早期肺癌合并肺部感染患者病原菌分布及外周血EGFR-T790M基因突变分析

Distribution of pathogens and mutation of EGFR-T790M gene in peripheral blood of early-stage lung cancer patients complicated with lung infection

目的分析早期肺癌合并肺部感染患者病原菌分布及外周血ctDNA检测样本中EGFR-T790M基因突变情况。方法将2016年8月-2017年12月因早期肺癌合并肺部感染疾病于医院治疗的125例患者作为研究对象,采用微生物鉴定仪器检测患者致病菌株,并统计其占比情况,对常见致病菌进行药敏试验,明确具体用药方案,采用超级扩增阻碍突变系统对患者外周血血液样本中EGFR-T790M基因突变情况进行检测。结果 125例早期肺癌合并肺部感染患者痰液标本中共分离出144株病原菌,其中革兰阴性菌79株占54.86%,革兰阳性菌38株占26.39%,真菌27株占18.75%;铜绿假单胞菌对氨苄西林/舒巴坦耐药株数最多,对亚胺培南耐药株数最少;125例患者中,11例患者出现EGFR-T790M基因突变,结果显示:使用过TKIs药物治疗的患者EGFR-T790M基因突变发生率高于未使用TKIs药物治疗的患者(P<0.001)。结论早期肺癌合并肺部感染患者病原菌以革兰阴性菌为主,其次为革兰阳性菌,综合药敏试验结果可考虑采用亚胺培南与万古霉素进行治疗,但实际用药情况还需根据患者自身情况决定。临床中对EGFR-T790M基因突变情况进行检测可有效预测患者病情变化,并指导改善用药。

OBJECTIVE To analyze the distribution of pathogens and the mutation of EGFR-T790M gene in peripheral blood samples of patients with early lung cancer complicated with pulmonary infcction. METHODS 125 patients with early-stage lung can cer complicated with pulm on ary infection treated in the hospital from Aug. 2016 to Dec. 2017 were enrolled in the study. Pathogens were detected using the microbial idcntification instrument , and their proportions was counted. Drug susceptibility tests were carried out on common pathogens to determine the specific drug regimen. Then, the mutation of EGFR-T790M gene in peripheral blood samples of patients was detected by super amplification impediment mutation system. RESULTS A total of 144 strains of pathogens were isolated from sputum samples of the 125 patients with early lung cancer complicated with pulmonary infection, of which 79 were gram-negative bacteria (54.86%), 38 were gram-positive bacteria (26.39%) and 27 were fungi (18.75%). Pseudomonas aeruginosa had the most ampicillin/sulbactam resistant strains and the least imipenem resistant strains. 11 of the 125 patients had EGFR-T790M gene mutation. The results showed that the incidence of EGFR -T79OM gene mutation in patients treated with TKIs was higher than that in patients not treated with TKIs (P<0.001). CONCLUSION Gram-negative bacteria are the main pathogens in early-stage lung cancer patients with pulm on ary infection, followed by gram-positive bacteria. The drug sensitivity test results suggest use of imipenem and vancomycin for treatment, but the actual use of antibiotics needs to be determined according to the patients own conditions. Detection of EGFR-T790M gene mutation in clinic can effectively predict the changes in the patients condition and guide the improvement of medication.