Low prevalence of anti-SSA (anti-Ro) and anti-SSB (anti-La) autoantibodies in female patients with rheumatoid arthritis with a wish to conceive

OBJECTIVES: Guidelines advise to test for anti–Sjögren's-syndrome-related antigen A (anti-SSA) and anti–Sjögren's-syndrome-related antigen B (anti-SSB) antibodies in all patients with rheumatoid arthritis (RA) who wish to conceive. Our objective was to determine the prevalence and titres of anti-SSA and anti-SSB autoantibodies in patients with RA with a wish to conceive or pregnant. METHODS: Patients were derived from two large cohorts on RA and pregnancy (PARA cohort and PreCARA cohort). In addition, to determine the clinical relevance of searching for anti-SSA and anti-SSB in patients with RA, we studied the prevalence of the maternal diagnosis of RA in the French national registry of neonatal lupus syndrome (NLS) and congenital heart block (CHB). RESULTS: 26 out of 647 patients with RA had detectable anti-SSA and/or anti-SSB. Anti-SSA was detected in 25 out of 647 patients (3.9%) (Ro-52, n=17; Ro-60, n=19), anti-SSB in 7 out of 647 (1.1%). Thirteen women had a titre of >240 units/mL of anti-SSA antibodies. The prevalence of anti-SSA and/or anti-SSB was higher in rheumatoid factor (RF)-positive patients compared with RF-negative patients (5.1% vs 1.6%, p=0.04). No cases of CHB and/or NLS in the offspring were observed. In the French national register, the prevalence of RA in mothers with SSA related CHB was 1.5%. CONCLUSION: Anti-SSA and anti-SSB have a low prevalence in patients with RA who wish to conceive. Especially for RF-negative patients, the current advise to test for anti-SSA and anti-SSB should be reconsidered.