探讨儿童慢性特发性血小板减少性紫癜(CITP)发病中，T辅助细胞(Th)亚群细胞因子的变化。

采用定量夹心酶联免疫测定技术检测30例CITP患儿疾病活动期及治疗达完全缓解后，血清中Th1细胞因子白细胞介素(IL)－2、干扰素(IFN)－γ，Th2细胞因子IL－4，IL－5，IL－10和Th3细胞因子转化生长因子(TGF)－β₁的变化。

①在疾病活动期，Th1型细胞因子IL－2和IFN－γ浓度较正常对照组儿童显著升高，差异有显著意义(P<0.01)；Th2型细胞因子IL－4，IL－5和IL－10浓度较正常对照组儿童降低，其中IL－4和IL－10显著低于对照组(P<0.01)；Th1/Th2，(IL－2＋IFN－γ)/(IL－4＋IL－5)明显高于对照组(P<0.01)，并且与患儿外周血小板计数呈负相关(RR＝0.2515，P＝0.0174)；血清TGF－β₁较对照组减少(P<0.01)。②治疗缓解期，血清中Th2型细胞因子较疾病活动期明显升高，Th1/Th2明显下降，差异有显著意义(P<0.01)，血清TGF－β₁明显增加，显著高于疾病活动期(P<0.01)。

CITP患儿存在异常的淋巴细胞极化状态，是一种Th1类优势疾病。疾病活动期，患儿具有Th1细胞因子活动模式，在疾病缓解期，Th1向Th2模式迁移，血清TGF－β₁明显增加，Th3与Th2细胞协同发挥负性免疫调节作用，血小板逐渐上升。控制CITP中细胞因子反应，可能是免疫治疗的一种有效方式。

To investigate the roles of T helper cell(Th) polarized populations in the pathogenesis of chronic idiopathic thrombocytopenic purpura (CITP) in children.

The serum levels of Th1 type cytokines IL-2, IFN-γ, Th2 type cytokines IL-4, IL-5, IL-10 and Th3 type cytokines transforming growth factor -beta1 (TGF-β₁) in 30 children with CITP were measured by using quantitative sandwich enzyme immunoassay technique in the stage of attack and remission respectively.

The results showed that: ① In the period of onset, IL-2 and IFN-γ were significantly increased in children with CITP than in healthy controls (P<0.01). By contrast, the serum levels of IL-4, IL-5 and IL-10 were decreased, and IL-4 and IL-10 were significantly lower than those in normal controls(P<0.01). Th1/Th2 cytokine ratio (IL-2+ IFN-γ/IL-4+ IL-5) was markedly higher in children with CITP than in healthy controls (P<0.01), and which showed a negative correlation with peripheral platelet count (RR=0.2515, P=0.0174). The serum levels of TGF-β₁ in CITP patients was significantly lower than that in normal controls(P<0.01). ② In the remission stage, Th2 type cytokines and the serum levels of TGF-β₁ were markedly increased than that in the period of onset(P<0.01), and Th1/Th2 cytokine ratio were markedly decreased in the period of onset(P<0.01).

Abnormal lymphocyte polarization phenomenon is indicated in children with CITP. In the period of onset, the lymphocytes in serum from children with CITP are mainly Th1 which secreted IFN-γ and IL-2, while Th2 which secreted IL-4, IL-5, IL-10 are increased in the remission stage and the serum levels of TGF-β₁ was markedly increased. Th3 cytokines cooperated with Th2 cytokines exert negative immunoregulation and, consequently, platelet progressively rise. How to regulate Th1/Th2/ Th3 cytokine balance to normal levels in children with CITP deserve further study.