[Pure red cell aplasia developing during the course of primary macroglobulinemia associated with pseudochylothorax and IgA nephropathy].

A 74-year-old man who had undergone artificial pneumothorax therapy for pulmonary tuberculosis 40 years earlier was admitted because of blurred vision, headache, and numbness of the lower limbs in October 1997. He presented with anemia and leukocytopenia with monoclonal gammopathy of IgM (kappa). His bone marrow was diffusely infiltrated with small lymphocytes, plasmacytoid lymphocytes, and plasma cells expressing IgM, kappa surface immunoglobulin. On the basis of these findings, primary macroglobulinemia (PMG) was diagnosed. CT scan of the chest demonstrated pleural effusion of the right lung encapsulated in a thickened pleura, and pseudochylothorax was diagnosed from a specimen of chyliform fluid which contained numerous cholesterol crystals and was positive for Mycobacterium tuberculosis (MT) on PCR assay. The patient's condition was also complicated by chronic renal failure due to IgA nephropathy, which may have been a consequence of the tuberculosis, possibly due to an abnormal IgA-mediated immune response to MT. The patient gradually developed pure red cell aplasia during the course, probably due to an autoimmune mechanism. Later in the course, immunoglobulin gene analysis of the malignant cells of PMG showed that they were derived from antigenically selected cells. In the context of antigenic stimulation, the role of MT antigen in the pathogenesis of PMG was of interest in this patient.