合并支原体感染的大叶性肺炎患儿肺泡灌洗液中常规细胞学检测及意义*

Cell suspension and level of IL-17 in bronchoalveolar lavage fluid (BALF) of children with labor pneumonia combined with mycoplasma pneumonia and its clinical significance*

摘要:

目的  研究大叶性肺炎患儿支气管肺泡灌洗液（BALF）中常规细胞学形态学检测、肺炎支原体-DNA（MP-DNA）及细胞因子白细胞介素-17（IL-17）水平，探讨其临床意义及相互关系。方法  选取确诊为大叶性肺炎并行支气管肺泡灌洗术（BAL）的患儿87例，行BAL当天对患儿行临床肺部感染评分（CPIS）分为：重症组27例，轻症组60例；根据BALF免疫荧光定量MP-DNA结果，分为支原体感染73例：中拷贝组32例、高拷贝组41例，无支原体感染14例；ELISA法检测BALF中IL-17水平，对BALF中细胞HE染色后放大100倍计数，比较各组间常规细胞学计数百分比差异。结果  BALF中中性粒细胞百分比（NE%）、淋巴细胞百分比（LY%）与血清中NE%和LY%无相关性（P >0.05）；轻症组患儿BALF中柱状上皮细胞计数百分比高于重症组，并且重症组患儿BALF中巨噬细胞百分比高于轻症组（P <0.05）；高拷贝组NE%高于中拷贝组（P <0.05），且NE%与BALF中IL-17水平及MP-DNA拷贝均呈正相关（r1 =0.49，P =0.000，r2 =0.48，P =0.000）。结论  大叶性肺炎肺泡灌洗液中成分更能反应大叶性肺炎局部炎症情况；大叶性肺炎发生时柱状上皮细胞受损脱落，同时巨噬细胞趋化聚集参与炎症反应；肺炎支原体感染时，IL-17通过中性粒细胞募集作用发挥抗感染能力，BALF中NE%可间接反映患儿局部感染支原体拷贝数。

Abstract:

Objective To explore cell suspension and level of IL-17 in bronchoalveolar lavage fluid (BALF) of children with labor pneumonia combined with mycoplasma pneumonia and its clinical significance. Methods 87 children with labor pneumonia who had been done BAL were divided into CPIS ≥ 6 group and CPIS < 6 group according to the clinical pneumonia infection score (CPIS). Meanwhile, according to the results of MP-DNA, we grouped the children above into combined with mycoplasma pneumonia infection group and no mycoplasma pneumonia infection group, then combined with mycoplasma pneumonia infection group into group of MP-DNA: 103～106 and group of MP-DNA: 106~. ELISA method was used to detect IL-17 level, HE staining and microscopy to sort cells, PCR detect MP-DNA. Results The percentage of neutrophils and lymphocytes in BALF are not related to that in blood (P > 0.05). The percentage of columnar epithelial cells in CPIS < 6 group were higher than CPIS ≥ 6, however, macrophagocyte was lower (P < 0.05). The percentage of neutrophils are related with both MP-DNA (r = 0.48, P = 0.000) and IL-17 (r = 0.49, P = 0.000). Conclusions The composition of BALF is more appropriate to react the circumstance of lobar pneumonia. When lobar pneumonia occurs, columnar epithelial cells are damaged, macrophagocyte gathered to participate in the inflammatory response. In Mycoplasma pneumonia infection group, IL-17 raises neutrophils to resist infection, NE% in BALF can indirectly reflect the mycoplasma infection degree.