Biomarkers include hand-grip strength, orthostatic intolerance, lab measures
Hand-grip strength, as assessed by 10 repeat grips at maximum force and repeated after 60 minutes, were lower for all those meeting ME/CFS criteria, compared with the healthy controls. Hand-grip strength parameters were also positively correlated with laboratory hemoglobin measures in both PCS groups who did and didn’t meet the Canadian ME/CFS criteria.
A total of three patients with PCS who didn’t meet ME/CFS criteria and seven with PCS who met ME/CFS criteria had sitting blood pressures of greater than 140 mm Hg systolic and/or greater than 90 mm Hg diastolic. Five patients with PCS – four who met ME/CFS criteria and one who didn’t – fulfilled criteria for postural orthostatic tachycardia syndrome. Orthostatic hypotension was diagnosed in a total of seven with PCS, including one who did not meet ME/CFS criteria and the rest who did.
Among significant laboratory findings, mannose-binding lectin deficiency, which is associated with increased infection susceptibility and found in only about 6% of historical controls, was found more frequently in both of the PCS cohorts (17% of those with ME/CFS and 23% of those without) than it has been in the past among those with ME/CFS, compared with historical controls (15%).
There was only slight elevation in C-reactive protein, the most commonly measured marker of inflammation. However, another marker indicating inflammation within the last 3-4 months, interleukin 8 assessed in erythrocytes, was above normal in 37% with PCS and ME/CFS and in 48% with PCS who did not meet the ME/CFS criteria.
Elevated antinuclear antibodies, anti–thyroid peroxidase antibodies, vitamin D deficiencies, and folic acid deficiencies were all seen in small numbers of the PCS patients. Angiotensin-converting enzyme 1 levels were below the normal range in 31% of all patients.
“We must anticipate that this pandemic has the potential to dramatically increase the number of ME/CFS patients,” Dr. Kedor and colleagues write. “At the same time, it offers the unique chance to identify ME/CFS patients in a very early stage of disease and apply interventions such as pacing and coping early with a better therapeutic prognosis. Further, it is an unprecedented opportunity to understand the underlying pathomechanism and characterize targets for specific treatment approaches.”
Dr. Scheibenbogen and Dr. Komaroff reported no relevant financial relationships.
A version of this article first appeared on Medscape.com.