Do Autoantibodies Predict Autoimmune Liver Disease in Primary Sjögren's Syndrome? Data of 180 Patients upon a 5 Year Follow‐Up

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.