Associations of complement proteins and immunoglobulins with cognitive impairment in type 2 diabetes mellitus: a cross-sectional study.

Rheumatoid arthritis (RA) is a systemic autoimmune disease that causes inflammation in joints and may affect internal organs. The disease often affects women of fertile age, and rheumatologists have long studied the relationship between RA and pregnancy. The earliest reports described a near-complete remission in almost all women during pregnancy []. Later studies with a larger number of patients and more objective measures of disease activity did not find the same unambiguous results regarding improvement. A meta-analysis in 2019 found that 60% of patients with RA improved during pregnancy and 47% relapsed postpartum []. Later studies with a higher percentage of patients using biological disease-modifying anti-rheumatic drugs (bDMARDs) have not found any significant differences in disease activity during pregnancy [, ]. Earlier studies have also found conflicting results regarding the presence of anti-cyclic citrullinated peptide (ACPA), Rheumatoid Factor (RF), and erosions and their possible associations with disease activity during pregnancy [, ]. The introduction of bDMARDs has transformed the treatment of RA. The first tumor necrosis factor-α inhibitor (TNFi) was introduced in 1998, but it was initially not considered safe for use in pregnancy []. The use has increased in the last decade after The European Alliance of Associations for Rheumatology (EULAR) published their first guidelines for the use of bDMARDs in pregnancy in 2016 [] and The American College of Rheumatology (ACR) in 2020 [], both supporting increased use of TNFi during pregnancy [, ]. The optimal treatment length of bDMARDs during pregnancy is not yet established. The objectives of this study were to investigate disease activity in women with RA from preconception, throughout pregnancy, and one year postpartum. Next, to assess whether the presence of ACPA, RF, or erosive disease was associated with increased disease activity, and finally, to explore how disease activity in pregnancy has changed over time.