[IFN-gamma enzyme-linked immunospot assay versus PPD tuberculin skin test in the diagnosis of tuberculous epididymitis].

ABSTRACT

OBJECTIVE: To explore the potential application of IFN-gamma enzyme-linked immunospot (ELISPOT) assay in the diagnosis of tuberculous epididymitis (TE) by comparing ELISPOT assay with the traditional purified protein derivative (PPD) tuberculin skin test. METHODS: We examined 13 TE patients using an in-house ELISPOT kit, another 11 TE patients by PPD skin testing, and 57 healthy male volunteers by parallel test with both the methods. RESULTS: Twelve (92.3%) of the 13 TE cases were positive on ELISPOT assay, and 10 (90.9%) of the 11 TE cases positive on PPD skin test, with no statistically significant differences between the two groups (P > 0.05). Among the 57 healthy male volunteers, 8 (14.0%) were positive on ELISPOT, and 28 (49.1%) positive on PPD test, the latter significantly higher than the former (P < 0.001). CONCLUSION: In terms of sensitivity, ELISPOT assay is similar to PPD test in the examination of tuberculous epididymitis. As for specificity, ELISPOT assay seems better than PPD test in differentiating tuberculous epididymitis patients from healthy males.