γ-干扰素释放试验中植物血凝素反应的影响因素

Factors influencing phytohemagglutinin response in gamma-interferon release assay

目的探讨用γ-干扰素释放试验(gamma interferon release assay,IGRA)检测结核分枝杆菌感染时植物血凝素(phytohemagglutinin,PHA)反应的影响因素。方法选取2019年1月—2021年12月于四川大学华西医院接受IGRA检测的360例住院患者进行回顾性病例对照研究,根据PHA反应强弱(以IFN-γ含量表示),将住院患者分为PHA反应阴性组(IFN-γ<2 pg/ml)、PHA反应弱阳性组(IFN-γ:2~100 pg/ml)和PHA反应正常组(IFN-γ>400 pg/ml)。结果在360例患者中,合并免疫性疾病与PHA反应阴性(OR=0.34,95%CI:0.17~0.72,P=0.004)和弱阳性(OR=0.29,95%CI:0.16~0.55,P<0.001)独立相关;合并非结核分枝杆菌的其他病原体感染与PHA反应阴性独立相关(OR=0.266,95%CI:0.09~0.83,P=0.023),而免疫功能低下与PHA反应弱阳性独立相关(OR=0.280,95%CI:0.12~0.63,P=0.002)。PHA反应水平与血清白蛋白、血红蛋白、中性粒细胞和淋巴细胞计数显著相关(P<0.001)。结论免疫性疾病和免疫功能低下均能影响PHA反应水平,因此临床医生在对IGRA检测结果解读中应着重关注PHA反应水平,防止出现误诊和漏诊。同时,PHA反应水平在一定程度上也能反映住院患者的感染状态。

Objective To investigate the factors influencing phytohemagglutinin(PHA)response in the detection of Mycobacterium tuberculosis infection by gamma interferon release assay(IGRA).Methods A retrospective case-control study was conducted on 360 hospitalized patients who received IGRA in West China Hospital of Sichuan University from January 2019 to December 2021.According to PHA response(IFN-γlevel),they were divided into three groups:negative mitogen response group(IFN-γ<2 pg/ml),weak positive mitogen response group(IFN-γ:2-100 pg/ml),and normal mitogen response group(IFN-γ>400 pg/ml).Results Immune diseases were independently associated with negative(OR=0.34,95%CI:0.17-0.72,P=0.004)and weak positive mitogen responses(OR=0.29,95%CI:0.16-0.55,P<0.001).Infections caused by pathogens other than Mycobacterium tuberculosis was independently associated with negative mitogen response(OR=0.266,95%CI:0.09-0.83,P=0.023),while immunodeficiency was independently associated with weak positive mitogen response(OR=0.280,95%CI:0.12-0.63,P=0.002).Mitogen response was significantly correlated with the levels of albumin and hemoglobin in serum and the counts of neutrophils and lymphocytes(P<0.001).Conclusions Immune diseases and immunodeficiency can affect mitogen response.Therefore,clinicians should give attention to mitogen response in the interpretation of IGRA test results to prevent misdiagnosis and underdiagnosis.Besides,to a certain extent,mitogen response can reflect the infection status of hospitalized patients.