Limits...
Loss of receptor on tuberculin-reactive T-cells marks active pulmonary tuberculosis.

Streitz M, Tesfa L, Yildirim V, Yahyazadeh A, Ulrichs T, Lenkei R, Quassem A, Liebetrau G, Nomura L, Maecker H, Volk HD, Kern F - PLoS ONE (2007)

Bottom Line: The percentage of tuberculin-specific T-helper-cells lacking the surface receptor CD27, a state associated with advanced differentiation, varied considerably between individuals (from less than 5% to more than 95%).It is simple and will be of great utility in situations where sputum specimens are difficult to obtain or sputum-smear is negative.It will also help avoid unnecessary hospitalization and patient isolation.

View Article: PubMed Central - PubMed

Affiliation: Institut für Medizinische Immunologie der Charité, Charité Universitätsmedizin Berlin, Berlin, Germany.

ABSTRACT

Background: Tuberculin-specific T-cell responses have low diagnostic specificity in BCG vaccinated populations. While subunit-antigen (e.g. ESAT-6, CFP-10) based tests are useful for diagnosing latent tuberculosis infection, there is no reliable immunological test for active pulmonary tuberculosis. Notably, all existing immunological tuberculosis-tests are based on T-cell response size, whereas the diagnostic potential of T-cell response quality has never been explored. This includes surface marker expression and functionality of mycobacterial antigen specific T-cells.

Methodology/principal findings: Flow-cytometry was used to examine over-night antigen-stimulated T-cells from tuberculosis patients and controls. Tuberculin and/or the relatively M. tuberculosis specific ESAT-6 protein were used as stimulants. A set of classic surface markers of T-cell naïve/memory differentiation was selected and IFN-gamma production was used to identify T-cells recognizing these antigens. The percentage of tuberculin-specific T-helper-cells lacking the surface receptor CD27, a state associated with advanced differentiation, varied considerably between individuals (from less than 5% to more than 95%). Healthy BCG vaccinated individuals had significantly fewer CD27-negative tuberculin-reactive CD4 T-cells than patients with smear and/or culture positive pulmonary tuberculosis, discriminating these groups with high sensitivity and specificity, whereas individuals with latent tuberculosis infection exhibited levels in between.

Conclusions/significance: Smear and/or culture positive pulmonary tuberculosis can be diagnosed by a rapid and reliable immunological test based on the distribution of CD27 expression on peripheral blood tuberculin specific T-cells. This test works very well even in a BCG vaccinated population. It is simple and will be of great utility in situations where sputum specimens are difficult to obtain or sputum-smear is negative. It will also help avoid unnecessary hospitalization and patient isolation.

Show MeSH

Related in: MedlinePlus

Significantly fewer tuberculin-reactive CD4 T-cells express CD27 in TB-patients than in controls.Proportions of CD27-positive and negative cells were based on a minimum of 50 IFN-γ positive events. Vertical numbers indicate evaluated events (median and range). Controls included unexposed controls, professionally TB-exposed health care workers, and donors with latent infection. A threshold of 49% would effectively discriminate between patients and controls (dotted line). Controls with latent TB infection had higher values than individuals with no known exposure to TB.
© Copyright Policy
Related In: Results  -  Collection


getmorefigures.php?uid=PMC1936433&req=5

pone-0000735-g003: Significantly fewer tuberculin-reactive CD4 T-cells express CD27 in TB-patients than in controls.Proportions of CD27-positive and negative cells were based on a minimum of 50 IFN-γ positive events. Vertical numbers indicate evaluated events (median and range). Controls included unexposed controls, professionally TB-exposed health care workers, and donors with latent infection. A threshold of 49% would effectively discriminate between patients and controls (dotted line). Controls with latent TB infection had higher values than individuals with no known exposure to TB.

Mentions: The expression of “classic” markers of T-cell differentiation [12], [14] on tuberculin-reactive CD4 T-cells in a representative patient with smear and/or culture positive TB is shown in Figure 2. Expression of CD27 was high, intermediate, or absent (black highlighted events in panel B), expression of the chemokine receptor, CCR7, and the adhesion molecule, L-Selectin (CD62L), was generally absent, and expression of the costimulatory receptor, CD28, was generally high (panels C and D). Expression of both the traditional memory markers, CD45RA and RO, was intermediate (not shown). As previously reported [11], the majority of IFN-γ-producing tuberculin-reactive CD4 T-cells also produced TNF-α and IL-2 (not shown). The phenotype of tuberculin-reactive T-helper cells was similar in the control group (BCG vaccines) with one exception: the percentage of CD27-negative tuberculin-reactive CD4 T-cells was clearly higher in the patients. In particular, there was a significant difference between patients with smear and/or culture positive pulmonary TB and unexposed controls (Fig.3). Five individuals classified as having latent TB infection had values in between the patients and the unexposed/highly exposed controls (Fig. 3).


Loss of receptor on tuberculin-reactive T-cells marks active pulmonary tuberculosis.

Streitz M, Tesfa L, Yildirim V, Yahyazadeh A, Ulrichs T, Lenkei R, Quassem A, Liebetrau G, Nomura L, Maecker H, Volk HD, Kern F - PLoS ONE (2007)

Significantly fewer tuberculin-reactive CD4 T-cells express CD27 in TB-patients than in controls.Proportions of CD27-positive and negative cells were based on a minimum of 50 IFN-γ positive events. Vertical numbers indicate evaluated events (median and range). Controls included unexposed controls, professionally TB-exposed health care workers, and donors with latent infection. A threshold of 49% would effectively discriminate between patients and controls (dotted line). Controls with latent TB infection had higher values than individuals with no known exposure to TB.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC1936433&req=5

pone-0000735-g003: Significantly fewer tuberculin-reactive CD4 T-cells express CD27 in TB-patients than in controls.Proportions of CD27-positive and negative cells were based on a minimum of 50 IFN-γ positive events. Vertical numbers indicate evaluated events (median and range). Controls included unexposed controls, professionally TB-exposed health care workers, and donors with latent infection. A threshold of 49% would effectively discriminate between patients and controls (dotted line). Controls with latent TB infection had higher values than individuals with no known exposure to TB.
Mentions: The expression of “classic” markers of T-cell differentiation [12], [14] on tuberculin-reactive CD4 T-cells in a representative patient with smear and/or culture positive TB is shown in Figure 2. Expression of CD27 was high, intermediate, or absent (black highlighted events in panel B), expression of the chemokine receptor, CCR7, and the adhesion molecule, L-Selectin (CD62L), was generally absent, and expression of the costimulatory receptor, CD28, was generally high (panels C and D). Expression of both the traditional memory markers, CD45RA and RO, was intermediate (not shown). As previously reported [11], the majority of IFN-γ-producing tuberculin-reactive CD4 T-cells also produced TNF-α and IL-2 (not shown). The phenotype of tuberculin-reactive T-helper cells was similar in the control group (BCG vaccines) with one exception: the percentage of CD27-negative tuberculin-reactive CD4 T-cells was clearly higher in the patients. In particular, there was a significant difference between patients with smear and/or culture positive pulmonary TB and unexposed controls (Fig.3). Five individuals classified as having latent TB infection had values in between the patients and the unexposed/highly exposed controls (Fig. 3).

Bottom Line: The percentage of tuberculin-specific T-helper-cells lacking the surface receptor CD27, a state associated with advanced differentiation, varied considerably between individuals (from less than 5% to more than 95%).It is simple and will be of great utility in situations where sputum specimens are difficult to obtain or sputum-smear is negative.It will also help avoid unnecessary hospitalization and patient isolation.

View Article: PubMed Central - PubMed

Affiliation: Institut für Medizinische Immunologie der Charité, Charité Universitätsmedizin Berlin, Berlin, Germany.

ABSTRACT

Background: Tuberculin-specific T-cell responses have low diagnostic specificity in BCG vaccinated populations. While subunit-antigen (e.g. ESAT-6, CFP-10) based tests are useful for diagnosing latent tuberculosis infection, there is no reliable immunological test for active pulmonary tuberculosis. Notably, all existing immunological tuberculosis-tests are based on T-cell response size, whereas the diagnostic potential of T-cell response quality has never been explored. This includes surface marker expression and functionality of mycobacterial antigen specific T-cells.

Methodology/principal findings: Flow-cytometry was used to examine over-night antigen-stimulated T-cells from tuberculosis patients and controls. Tuberculin and/or the relatively M. tuberculosis specific ESAT-6 protein were used as stimulants. A set of classic surface markers of T-cell naïve/memory differentiation was selected and IFN-gamma production was used to identify T-cells recognizing these antigens. The percentage of tuberculin-specific T-helper-cells lacking the surface receptor CD27, a state associated with advanced differentiation, varied considerably between individuals (from less than 5% to more than 95%). Healthy BCG vaccinated individuals had significantly fewer CD27-negative tuberculin-reactive CD4 T-cells than patients with smear and/or culture positive pulmonary tuberculosis, discriminating these groups with high sensitivity and specificity, whereas individuals with latent tuberculosis infection exhibited levels in between.

Conclusions/significance: Smear and/or culture positive pulmonary tuberculosis can be diagnosed by a rapid and reliable immunological test based on the distribution of CD27 expression on peripheral blood tuberculin specific T-cells. This test works very well even in a BCG vaccinated population. It is simple and will be of great utility in situations where sputum specimens are difficult to obtain or sputum-smear is negative. It will also help avoid unnecessary hospitalization and patient isolation.

Show MeSH
Related in: MedlinePlus