A new study provides yet more evidence that a significant subset of people who experience persistent fatigue and exercise intolerance following COVID-19 will meet diagnostic criteria for myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS).
Data from the prospective observational study of 42 patients with “post-COVID-19 syndrome (PCS),” including persistent fatigue and exercise intolerance, suggest that a large proportion will meet strict diagnostic criteria for ME/CFS, including the hallmark postexertional malaise (PEM). Still others may experience similar disability but lack duration and/or severity requirements for the diagnosis.
Dr. Carmen Scheibenbogen
Moreover, disease severity and symptom burden were found similar in those with ME/CFS following COVID-19 and in a group of 19 age- and sex-matched individuals with ME/CFS that wasn’t associated with COVID-19.
“The major finding is that ME/CFS is indeed part of the spectrum of the post-COVID syndrome and very similar to the ME/CFS we know after other infectious triggers,” senior author Carmen Scheibenbogen, MD, acting director of the Institute for Medical Immunology at the Charité University Medicine Campus Virchow-Klinikum, Berlin, told this news organization.
Importantly, from a clinical standpoint, both diminished hand-grip strength (HGS) and orthostatic intolerance were common across all patient groups, as were several laboratory values, Claudia Kedor, MD, and colleagues at Charité report in the paper, published online in Nature Communications.
Of the 42 with PCS, including persistent fatigue and exercise intolerance lasting at least 6 months, 19 met the rigorous Canadian Consensus Criteria (CCC) for ME/CFS, established in 2003, which require PEM, along with sleep dysfunction, significant persistent fatigue, pain, and several other symptoms from neurological/cognitive, autonomic, neuroendocrine, and immune categories that persist for at least 6 months.
Of the 23 who did not meet the CCC criteria, 18 still experienced PEM but for less than the required 14 hours set by the authors based on recent data. The original CCC had suggested 24 hours as the PEM duration. Eight subjects met all the Canadian criteria except for the neurological/cognitive symptoms. None of the 42 had evidence of severe depression.
The previously widely used 1994 “Fukuda” criteria for ME/CFS are no longer recommended because they don’t require PEM, which is now considered a key symptom. The more recent 2015 Institute (now Academy) of Medicine criteria don’t define the length of PEM, the authors note in the paper.
Dr. Scheibenbogen said, “Post-COVID has a spectrum of syndromes and conditions. We see that a subset of patients have similar symptoms of ME/CFS but don’t fulfill the CCC, although they may meet less stringent criteria. We think this is of relevance for both diagnostic markers and development of therapy, because there may be different pathomechanisms between the subsets of post-COVID patients.”
She pointed to other studies from her group suggesting that inflammation is present early in post-COVID (not yet published), while in the subset that goes on to ME/CFS, autoantibodies or endothelial dysfunction play a more important role. «At the moment, it’s quite complex, and I don’t think in the end we will have just one pathomechanism. So I think we’ll need to develop various treatment strategies.”
Dr. Anthony L. Komaroff
Asked to comment on the new data, Anthony L. Komaroff, MD, professor of medicine at Harvard Medical School, senior physician at Brigham and Women’s Hospital, both in Boston, and editor in chief of the Harvard Health Letter, told this news organization, “This paper adds to the evidence that an illness with symptoms that meet criteria for ME/CFS can follow COVID-19 in nearly half of those patients who have lingering symptoms. This can occur even in people who initially have only mild symptoms from COVID-19, although it is more likely to happen in the people who are sickest when they first get COVID-19. And those who meet criteria for ME/CFS were seriously impaired in their ability to function, [both] at work and at home.”
But, Dr. Komaroff also cautioned, “the study does not help in determining what fraction of all people who are infected with SARS-CoV-2 go on to develop a condition like ME/CFS, nor how long that condition will last. It is crucial that we get answers to these questions, as the impact on the economy, the health care system, and the disability system could be substantial.”
He pointed to a recent report from the Brookings Institution (2022 Aug 24. “New data shows long Covid is keeping as many as 4 million people out of work” Katie Bach) “finding that “long COVID may be a major contributor to the shortage of job applicants plaguing many businesses.”