RT Journal Article
SR Electronic
T1 Intracellular ESAT-6 vs flow cytometric analysis of CD4+IFN-γ+ cells for the diagnosis of mycobacterium tuberculosis infection in immunosuppressed patients
JF European Respiratory Journal
JO Eur Respir J
FD European Respiratory Society
SP PA2697
DO 10.1183/13993003.congress-2016.PA2697
VO 48
IS suppl 60
A1 Chrysovalantis V. Papageorgiou
A1 Angelos D. Gritzapis
A1 Maria Ploussi
A1 Michail Leventopoulos
A1 Andreas Anastasopoulos
A1 Simona Karabela
A1 Kyriakos Fotiadis
A1 Evangelos Vogiatzakis
A1 Vassilis Tsilivakos
A1 Nikolaos Poulakis
YR 2016
UL http://erj.ersjournals.com/content/48/suppl_60/PA2697.abstract
AB Background: CD4+ cells expressing IFN-γ following stimulation with the mycobacterial antigen ESAT-6, identified with flow cytometry (FCM-CD4+IFN-γ+ESAT-6+) indicate Mycobacterium Tuberculosis (MTB) infection. Another novel method to identify MTB infection is to examine the expression of intracellular ESAT-6 (i/cESAT-6) directly in host cells, thus verifying the presence of active bacilli (Poulakis, N. et al. Cytometry B 2014; doi: 10.1002/cyto.b.21220). We assessed the expression of i/cESAT-6 in comparison to FCM-CD4+IFN-γ+ESAT-6+ in medically immunosuppressed patients under biologic treatment.Methods: We performed FCM-CD4+IFN-γ+ESAT-6+ analysis and examined i/cESAT-6 expression in the blood of 64 patients with rheumatic diseases, under treatment with anti-TNFa and other biologic agents.Results: From 31 immunosuppressed patients positive for FCM, only 20 were i/cESAT-6 positive, possibly identifying the subgroup with true infection that would benefit from chemoprophylaxis. Ten FCM negative patients were i/cESAT-6 positive, possibly identifying patients that immunosuppressive treatment impaired immune response and memory but are at increased risk for progression to active disease and may require chemoprophylaxis. The fact that 11 patients are positive for IFN-γ production and negative for the presence of i/cESAT-6 protein possibly reflects previously acquired immunity.i/cESAT-6 (+) (n=32)i/c ESAT-6 (-) (n=32)FCM ESAT-6+ (n=31)2011FCM ESAT-6- (n=26)1016Indeterminate (n=7)25Conclusion: Intracellular ESAT-6 detection could help refine chemoprophylaxis administration in immunosuppressed patients.