Akademik Veri Yönetim Sistemi
JOURNAL OF ISTANBUL FACULTY OF MEDICINE-ISTANBUL TIP FAKULTESI DERGISI, 2024 (ESCI)
Objective: Lupus nephritis (LN) is a detrimental consequence of systemic lupus erythematosus (SLE). The anti-C1q antibody was shown to be related to LN, or global disease activity, in various studies. Our purpose was to determine its prevalence and association with LN or disease activity in Turkish patients with SLE. Material and Method: We conducted a cross-sectional single-centre study to investigate the clinical and laboratory findings, disease activity, and anti-C1q levels in 150 patients with SLE. The anti-C1q antibody was analyzed using an enzyme-linked immunosorbent assay and compared with 150 healthy-control patients. Result: Lupus nephritis was present in 72 patients. The frequency of anti-C1q positivity was 17% (26/150) in patients with SLE and 3% (5/150) in control group (p<0.001). Patients with anti-C1q also had anti-Sm, direct Coombs' test, and thrombocytopenia more commonly (p=0.001, p=0.007, p=0.009 respectively). Anti-C1q was positively correlated with proteinuria, haematuria, systemic lupus erythematosus disease activity index (SLEDAI) (p<0.001), anti-dsDNA (p=0.03), and negatively correlated with C3 (p<0.001) and C4 (p=0.015). Patients with active LN had higher anti-C1q (p=0.01) and anti-dsDNA (p<0.001) titres than inactive LN patients, although in multivariate logistic regression analysis, anti-C1q was not significant for LN history. It was significant for SLEDAI severity (p=0.036). Conclusion: Our study demonstrated a significant association of anti-C1q with SLE, proteinuria, haematuria, thrombocytopenia, general disease activity, and active LN, but not with inactive renal disease. This is the first study investigating the clinical significance of this antibody in Turkish patients. Further studies are needed to clarify the pathogenesis of lupus nephritis.