Systemic lupus Erythematosus and IgA multiple myeloma: a rare association?

The coexistence of systemic lupus Erythematosus (SLE) and multiple myeloma (MM) is uncommon and the pathogenetic mechanisms underlying this association remain unclear. We report the case of a woman who was diagnosed with SLE in 1993 aged 57, then developing IgA lambda type MM in the IIB clinical stage 7 years later. The SLE was treated successfully with methylprednisolone and chloroquine, and low dose maintenance steroid was continued with bisphosphonate protection until December 1994 when she suffered multiple vertebral fractures. She continued to receive 4 mg alternate day methylprednisolone and calcitonin until she decided to discontinue her own treatment 2 years later. In 2000, while still in stable SLE remission, she was diagnosed with MM. Protein electrophoresis revealed the IgA lambda paraprotein (40.5 g/l) and she had a Bence Jones (BJ) proteinuria of the lambda light chain type. Bone marrow trephine biopsy revealed a massive patchy infiltrate of abnormal plasmocytes (70%), while an extensive x-ray skeletal survey did not show any new fractures or osteolysis. The patient was treated according to the VMCP protocol without attaining a plateau phase. There was a similar poor clinical response to second and third line treatments (VAD, Thalidomide, Melphalan, and high dose dexamethasone). After 4 years of refractory disease the patient died from severe bilateral pneumonia. This case is discussed with reference to the literature.