FACTOR-V-LEIDEN, PROTEIN-C, AND LIPOPROTEIN (A) IN CATHETER-RELATED THROMBOSIS IN CHILDHOOD - A PROSPECTIVE-STUDY

Objective: To determine the association between catheter-related throm boses and hereditary causes of thrombophilia, including the factor V L eiden mutation, deficiencies of protein C or protein S, or increased l ipoprotein (a). Study design: To evaluate the incidence of genetic ris k factors for familial thrombophilia in catheter-related thrombosis, 1 63 consecutively admitted infants and children (cardiac disease and ca theter placement [C] n = 140; Broviac catheter [B] n = 23) were prospe ctively investigated. In addition, an age-matched, healthy control gro up undergoing elective surgery (S: n = 155) was investigated. Results: Heterozygous factor V Leiden mutation was diagnosed in 20 of the 318 study subjects (C: n = 5; B: n = 4; S: n = 11), homozygous factor V Le iden mutation was found in two subjects (C: n = 1; S: n = 1), protein C deficiency type I was diagnosed in nine subjects (C: n = 4; B: n = 1 ; S: n = 4), and five subjects showed increased lipoprotein (a) (C: n = 3; S: n = 2). The frequency of thrombosis (C: n = 13; B:,2 = 5) in p atients with familial thrombophilia was significantly higher (p < 0.00 01; chi square: 27.79) in the catheter groups (15 of 17 subjects) than in control subjects after minor elective surgery (none of 18). Fiftee n of the 18 infants with thrombosis had congenital thrombophilia; two children with congenital thrombophilia did not have documented thrombo sis, and three infants with vascular occlusion had no inherited predis position to thrombophilia. Conclusions: Genetic risk factors for famil ial thrombophilia play an important role in the manifestation of cathe ter-related thromboembolism in children.