[Multiple myeloma with double gammopathy (IgA-kappa, IgA-lambda) : induction of complete remission from plateau phase...

Multiple myeloma is manifested by a malignant proliferation of plasma cells producing a specific monoclonal immunoglobulin, referred to as an M component. The presence of two M components in the serum or urine (double gammopathy) in multiple myeloma constitutes an uncommon event. The author observed an unusual case of multiple myeloma with double gammopathy (IgA-kappa, IgA-lambda). By double immunofluorescence staining, 80% of kappa-positive myeloma cells were found to be lambda-positive. These results indicated that cells of common clonal origin produced monoclonal IgA of both kappa and lambda type. On the other hand, the two M components fell in a parallel fashion with a conventional chemotherapy. This concordant pattern which represents a common cell line producing both M components exactly coincided with the results of double immunofluorescence study. Generally speaking, interferons prolong the plateau phase but bring about no further reduction in the tumor load. In this case, however, a complete remission was induced with interferon-alpha 2a alone after a plateau phase achieved with a conventional chemotherapy. This fact indicates the effectiveness of interferon-alpha 2a in treating a part of patients with refractory multiple myeloma.