The role and significance of serum B factor in the pathogenesis of systemic lupus erythematosus

Abstract

Objective To investigate the expression of serum B factor in the peripheral blood of patients with systemic lupus erythematosus (SLE), and explore its role in the pathogenesis. Methods Seventy eight patients with SLE in our hospital and 46 healthy persons were eligible to participate in this study. Rate nphelometyr was used to test serum B factor for 78 patients with SLE and 46 healthy controls. According to systemic lupus erythematosus disease activity index (SLEDAI), participants were divided into steady SLE group (SLEDAI<5) and active SLE group (SLEDAI ≥5), which was further divided into mild, moderate, and serious subgroups. The differences in serum B factor between SLE patients and healthy controls, including SLE patients with different severity, were all compared. Then we analyzed the differences in serum B factor and other laboratory and clinical indexes between active and steady SLE patients. The correction of serum B factor and other laboratory and clinical indexes were also analyzed. Results Compared to healthy controls, patients with SLE had significantly lower value of serum B factor [(27.13±8.98) mg/dl vs (36.73±5.47) mg/dl, t=7.4, P<0.01]. Compared to steady SLE group, SLE active group had significantly lower level of serum factor B, C3 and C4, and also had significant higher level of C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR) (all P<0.05). Moreover, There were significant differences in the lower level of serum B factor between subgroups. Correlation analysis showed that the level of serum B factor was negatively associated with the levels of CRP and SLEDAI scores, whereas serum B factor was positively associated with the levels of C3 and C4 (all P<0.05). Conclusions Serum B factor is related to SLE. Serum B factor might be involved in the pathogenesis of SLE. Detection of serum B factor is helpful for diagnosis and evaluation of SLE disease activity. Key words: Lupus erythematosus, systemic/ME; Complement factor B/ME