Activity of Protein S-C4b Binding Protein and Total TFPI Levels in Egyptian SLE Patients: A Cross-Sectional Study

Abstract

BACKGROUND: Systemic lupus erythematosus (SLE) is an immune disorder with alternating active and remission phases. Cardiovascular diseases and thrombosis are the major causes of mortality in SLE. The anticoagulant activity of Protein S (PS) is complemented by C4 binding protein (C4BP) and tissue factor pathway inhibitor (TFPI). AIM: This study aims to determine the extent of change in the levels of PS activity, C4BP, and total TFPI in active SLE in comparison to the SLE remission phase and their association with thrombosis during SLE flare. METHODS: The study included 180 Egyptian SLE patients who were classified into two groups: 100 SLE cases as the active group and 80 SLE cases as the remission group. The PS activity levels were processed on automated coagulation analyzers, whereas the C4BP and total TFPI levels were measured via enzyme-linked immunosorbent assay. RESULTS: The PS activity and C4BP levels were lower in the active SLE cases than in the remitted ones (p < 0.05). The levels of PS activity and C4BP were revealed to be independent predictors of SELENA-SLEDAI flare scores. In active SLE cases, the PS activity and C4BP levels were rated as excellent and fair classifiers of thrombotic risk in SLE flare, respectively. The total TFPI levels showed no association with SLE activity or its thrombotic consequences. CONCLUSIONS: The levels of PS activity and C4BP act as important biomarkers for SLE activity. Both can be implanted as predictive tools for thrombosis during activity.