‘Killer cells’ aid TB treatment

NATURAL killer cells may play a role in controlling TB (tuberculosis) infections, according to research published in Nature this week.

Natural killer (NK) cells are part of the human immune system. They are white blood cells that can kill certain bacteria, viruses and other disease-causing organisms, often by destroying human cells that have been infected or damaged.

Scientists compared NK cell levels in patients with no TB infection, those with latent TB infection (healthy patients with infection but no symptoms), and those with active TB infection (ill patients with symptoms).

Professor Gerhard Walzl and Dr Stephanus Malherbe, of the DST-NRF Centre of Excellence for Biomedical Tuberculosis Research at Stellenbosch University’s faculty of medicine and health sciences, were part of an international team who explored the role of so-called “natural killer cells” in the development of active TB infection.

They found higher levels of NK cells in patients with latent TB, while those with active TB had lower levels of the cells. Levels of NK cells increased when patients started treatment and recovered from the disease.

The finding suggests that NK cells may play a protective role in the context of TB infection.

It is estimated that a quarter of the world’s population has latent TB, although fewer than 10% of latent TB cases end up progressing to an active state.