Transient monoclonal immunoglobulin G with anti-dextran activity.

A patient with regional enteritis had received iron dextran for treatment of iron deficiency. Subsequently he developed a large (3.1 g/100 ml) IgG-K serum spike which had precipitin activity against dextran sulfate but not a variety of other antigens. There has been no evidence of multiple myeloma and the spike gradually disappeared spontaneously over the course of 2 years. We speculate that the monoclonal protein may have developed as a response to the iron dextran injections under the immunologic stress of a chronic inflammatory disease.