Interferon-gamma release assay as a diagnostic test for tuberculosis-associated uveitis

A novel five year Test and Vaccinate or Remove (TVR) wildlife research intervention project in badgers (Meles meles) commenced in 2014 in a 100km2 area of Northern Ireland. It aimed to increase the evidence base around badgers and bovine TB and help create well-informed and evidence-based strategies to address the issue of cattle-to-cattle spread and spread between cattle and badgers. It involved real-time trap-side testing of captured badgers and vaccinating those that tested negative for bTB (BadgerBCG–BCG Danish 1331) and removal of those that tested bTB positive using the Dual-Path Platform VetTB test (DPP) for cervids (Chembio Diagnostic Systems, Medford, NY USA). Four diagnostic tests were utilised within the study interferon gamma release assay (IGRA), culture (clinical samples and post mortem), DPP using both whole blood and DPP using serum. BCG Sofia (SL222) was used in the final two years because of supply issues with BadgerBCG. Objectives for this study were to evaluate the performance of the DPP in field conditions and whether any trend was apparent in infection prevalence over the study period. A Bayesian latent class model of diagnostic test evaluation in the absence of a gold standard was applied to the data. Temporal variation in the sensitivity of DPP and interferon gamma release assay (IGRA) due to the impact of control measures was investigated using logistic regression and individual variability was assessed. Bayesian latent class analysis estimated DPP with serum to have a sensitivity of 0.58 (95% CrI: 0.40–0.76) and specificity of 0.97 (95% CrI: 0.95–0.98). The DPP with whole blood showed a higher sensitivity (0.69 (95% CrI: 0.48–0.88)) but similar specificity (0.98 (95% Crl: 0.96–0.99)). The change from BCG Danish to BCG Sofia significantly impacted on DPP serum test characteristics. In addition, there was weak evidence of increasing sensitivity of IGRA over time and differences in DPP test sensitivity between adults and cubs. An exponential decline model was an appropriate representation of the infection prevalence over the 5 years, with a starting prevalence of 14% (95% CrI: 0.10–0.20), and an annual reduction of 39.1% (95% CrI: 26.5–50.9). The resulting estimate of infection prevalence in year 5 of the study was 1.9% (95% CrI: 0.8–3.8). These results provide field evidence of a statistically significant reduction in badger TB prevalence supporting a TVR approach to badger intervention. They give confidence in the reliability and reproducibility in the DPP Whole Blood as a real time trap-side diagnostic test for badgers, and describe the effect of vaccination and reduced infection prevalence on test characteristics.

Download Full-text

Cost-effectiveness of M. tuberculosis specific Interferon-gamma release assay testing for the treatment of latent tuberculosis infection in Switzerland

Pneumologie ◽

10.1055/s-2007-973117 ◽

2007 ◽

Vol 61 (S 1) ◽

Author(s):

R Diel ◽

P Wrighton-Smith ◽

J Zellweger

Keyword(s):

Cost Effectiveness ◽

Interferon Gamma ◽

Latent Tuberculosis Infection ◽

Latent Tuberculosis ◽

Tuberculosis Infection ◽

Interferon Gamma Release Assay ◽

Release Assay

Download Full-text

The value of single or combined use of pleural fluid interferon gamma release assay in the diagnosis of tuberculous pleurisy

Tropical Medicine & International Health ◽

10.1111/tmi.13659 ◽

2021 ◽

Author(s):

Xiang Tong ◽

Zhenzhen Li ◽

Junjie Zhao ◽

Sitong Liu ◽

Hong Fan

Keyword(s):

Pleural Fluid ◽

Interferon Gamma ◽

Interferon Gamma Release Assay ◽

Combined Use ◽

Release Assay ◽

Tuberculous Pleurisy

Download Full-text

Role of interferon gamma release assay in the diagnosis and management of Mycobacterium tuberculosis-associated uveitis: a review

BMJ Open Ophthalmology ◽

10.1136/bmjophth-2020-000663 ◽

2021 ◽

Vol 6 (1) ◽

pp. e000663

Author(s):

Samra Rahman ◽

Muhammad Irfan ◽

M A Rehman Siddiqui

Keyword(s):

Interferon Gamma ◽

Interferon Gamma Release Assay ◽

Limited Evidence ◽

Ocular Tuberculosis ◽

Diagnosis And Management ◽

Pubmed Database ◽

Interferon Gamma Release Assays ◽

Infectious Uveitis ◽

Release Assay

Tuberculosis (TB)-associated uveitis is a common cause of infectious uveitis in the developing world. Diagnosis of TB uveitis remains a challenge. The role of interferon gamma release assays (IGRAs) is uncertain. Herein we summarise the available literature on the utility of IGRAs in the diagnosis and management of TB uveitis. We searched PubMed database from 1 August 2010 to 31 July 2020 using the following keywords alone and in combination: ‘interferon-gamma release assay’, ‘QuantiFERON’, ‘T-SPOT.TB’, ‘TB uveitis’, ‘serpiginous like choroiditis’, ‘tuberculoma’, ‘TB vasculitis’, ‘TB panuveitis’ and ‘ocular tuberculosis’. Data from 58 relevant studies were collated. The review is focused on currently marketed versions of IGRA tests: QuantiFERON-TB Gold In-Tube assay, QuantiFERON-TB Gold Plus assay (QFT-Plus) and T-SPOT.TB. We found limited evidence regarding the diagnostic utility of IGRA in patients with uveitis. No study was identified evaluating the newer QFT test—the QFT-Plus—in patients with uveitis. Similarly, there is lack of data directly comparing QFT-Plus with T-SPOT.TB specifically for the diagnosis of TB uveitis.

Download Full-text