巯嘌呤剂量个体化治疗儿童特发性肺含铁血黄素沉着症15例

Maintenance therapy with dose-adjusted 6-mercaptopurine in 15 cases of idiopathic pulmonary hemosiderosis

目的 总结特发性肺含铁血黄素沉着症（IPH）的诊断,评估剂量个体化的巯嘌呤（6MP）治疗IPH的长远疗效.方法 IPH的诊断是通过住院检查和随访1年以上排除其他疾病后确定.15例患儿符合诊断并纳入分析,诊断时的年龄2～13岁（中位7岁）.疾病急性期口服泼尼松2 mg/（kg·d）,4周减停,6MP同时开始口服,60 ms/（m2·d）,维持治疗3年.结果 多数患儿由于起病症状不典型而被延误诊断,延误的时间是2周～108个月（中位8个月）.所有病例经治疗后都能缓解并成功撤除激素.随访2.5～9.5年（中位6年）,15例患儿在6MP维持治疗期间有相对低白细胞血症（3×109/L～6×109/L）的患者8例中只有1例复发,而另外7例有5例复发（P〈0.05）.复发的5例将6MP剂量上调使白细胞降低后4例未再复发.结论 诊断延误仍然是突出的问题.本组多数IPH患儿对6MP维持治疗耐受好且获长期缓解,提示有可能避免长期依赖激素治疗及因此对生长发育带来长远的不良影响 6MP代谢个体差异大,剂量个体化治疗可避免部分病例未得到足够治疗剂量或治疗过度,有助于改善预后,白细胞计数可能是一个简单而有用的衡量指标.

Objective To review the diagnosis of idiopathic pulmonary hemosiderosis （ IPH）,and to evaluate the efficacy of maintenance therapy with dose-adjusted 6-mercaptopurine （6MP） in IPH children. Methods The diagnosis of IPH was confirmed by in-patient examination and at least 1 year follow-up to exclude secondary causes of pulmonary hemorrhage. Fifteen children met the criteria of IPH and were enrolled. The age at diagnosis was 2-13 years （ median 7 years）. Prednisone was administered at 2 mg/（ kg·d） for 4 weeks in acute phase of the disease followed by taper. 6MP was also started at 60 mg/（ m2·d） simultaneously and continued for 3 years. Results The diagnosis was delayed in most children, which was due to the lack of initial classical manifestation of the disease. The time between the onset of symptoms and diagnosis ranged from 2 weeks to 108 months （ median 8 months） . All the patients exhibited response to the initial treatment and prednisone was successfully tapered off. Only 1 of 8 patients with relative leucopenia （3 × 109/L -6 × 109/L） on 6MP maintenance recurred while 5 of 7 others recurred （P 〈 0. 05） during median 6-year （range 2. 5 - 9. 5 years） follow-up. Of the latter 5 patients who recurred,4 remained recurrence-free after adjusting the dose of 6MP upwards to keep relative leucopenia. Conclusions Diagnostic delayed is still a main problem in pediatric IPH. Most IPH children in our group tolerated maintenance treatment with 6MP and achieved long-term remission, and these suggested growth retardation on long-term steroids therapy could be avoided. Because of interindividual difference in 6MP metabolism, adjusting the dose of 6MP may be necessary for treatment of IPH children and avoid under-treatment or overtreatment in some children,and thus improve the prognosis. White blood count could be a simple and useful indicator to predict clinical response in most IPH children on 6MP.