We studied the extent to which patient characteristics influenced outcome in childhood idiopathic thrombocytopenic purpura in a historical cohort of 289 children over a 20 year period (1968-87). Outcome was classified as acute or chronic depending on whether the platelet count had returned to normal (150 X 10(9)/l) by six months after diagnosis. Fifty three cases (18%) had chronic idiopathic thrombocytopenic purpura. The likelihood of chronic disease was determined by logistic regression analysis of five patient variables: age, sex, season of onset of symptoms, history of recent viral illness, and duration of symptoms at presentation. A history of symptoms of greater than 14 days at presentation, adjusted for the other variables, was strongly predictive of chronic idiopathic thrombocytopenic purpura; the other variables did not significantly affect outcome. At 28 days after diagnosis 138 (47%) of the study cohort had normal platelet counts. Children whose platelet counts were less than 150 X 10(9)/l had a threefold risk of progressing to chronic idiopathic thrombocytopenic purpura, which increased to fivefold if counts were less than 50 X 10(9)/l. Two thirds of patients in the chronic group, irrespective of treatment, remained thrombocytopenic two years after diagnosis. We conclude that a history of symptoms for greater than two weeks at presentation is strongly predictive of chronic idiopathic thrombocytopenic purpura. If platelet counts are subnormal 28 days after diagnosis the risk of chronic idiopathic thrombocytopenic purpura is increased with prolonged thrombocytopenia being very likely if platelet counts remain low three months after diagnosis.
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机译:我们在20年期间(1968-87年)的289名儿童的历史队列研究了患者特征对儿童特发性血小板减少性紫癜预后的影响程度。根据诊断后六个月内血小板计数是否已恢复正常(150 X 10(9)/ l),将结果分为急性或慢性。慢性特发性血小板减少性紫癜有53例(18%)。慢性疾病的可能性通过对五个患者变量的逻辑回归分析确定:年龄,性别,症状发作的季节,近期病毒病的病史以及出现症状时的病程。根据其他变量进行校正后,就诊时出现症状超过14天的病史强烈预示了慢性特发性血小板减少性紫癜。其他变量没有显着影响结果。确诊后28天,研究队列中的138名(47%)血小板计数正常。血小板计数低于150 X 10(9)/ l的儿童发展为慢性特发性血小板减少性紫癜的风险是三倍,如果计数低于50 X 10(9)/ l,则儿童的血小板升高为五倍。慢性组中有三分之二的患者,不论治疗如何,在诊断后两年仍保持血小板减少。我们得出的结论是,就诊时出现症状超过两周的病史强烈预测了慢性特发性血小板减少性紫癜。如果诊断后28天血小板计数低于正常水平,则慢性原发性血小板减少性紫癜的风险会增加,如果血小板计数在诊断后3个月仍保持在较低水平,则很可能会出现血小板减少症。
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