IACFS/ME Conference – Dr Avindra Nath on ME/CFS and Long-COVID: overlapping or distinct entities

The 2^nd Virtual Scientific Conference for the International Association for Chronic Fatigue Syndrome/ Myalgia Encephalomyelitis was held on the 19^th – 21^st August 2021 (streamed on zoom). The conference promoted unpublished data and included both clinicians and biomedical researchers. 

The talks were grouped into different sections, including the longer 45 minute talks in the Professional Workshops and shorter talks covering topics of infectious diseases, immunology and clinical cases. 

We have chosen a selection of the talks which will hopefully be of interest to you, which are listed below. Here we report on our fifth talk in this series with a talk from Dr Avindra Nath who was the keynote speaker at the IACFS/ME conference, with his presentation titled “ME/CFS and Long-COVID: overlapping or distinct entities”. The further talks we will cover are shown below and these will be available in one report by the end of October 2021. 

Due to the format of the conference and the focus on unpublished data, no direct recordings or pictures are available freely as this may jeopardise publication. The full conference programme can be found on the IACFS/ME website here, where recorded presentations may be purchased. 

5. ME/CFS and Long-COVID: overlapping or distinct entities 

Avindra Nath, MD  
US National Institutes of Health, NINDS; Bethesda, MD, USA 

Dr Avindra Nath was the keynote speaker at the IACFS/ME conference 2021. Dr Nath is a physician and scientist who specialises in neuroimmunology and neurological infections and is currently the Clinical Director for the NIH. The key takeaway messages from his presentation were that there are phenotypically overlaps between long-COVID and ME/CFS and long-COVID has been found to have an immune dysregulation in the innate immune response. 

Dr Nath started with an overview of the key facts and figures relating to the number of COVID infections and death rates. There are many complications which can been seen after a COVID infection, these can be divided into two – parainfection (occurring at the time of and associated with an infection) and post-viral (immune mediated). Parainfectious manifestations include: anosmia, encephalopathy, stroke, and seizures. While post-viral syndromes include multi-inflammatory syndrome, dysautonomia and have many overlapping features with ME/CFS. 

Dr Nath went on to explain more about encephalopathy in COVID patients (any diffuse disease of  the brain that alters brain function or structure). He explained that following a COVID infection 1/3 of the people hospitalised have an altered mental state and tend to spend a third longer in hospital. In this case mortality rate is six times higher, and neurological symptoms are common in the young. 

Dr Nath stressed it is very important to note that long haul COVID is not the only result and post infection complications can follow a COVID infection (i.e. not all complications are long-COVID). 

Dr Nath’s presentation then focused on long-COVID where patients fall into four groups: (1) fatigue/ exercise intolerance, (2) brain fog/ cognitive dysfunction, (3) autonomic dysfunction (including; tachycardia, night sweats, temperature dysregulation, gastroparesis, gut problems, peripheral vasoconstriction) and (4) aches and pains (fibromyalgia type symptoms). Long- COVID is seen in 10-30% of patients, mostly in women and at an average age of 40. Two mechanisms have been proposed for the pathophysiology, evidence currently exists for both:  persistent infection and / or persistent immune activation. 

Dr Nath discussed some of the findings and studies relating to the four different groups listed above, such as evidence for cognitive impairment and altered cerebral glucose metabolism (Hosp et al., 2021).  Dr Nath also briefly talked about immunotherapy, where months after infection COVID patients can be treated (Cao et al., 2020).  

Dr Nath went on to discuss some of the other published studies, such as T cell exhausting only being seen in patients with neurology problems (Heming et al., 2021) which suggests problems with the innate immune system which is hard to turn off once activated, and this is the most important immune abnormality currently found. Dr Nath also discussed further changes in the brain currently found from autopsy studies, which showed microvascular injury, fibrinogen leakage, vascular leakage and leukocyte infilitration (Lee et al., 2020). Dr Nath also stressed not  forgetting about children when it comes to long-COVID where multi-system inflammatory syndrome has also been seen (overlapping with CFS) (LaRovere et al., 2020). 

Dr Nath concluded his talk with a brief summary of the treatment options which can be used to modify the disease including anti-viral and immune modulatory agents which could supress the innate immune system or reverse T-cell exhaustion. These are both targeted immune therapy treatments, but studies are needed, especially with a focus on early intervention. There is a clear need to investigate viral persistence and viral protein-mediated immune response in long-COVID.  Dr Nath also concluded with the two studies he currently has running, one looking at neurological function and the other looking at the recovery following COVID infection.  

Katrina Pears, Research Correspondent, ME Association