Anti-SSA Ro52/Ro60 antibody testing by immunodot could help the diagnosis of Sjogren's syndrome in the absence of anti-SSA/SSB antibodies by ELISA.

OBJECTIVE: The objective of this study was to assess the diagnostic value of anti-Ro52/60 antibodies by immunodot in patients with suspected SS.

METHODS: All patients between 2008 and 2012 with suspected SS without anti-SSA/SSB antibodies by ELISA and who had a determination of anti-SSA (Ro52/Ro60) antibodies by immunodot (Euroimmun, Germany) were retrospectively analysed.

RESULTS: Eighty-four patients (median age 62 years; males 35 cases) were included. Forty-five patients had associated interstitial lung disease (ILD). American-European Consensus Group (AECG) criteria for SS were fulfilled in 10 patients (12%) with a positive salivary gland biopsy, and among them 2 patients had anti-Ro52 antibodies by dot (20%). Among 74 patients with a negative salivary gland biopsy, 16 (22%) had anti-Ro52/60 antibodies and 10 (14%) fulfilled AECG criteria when including Ro52/60 antibodies. A comparison of patients with and without anti-Ro52/60 antibodies revealed no differences, except gamma globulin levels and more frequent steroid use in patients with anti-Ro52/60 antibodies (P < 0.05). In 45 patients with ILD and dry eye/mouth syndrome, 10 (22%) had positive anti-Ro52/60 antibodies. In these patients 2 (4%) fulfilled AECG criteria without anti-Ro52/60 antibodies vs 4 (8%) patients if anti-Ro52/60 antibodies were included.

CONCLUSION: In patients with dry eye/mouth syndrome without anti-SSA/SSB antibodies by ELISA, the detection of anti-Ro52/Ro60 antibodies by dot could help in the diagnosis of SS. In patients with ILD, the lower frequency of a Chisholm score ≥3 enhances the interest of anti-Ro52/Ro60 screening.