Researchers Find a Link between Ethnicity and Tuberculosis
In the medical field, researchers have repeatedly studied the role of ethnicity on diseases. According to previous studies, certain ethnic backgrounds could increase one's risk of diseases. In a new study, researchers from the Queen Mary, University of London in the United Kingdom worked with the Medical Research Council's National Institute for Medical Research (NIMR). The research team found that people from European and Asian descents had different genetic markers for tuberculosis when compared to people from African descent who were all from the UK.
The researchers recruited 128 people who were recently diagnosed with mycobacterium tuberculosis or TB bacterium. The participants were composed of 45 Africans, 27 Europeans, 55 Asians, and one from mixed European and Asian ancestry. The researchers analyzed the levels of multiple inflammatory markers measured via blood samples. They found differences in how the body's immune system responded to the TB bacterium infection. The researchers noted that the differences between European and Asian participants, and African ones were due to genetic markers and not the strain of TB bacteria.
"The TB bacterium has co-evolved with humans following migration to Europe and Asia some 70,000 years ago, and different strains of the TB bacterium disproportionately infect particular ethnic groups," Dr. Adrian Martineau, lead researcher of the study from Queen Mary, said according to a press release. "Our study has shown, for the first time, that it is actually ethnic differences in the patient's genetic make-up that cause most of this variation in immune responses - with little effect of the TB strain they are infected with."
The researchers then took blood samples from 85 participants who were a part of the original cohort. The samples were taken after eight weeks of treatment. The first part of the experiment had tested for inflammatory markers before any treatment was administered. In this part of the study, researchers found that after treatment, the ethnic variance was even more marked than before.
"These findings have important implications, both for the development of new diagnostic tests, which increasingly rely on analyzing the immune response, and also for work to identify candidate biomarkers to measure response to anti-TB treatment. In the future, diagnostic tests and biomarkers will need to be validated in different ethnic populations." Dr. Anna Coussens, who measured immune responses in patient samples at NIMR, said.
The researchers reasoned that the ethnic variance they discovered could be tied to a protein that binds to vitamin D. Although they did not find any definitive reasons for the differences between people, the researchers believe that their findings could help with the development of targeted drug treatments for tuberculosis.
The study was published in PLOS Pathogens. It was funded by the British Lung Foundation and the Medical Research Council (MRC).