RESUMO
Antiphospholipid antibodies are among the most important risk factors of arterial and venous thrombosis. Various studies have demonstrated that these antibodies are seen in patients with deep vein thrombosis [DVT] and pulmonary embolism [PE] more than normal individuals but there are a few studies about prevalence of these antibodies in patients younger than 50 years old with venous thromboembolism [VTE]. This study aimed to evaluate these antibodies in this age group. This was a case-control study. Fifty patients younger than 50 years old with venous thromboembolism [DVT, PE or both] who were diagnosed according to the standard criteria were compared with 48 subjects in the control group. Subjects in the control group were age and sex matched with patients and had no history of venous thromboembolism. Both groups had no history of malignancy or other chronic diseases. Lupus anti-coagulant and serum anticardiolipin antibodies [IgG and IgM] were measured in both groups. Data were analyzed using SPSS version 11.5 software. Fifty VTE patients younger than 50 years of age enrolled in this study [28 males and 22 females; mean age: 38.14 +/- 6.5 yrs]. Forty-eight subjects were selected as healthy controls [27 males and 21 females; mean age: 38.35 +/- 5.06 yrs]. Mann-Whitney test showed a significant difference between serum IgM anticardiolipin antibody levels of VTE patients [8.04 MPL units/ml] and those of healthy subjects [1.85 MPL units/ml] [P=0.001]. Also, a significant difference was found between serum IgG anticardiolipin antibody levels of VTE patients [8.29 GPL units/ml] and those of healthy subjects [3.51 GPL units/ml] [P=0.001]. In VTE group, 7 patients [M/F=4/3] had an IgG level >10 GPL units/ml and 6 patients [M/F=2/4] had an IgM level >10 MPL units/ml while none of the healthy subjects had IgG or IgM levels higher than 10 [P[IgM] = 0.015 and P[IgG] = 0.007]. Lupus anti-coagulant was positive in four [8%] but negative in all healthy subjects [P=0.04]. This study demonstrated that antiphospholipid antibodies were more prevalent in VTE patients younger than 50 years old compared to healthy subjects. Considering the fact that these patients need stronger and longer treatment, it seems necessary to evaluate every VTE patient younger than 50 yrs for antiphospholipid syndrome