Idiopathic Mixed Cryoglobulinemia in Two Sisters

A. Weinberger, S. Berliner, Y. Shoenfeld, J. Pinkhas, Department of Internal Medicine ‘D’ and the Rheumatology Clinic, Sackler School of Medicine, Tel Aviv University, Beilinson Medical Center, Petah Tikva (Israel) To the Editor, The increasing number of reports concerning the familial occurrence of cryoglobulinemia [1-5] raises the possibility of a genetic and/or an environmental influence for the development of cryoimmunoglo-bulinemia. We herewith present 2 sisters with idiopathic mixed IgM-IgG cryoglobulinemia. Case Histories A 32-year-old woman was admitted because of recurrent episodes of arthralgia. Detailed clinical and laboratory investigations disclosed only the presence of mixed IgM-IgG cryoglobulin. The same type of cryoglobulin was detected in her 35-year-old asymptomatic sister. Both sisters had no evidence for an underlying disease and no history or serological evidence for recent bacterial or viral infection. The HBsAg and its antibody were negative in both of them. Discussion The etiology of idiopathic mixed cryoglobulinemia is unknown. In the past, several authors reported on the occurrence of cryoglobulinemia in families [1-5]. A common denominator cannot be drawn between all these reports and it is not clear whether they represent a mere coincidence or whether some common genetic background or environmental influence might predispose or precipitate the appearance of cryoglobulin. Moreover, it is not clear whether these cryoglobulins are congential or acquired. Considering the increasing number of reports dealing with this problem, it is advisable to screen the family members of patients with cryoglobulinemia for the presence of cold insoluble immunoglobulins. References 1 Waterman, J.R.; Winkelstein, J.A.; Berzofsky, R.N.; Hsu, S.H.; Bias, W.B.; Arnett, F.C.: Early complement component depletion and 220 Weinberger/Berliner/Shoenfeld/Pinkhas