Abstract
Two cases of IgD myeloma are reported. The first patient, 53 year-old male, was referred to Mitsubishi Nagoya Hospital because of proteinuria, and diagnosed as multiple myeloma by serum and urine analysis as well as bone marrow findings. Although he had responded partially to steroid and Melphalan therapy, he developed renal failure and died one year after the diagnosis. M-component of the patients serum was identified as IgD by immunoelectrophoresis with anti-IgD serum, and the serum level of IgD varied from 1,300 mg to 2,850 mg/dl during his course. Light chain of the M-component and Bence-Jones protein was of λ-type. The M-component had a sedimentation constant of 5.95 S and the myeloma cells were shown to produce IgD by immunofluorescence technique.
The second patient, 28 year-old male, with the complaint of chest pain was diagnosed as multiple myeloma because of multiple bone lesion with plasma cell proliferation and urinary excretion of profuse Bence-Jones protein (type κ). Increase of serum IgD level (46 mg/dl) and decrease of other classes of immunoglobulin were shown by immunoelectrophoresis and by quantitation with radial immunoffusion, whereas no apparent M-component was revealed by conventional electrophoresis on cellulose acetate membrane.
Some discussion were made on the clinical and morphological characteristics of IgD myeloma and on the importance for serum analysis with anti-IgD serum especially in cases of Bence-Jones type myeloma.
