title: Comparative prevalence of antiphospholipid antibodies and thrombophilic genotypes in consecutive patients with venous thrombosis.
abstract: The prevalence of antiphospholipid antibodies (aPL) and thrombophilic genotypes was compared and their reciprocal interactions assessed in consecutive patients with venous thrombosis (n = 101; 58 male, 43 female; mean age, 56 +/- 16 years) and in blood donors (n = 121; 55 male, 46 female; mean age, 43 +/- 12 years). Multiple aPL were detected by enzyme-linked immunosorbent assay (ELISA) and factor V Leiden (FVL), methylenetetrahydrofolate reductase (MTHFR) C677 <-- T and prothrombin (PT) G20210 <-- A by polymerase chain reaction. A pro-thrombotic state, including aPL, was found in 81% (82/101) of patients and 23% (29/121) of controls (P < 0.0001, odds ratio = 13.69, 95% confidence interval = 7.14-26.25). The prevalence of total aPL-positives was lower than MTHRF+/+ (homozygous state), FVL and PT G20210 <-- A (P < 0.0001) in the control group, but in line with the prevalence of total thrombophilic genotypes in the patient group: MTHFR+/+, 29%; FVL, 19%; PT, 14%; aPL, 20%. Having variously combined aPL and thrombophilic genotypes, only aPL remained as the most common pro-thrombotic factor in the patient group (P = 0.003). In patients without circumstantial factors for thrombosis, carriers of MTHFR+/+ + aPL showed a lower age at event than carriers of MTHFR+/+ alone or aPL alone (38 +/- 24 versus 65 +/- 10 years, P < 0.05 and 38 +/- 24 versus 63 +/- 16 years, P < 0.05, respectively). In the same patients, mean plasma homocysteine measured by an ELISA method was significantly higher in the MTHFR+/+ + aPL group than in the MTHFR+/+ alone or aPL alone groups (P = 0.01). Antiphospholipid antibodies are as common as thrombophilic genotypes in patients with venous thrombosis, and the interaction of aPL with MTHFR+/+ may influence age at first event via elevated plasma homocysteine.
authors.affiliation: Atherosclerosis Unit, IRCCS 'Casa Sollievo della Sofferenza', Foggia, Italy.
authors.forename: G
authors.initials: G
authors.lastname: Cappucci
authors.forename: M
authors.initials: M
authors.lastname: Margaglione
authors.forename: P R
authors.initials: PR
authors.lastname: Ames
mesh_terms: D000328:Adult; D017668:Age of Onset; D000368:Aged; D017153:Antibodies, Anticardiolipin / Q000097:blood; D017152:Antibodies, Antiphospholipid / Q000097:blood*; D016022:Case-Control Studies; D004797:Enzyme-Linked Immunosorbent Assay / Q000592:standards; D005260:Female; D005838:Genotype; D006710:Homocysteine / Q000097:blood; D006801:Humans; D008297:Male; D015995:Prevalence; D012307:Risk Factors; D019851:Thrombophilia / Q000097:blood / Q000235:genetics*; D020246:Venous Thrombosis / Q000097:blood / Q000209:etiology* / Q000235:genetics
chemical_list: D017153:Antibodies, Anticardiolipin; D017152:Antibodies, Antiphospholipid; D006710:Homocysteine