Use of a T-cell interferon-γ release assay for the diagnosis of tuberculous pleurisy

Abstract

The diagnosis of pleural tuberculosis (plTB) by the analysis of pleural effusions (PEs) with standard diagnostic tools is difficult. In routine clinical practice, the present authors evaluated the performance of a commercially available Mycobacterium tuberculosis (MTB)-specific enzyme-linked immunospot assay on peripheral blood mononuclear cells (PBMCs) and pleural effusion mononuclear cells (PEMCs) in patients with suspect plTB.The T-SPOT.TB test (Oxford Immunotec Ltd, Abingdon, UK) was performed on PBMCs and PEMCs in 20 patients with a clinical and radiological suspect of plTB and in 21 control subjects with a diagnosis of PE of nontuberculous origin at four centres participating in the European Tuberculosis Network.In total, 18 (90%) out of 20 patients with plTB tested T-SPOT.TB-positive on PBMCs and 19 (95%) out of 20 on PEMCs. Among controls, T-SPOT.TB was positive in seven out of 21 (33%) patients when performed on PBMCs (these patients were assumed to be latently infected with MTB) and five (23%) out of 21 when performed on PEMCs. Sensitivity and specificity of T-SPOT.TB for the diagnosis of active plTB when performed on PEMCs were 95 and 76%, respectively.Enumerating Mycobacterium tuberculosis-specific T-cells in pleural effusion mononuclear cells by ELISPOT is feasible in routine clinical practice and may be useful for a rapid and accurate diagnosis of pleural tuberculosis.

The risk of tuberculosis in transplant candidates and recipients: a TBNET consensus statement

“…New diagnostic approaches are needed that allow for a more targeted identification of patients at risk to develop TB. This may involve modifications of in vitro immunodiagnostic assays such as the use of novel stimulatory antigens [15,164,165], alternative biomarkers other than IFN-c [166][167][168][169][170][171][172], variations in incubation time [173,174], the readout system [9,12,13,175,176] or the clinical specimen instead of blood [177][178][179]. In addition, both for the detection of LTBI with a risk of reactivation and for suspected active TB, a novel approach based on a whole blood transcriptional signature could provide a biomarker system with high discriminative potential [180].…”

LTBI: latent tuberculosis infection or lasting immune responses toM. tuberculosis? A TBNET consensus statement

“…Moreover, as active tuberculosis involves recruitment of antigen-specific T-cells to the site of the active infection, the comparative analysis of antigenspecific cells from the blood and the site of disease (e.g. bronchoalveolar lavage, pleural effusion and cerebrospinal fluid effusion) may help to distinguish tuberculosis from latent infection with M. tuberculosis [64][65][66][67][68][69]. In immunocompromised hosts, all available data should be used to demonstrate or exclude latent infection with M. tuberculosis.…”

Diagnosis of tuberculosis infection using interferon-γ-based assays

“…Detection of M. tuberculosis specific T cells in samples other than blood with ELISPOT is a promising tool for the diagnosis of smear-negative pulmonary TB 76 and other paucibacillary forms of TB. 78,81 The methodological procedures and appropriate cut-offs should be established.…”

“…These cells were not found in the pleural fluid of 8 patients with nontuberculous pleuritis. 73 In a TBNET study, 78 T-SPOT.TB was performed on mononuclear cells from blood and pleural fluid in 20 patients with pleural TB and in 21 with pleural effusion of other causes. T-SPOT.TB was positive in 90% of cases on blood samples and in 95% of cases pleural fluid.…”