[Natural type interferon-alpha (Namalwa) therapy for multiple myeloma complicated by hemolytic anemia].

A 45-year-old woman with Bence-Jones type multiple myeloma was treated with natural type alpha-interferon (Namalwa interferon), 3 million IU every other day subcutaneously. After about 5 months, she developed hemolytic anemia. However, screening tests for autoantibodies, including direct and indirect antiglobulin (Coombs' tests), were negative. This report is the first case in which hemolytic anemia appeared to be caused by natural type alpha-interferon. It is likely that interferons will be used in treating increasing numbers of patients and that more patients will develop this complication.