IgD multiple myeloma. A report of three cases.

Three patients suffering from IgD myeloma, which a rare variant of multiple myeloma which often has an aggressive course, were studied retrospectively in order to elucidate the existence of clinical or laboratory features in relationship to survival time. The patients were monitored in follow-up for a time variable for 8 to 52 months. All patients received courses of chemotherapy using an association of Melphalan and Prednisone (MP); one patient also received recombinant interferon alpha in association. Response to chemotherapy, with a > 50% reduction of serum M component, disappearance of Bence Jones proteinuria and permanent control of the disease was achieved in all patients. The median duration of survival in IgD myeloma is shorter than that currently observed in patients with other myeloma types: in our series one patient died 8 months after diagnosis but other two patients are still alive 8 and 52 months after diagnosis, respectively. Great difficulty was encountered in analysis of unfavourable prognostic clinical and laboratory data: in our series, in spite of the small number of cases, the Authors observe that only the relief of increased serum levels of Lactate Dehydrogenase (LDH) seem to be in relationship with a trend of shorter survival. The authors, confirming the particular clinical and laboratory aspects of this myeloma, stress that there may coexist cases in which standard chemotherapy failed to control the diseases: these seem to indicate neoplasia with fast growth kinetics. Further studies are necessary in order to identify new prognostic index which allows the identification of selected groups of patients who can profit from a combination chemotherapy regimen other than the standard MP association.