Use of Interferon‐γ release assay for the diagnosis of female genital tuberculosis in Northwest China

Background Female genital tuberculosis ( FGTB ) is one of the major causes of infertility. However, nonspecific manifestations and the lack of easy access to gold‐standard diagnostic test render a diagnostic difficult for FGTB . The objective of this study was to determine T‐ SPOT . TB (an interferon‐γ release assay, IGRA ) performance in patients with FGTB . Methods A total of 213 female patients with validated T‐ SPOT . TB results were recruited in this retrospective study. Among which, 103 were confirmed FGTB , and 110 were excluded from tuberculosis (control). Of the confirmed FGTB patients, 52 were confirmed by microbiologically/histopathologically examination, while the remaining 51 were clinically confirmed (successfully responsive to anti‐tuberculosis treatment). T‐ SPOT . TB test was performed in both FGTB and control group during the diagnostic procedure. Results The overall sensitivity and specificity of T‐ SPOT . TB were 86.41% and 75.45% respectively. Sensitivity of T‐ SPOT . TB was significantly higher when compared with conventional tuberculosis diagnostic tests. Moreover, T‐ SPOT . TB test using pelvic effusion ( PE ) showed higher sensitivity than using corresponding peripheral blood ( PB ) (94.44% vs 72.22%, P  <   0.001). Mean value of spot forming cells ( SFC s) of T‐ SPOT . TB using PE was significantly higher than that of PB in FGTB group (193 ( IQR 105‐280) SFC s/2.5 × 10 5 PEMC s vs 71 ( IQR 36‐107) SFC s/2.5 × 10 5 PBMC s, P  =   0.01), while this was not detected in control group (11 ( IQR 0‐22) SFC s/2.5 × 10 5 PEMC s vs 9 ( IQR 0‐18) SFC s/2.5 × 10 5 PBMC s, P  =   0.77). Conclusion These results demonstrated that T‐ SPOT . TB , especially PE T‐ SPOT . TB , is an useful adjunct in FGTB diagnosis.