Objective: To evaluate the clinical value of autoantibodies as serological markers to predict autoimmune liver diseases in primary Sjögren's syndrome (SS).
Materials and methods: 180 patients who met the European diagnostic criteria for SS but without a history of liver disease were studied upon a 5 year follow-up. Sera taken at enrolment were evaluated by immunofluorescence analysis (IF-AMA) on rat liver, stomach and kidney sections, enzyme-linked immunosorbent assay using rat mitochondrial, microsomal and soluble liver antigens and Western blot (WB) analysis using rat mitochondrial antigens.
Results: At presentation, 152 (84%) sera had autoantibodies. Antinuclear antibodies (ANA) were expressed in 58% of patients and displayed three distinct patterns (speckled, homogenous and anticentromere). Smooth muscle autoantibodies (SMAs) and parietal cell autoantibodies were found in 39 and 4.5% of patients, respectively. Three patients presented antimitochondrial antibodies by IF-AMA, and two of them developed symptomatic primary biliary cirrhosis (PBC). Two patients without IF-AMA and without evidence of cholestasis had PBC-specific AMA (anti-PDC-E2 and anti-BCKADC-E2). However, these two patients and the third IF-AMA-positive woman remained free from symptoms and biochemical signs of PBC. Autoimmune hepatitis (AIH) (n = 2), 'overlap syndrome' of AIH and chronic hepatitis C (n = 1) and autoimmune cholangiopathy (AIC) (n = 1) were diagnosed in four patients.
Conclusions: Patients with IF-AMA usually develop symptomatic PBC upon a 5 year follow-up. Our findings support the idea that patients without IF-AMA, who express PBC-specific AMA, are in early, asymptomatic stage of the disease. High-titre SMA and IF-AMA are the most specific indicators for AIH and PBC.