目的 探讨难治性肺炎支原体肺炎（RMPP）患儿肺泡灌洗液（BALF）中sB7-H3的表达水平，及其与各细胞因子的关系及临床意义。方法 收集43例急性RMPP患儿纤维支气管镜检查时的BALF，其中13例仅在急性期灌洗1次（单次灌洗组），30例急性期后再次灌洗（再次灌洗组）；以同期15例支气管异物患儿为对照组。采用酶联免疫吸附试验（ELISA）检测BALF中sB7-H3、IL-1β、IL-2、IL-36表达水平，并比较各组间的差异，以及RMPP患儿急性期BALF中sB7-H3水平与IL-1β、IL-2、IL-36的相关性。结果 再次灌洗组首次灌洗时BALF中sB7-H3、IL-1β、IL-36水平显著高于单次灌洗组和对照组，单次灌洗组也均高于对照组，差异有统计学意义（P均 < 0.05）；再次灌洗组在第二次灌洗时BALF中sB7-H3、IL-1β、IL-2、IL-36水平较首次灌洗时显著降低（P均 < 0.05）；再次灌洗组第二次灌洗时BALF中IL-1β、IL-36与对照组差异无统计学意义（P均 > 0.05），sB7-H3、IL-2水平仍高于对照组，差异有统计学意义（P均 < 0.05）。RMPP急性期BALF中sB7-H3水平与IL-1β、IL-2、IL-36水平呈正相关（P均 < 0.001）。结论 sB7-H3可能通过调控IL-1β、IL-2、IL-36等炎症因子的分泌，参与RMPP的发生及发展。

Objective To explore the level of expression, clinical significance of sB 7 -H 3 in the bronchoalveolar lavage fluid (BALF) of refractory Mycoplasma pneumoniae (MP) pneumonia (RMPP) in children and the relationship between sB 7 -H 3 and various cytokines. Methods The BALF of forty-three hospitalized children with RMPP (RMPP group) were collected for the diagnosis and treatment. Thirteen cases were lavaged only once and the other thirty cases had collected the BALF twice. The BALF of fifteen hospitalized children with bronchial foreign body were collected as control group. The expression levels of sB 7 -H 3 , IL- 1 β, IL- 2 and IL- 36 in the BALF were detected by enzyme-linked immunosorbent assay. The expression levels of sB 7 -H 3 , IL- 1 β, IL- 2 and IL- 36 in the BALF at the acute phase were compared with control group and the group after treatment. Analyzed the correlation between the level of sB 7 -H 3 and IL- 1 β, IL- 2 , IL- 36 in the BALF of RMPP children at acute stage. Results The levels of sB 7 -H 3 , IL- 1 β and IL- 36 in the BALF of the first lavage group were higher than those of single lavage group and control group (all P< 0 . 05 ). The levels of sB 7 -H 3 , IL- 1 β, IL- 2 and IL- 36 in the BALF of single lavage group were higher than those of control group (all P<0.05). The levels of sB7-H3, IL-1β, IL-2 and IL-36 in the BALF of the second lavage group were lower than those of the first lavage group (all P< 0 . 05 ).The levels of sB 7 -H 3 , IL- 2 in the BALF of the second lavage group were higher than those in the control group (both P< 0 . 05 ), but the levels of IL- 1 β, IL- 36 in the BALF showed no difference between the second lavage group and the control group (both P> 0 . 05 ). The levels of sB 7 -H 3 had positive correlation with the levels of IL- 1 β, IL- 2 and IL- 36 (all P< 0 . 001 ). Conclusions sB 7 -H 3 may control the secretion of IL- 1 β, IL- 2 and IL- 36 , and participate in immune response and lung injury after MP infection, which may lead to occurrence and development of RMPP.