他克莫司治疗儿童重症肌无力的疗效研究

目的 评价他克莫司治疗儿童重症肌无力（MG）的疗效及安全性。方法 采用他克莫司治疗28例MG儿童，运用重症肌无力日常生活（MG-ADL）量表于治疗1、3、6、9、12个月时评估他克莫司的疗效及安全性。结果 他克莫司治疗1、3、6、9、12个月时的MG-ADL绝对评分与基线水平相比均降低（P < 0.05），且呈逐渐降低趋势。他克莫司治疗1、3、6、9、12个月时的有效率分别为59%、81%、84%、88%、88%。他克莫司治疗6、9、12、18个月时累计停用泼尼松4、13、14、15例。所有患儿治疗期间均未出现病情反复。主要不良反应/事件有无症状血镁降低（5例）；尿潜血阳性（1例），后自行转为阴性；均未因不良反应/事件停药。1例患儿因反复呕吐自行停药。根据CYP3A5基因型分为慢代谢组（慢代谢型，n=19）、非慢代谢组（快代谢型+中间型，n=9），慢代谢组患儿他克莫司剂量低于非慢代谢组（P < 0.05），非慢代谢组他克莫司血药谷浓度低于慢代谢组（P < 0.05），慢代谢组有效率高于非慢代谢组（P < 0.05）。结论 他克莫司治疗儿童MG疗效显著、安全性好，是需要免疫抑制剂治疗的MG患儿的良好选择。CYP3A5基因型对他克莫司使用剂量有一定的指导意义。

Clinical effect of tacrolimus in the treatment of myasthenia gravis in children

Objective To evaluate the efficacy and safety of tacrolimus in the treatment of children with myasthenia gravis (MG). Methods A total of 28 children with MG were treated with tacrolimus. MG-Activities of Daily Living (MG-ADL) scale was used to assess clinical outcome and safety after 1, 3, 6, 9, and 12 months of treatment. Results After tacrolimus treatment, the MG-ADL score at 1, 3, 6, 9 and 12 months was lower than that at baseline (P < 0.05), and the MG-ADL score showed a gradually decreasing trend. The response rates to tacrolimus treatment at 1, 3, 6, 9, and 12 months were 59%, 81%, 84%, 88%, and 88% respectively. At 6, 9, 12, and 18 months of treatment, 4, 13, 14, and 15 children respectively were withdrawn from prednisone. No recurrence was observed during treatment. Major adverse reactions/events were asymptomatic reduction in blood magnesium in 5 children and positive urine occult blood in 1 child, which turned negative without special treatment, and tacrolimus was not stopped due to such adverse reactions/events. One child was withdrawn from tacrolimus due to recurrent vomiting. According to CYP3A5 genotypes, all of the patients were divided into two groups:slow metabolic type (n=19) and non-slow metabolic type (fast metabolic type + intermediate type; n=9). The non-slow metabolism group received a higher dose of tacrolimus, but had a lower trough concentration of tacrolimus than the slow metabolism group (P < 0.05). The slow metabolism group had a higher response rates to tacrolimus treatment than the non-slow metabolism group (P < 0.05). Conclusions Tacrolimus appears to be effective and safe in the treatment of children with MG and is thus an option for immunosuppressive therapy. CYP3A5 genotyping has a certain guiding significance for determining the dosage of tacrolimus.