Specific Mycobacterium tuberculosis T cell responses to RD1-selected peptides for the monitoring of anti-tuberculosis therapy

Abstract

Background: Recently, a selection of HLA class II-restricted epitopes of ESAT-6 and CFP-10 Mycobacterium tuberculosis proteins from the region of difference (RD) 1 have been described. We have evaluated the host interferon-gamma (IFN-γ) T cell response to these RD1 selected peptides at the beginning and during anti-tuberculosis therapy. Methods: We studied 29 pulmonary TB patients enrolled at the beginning of treatment and 24 enrolled during treatment. We performed T-SPOT.TB and ELISPOT with RD1 selected peptides. Results: Patients included at the beginning of treatment responded producing IFN-γ after antigen stimulation in 89.7% by means of T-SPOT.TB and 79.3% by means of RD1 selected ELISPOT. In contrast, for patients included during treatment the percentages were 87.5% and 25%, respectively. Differences in sensitivities between patients evaluated at the beginning and during treatment were only significant for RD1 selected ELISPOT (p < 0.0001). Conclusions: The host immune response to RD1 selected peptides is lower than to T-SPOT.TB during therapy. Immunological assays based on RD1 selected peptides may be useful tools for studying the immune response during anti-tuberculosis therapy.

Keywords::

• Mycobacterium tuberculosis
• IFN-γ assays
• RD1 selected peptides
• monitoring anti-TB treatment
• immune response

Acknowledgements

We thank the nursing staff of the Unitat de Prevenció i Control de la Tuberculosi of Barcelona, and C. Ramil, L. Haba, and M.A. Cuesta for technical assistance. The authors are members of the TBNET group. J. Domínguez is a researcher funded by the Miguel Servet programme of the Instituto de Salud Carlos III (Spain). This work was supported by a grant from the Sociedad Española de Neumología y Cirugía Torácica; the Societat Catalana de Pneumologia (SOCAP); Fundació Catalana de Pneumologia (FUCAP); and Instituto de Salud Carlos III-RETIC (RD06/0018), Red de Actividades Preventivas y Promoción de la Salud (REDIAP).

Declaration of interest: None of the investigators have relevant financial interest in or a financial conflict with the subject matter or materials discussed in this manuscript. None of the scientific societies, neither Cellestis (Carnegie, Australia) nor Oxford Immunotec (Abingdon, UK) had a role in the study design, conduct, collection, management, analysis, or interpretation of the data, or preparation, review, or approval of the manuscript.