Cryoglobulinemia in primary Sjogren's syndrome: Prevalence and clinical characteristics in a series of 115 patients

Objectives: To determine the prevalence and nature of cryoglobulins in a la rge series of patients with primary Sjogren's syndrome (SS) and identify th e clinical and immunologic features related to their presence. Methods: In a cross-sectional study, we investigated 115 consecutive patien ts (107 women and eight men) with primary SS. All patients fulfilled four o r more of the preliminary diagnostic criteria for SS proposed by the Europe an Community Study Group in 1993. Serum cryoglobulinemia was measured in al l patients. Serum samples were obtained at 37 degrees C, and cryoglobulinem ia was estimated by centrifugation after incubation at 4 degrees C for 7 da ys. The type of cryoglobulinemia was identified by agarose gel electrophore sis and immunofixation. Results: Cryoglobulins were detected in the sera of 18 (16%) of our patient s with primary SS; most were IgM kappa monoclonal/IgG polyclonal. When comp ared with patients without cryoglobulins, those with cryoglobulins presente d a higher prevalence of leukocytoclastic cutaneous vasculitis (56% v8%, P < .001), hypocomplementemia (75% v 2%; P < 0.001) and antibodies to hepatit is C virus (HCV) (47% v 8%, P < .001). Liver involvement (clinical signs, b iochemical features, or ultrasound/histological data of liver disease) was present in all patients (100%) with cryoglobulins and HCV infection but in only 11% of patients with cryoglobulins without HCV infection (P < .001). Conclusions: Leukocytoclastic cutaneous vasculitis, hypocomplementemia, and HCV infection are associated with the presence of cryoglobulins in the ser a of patients with primary SS. Testing for HCV infection is recommended for patients with SS and cryoglobulinemia because of its high prevalence and i ts strong association with liver disease. Copyright (C) 1998 by W.B. Saunde rs Company.