Abstract
Background: Some new TB patients can have negative results with specific antigens tests. We estimated a skin test with a recombinant protein combination of CFP10-ESAT6 and evaluated blood levels of IFN-g, TNF-a, IL-2 in ELISA after induction with CFP10-ESAT6-TB7.7 antigens in TB patients blood.
Methods: 36 new TB patients enrolled (mean 32,7 years old), 16 (44%) had destruction in lung tissue, 16 (44%) had more than 2 lung segments involved, 7 (19,4%) were Drug Resistant-TB (MBT+DR+), 13 (36,1%) - sputum positive without DR (MBT+DR-) and 16 (44,4%) – sputum negative (MBT-). In 7 (19,4%) patients negative skin test result was obtained – no reaction after 72h of intradermal injection. IFN-g, TNF-a, IL-2 were evaluated in ELISA after 24h incubation with ESAT-6-CFP-10-TB7.7. T cells subpopulations in peripheral blood were estimated by flow cytometry analysis. Results: Of 7 TB patients with negative skin test 5 had destruction in lung tissue, 3 had more than 2 lung segments involved, 3 were sputum positive, 1 had resistance to S,H. There were no significant differences in groups. We received no differences in T cells subpopulations in positive and negative skin test patients. Patients with negative skin test had statistically lower levels of IFN-g (10,2±6,02 vs 114,3±27,4 in positive; Mann-Whitney Test p=0,029), TNF-a (0,89±0,9 vs 316,3±115,0; Mann-Whitney Test p=0,006), IL-2 (13,9±9,1 vs 164,5± 40,6; Mann-Whitney Test p=0,017).
Conclusion: We obtained significant correlation between negative skin results with the recombinant protein combination of CFP10-ESAT6 and low levels of IFN-g, TNF-a, IL-2 in blood after the induction with similar antigens in ELISA.
- © 2013 ERS