痰液炎性细胞在儿童呼吸道感染后咳嗽与咳嗽变异性哮喘的比较及意义

Comparison of sputum inflammatory cells in postinfectious cough and cough variant asthma in children

目的 探讨反映气道炎症状况的痰液炎性细胞测定在慢性咳嗽儿童中的临床应用价值。方法 应用Pin等的诱导痰技术 ,对 70例慢性咳嗽 (感染后咳嗽组 39例 ,咳嗽变异性哮喘组 31例 )和 38例缓解期哮喘儿童的新鲜痰涂片 ,进行迈 格氏加姬姆萨 (May Gr櫣ｎｗａｌｄ’ｓ +Gimsa)复染法和巴氏 (Papanicolaou)染色法染色 ,做细胞学分类计数 ,测定痰液炎性细胞百分比 ,同步检测变应原皮肤试验和肺通气功能。结果 感染后咳嗽组中痰液嗜酸细胞和中性粒细胞的中位数分别为 0 8%、5 8 0 % ,与咳嗽变异性哮喘组 (分别为 2 4 0 %、2 3.8% )比较 ,两种细胞的组间差异均有显著性 (均 P <0 0 1)。感染后咳嗽持续或反复发作的迁延时间较咳嗽变异性哮喘组更长 ,差异具统计学意义 (P <0 0 5 )。咳嗽变异性哮喘组痰液嗜酸细胞、肥大细胞水平与咳嗽持续时间呈显著正相关 (r=0 4 13,0 80 5 ,均P <0 0 5 )。两组慢性咳嗽儿童的痰液嗜酸细胞均与肺呼气峰流速占预计值的百分比 (PEF %pred)以及最大呼气中段流速 (MMEF) 75 / 2 5呈显著负相关 (r =- 0 2 71,- 0 32 4 ,均P <0 0 5 )。结论 痰液炎性细胞可能成为反映气道炎症类型、鉴别感染后咳嗽与咳嗽变异性哮喘的一项参考指标。

Objective To evaluate the clinical applications of the detection of sputum inflammatory cells reflecting the state of airway inflammation in children with chronic cough.Methods 70 children with chronic cough at persistent postinfectious cough (groupⅠ,n=38) or cough variant asthma (groupⅡ,n=31), 38 cases of asthma remission (groupⅢ). Sputum samples were obtained by spontaneous expectoration or by hypertonic saline aerosol induction. Sputum smear was stained by May Grünwald's+Gimsa and Papanicolaou's. Differential inflammatory cells counts were performed by counting 500 cells under the light microscope, while patients were tested for allergy by skin prick test and pulmonary function. Results The percentage of eosinophils in sputum of groupⅠwas significantly lower than that of groupⅡ (median 0 8% vs 24 0%, P<0 01). Contrarily, the percentage of P<0.05 neutrophils in sputum of group Ⅰ was significantly higher compared with groupⅡ(median 58 0% vs 23.8%, P<0 05). Persistent cough of groupⅠwas significantly longer than groupⅡ(P<0 05). Sputum eosinophils or mast cells were positively correlated with cough persistency in groupⅡ(r=0 413, 0 805, P<0 05). There were significant correlation between sputum eosinophils and PEF%pred or MMEF75/25 in children with chronic cough in groupⅠandⅡ (r=-0 271, -0 324, P<0 05). Conclusion Sputum inflammatory cells may be a useful marker reflecting the type of airway inflammation and differing between postinfectious cough and cough variant asthma.