RÉSUMÉ
Venous thromboembolism is a serious medical problem causing considerable suffering and occasional death. In this study a search for the presence of some causes of prothrombotic states such as deficiency of protein C, protein S and anti-thrombin III [ATIII], and the presence of activated protein C resistance [APCR] and anti-cardiolipin antibodies was done in patients with chronic deep vein thrombosis [CDVT] in Alexandria. The study included 30 patients with CDVT, 20 females and 10 males with a mean age of 41.35 +/- 12.2 years and the results were compared with those of 20 healthy subjects of matched age and sex. The results showed that APCR defined as normalized activated protein C resistance ratio [n-APCR-ratio<0.8] was found in 23.3%, ATIII deficiency in 23.3%, Protein S deficiency in 10%, and protein C deficiency in 3.3% of the patients while anti-cardiolipin antibodies expressed as > 10 GPL unites for IgG and > 7 MPL unites for IgM were detected in 20% of the patients. These results revealed that APCR and ATIII deficiency are the most common finding in CDVT in Alexandria followed by ACA. It is mandatory that the laboratory examination for thrombophilia should be routinely applied to the cases of CDVT not only for diagnostic purposes but also for appropriate treatment