ANTIPHOSPHOLIPID SYNDROME - CLINICAL AND THERAPEUTIC ASPECTS

The purpose of the present study was to evaluate patients with the antiphospholipid syndrome with particular attention to their initial clinical features, final diagnoses and the course of thrombotic events in association with therapy. The methodology applied was the following: retrospective analysis of 30 patient files (20 female, 10 male) with antiphospholipid syndrome (APS). Four types of therapy were evaluated for their efficacy to prevent thrombotic recurrences, aspirin 100 mg daily plus low-dose prednisone 10-15 mg daily, warfarin (with international normalized ratio 2 to 2.6), immunotherapy alone and no therapy. None of the patients was followed-up during pregnancy. The probability of thrombosis-free survival was estimated according to Kaplan-Meier method, while the statistical significance was tested by the log rank test. There were 21 patients with primary APS and 9 with secondary, 8 of whom had SLE and one patient who had primary Sjogren’s syndrome. The age at onset and the disease duration did not differ between men and women, while patients with secondary APS had a longer disease duration than patients with primary APS, a finding indicating that SLE patients develop, for unknown reasons, APS a long time after the initiation of their disease. Twenty patients experienced recurrent thrombotic events (a total of 46 recurrences) of which 43 (93%) were identical to the first event. Thus, in the majority of the cases arterial were followed by arterial and venous by venous thrombotic events: a finding suggesting a tissue-related factor for initiation of thromboses. Total follow-up of the patients was 154 patient years, of which 98 patient years were after the first thrombotic episode. More specifically: aspirin plus low-dose prednisone, 38 patient years; warfarin therapy, 15; immunotherapy alone, 10; no therapy, 35. The recurrence rates of thrombotic events were 0.13, 0.20, 0.70 and 0.88, respectively. The thrombosis-free survival after the first thrombotic event was significantly longer with aspirin plus low-dose of prednisone and warfarin therapy than with no therapy (P < 0.005 and P < 0.05, respectively). Immunotherapy alone did not prolong significantly the thrombosis-free survival compared with no therapy. Prospective studies are necessary to identify the optimum type and duration of therapy. Although immunotherapy and warfarin therapy cannot be definitely tested due to the small number of patients, the short follow-up and in the case of warfarin the low intensity of therapy, our data suggests that aspirin with low doses of prednisone and warfarin seem to be the most effective anti-thrombotic therapies in APS.