The effects of lupus anticoagulant on pulmonary thromboembolism

Objective: To evaluate the effects of lupus anticoagulant (LA) on pulmonary thromboembolism (PTE).

Methods: Thirty-eight patients with PTE (17 massive and 21 submassive) and 30 healthy adults were studied. Russell's viper venom time (RVVT) was used to examine the ratio of LA (LAR), and a colorimetric method was used to detect the activity of plasma protein C (PC:A) and radioimmunoassay (RIA) was employed to measure the level of plasma thromboxane B(2) (TXB(2)) and 6-keto-prostaglandin F1alpha (6-keto-PGF1alpha).

Results: Compared with the normal group, LAR, TXB(2) and TXB(2)/6-keto-PGF1alpha showed significant increase in the massive PTE and the submassive PTE groups (P < 0.01), and the levels were higher in the massive group than in the submassive group (P < 0.01). Both groups showed significant decrease in PC:A and 6-keto-PGF1alpha compared with the normal group (P < 0.01).

Conclusions: LA can increase TXB(2)/6-keto-PGF1alpha and decrease PC:A in patients with PTE. It is suggested that there may be an association between the increase of LAR and the presence of PTE.