Monoclonal cryoglobulinemia with high thermal insolubility

It is generally believed that the severity of symptoms associated with cryoglobulinemia is a function of the concentration of the abnormal protein in the plasma. We have seen two patients with a small monoclonal cryoglobulin (type I) of ess than 2 g/dl with dramatic symptoms when exposed to minimal lowering of the temperature. Both patients had a monoclonal protein that precipitated in vitro at temperatures higher than 25 degrees C. We have found only seven additional case reports in the literature which were similar to ours. We wish to bring attention to this rare problem and discuss treatment.