The value of T cell spot test of tuberculosis infection and inflammatory indicators for diagnosis of active tuberculosis in patients with fever of unknown origin / 中华传染病杂志

ABSTRACT

Objective@#To evaluate the value of T cell spot test of tuberculosis infection(T-SPOT.TB) and inflammatory indicators for diagnosis of active tuberculosis in patients with fever of unknown origin (FUO). @*Methods@#Patients with FUO in Tongji Hospital from Jan 1st 2014 to Feb 28th 2015 were retrospectively enrolled, and general condition, laboratory examination including T-SPOT.TB, blood routine test, procalcitonin (PCT), high sensitivity C-reactive protein (hs-CRP), erythrocyte sedimentation rate (ESR), lactate dehydrogenase (LDH), serum ferritin (SF) and final diagnosis were collected and analyzed. @*Results@#A total of 395 hospitalized patients with FUO were retrospectively enrolled into this study, among which there were 36 (9.11%) confirmed active tuberculosis (including 7 pulmonary cases and 29 extra-pulmonary cases), 189 (47.85%) bacterial infections, 50 (12.66%) viral infections, 4 (6.32%) fungal infections, 20 (5.06%) neoplastic diseases, 51(12.91%) autoimmune diseases, 25 (6.32%) other diseases. While 20 (5.06%) patients remained un-diagnosed. The sensitivity of T-SPOT.TB for the diagnosis of active TB in patients with FUO was 80.56% (95%CI 63.43%-91.20%), and the specificity was 83.57% (95%CI 79.23%-87.16%). The positive predictive value was 32.95% (95%CI 23.52%-43.89%), and the negative predictive value was 97.72% (95%CI 95.16%-99.00%). There were significant differences in positive LDH levels (187[141, 255] U/L vs 209[160, 343] U/L) and SF levels (296.2[191.3, 494.8] g/L vs 528.1[281.1, 1 022.0] μg/L) between active tuberculosis group and bacterial infection group (χ2=77.692, H=13.442, H=16.142, all P<0.05). The combination of T-SPOT.TB and multiple inflammatory indicators obtained most valuable efficiency (AUC=0.866) for TB diagnosis. Similarly, there were significant differences in positive ESR (31[15, 78] mm/1 h vs 10[6, 19] mm/1 h), ratio of neutrophil granulocytes ([71.17±12.59]% vs [57.08±20.38]%) between active tuberculosis group and viral infection group (H=32.797, F=6.171, all P<0.05). The combination acquired most valuable efficiency (AUC=0.929). @*Conclusions@#For patients with FUO, T-SPOT.TB combined with inflammatory indicators are valuable for the diagnosis of active tuberculosis.