Immunoglobulin D amyloidosis: a distinct entity.

IgD monoclonal gammopathies are uncommon. They are seen rarely as a monoclonal gammopathy of undetermined significance and are present in 1%-2% of patients with multiple myeloma. In light-chain amyloidosis, IgD monoclonal proteins are found in ap-proximately 1% of patients. When an IgD monoclonal protein is found, amyloidosis is often omitted from the differential diagnosis. In the present study, we reviewed the natural history of IgD-associated amyloidosis among 53 patients seen over 41 years. The distribution of clinical syndromes suggests that these patients have a lower frequency of renal and cardiac involvement. The overall survival of these patients does not appear to be different from that of patients who have light-chain amyloidosis associated with another monoclonal protein.