Improving the diagnosis of tuberculosis

Mycobacterium tuberculosis replicates within phagosomes of macrophages and commonly causes latent infections of the lung, 5% of which will lead to active disease. In addition, HIV patients present with a 200-fold higher risk of developing TB as an opportunistic infection.

In terms of therapy, the appearance of multiple-drug resistant (MDR) and extra-drug resistant (XDR) strains of M. tuberculosis hamper effective treatment. M. bovis BCG is the only vaccine available but is often associated with inefficiency. With respect to farm animals, despite the efficient TB programmes currently in place, incidence of infection seems to increase.

There is an urgent need for novel tests that offer rapid and prompt diagnosis of active human and bovine TB. The EU-funded DEMO-NOPERSIST (Demonstration of NOPERSIST results leading to novel, validated diagnostic tests for active human and bovine tuberculosis) project put the results of the previous EU project NOPERSIST into practice.

One of the developed assays relied on the detection of Interleukin-2 in the blood of patients while another immunological kit was developed for detecting active TB accurately.

The bovine test provided fast and reliable detection of antibodies against mycobacterial antigens in serum or plasma samples from cattle or other animals. It could be used on site at the farm with extremely high specificity and approximately 60% sensitivity. To improve the overall test sensitivity, partners proposed its application in combination with the tuberculin skin test for the diagnosis of bovine TB.

Considering that there are millions of patients with latent TB that appear otherwise healthy, the DEMO-NOPERSIST kits will facilitate their prompt diagnosis and subsequent treatment. This is expected to alleviate the socioeconomic burden imposed by TB.