Background and Aim:\ Systemic Lupus Erythematosus is an autoimmune chronic disease resulting in multi organ damage and impairment of immune response. Complements such as C3 and C4 are considered important in disease progression and often used for disease activity measurements. The purpose of this research is to assess the frequency of complements deficiencies in SLE patients, and identify associations with symptoms and disease severity. Material and Methods:\ This single-center, cross sectional study involved 50 SLE patients classified in to four groups according to their serum C3 and C4 values. Symptoms, signs of disease severity, immunologic indicators Erythrocyte Sedimentation Rate (ESR), Antinuclear Antibodies (ANA) and anti-dsDNA antibody (anti-dsDNA) were recorded. The statistical methods used include ROC analysis, Spearman correlation coefficient, and Mann-Whitney U test. Results:\ In total, 66% of SLE patients had complements deficiency. The most frequent type of this disorder was isolated low C4 (32%). The only symptom that correlated significantly with complements deficiency was renal involvement (r = 0.364, p = 0.009). Overall no association was found between the level of complements and disease severity (p = 0.718). No individual marker showed adequate ability to distinguish severe from milder cases (complements AUC = 0.490). However, a combination of renal involvement, anti-dsDNA and complements deficiency proved high discriminatory ability (AUC = 0.781, sensitivity 82.1%, specificity 77.3%). Conclusion:\ While complement deficiency is highly common among SLE patients (66%), it offers little significance as an independent biomarker for predicting SLE disease activity. The statistically significant relationship between complement deficiency and kidney involvement indicates its importance in terms of organ-specific activity. The better predictive ability of the multi-marker model (AUC = 0.781) emphasizes the need to use a more comprehensive strategy for clinical prediction instead of complement deficiency alone.
Zahra'a Abdul AL-Aziz Yousif (Wed,) studied this question.