To determine whether changes in levels of anti-cyclic citrullinated peptide (anti-CCP) and rheumatoid factor (RF) are associated with the spontaneous improvement of rheumatoid arthritis (RA) during pregnancy and with the subsequent flare post partum.
Disease activity scores from the Pregnancy-induced Amelioration of Rheumatoid Arthritis (PARA) study of 118 patients were available for analysis. Before conception (if applicable), at each trimester and at 6, 12 and 26 weeks post partum, levels of the autoantibodies anti-CCP, IgM-RF, IgG-RF and IgA-RF were determined. Responses in disease activity were classified according to European League Against Rheumatism (EULAR) response criteria during pregnancy and post partum, and associated with the presence or absence of autoantibodies.
The median levels of anti-CCP and all subclasses of RF during pregnancy were stable, whereas post partum the levels of anti-CCP, IgM-RF and IgA-RF declined. A significantly higher percentage of women without autoantibodies (negative for anti-CCP and RF) improved compared with women positive for either or both autoantibodies (75% vs 39%, p = 0.01). The occurrence of a flare post partum was comparable between these groups.
Improvement of disease activity of RA during pregnancy was not associated with changes in levels of autoantibodies during pregnancy, however, improvement may occur more frequently in the absence of anti-CCP and RF.