Irish scientists have made a breakthrough in relation to how the body's immune system responds to tuberculosis(TB), which could open the door to more personalised treatments for patients.

TB is a serious bacterial disease that usually affects the lungs, but can also affect other organs. Symptoms can include fever, coughing and blood in the phlegm.

Cases of the disease have been declining steadily in Ireland since the mid-20th century. There were nearly 7,000 cases a year in the early 1950s, but only around 400 cases are now notified annually.

However, TB remains one of the biggest killers worldwide. In 2014, 9.6 million people were infected and 1.5 million died of the disease. It is contagious and is spread when an infected person coughs or sneezes.

While antibiotics have been extremely successful in treating TB in the past, the increasing prevalence of drug-resistant TB means that new treatments are essential.

The Irish scientists from Trinity College Dublin (TCD) and St James's Hospital have made a breakthrough, which could lead to more effective vaccines and more personalised therapies.

They were curious about why different people responded to TB bacteria in different ways. For example, TB was rife in Dublin's tenements 100 years ago as conditions were so overcrowded. Yet not everyone who became infected got sick and this is unlike most infectious diseases.

The scientists focused on the protein Mal and its role in the body's response to TB. This particular protein was of interest because around one in four Europeans have a different form of Mal and they tend to be more susceptible to getting sick when infected with TB. Until now, the reasons for this have been unclear.

This Irish research has shown, for the first time, that Mal is involved in the signaling of cells in response to Interferon Gamma, which is considered a master chemical in the body's immune response to illness.

The scientists noted that producing Interferon Gamma is like adding a fire lighter to a fire - it produces a strong immune response when an infection is present.

"Having this different form of Mal affects how intensely you respond to Interferon Gamma - if you've one form you have a big response, if you have another form you have a dampened down response. We've discovered a whole new function for this protein Mal," explained the study's lead author, Dr Cliona Ni Cheallaigh.

These findings are significant because they mean that people with TB can benefit from more targeted treatments that are personalised to their specific immune system. This is particularly the case for difficult-to-treat patients.

"In St James's Hospital, we treat drug-resistant TB patients who need novel immune treatments, like Interferon, which can be optimised because of this research," noted the study's senior author, Prof Ed Lavelle.

He also pointed out that these findings have implications for the treatment of other illnesses that involve Interferon Gamma, including cancer. Furthermore, the form of Mal a person has may also affect how they respond to vaccines.

Details of these findings are published in the journal, Immunity.