Elahi (2026)
- Authors: Shokrollah Elahi
- Institutes: University of Alberta, Edmonton, AB, Canada
- Publisher: Trends in Molecular Medicine
- Link: DOI
Summary
This paper introduces a unifying framework for Long COVID, shifting the focus from persistent infection to a failure of coordinated physiological recovery. It identifies the ‘erythroid-hormonal axis’—the interplay between red blood cell production and endocrine balance—as a primary driver of chronic fatigue and metabolic stress. For patients, this suggests that persistent symptoms may be tied to ‘stress erythropoiesis’ and low cortisol, providing a biological basis for symptoms that often appear invisible on standard blood tests. The research highlights sex-specific hormonal dysregulation, pointing toward the potential use of hormone replacement therapies as a targeted treatment direction. This work strengthens the case for viewing Long COVID and ME/CFS through the lens of systemic endocrine and hematological dysfunction.
What was researched?
The research examines how the disruption of erythropoiesis (the production of red blood cells) and the endocrine system forms a central mechanism for the persistence of Long COVID symptoms.
Why was it researched?
It was researched to explain why many patients experience profound fatigue and cognitive impairment despite the absence of active viral replication, focusing on the failure of the body’s physiological recovery pathways.
How was it researched?
The author synthesized multi-omics data, including blood transcriptomics and metabolomics from Long COVID cohorts, to analyze the role of CD71+ erythroid precursors and hormonal markers like cortisol 💊 and sex steroids.
What has been found?
The study found that inflammation-driven ‘stress erythropoiesis’ leads to an expansion of immunosuppressive CD71+ cells, which can be infected by SARS-CoV-2. Additionally, Long COVID is characterized by significant hormonal imbalances, particularly low cortisol and sex-specific drops in testosterone or estradiol. These disruptions create a state of persistent metabolic stress and ‘anemia of inflammation’ that correlates with symptom severity.
Discussion
The framework highlights that standard hemoglobin tests may miss ‘stress erythropoiesis’ which still impairs oxygen delivery and immune function. A major limitation discussed is the complexity of individual variability in hormonal recovery and the need for more sex-tailored clinical trials.
Conclusion & Future Work
The paper concludes that targeting the erythroid-endocrine pathways offers a promising therapeutic strategy. Future research should prioritize investigating hormone replacement and treatments that stabilize red blood cell maturation to restore physiological homeostasis.