A 71-year-old woman with multiple myeloma status after stem cell transplantation.

A 71-year-old woman with a 9-year history of monoclonal gammopathy of undetermined significance presented with anemia [hemoglobin, 11.6 g/dL (116 g/L); reference interval (RI), 12–15.5 g/dL (120 –155 g/L)], an increased serum calcium concentration [10.2 mg/dL (2.55 mmol/L); RI, 8.9 –10.1 mg/dL (2.22–2.52 mmol/L)], and a 4800-mg/dL (48-g/L) monoclonal protein band (M-spike) after serum protein electrophoresis (SPEP). Immunofixation electrophoresis (IFE) revealed a monoclonal IgA protein. Her IgA concentration was markedly increased to 4720 mg/dL [47.2 g/L; RI, 61–356 mg/dL (0.61–3.56 g/L)], and the serum immunoglobulin free light chain (FLC) / ratio was 7 (RI, 0.26 –1.65). A bone marrow biopsy confirmed 40% involvement by monoclonal -restricted plasma cells with a plasma cell labeling index of 0.4% (intermediate). A bone survey revealed diffuse osteopenia, multiple small lytic lesions throughout the skeleton, and a lesion consistent with a plasmacytoma at T7. A diagnosis of multiple myeloma (MM) (Durie– Salmon stage IIIA, international stage 2) was confirmed. The patient was initially treated medically and then underwent successful autologous stem cell transplantation. The patient was asymptomatic, with negative results in serum and urine protein electrophoresis and IFE evaluations for 1.5 years. A follow-up SPEP evaluation 2 years after the patient received her transplant revealed an M-spike of 3920 mg/dL (39.2 g/L) and an IgA concentration of 3810 mg/dL (38.1 g/L). A bone marrow biopsy showed 60%–70% involvement by monoclonal plasma cells. The results of a urine IFE test were negative. The patient was treated with a regimen of 25 mg Revlimid daily on days 1–21 and 20 mg dexamethasone weekly. The patient’s M-spike decreased to 1100 mg/dL (11 g/L) by 1 month after treatment, and her IgA concentration was reduced to 1260 mg/dL (12.6 g/L). Two months into treatment, the patient had detectable monoclonal protein but no measurable M-spike, and her IgA concentration was 402 mg/dL (4.02 g/L). The dexamethasone dosage was reduced to 10 mg weekly for the third month, and her serum IgA concentration decreased further, to 340 mg/dL (3.4 g/L), which is within the RI. The patient was maintained on pamidronate monthly and with 25 mg Revlimid daily as a single agent. Bimonthly monitoring by SPEP and IFE testing and measurement of her IgA concentration were continued for 1 year. Follow-up SPEP and IFE results were normal (Fig. 1); however, the serum IgA concentration steadily increased above the upper reference limit, even in the presence of normal IFE results and normal serum FLC ratios (Table 1). Because of the patient’s history of IgA disease, her hematologist felt this increase in IgA might be a sign of relapsed disease.