Madalina-Pusa Rosu(1,*), Andreea-Alexandra Preda (1), Daniela Opris-Belinski(3), Violeta-Claudia Bojinca(2,3), Andra-Rodica Balanescu(2,3), Narcis Copca(4,5), Denisa Predeteanu(1)
1) Department of Rheumatology, “Sf. Maria” Clinical Hospital, Bucharest, Romania
2) Department of Internal Medicine and Rheumatology, “Sfanta Maria” Clinical Hospital, Bucharest, Romania
3) Carol Davila University of Medicine and Pharmacy, 050474 Bucharest, Romania
4) Department of Surgery, “Sfanta Maria” Clinical Hospital, Bucharest, Romania
5) Department of Research Center University of Medicine Carol Davila, Bucharest, Romania
Background: Systemic Lupus Erythematosus (SLE) is a prototypic autoimmune disease with a strong genetic component. Familial clustering of autoimmunity suggests that first-degree relatives (FDRs) of SLE patients may harbor immunologic abnormalities even in the absence of clinical disease. This study aimed to evaluate the prevalence of specific autoantibodies in asymptomatic FDRs of SLE patients compared to healthy controls. Antinuclear antibodies (ANA) prevalence among FDRs typically ranges from 30-37%, far exceeding controls. Autoantibodies often emerge years prior to clinical disease, supporting their potential role to preclinical risk stratification.
Methods: We conducted a cross-sectional, case-control study including asymptomatic first-degree relatives (FDRs) of patients diagnosed with systemic lupus erythematosus (SLE), and age- and sex-matched healthy controls with no personal or familial historu of autoimmune disease. Participants were recruited from outpatient rheumatology clinics and through patient referrals. The control group was selected from the general population and hospital staff.
Results. A total of 67 asymptomatic FDRs of patients with SLE and 65 healthy controls were included. The two groups were comparable in terms of age (mean age 38.6+-12.2 years in FDRs vs. 37.9 +- 11.5 years in controls, p=0.71) and sex distribution (78.3% females in FDRs group vs. 74% in controls, p=0.48). Among FDRs, 25 individuals (37.3%) were ANA-positive and 4 (5.9%) tested positive for anti-dsDNA antibodies. In the control group, only 3 individuals (4.6%) were ANA-positive and 1 (1.5%) was anti-dsDNA positive.
Conclusions. ANA autoantibodies were significantly more prevalent in asymptomatic FDRs compared with healthy controls. A notable proportion of FDRs exhibited serologic autoimmunity in the absence of clinical disease, highlighting the relevance of preclinical screening in high-risk populations.
Keywords: systemic lupus erythematosus, familial aggregation, autoantibody, autoimmunity, preclinical autoimmunity
Corresponding author(s): Madalina Pusa Rosu, Department of Rheumatology, "Sfanta Maria" Clinical Hospital, Bucharest, Romania, email: madalina.duna@yahoo.com