Long Covid Linked to Overactive Immune System

January 17, 2022

Today, the Pain News Network shared an article discussing a research study that has identified biomarkers of sustained inflammatory response in long Covid patients.


“This study provides the strongest evidence to date for a clear biological basis for the clinically apparent syndrome of long COVID,” Professor Anthony Kelleher, Director of the Kirby Institute at UNSW Sydney, said in a press release.

Kelleher and his colleagues analyzed blood samples from 62 patients enrolled in the ADAPT study at St. Vincent’s Hospital, who were diagnosed with COVID-19 between April and July 2020 – before any vaccines were available. The blood samples were collected at three, four and eight months following initial infection, and compared to control groups.”

MEA Comment

Dr Charles Shepherd, Honorary Medical Adviser to the ME Association comments:

As the researchers correctly note, this finding of on-going immune system activation in Long Covid has also been reported in ME/CFS.

Linked to this very interesting overlap between Long Covid and ME/CFS is the involvement of immune system chemicals called cytokines – which cause inflammation and many of the symptoms associated with any acute infection.

During the acute stage of COVID-19 there can be what is termed a cytokine storm – with a massive overproduction of cytokines causing inflammation in the lungs and serious respiratory complications. There is also research evidence in ME/CFS to indicate that an on-going cytokine response involving what are called pro-inflammatory cytokines fails to ‘switch off’ after the initial triggering infection.

Cytokines can then pass through what is called the blood-brain barrier and affect an area of the brain called the hypothalamus (which acts as a thermostat for temperature control along with appetite, sleep and hormone regulation) and control centres in the brain for the autonomic nervous system (which controls heart rate and blood pressure and leads to orthostatic intolerance and PoTS).

However, I think it’s important to note that Long Covid is an umbrella term that covers a wide range of on-going health problems that occur after COVID-19 infection and there are also likely to be a number of causative mechanisms involved – not just on-going low level immune system activation.

Dr Charles Shepherd,
Trustee and
Hon. Medical Adviser
to the ME Association.
Member of the 2018-2021 NICE Guideline Committee.
Member of the 2002 Independent Working Group on ME/CFS.

Dr Charles Shepherd
Shopping Basket