Antiphospholipid antibody profiles and their clinical associations in Chinese patients with systemic lupus erythematosus.
OBJECTIVE
Different prevalences of antiphospholipid antibodies (aPL) have been reported in different populations of patients with systemic lupus erythematosus (SLE). Chinese are generally believed to have lower risk of vascular thrombosis. We examined the prevalence of aPL including lupus anticoagulant (LAC), anticardiolipin (aCL) and anti-beta2-glycoprotein I (anti-beta2-GPI) antibodies, the level of thrombotic risk, and the association of aPL with thrombotic and pregnancy outcomes in a Chinese cohort with SLE at the university lupus clinic during the period 1986-2003.


METHODS
aPL were measured in 272 SLE patients, and medical records were reviewed for vascular thrombosis and pregnancy outcomes.


RESULTS
The prevalence of LAC, IgG aCL, and IgG anti-beta2-GPI antibodies was 22.4%, 29.0%, and 7.7%, respectively. There were 38 episodes of thrombosis after a mean duration of followup of 11.0 +/- 6.8 SD years, giving a thrombotic rate of 1.26/100 patient-years. All aPL were shown to be associated with vascular thrombosis. IgG anti-beta2-GPI antibodies were found to be associated with recurrent thrombosis [8.0/100 patient-years or 25.0% (7/28)]. Patients taking hydroxychloroquine were found to have fewer thrombotic complications than those who were not (OR 0.17, 95% CI 0.07-0.44; p < 0.0001). LAC was the strongest factor associated with recurrent miscarriages [relative risk 12.3, 95% CI 1.22-123.31; p = 0.03). The diagnosis of secondary antiphospholipid syndrome was satisfied in 8.9% of patients.


CONCLUSIONS
The lifetime and recurrent thrombotic rates in our patients with aPL were not particularly different from those in the literature. However, the lower prevalence of aPL in our cohort may suggest a role of other prothrombotic factors in predisposition to thrombosis.
Mok
Mo Yin
MY
Department of Medicine, and the Clinical Trials Centre, Queen Mary Hospital, Hong Kong. mymok@netvigator.com
Chan
Eric Yuk Tat
EY
Fong
Daniel Yee Tak
DY
Leung
Kate Fung Shan
KF
Wong
Woon Sing
WS
Lau
Chak Sing
CS
D000026:Abortion, Habitual / Q000150:complications / Q000208:ethnology / Q000276:immunology*; D000293:Adolescent; D000328:Adult; D000368:Aged; D017152:Antibodies, Antiphospholipid / Q000097:blood*; D044466:Asian People; D005260:Female; D006723:Hong Kong / Q000453:epidemiology; D006785:Hospitals, University; D006801:Humans; D008137:Longitudinal Studies; D008180:Lupus Erythematosus, Systemic / Q000150:complications / Q000208:ethnology / Q000276:immunology; D008297:Male; D008875:Middle Aged; D011247:Pregnancy; D011250:Pregnancy Complications, Hematologic / Q000208:ethnology / Q000276:immunology*; D013927:Thrombosis / Q000150:complications / Q000208:ethnology / Q000276:immunology*
D017152:Antibodies, Antiphospholipid