The Coinicidence of Venous and Arterial Thrombosis in Patients with Antiphospholipid Syndrome - Correlation with Laboratory Findings.

The antiphospholipid syndrome (APS) is one of the most common acquired causes of thrombosis on the venous or arterial site. The initial type of the thrombosis appears to be the most likely type of event to recur. In general, APS patients present more common venous thrombosis, especially deep vein thrombosis of the legs. Arterial thromboses are less common and mostly manifest with ischemia or infarction. It is not clear whether a combination of phospholipid antibodies or the additional presence of lupus anticoagulants in patients with anticardiolipin antibodies increase the risk of manifestation of APS.

Methods: We investigated retrospectively 300 patients with elevated aCL antibodies. IgG and IgM aCL antibodies were tested by enzyme-linked immunosorbent assay (ELISA). LA were tested by more than 2 different methods according to the proposed criteria of the SSC of the ISTH.

Results: Of these patients, 61 % suffered from manifestations of APS, 35 % from venous and 28 % from arterial thrombosis, 7 % of the patients had abortions. In 39 % no thromboembolic disease was found. The coincidence of venous and arterial thrombosis was found in 25/300 (8 %) of the patients. An increased titer of IgG aCL was found in 135 of 300 patients (45 %, median 49 GPL-U/ml, normal range: - 11,3 GPL-U/ml), and an increased titer of IgM aCL in 260 patients (87 %, median 13 MPL-U/ml, normal range: 5,6 MPL-U/ml). Lupus anticoagulants were additionally detected in 130/300 patients (43 %). The rate of clinical manifestations did not differ between LA-positive patients (78 of 130 patients, 60 %) and LA-negative patients (105 of 170, 62 %) patients with elevated aCL antibodies. Regarding the patients with the coincidence of venous and arterial thrombosis, we found a significantly higher rate of positive lupus anticoagulants than in the patients with APS manifestation of one site only (17/25 vs. 113/275, p < 0.05, OR 3.04; 95 % CI 1.31 – 7.06). An elevation of IgG-aCL titres were more frequently found, too.

Table 1: Characteristics of the patients with a coincidence of venous and arterial thrombosis compared to patients with thrombosis of one site only

Conclusion: The additional presence of lupus anticoagulants in patients with anticardiolipin antibodies identifies a group of patients with high risk of recurrent manifestations of the antiphospholipid syndrome. Particularly the risk of manifestation of both, arterial and venous thrombosis in these patients should be early recognized to initiate a careful follow-up and antithrombotic therapy in these patients.