Table 3.

Recognition and boosting effect of p51-65 in the HIV negative cohort.

	QFT performance	QFTB performance
Number tested n =	55	55
Median IU/ml (IQR)a	1.83 (0.32–6.90)	2.83 (0.32–11.54)
Comparison of median IU/ml responseb	** (p = 0.002)
No. of positive respondersc	40	41
Responders %d	73	75
Sensitivity % (95% CI)e	95 (83.8–99.4)	98 (87.1–99.9)

Blood samples of 55 HIV uninfected participant were assayed in commercially available QFT and p51-65 peptide boosted QFT (QFTB). The cut-off for positive recognition was 0.35 IU/ml above nil.

^aMedian IU/ml value in QFT or QFTB assay and interquartile range.

^bSignificance was calculated using Wilcoxon matched pairs test. **p < 0.01.

^cNumber of positive responders/number tested.

^dPercentage of responders out of all donors tested.

^eSensitivity was calculated as a ratio of the number of true positive responders over the number of false negative plus true positive responders. False negativity was confirmed by ELISpot using ESAT-6/CFP-10 antigens. The difference in sensitivity statistically is not significant.