Amyloidosis associated with dermatomyositis and features of multiple myeloma. The progression of amyloidosis associated with corticosteroid and cytotoxic drug therapy.

Described here is a 59 year old man with dermatomyositis and hypogammaglobulinemia. His muscle power improved after corticosteroid therapy, but extensive amyloidosis and repeated infections appeared. Bone marrow morphology suggested multiple myeloma, but treatment with cytotoxic drugs had no beneficial effect on the amyloidosis. Because of rapid progression of the amyloidosis and further infections, cytotoxic drug therapy was stopped, corticosteroid dosage was decreased, and supplementary immunoglobulin therapy was instituted. The infections occurred less frequently and the amyloidosis appeared to regress. This case suggests that immunosuppressive therapy may exacerbate amyloidosis. The literature is reviewed, and the possible role of humoral immunodeficiency in the pathogenesis of amyloidosis is discussed. It is suggested that supplementary immunoglobulin may be beneficial in amyloidosis.