Low-titer cold agglutinin disease with systemic sclerosis.

A 60-year-old woman with systemic sclerosis (SSc) was admitted because of severe anemia and Raynaud's phenomenon. Her anemia was associated with a low serum haptoglobin level and positive results of direct Coomb's tests, which indicated the presence of autoimmune hemolysis. Other laboratory investigations revealed positive anti-nuclear antibodies, anti-topoisomerase antibody, cold agglutinins, as well as low serum levels of IgM, C3, C4 and CH50. Bone marrow aspiration showed discrete hyperplasia of the erythropoietic system. She was diagnosed as low-titer cold agglutinin disease rousing secondarily to SSc. The anemia was alleviated with the oral administration of prednisolone. This case emphasized, in terms of pathogenesis, the close association between systemic rheumatic diseases and hematological abnormalities evoked by autoimmunity.