Immunoglobin D Multiple Myeloma: A Single Centre Experience

Abstract

Background: Immunoglobulin D (IgD) myeloma is an uncommon subtype of multiple myeloma that accounts for 1-2% of all myeloma cases. IgD myeloma is often associated with a high incidence of renal insufficiency, hypercalcaemia, extraosseous disease, amyloidosis, and Bence-Jones proteinuria.Materials and Methods: The authors discuss the clinical presentation and treatment results of 12 cases of IgD myeloma, treated at a single centre.Results: The study included nine males and three females, with a median age of 48.5 years. All had lytic bone lesions, eight had anaemia, five had renal impairment, three had hypercalcaemia, three had features of amyloidosis, and one had polyneuropathy, organomegaly, endocrinopathy, M-protein, and skin changes syndrome. On immunofixation electrophoresis, 10 patients had IgD λ subtype, and two had IgD κ. Urine Bence-Jones protein was positive for five patients. Eleven patients received bortezomib-based chemotherapy. Three patients achieved complete response, two had a very good partial response, two achieved partial response,three progressed, and one discontinued treatment. At 2 years, six patients were alive (50%). Median overall survival of the series was 21 months (range: 1-80 months).Conclusion: IgD myeloma is an uncommon subtype of myeloma associated with a high incidence of hypercalcaemia, renal insufficiency, extraosseous lesions, amyloidosis, and Bence-Jones proteinuria. IgD λ disease is more frequent, unlike other subtypes of IgD myeloma. Management is similar to other myeloma types, but with poorer outcomes.