Abstract: Objective To explore the significance of activated protein C resistance (APCR) and antiphospholipid antibody(APA) in patients with neuropsychiatric lupus erythematosus(NPLE). Methods APCR, anticardiolipid antibody (ACA)(IgG, M, A), lupus anticoagulant (LA) were measured with APTT±APC, ELISA, PTT-LA methods, respectively, in 21 NPLE patients and 88 SLE patients without NPLE(NNPLE). Results The positive rates of APCR and ACA(IgG) in NPLE group were 78.9% (15/19) and 52.4% (11/21), respectively, which were significantly higher than those in NNPLE group:44.3% (39/88) and 22.7% (20/88), respectively (P<0.05). Conclusion High prevalences of APCR and ACA-IgG are found in NPLE group. The acquired APCR induced by ACA may be a major factor of pathogenic mechanism in NPLE.

Key words: Lupus erythematosus,systemic, Activated protein C resistance, Antibodies,antiphospholipid