Latency Antigens as Sensors of Different Stages of Tuberculosis.

PONTINO MÓNICA; MEIKLE VIRGINIA; JURADO JAVIER; PASQUÍNELLI VIRGINIA; LISTE MÓNICA; CATALDI ÁNGEL; GARCÍA VERÓNICA; ALITO ALICIA

Colombia

Congreso; INTERNATIONAL CONGRESS Controlling Micobacterias one formidable Challenge for the Twenty First Century,; 2008

INTRODUCTION: Two Thousands millions people may suffer latent TB infections.  Latently infected individuals provide a highly relevant population to study what human protective immune responses against Mycobacterium tuberculosis look like. OBJETIVE: To test latency antigens and infection markers so as to identify latently infected individuals. METHODOLOGY: Whole blood was stimulated with. Latency antigens (HspX, Rv2624c,Rv2626c), CFP10, PPD and Pokeweed mitogen as controls.  Interferon gamma(IFN-g) was measured in stimulated plasmas belonging to seven cohorts:1st)Mantoux negative; 2nd) Mantoux positive; 3erd) TB patients without antibiotic treatment;4th) TB patients with antibiotic treatment; 5th) exTB patients; 6th9 relapse patients; 7th) patients with other pulmonary disease.  Four out of eight individuals of cohort 1st are working at TB lab.  The others are contacts of TB patients. RESULTS: HspX produced high levels of IFN-g (1st, 2nd, 4th).  Middle levels of IFN-g were observed(5th).  Low responses were shown (3rd, 6th, 7th) Rv2624c and Rv2626c produced very low levels of IFN-g in all cohorts. CFP10 showed variable values of stimulation (2nd,3rd,5th, 6th).  Low levels of IFN-g were produced as expected(1st, 7th) CONCLUSIONS: HspX produces high levels of IFN-g in healthy individuals (1st 2nd)( and in those with antibiotic treatment (4th 5th).  First cohort is latently infected but could not be detected by Mantoux. Rv2624c and Rv2626c do not show a stimulation pattern similar to HspX. CFP10 does not show its condition of infection marker (small size of the sample).  Immunodiagnostic can be improved by latency antigens as a contribution to detect latently infected individuals.