Immune system could be linked to lower heart attack risk

20 June 2016        

Close up of red blood cells

Research that we've part-funded, published today in the scientific journal Ebiomedicine, shows a link between the amount of IgG antibodies in a person’s blood and their likelihood of being protected against an adverse cardiac event, such as a heart attack.

IgG is the most abundant form of antibody and is found within all bodily fluids. It is responsible for protecting the body against bacterial and viral infections.

Measuring IgG – a component of the immune system – is simple and cheap, so the scientists suggest that this finding may in the future make it easier for clinicians to more accurately determine a person’s risk of having a heart attack.

The team at Imperial College London and UCL studied patients who suffered a heart attack or stroke from the Anglo Scandinavian Cardiac Outcomes Trial (ASCOT) with their matched controls. People enrolled on the ASCOT trial had high blood pressure and were at high risk of a cardiovascular event.

The researchers measured levels of total IgG and IgM antibodies, as well as levels of antibodies that are particular to an oxidised form of ‘bad’ cholesterol (oxLDL), which is known to promote atherosclerosis – the build-up of fatty material in the artery walls that can lead to heart attacks.

The researchers found that the people who had higher levels of general antibodies (IgG/IgM) as well as antibodies against oxLDL were less likely to have a heart attack. Surprisingly, total IgG levels showed the strongest association with reduced heart attack risk, independent of other risk factors such as cholesterol levels or blood pressure.