Anti-Ro Positivity in Systemic Lupus Erythematosus: Association with Clinical Phenotypes and Other Antibodies

Abstract

Background: Anti-Ro antibody positivity (anti-Ro+) can have possible association with the clinical features and serology in patients with systemic lupus erythematosus (SLE). Methods: This retrospective observational study enrolled 158 SLE patients at the Rheumatology department, Fauji Foundation Hospital, from 1st May to 31st October 2023. Demographic and clinical data were collected. Patients were stratified by anti-Ro (positive vs negative), concomitant anti-La (anti-Ro+/ anti-La+; anti-Ro- / anti-La-; anti-Ro+/anti-La- and anti-Ro-/anti-La+), and ANA status (positive vs negative). Mann-Whitney U and Chi-square tests were employed for comparisons, with statistical significance set at p[Formula: see text]0.05 Results: Study population consisted mainly of females (98.7%), with median age of 30± 20 years. Anti-Ro antibodies were positive in 74(46.8%) patients. This group had significantly higher discoid rash (16.2% vs 6%, p-value 0.04), sicca symptoms (41.1% vs 31%, p-value 0.005), anemia (71.6% vs 56%, p-value 0.04) compared to anti-Ro negative group. No significant differences were observed in nephritis (29.7% vs 34.5%, p=0.52) or neurological disease (9.5% vs 11.9%, p=0.69) between the two groups. Anti-Ro+ /anti-La+ group had higher myositis (20.6%), sicca symptoms (55.9%) and fever (70.6%) compared to other groups. ANA+/anti-Ro+ group (48.6%) had significant association with sicca symptoms (50.7%) and fever (64.2%). Conclusion: Anti-Ro positivity in SLE is associated with muco-cutaneous manifestations and anemia. Concomitant anti-La positivity is linked to increased xerophthalmia, myositis, and fever. While anti-Ro status is independent of ANA, the combination of both autoantibodies is associated with increased sicca symptoms and fever in SLE patients.