目的 探讨共刺激分子4-1BB/4-1BBL在过敏性紫癜性肾炎（HSPN）患儿外周血单个核细胞（PBMC）中 的表达及其临床意义。方法 选取初发过敏性紫癜无肾炎（HSP组）、初发过敏性紫癜性肾炎（HSPN组）患儿各20例（其 中15例进行了肾脏病理检查），20例正常儿童为对照组，分离培养PBMC。应用逆转录-聚合酶链式反应（RT-PCR）检测并 比较三组PBMC中4-1BB mRNA和4-1BBL mRNA的变化，分析4-1BB/ 4-1BBL mRNA变化与肾脏病理的关系。结果  HSPN、HSP患儿PBMC中4-1BB mRNA、4-1BBL mRNA的表达均高于对照组，差异有统计学意义（P均 ＜ 0.01）。HSPN 患儿的病理积分与4-1BB/4-1BBL mRNA表达呈正相关关系（r =0.570、0.515， P均 ＜ 0.05）。PBMC中，加入植物血凝素后， HSPN组、HSP组和对照组4-1BB/4-1BBL mRNA的表达均高于空白对照组，差异有统计学意义（P均 ＜ 0.01），其中HSP、 HSPN组增高幅度较对照组明显，HSPN组增高幅度较HSP组更为显著，差异有统计学意义（P均 ＜ 0.01）；加入地塞米松后， HSPN组、HSP组4-1BB/4-1BBL mRNA的表达均较空白对照组减少，差异有统计学意义（P均 ＜ 0.01）。 结论  HSPN患 儿PBMC中共刺激分子4-1BB/4-1BBL mRNA的表达显著增高，植物血凝素能诱导其高表达，而地塞米松能抑制其表达， 提示4-1BB/4-1BBL可能参与HSPN的发病。

Objectives To investigate the expression and the clinical significance of costimulatory molecules 4-1BB and 4-1BBL in the peripheral blood mononuclear cell of children with Henoch-Schönlein purpura nephritis (HSPN). Methods Twenty children with incipient HSP were included as one group, 20 children with incipient HSPN as another group (15cases of them with renal pathologic examination), and 20 healthy children as the normal control group. RT-PCR was used to detect the change of 4-1BB/4-1BBLmRNA in PBMC, and to analyze the relationship between the change of 4-1BB/ 4-1BBLmRNA in PBMC of the HSPN group and the pathology of the kidney. Results The expression of 4-1BBmRNA, 4-1BBLmRNA in children with HSPN and HSP  were significantly higher than that of the normal control group (P