Trombofilia primaria en México: parte VI: falta de asociación estadística entre las condiciones trombofílicas heredadas / Primary thrombophilia in México: VI: lack of statistical association among the inherited thrombophilic conditions

Objetivo: En un periodo de 70 meses estudiamos de manera prospectiva a 100 pacientes mestizos mexicanos con algún marcador clínico de trombofilia: a) Trombosis antes de los 40 años, b) Historia familiar de trombosis, c) Trombosis recurrente sin la presencia de un factor precipitante aparente, d) Trombosis en sitios anatómicos inusuales, o e) Resistencia a la terapia antitrombótica convencional. Métodos: En estos pacientes, investigamos el síndrome de las plaquetas pegajosas, la mutación 677 C —>T del gen de la 5,10-metilentetrahidrofolato reductasa (MTHFR), el fenotipo de resistencia a la proteína C activada (RPCa), la presencia de anticuerpos antifosfolípidos, las mutaciones Leiden, Cambridge, Liverpool y Hong Kong del gen del factor V, el haplotipo HR2 del mismo gen del factor V, el polimorfismo G20210A de la región 3´-no traducida del gen de la protrombina y las deficiencias de proteínas C y S y de antitrombina III. Resultados: En el 94 % de los casos encontramos por lo menos alguna alteración; de estos casos con alteración, la mayoría (81 %) tuvo dos o más condiciones trombofílicas asociadas. El análisis multivariado de todas estas variables sólo mostró asociación estadística entre la mutación tipo Leiden del gen del factor V y el fenotipo de RPCa (r = .495; p < 0.001). Conclusiones: Se concluye que, realizando este grupo de estudios, es posible identificar alguna alteración trombofílica en la mayoría de los pacientes mestizos mexicanos con algún marcador clínico de trombofilia y que las alteraciones no se asocian entre sí.

OBJECTIVE: Over a 70-month period, 100 consecutive Mexican mestizo individuals with a clinical marker associated with a primary hypercoagulable state were studied. METHODS: We prospectively assessed: the sticky platelet syndrome (SPS), the activated protein C resistance (aPCR) phenotype, coagulation protein C activity and antigen, coagulation protein S, antithrombin III, plasminogen, IgG and IgM isotypes of antiphospholipid antibodies, homocysteine levels, the factor V gene Leiden, Cambridge, Hong Kong, and Liverpool mutations, the 677 C-->T mutation in the 5,10-methylenetetrahydrofolatereductase (MTHFR), and the G20210A polymorphism in the 3'-untranslated region of the prothrombin gene. RESULTS: Of the 100 consecutive patients prospectively accrued in the study, only 29% were males. In only 6 individuals could we not record any abnormality, whereas in most individuals (81%), two to five co-existing abnormalities were identified. In a multivariate analysis of the association of all these assesments, the only significant association was found between the factor V Leiden mutation and the aPCR phenotype (r = .495; p < 0.001). CONCLUSIONS: These results confirm previous observations on thrombophilia in Mexico underlining that it is a multifactorial disease. They also suggest that the abnormalities detected are not associated to each other.

prevalence of activated protein C resistance in patients with repeated fetal losses

This study was conducted for the prevalence of activated protein C resistance [APCR] on 20 patients with past history of recurrent fetal losses in their first trimester, 13 patients in their second trimester and 20 women with no past history of fetal losses taken as controls. All women were negative for rubella, toxoplasma, cardiolipins IgG and IgM. All patients and controls had normal coagulation profile as regards prothrombin time, APTT, protein C activity, total protein S and antithrombin III. APCR was done for all groups. The prevalence of phenotypic APCR in the first trimester fetal loss group was 5%, while it was 23% in the second trimester fetal loss group. APCR is 5-10 times more common than any of the other known inherited deficiencies of anticoagulant proteins