γ干扰素释放试验与结核菌素皮肤试验筛查预测活动性结核病的比较

摘要

为评估γ干扰素释放试验（T-SPOT ．TB）和结核菌素皮肤试验（TST ）在我国活动性肺结核病患者的家庭接触者中预测活动性结核病的能力，选取157例家庭接触者行T-SPOT ．TB和TST筛查，并前瞻性随访6年。将121例参与随访的家庭接触者纳入分析，T-SPOT ．TB阳性率为49．6％，与年龄﹝ OR＝1．03（95％CI 1．00～1．05），P＝0．032﹞和接触菌阳患者﹝ OR＝2．13（95％ CI为1．01～4．51），P＝0．048﹞呈正相关。TST≥5 mm和TST≥10 mm的接触者分别占57．5％和37．2％，其中TST≥10 mm与接触菌阳患者呈正相关﹝ OR＝2．30（95％ CI为1．05～5．06），P＝0．038﹞。共随访626人年，7例发展为活动性结核病，发病率为11．0／1000人年。T-SPOT ．TB的阳性预测值（PPV）为8．3％，阴性预测值（NPV）为96．7％。TST≥5 mm和TST≥10 mm的PPV分别为7．7％和9．5％，NPV均为95．8％。总之，活动性肺结核病患者的家庭接触者发展为活动性结核病的风险高于一般人群，而T-SPOT ．TB与TST对活动性结核病的预测能力相当。%The purpose of the present study is to investigate the performance of interferon γ release assay (IGRA) and tuberculin skin test (TST) in household contacts of tuberculosis patients ,and to evaluate the predictive values of the two tests for disease progression from latent tuberculosis infection (LTBI) to active tuberculosis in China .Household contacts of active pulmonary tuberculosis patients were offered both IGRA (T-SPOT .TB) and TST ,and then followed up for 6 years .The final cohort comprised 121 household contacts .T-SPOT .TB was positive in 49 .6% of the contacts;the positive rate was associated with increasing age﹝ OR=1 .03 (95% CI 1 .00-1 .05) ,P=0 .032﹞ and contacting with smear-positive patients ﹝ OR=2 .13 (95% CI 1 .01-4 .51) ,P=0 .048﹞ .TST≥5 mm and TST≥10 mm accounted for 57 .5% and 37 .2% of the contacts , respectively . TST ≥ 10 mm was positively associated with contacting with smear-positive patients﹝ OR=2 .30 (95% CI 1 .05-5 .06) ,P=0 .038﹞ .Seven cases progressed to tuberculosis within 626 person-years of follow-up ,showing an overall incidence rate of 11 .0 per 1 000 person-years .The positive predictive value (PPV ) and negative predictive value (NPV ) was 8 .3% and 96 .7% for T-SPOT .TB .The PPVs for TST≥5 mm and TST≥10 mm were 7 .7% and 9 .5% respectively;NPVs were both 95 .8% .In conclusion , there is a high incidence rate of active tuberculosis among household contacts compared to general population in China .The predictive values of IGRA and TST for progression to active tuberculosis among household contacts are comparable .