RESUMEN
Thrombotic thrombocytopenic purpura (TTP) is characterized by intravascular thrombosis leading to consumption of large or unusually large von Willebrand factor (VWF) multimers. The usefulness of VWF collagen binding (VWF:CB) assay was assessed in detecting the decrease/absence of large VWF multimers or the presence of abnormally large forms in patients with TTP. Nine patients with TTP were studied during the acute phase of the disorder and the absence of large VWF multimers was demonstrated by means of the VWF:CB assay. These findings were confirmed by VWF multimer pattern analysis; VWF:CB deficiency appeared to correlate with abnormalities in large VWF multimers. The diagnostic potency of VWF:CB was especially evident when the values were expressed as VWF:CB/VWF:Ag ratio. VWF:CB was also used during the follow-up of the disorder to document improvement or restoration of large VWF multimers. VWF:CB was able to detect the absence or decrease of large VWF multimers better than VWF ristocetin cofactor (VWF:RCo); in fact, VWF:CB was defective when large VWF multimers persisted to be decreased, in contrast with what observed with VWF:RCo. In conclusion, VWF:CB is a simple test that appears to be useful, together with clinical symptoms and reduced platelet count, for the diagnosis and follow-up of TTP.
Asunto(s)
Colágeno Tipo III/metabolismo , Ensayo de Inmunoadsorción Enzimática/métodos , Púrpura Trombocitopénica Trombótica/diagnóstico , Factor de von Willebrand/análisis , Enfermedad Aguda , Adulto , Técnicas y Procedimientos Diagnósticos , Dimerización , Ensayo de Inmunoadsorción Enzimática/normas , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Unión Proteica , Factor de von Willebrand/metabolismoRESUMEN
This study was undertaken to investigate the effect of age on oral contraceptive-induced venous thrombosis. All women seen in the University of Padua Department of Medical and Surgical Science who had had two courses of oral contraceptive therapy at different ages were included. A total of 28 subjects met these criteria. Fifteen patients had a congenital or acquired prothrombotic condition, whereas 13 women were normal subjects. The mean age at which thrombosis occurred was 33.3 and 36.3 years for women with or without a prothrombotic condition, respectively. The ages during which the women remained asymptomatic were 23.1 and 23.3 years for women with or without a predisposing defect, respectively. Thrombosis occurred, during the second course of oral contraceptive therapy, after the mean duration of 6.5 cycles or 18.4 cycles in women with or without prothrombotic defects, respectively. During the asymptomatic course, approximately the same number of women took old progestins or third-generation compounds. On the contrary, during the second period, 21 of 28 women took progestins with third-generation compounds. Age seems to plays an important role in oral contraceptive-induced venous thrombosis. In normal women, thrombosis occurred after a greater number of oral contraceptive cycles as compared with the women with prothrombotic defects. Because the majority of women took preparations that contained third-generation progestins during the second course of therapy, concomitant contributing effects of these compounds cannot be excluded.
Asunto(s)
Anticonceptivos Hormonales Orales/efectos adversos , Congéneres de la Progesterona/efectos adversos , Trombofilia/complicaciones , Trombosis de la Vena/inducido químicamente , Resistencia a la Proteína C Activada/complicaciones , Resistencia a la Proteína C Activada/genética , Adolescente , Adulto , Factores de Edad , Edad de Inicio , Síndrome Antifosfolípido/complicaciones , Estudios de Cohortes , Factores de Confusión Epidemiológicos , Anticonceptivos Orales Combinados/efectos adversos , Utilización de Medicamentos , Estradiol/administración & dosificación , Estradiol/efectos adversos , Factor V/genética , Femenino , Predisposición Genética a la Enfermedad , Humanos , Incidencia , Persona de Mediana Edad , Congéneres de la Progesterona/administración & dosificación , Congéneres de la Progesterona/clasificación , Deficiencia de Proteína S/complicaciones , Trombofilia/genética , Trombosis de la Vena/epidemiología , Trombosis de la Vena/etiologíaRESUMEN
Twelve women with severe Factor XII (FXII) deficiency were under observation for an average period of about 16 years. During this time, these women had 19 pregnancies without any bleeding or thrombotic complications. The evaluation of the literature has shown that three patients manifested deep vein thrombosis during pregnancy. Five women also showed mild bleeding at delivery . The significance of these findings is not clear since thrombotic and bleeding complications may occur occasionally even in normal women. Five of our patients took oral contraceptive therapy during their fertile life for a variable period of time (2-10 years). No thrombosis was noted in any of these patients. From the scanty data gathered, in this respect, from the literature, it was shown that only three women with severe FXII deficiency took oral contraceptives and no thrombosis was noted. Altogether these results seem to indicate that the FXII deficiency does not play any significant role in the pathogenesis of bleeding and of thrombotic complications in pregnancy. However, the occurrence of deep vein thrombosis in 3 out of the 64 patients for whom sufficient data could be gathered indicates the need for further studies. This is more so if one considers that 3 out of the 6 cases of venous thromboses described altogether in the literature for females with severe FXII deficiency occurred during pregnancy or puerperium.