IgD multiple myeloma--a clinical profile and outcome with chemotherapy and autologous stem cell transplantation.

IgD myeloma accounts for 2% of myeloma subtypes and has higher incidence of complications and a poorer outcome. The characteristics and outcomes of 25 patients with IgD myeloma (2.6% of all myeloma patients), including 11 patients treated with autologous stem cell transplantation (ASCT) are reported. The presenting features were not unique for myeloma, but it appears that the commonest presenting symptom was bone pain in 20 (80%) patients. Other associated disorders were B-CLL in -1 patient and hairy cell leukemia in another. Three patients had a marked increase in bone marrow reticulin. Three (out of a total of 9) patients had 13q deletion (1 by cytogenetics and 2 by interphase fluorescence in situ hybridisation [FISH]), while 2 patients had a complex karyotype. A total of 11 patients were treated with ASCT, while 14 patients had chemotherapy alone. The response to treatment was: in the ASCT group 2 had a complete response (CR) and 9 had a good partial response (PR), while in the chemotherapy group 6 had a good PR with no CRs. The median overall survival (OS) and progression-free survival (PFS) after autologous peripheral blood stem cell transplantation (APBSCT) has not yet been reached after a median follow up of 4 years. The median PFS after chemotherapy was 1.23 years (95% CI 1.02-1.44). The mean OS transplantation was 5.09 years compared with 2.03 years for those treated with chemotherapy alone. However, this difference was not statistically significant (log rank p=0.09). This small series appears to suggest that outcome for IgD myeloma remains poor with chemotherapy and appears to be superior with ASCT, and larger studies are needed to confirm these findings.