Granito A et al. (2007) Antibodies to SS-A/Ro-52kD and centromere in autoimmune liver disease: a clue to diagnosis and prognosis of primary biliary cirrhosis. Aliment Pharmacol Ther 26: 831–838

Primary biliary cirrhosis (PBC) is a chronic cholestatic disorder that potentially leads to end-stage liver disease. It has an autoimmune component: patients have high serum levels of anti-mitochondrial and antinuclear antibodies. PBC is associated with various rheumatologic disorders and can exhibit serological positivity for the so called 'rheumatologic' antinuclear antibodies, which include antibodies to extractable nuclear antigens (anti-ENA), and anti-centromere antibodies (ACA). Traditionally, anti-ENA and ACA has been detected by counterimmunoelectrophoresis on thymic and spleen extracts and indirect immunofluorescence on HEp-2 cells, respectively.

More sensitive enzyme-linked and immunoblot assays can now also detect subclasses of specific antibodies within the range of anti-ENA reactivity. These assays have been used by Granito et al. to assess the patterns of antibody expression in 105 PBC patients, comparing them with those patterns seen in 162 patients with other autoimmune liver diseases, 30 patients with systemic lupus erythematosus and 50 blood donors. The presence of anti-ENA antibodies was significantly more prevalent in PBC patients than in patients with other autoimmune liver diseases, but less prevalent than in systemic lupus erythematosus. Anti-SSA/Ro-52kD antibodies were detected in 28% of PBC patients (those with more advanced disease), with very low levels in the other liver disorders. ACA were detected in 21% of PBC patients but not in the other subjects.

The authors conclude that anti-SSA/Ro-52kD and ACA have a high specificity for PBC and warrant further investigation for their diagnostic and prognostic potential.