Causes and outcome of deep-vein thrombosis in otherwise-healthy patients under 50 years

We examined thrombophilic mechanisms and outcome in 54 patients with deep-vein thrombosis (DVT), who were otherwise apparently healthy and aged < or = 50 years. Patients were followed up 6 years (median) after a confirmed first DVT between 1987-1992 with no known predisposing illnesses. Patients were traced through the hospital registry and compared with 25 matched controls. Tested thrombophilic mechanisms were either genetic (activated protein C [APC] resistance; anti-thrombin III deficiency [ATIII]; protein C or protein S deficiency [PC, PS]) or acquired (lupus anti-coagulant [LAC]/anti-cardiolipin antibodies [ACA]; subsequent diagnosis of cancer). Twenty-nine DVT patients attended for full studies. The remaining 25 were interviewed by phone and none had a reported neoplastic disease, confirmed by their hospital records and the National Cancer Registry. These patients' demographics, risk factors and subsequent course were similar in all respects to the studied group. In the control group, APC resistance was the only coagulopathy found (1/25, 4%), and it was also the most common abnormality among DVT patients (8/29, 28%) (p = 0.009). Three DVT patients had LAC/ACA (10%) and one each, ATIII, PC and PS deficiencies (3.3% each). No malignancy was encountered during a follow-up of 7.9 +/- 5.7 years. Circumstantial risk factors were found in 52% of the patients, 21% had a family history of DVT, and 41% had recurrent DVT. These characteristics were not significantly different when DVT patients with and without coagulopathy were compared.