The relationship between anti-phospholipid antibodies and activated protein C resistance / 中华风湿病学杂志

ABSTRACT

Objective To investigate the relationship between the anti-phospholipid antibodies (APLs)and activated protein C resistance (APCR). Methods The response to activated protein C (APC) was studied by an APTT-based (clotting) assay with a Stago autoanalyzer and expressed as the ratio between the APTT obtained in the presence and absence of exogenous APC. APC sensitive ratio higher than 2 was regarded as APCR. Anti-?2-glycoprotein Ⅰ (?2GP-Ⅰ) antibody and anti-cardiolipin antibodies (ACL) were measured by an enzyme-linked immunosorbent assay (ELISA). Lupus anticoagulant (LA) was tested by activated partial thromboplastin time (APTT). Results The existence of LA and acquired APCR showed significant correlation (?2=16.332, P=0.008). Acquired APCR was significantly associated with the presence of anti-?2GP-Ⅰ antibody (?2=6.179, P=0.012), but not ACL. The presence of APCR was associated with an increased frequency of history of thromboembolic events and/or recurrent abortions (?2=7.347, P=0.01). Conclusion This study suggests that APCR is linked to the presence of LA and anti-?2GP-Ⅰ antibody. APLs may interfere with the activation of protein C. APCR phenotype may be a major risk factor for thrombophilia in patients with APLs. Combined detection of APLs has the potential value for predicting thrombosis.