γ-干扰素释放试验对不同年龄组疑似肺结核的辅助诊断价值

Evaluation of T-SPOT.TB assay in the diagnosis of pulmonary tuberculosis within different age groups

目的 探讨结核感染T细胞斑点试验（T-SPOT.TB）对不同年龄疑似肺结核病例的辅助诊断价值.方法 回顾性分析2012年11月至2014年2月首都医科大学附属北京胸科医院收治的疑似肺结核病例1 518例,所有病例均无结核病史,并在抗结核治疗前行T-SPOT.TB检测.根据诊断结果分为肺结核确诊组599例,男388例,女211例,年龄16 ～89岁;非结核组235例,男144例,女91例,年龄14～ 85岁,剔除其余诊断不明和临床诊断肺结核病例684例.按照年龄将纳入人群分为中青年组536例（14 ～ 59岁）和老年组298例（60 ～ 89岁）.将T-SPOT.TB结果与诊断结果进行比较,分析T-SPOT.TB的诊断效能.组间样本率比较采用x2检验,组间非正态分布计量资料比较采用Mann-Whitney U检验.结果 T-SPOT.TB诊断的敏感度为90.1％（540/599）,特异度为65.5％（154/235）,阳性预测值为86.9％（540/621）,阴性预测值为72.3％（154/213）,阳性似然比为2.61,阴性似然比为0.15.中青年组T-SPOT.TB诊断的敏感度和特异度为92.6％（375/405）和75.6％（99/131）,老年组T-SPOT.TB诊断的敏感度和特异度为85.0％ （165/194）和52.9％ （55/104）,前者的诊断敏感度和特异度均显著高于后者（P＜0.01）,且外周血单个核细胞（PBMC）斑点形成数显著高于后者[300个（128 666个）/106pBMCs,258个（79 621个）/106pBMCs,P=0.037].结论 T-SPOT.TB对中青年肺结核有较好的辅助诊断价值,但对老年肺结核的诊断性能相对较低.

Objective To evaluate the value of T-SPOT.TB assay in the diagnosis of pulmonary tuberculosis within different age groups.Methods We analyzed 1 518 suspected pulmonary tuberculosis （PTB） patients who were admitted to the Beijing Chest Hospital from November 2012 to February 2014 and had valid T-SPOT.TB tests before anti-tuberculosis therapy.The 599 microbiologically and/or histopathologically-confirmed PTB patients （16-89 years old, 388 males and 211 females） and 235 non-TB patients （14-85 years old, 144 males and 91 females） were enrolled for the analysis of diagnostic performance of T-SPOT.TB, while patients with uncertain diagnosis or diagnosis based on clinical impression （n =684） were excluded from the analysis.The sensitivity, specificity, positive predictive value, negative predictive value, positive likelihood ratio, and negative likelihood ratio of the T-SPOT.TB were analyzed according to the final diagnosis.Furthermore, the diagnostic performance of T-SPOT.TB assay in the younger patients （14-59 years old） and elderly patients （60-89 years old） were also analyzed respectively.Categorical variables were compared by Pearson＇s Chi-square test, while continuous variables were compared by the Mann-Whitney U-test.Results The sensitivity, specificity, positive predictive value, negative predictive value, positive likelihood ratio, and negative likelihood ratio of the T-SPOT.TB in diagnosis of PTB were 90.1% （540/599）, 65.5% （154/235）, 86.9% （540/621）, 72.3% （154/213）, 2.61, and 0.15, respectively.The sensitivity and specificity of T-SPOT.TB assay were 92.6% （375/405） and 75.6% （99/131）, respectively in the younger patients, and 85.0% （165/194）, 52.9% （55/104） respectively in the elderly patients.The sensitivity and specificity of T-SPOT.TB assay in the younger patients were significantly higher than those in the elderly patients （P 〈 0.01） , and the spot forming cells in the younger PTB patients were significantly higher than in the elderly PTB patients [300 （126, 666）/106 PBMCs vs.258 （79, 621）/106 PBMCs, P =0.037].Conclusion T-SPOT.TB is a promising test in the diagnosis of younger patients （14-59 years old） with suspected PTB, but the diagnostic performance in elderly patients （60-89 years old） is relatively reduced.