Genetic variation that protected against Black Death still helps against respiratory diseases today, but increases autoimmune disease risks

March 10, 2023
New research.

The same genetics that helped some of our ancestors fight the plague is still likely to be at work in our bodies today, potentially providing some of the population with extra protection against respiratory diseases such as COVID-19, according to research led by scientists at University of Bristol. However, there is a trade-off, where this same variation is also linked to increased autoimmune diseases such as rheumatoid arthritis and inflammatory bowel disease.

In new research published in The American Journal of Human Genetics, Dr Fergus Hamilton and co-authors from the University’s MRC Integrative Epidemiology Unit (MRC IEU), in collaboration with colleagues at the universities of Edinburgh, Oxford, Cardiff and Imperial College London, reveal that the same variants are present in humans today and providing similar protection against not only bubonic plagues but also other infections including pneumonia and COVID-19. However, this is a situation of balance, and the same genetic makeup is likely to be linked with increases in various autoimmune diseases.

Dr Hamilton and colleagues looked at infection, autoimmune disease, and parental longevity across participants in three large contemporary genetic studies (UK Biobank, FinnGen, and GenOMICC). They used an analytical technique known as Mendelian Randomization to find associations between variation in the ERAP2 gene and risk of autoimmune disease and infection. 

Their findings point to antagonistic effects across these two groups of diseases driven by pressures likely to be more or less present in different human eras. 

University of Bristol release

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