1) 🇳🇴 A Norwegian study replicated the finding that ME/CFS patients have more extracellular vesicles (EV) than healthy controls. This may point to increased cellular communication.
2) Extracellular vesicles are tiny lipid particles that are released by cells and soft of act like mail carriers, transporting proteins, fats, and genetic material (RNA) from one cell to another. Their contents might give a clue to what's happening inside the body. 3) Previous studies by the teams of Oltra, Castro-Marrero, and Hanson have already looked at these vesicles in ME/CFS, but their studies were small and underpowered. The most consistent finding was an increase in these vesicles in ME/CFS. 4) This Norwegian study confirmed this in a sample of 49 ME/CFS patients (Canadian criteria) and 50 controls. Patients were tested before the SARS-CoV-2 pandemic. Although the study found more vesciles, it did not find a difference in size (as some previous studies suggested). 5) The authors also looked at the proteins inside the vesicles to try to decipher what the cellular communication might mean. Among the 424 detected proteins, 11 had different levels in ME/CFS patients.
6) Three 3 proteins that were increased (ITIH3, AMBP, and FGB) were liver-specific and expressed by hepatocytes. ITIH3 is involved in the stabilization of the extracellular matrix, while FGB is part of the coagulation cascade.
7) The EV proteins that were decreased in patients were mainly expressed by either red blood cells (specific to the bone marrow) or by plasma B cells (immune system-derived). 8 ) These included four proteins derived from the variable domains of immunoglobulin light chains (IGKV1-12, IGKV1-8, IGLV3-15 and IGHV3-7), three proteins related to hemoglobin (HBA1, HBB and HBD) and coagulation factor XIII A chain (F13A1). 9) A big caveat is that these 11 proteins did not survive correction for multiple comparisons (the differences might have been due to chance), and they also did not correlate with illness severity. The study was the biggest on EVs in ME/CFS, but still underpowered. 10) Link to the paper: Rydland 2026. Eploring differences in protein cargo of extracellular vesicles from ME/ CFS patient plasma compared to healthy controls.
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