. She was given another course of rituximab that again resulted in termination of hemolysis. The patient remained in remission since her last dose of rituximab 19 months previously.

Conclusion: To our knowledge, this is the first report of an adult case of refractory PCH successfully treated with rituximab.