Complements as a Predictive Biomarker of Lupus Nephritis in Female Patients with Systemic Lupus Erythematosus

Abstract

Background: Lupus nephritis (LN) has been demonstrated in about 40–50 percent of all systemic lupus erythematosus (SLE) patients. Patients having renal flares are at risk from suffering serious kidney damage, and usually have a poor prognosis. Unfortunately, renal flare pathogenesis in LN patients remains unclear, and no known predictions of an impending renal flare exist. Aim: The present study aims to measure circulating levels of anti-C1q antibodies, C3, C4, TNF-α and soluble TNF-α receptor, serum creatinine and blood urea nitrogen (BUN) as biomarkers for active LN. Materials and methods: The study included 180 SLE female patients meeting the revised classification requirements of the modified American College of Rheumatology (ACR); 90 female patients with active proliferative LN (biopsy-proven) and other 90 patients with inactive LN. Patients were receiving mycophenolate mofetil; and the study was conducted between 2018 and 2019. Results: We found that low levels of complement C3 and C4 in combination with high levels of BUN, creatinine, anti-C1q antibodies and positive anti-dsDNA antibodies were more likely to be associated with lupus nephritis development in SLE patients. Also, high levels of TNF-α and its soluble receptor can be used as an indication of active disease activity and flare development. Conclusion: Monitoring of Anti-C1q antibodies, C3, C4, serum creatinine, and BUN levels in SLE patients can improve LN prognosis. TNF-α can also be used as an indicator for active LN and concomitant flare. This early diagnosis combined with prompt care would help decrease morbidity and mortality in LN patients.