Clinical stable systemic mastocytosis with interferon alpha-2b therapy.

Systemic mastocytosis (SM) with progressive infiltration of various organs by mast cells is a rare disease with a mean survival of 2 years. So far there is no established therapy. We describe a patient with progressive mastocytosis who had a clinical response to interferon alpha-2b 3 x 5 Mio U s.c. three times a week. The response is stable 3 years after initiation of therapy and includes reduction of abdominal lymphadenopathy, ascites, decrease of serum and urinary histamine levels as well as pulmonary reticulonodular markings.