Characterization and differentiation of autoimmune versus viral liver involvement in patients with Sjögren's syndrome.

Objective: To analyze the prevalence and clinical significance of liver involvement in patients with Sjögren's syndrome (SS), focusing on the characterization and differentiation of autoimmune versus chronic viral liver disease.

Methods: We investigated liver involvement (clinical signs, analytical data, chronic viral infections, and autoantibodies) in 475 consecutive patients with SS. All patients fulfilled 4 or more of the 1993 European Community Study Group criteria for SS.

Results: Liver involvement was detected in 129 (27%) patients. After ruling out chronic illnesses or use of hepatotoxic drugs, the main etiologies were chronic viral liver disease in 64 (13%) cases [chronic hepatitis C virus (HCV) infection in 63 and HBV infection in one] and autoimmune liver diseases in 24 (5%; primary biliary cirrhosis in 16 patients and type-1 autoimmune hepatitis in 8). The analytical liver profile was not useful in differentiating between viral and autoimmune liver disease. In contrast, patients with SS and autoimmune liver disease presented higher mean values of erythrocyte sedimentation rate (p = 0.044), circulating gammaglobulins (p = 0.007), and a higher prevalence of antinuclear antibodies (p < 0.001), antimitochondrial antibodies (p < 0.001), anti-smooth muscle antibodies (p = 0.026), anti-Ro/SSA (p < 0.001), and anti-La/SSB (p = 0.01), while patients with chronic viral liver disease had a higher frequency of cryoglobulinemia (p < 0.001) and hypocomplementemia (p < 0.001).

Conclusion: Chronic viral liver disease (associated overwhelmingly with HCV) was the main cause of liver involvement in our patients with SS, with a prevalence of 13%, nearly 3-fold greater than that observed for autoimmune liver involvement. The immunological pattern played a key role in the differentiation of viral (predominance of cryoglobulins and low complement levels) and autoimmune (higher frequency of autoantibodies) liver involvement.