Significance Of Anti-Beta 2-Glycoprotein 1 Antibodies In Systemic Lupus Erythematosus

Objective To investigate the positive rate and the clinical significance of anti-beta 2-glycoprotein 1 antibodies (anti-beta 2-GPI) in systemic lupus erythematosus and to assess the correlation between antibodies and disease activity.Methods The serum levels of IgAGM anti-beta 2-GPI in 68 patients with SLE and 23 healthy subjects were detected by enzyme linked immunosorbent assay (ELISA). Recorded the clinical manifestation and laboratory findings, then the associations of anti-beta 2-GPI with laboratory findings and clinical disease activity were analyzed.Results (1) The prevalence of anti-beta 2-GPI in SLE patients and controls was 25% and 0%, respectively. The antibodies were detected in 26.2% of SLE patients of avtive phase (11/42), in 23.1% of SLE patients of inactive phase (6/26) , and in 0% of healthy controls(0/23).(2) The concentration of anti-beta 2-GPI in patients of active phase was higher than those of inactive phase and control population, but the disparity between the active phase and inactive phase was not statistically different (Wilcoxon Rank sum test). Moreover, there was not a statistically correlation between the concentration of anti-beta 2-GPI and SLEDAI scale scores (r= 0.189).(3) The frequency of thrombocytopenia, prolonged prothrombin time, livedo reticularis and dental ulcer was higher in patients with anti-beta 2-GPI than those patients without anti-beta 2-GPI.(4) There was a significant correlation between the assay of anti-beta 2-GPI and aCL(r= 0.642), but the anti-beta 2-GPI assay showed higher specificity for thrombocytopenia than the aCL in SLE (P<0.05).Conclusion (1) Anti-beta 2-GPI antibodies may occur in SLE, In the study, the antibodies were detected in 25% of SLE patients (17/68).(2) Anti-beta 2-GPI antibodies may occur in active phase and inactive phase of SLE. The higher concentration of anti-beta 2-GPI had not a strong association for active phase of SLE compared with inactive phase.(3) There was a statistically significant association between the presence of anti-beta 2-GPI and thrombocytopenia, prolonged prothrombin time. These results provide evidence that existence of the antibodies may cause disturbances of blood coagulation in SLE.(4) There was a significant correlation between the assay of anti-beta 2-GPI and aCL, but the anti-beta 2-GPI assay showed higher specificity for thrombocytopenia than the aCL in SLE. These findings raise the use of Anti-beta 2-GPI in SLE patients for APS follow up.