AUTHOR=Yu Shan-Fu , Chen Jia-Feng , Chen Ying-Chou , Wang Yu-Wei , Hsu Chung-Yuan , Lai Han-Ming , He Hsiao-Ru , Ko Chi-Hua , Chiu Wen-Chan , Cheng Tien-Tsai 

TITLE=The Impact of Seropositivity on Systemic Bone Loss in Rheumatoid Arthritis—A 3-Year Interim Analysis of a Longitudinal Observational Cohort Study

JOURNAL=Frontiers in Medicine

VOLUME=9

YEAR=2022

URL=https://www.frontiersin.org/journals/medicine/articles/10.3389/fmed.2022.885801

DOI=10.3389/fmed.2022.885801

ISSN=2296-858X

ABSTRACT=<sec><title>Objective</title><p>To explore the impact of seropositivity on systemic bone loss in rheumatoid arthritis (RA).</p></sec><sec><title>Methods</title><p>We conducted an interim analysis of the RA registry. Patients were examined with dual-energy X-ray absorptiometry at baseline and again 3 years later. Participants were grouped into seropositive (SPRA) and seronegative (SNRA) based on the presence or absence of rheumatoid factor (RF) and/or anti-cyclic citrullinated peptide antibodies (ACPA). After matching (1:2) for age and sex, SNRA and SPRA patients were divided into groups A and B. Each matched group (A or B) was further subdivided according to the number of antibodies present (0, group I; 1, group II; 2, group III). Multiple ordinary least squares regression was used with the dependent variables to develop a model to predict bone mineral density (BMD) change.</p></sec><sec><title>Results</title><p>A total of 477 participants who completed a 3-year observation period were included. After matching, 312 participants were enrolled (group A, 104; group B, 208). Three years later, group B had significant BMD reduction in the femoral neck (FN) (<italic>p</italic> &lt; 0.001), total hip (TH) (<italic>p</italic> = 0.001), and first through fourth lumbar vertebrae (L1–4) (<italic>p</italic> = 0.006), while group A had bone loss only at FN (<italic>p</italic> = 0.002). Groups I, II, and III included 104, 52, and 156 participants, respectively. Compared to baseline, BMD decreased significantly at FN (<italic>p</italic> = 0.002) in group I, FN (<italic>p</italic> &lt; 0.001) in group II, and FN (<italic>p</italic> &lt; 0.001), TH (<italic>p</italic> = 0.002), and L1–4 (<italic>p</italic> = 0.016) in group III. In terms of regression-adjusted percent change in BMD, more significantly negative changes were found at all measured sites in group B (<italic>p</italic> &lt; 0.001, all) and at TH and L1–4 within groups I-III (<italic>p</italic> for trend &lt; 0.001 and &lt; 0.001, respectively). Regardless of antibodies, anti-osteoporotic therapy can preserve bone density in RA patients.</p></sec><sec><title>Conclusion</title><p>After 3 years, SPRA patients lost more bone density than SNRA patients. More attention should be paid to SPRA patients, especially those with double-positive antibodies, including a vigorous evaluation of BMD and fracture risk. Anti-osteoporotic therapy can prevent BMD loss irrespective of autoantibodies.</p></sec>