Simpson, L O · The New Zealand medical journal · 1989
Researchers looked at red blood cells from 102 people with ME/CFS using a powerful microscope and compared them to healthy people and those with multiple sclerosis. They found that people with ME/CFS had fewer normal-shaped red blood cells and more cup-shaped red blood cells than the other groups. This suggests ME/CFS may have a physical cause that could potentially be detected through a blood test.
This study provides early evidence that ME/CFS may involve measurable physical changes in blood cells, supporting the concept that ME/CFS is organic rather than primarily psychological. If red blood cell abnormalities were confirmed in larger studies, they could potentially aid in diagnosis and help validate ME/CFS as a biomedically distinct condition.
This study does not establish whether red cell shape abnormalities cause ME/CFS symptoms, are a consequence of the disease, or are simply associated with it. The cross-sectional design cannot determine causation, and the findings require replication in larger, prospectively-designed studies before clinical diagnostic use. A single abnormal finding does not definitively prove an organic cause for the entire disease.
About the PEM badge: “PEM required” means post-exertional malaise was an explicit required diagnostic criterion for participant inclusion in this study — not that PEM was studied, observed, or discussed. Studies using criteria that do not require PEM (e.g. Fukuda, Oxford) are tagged “PEM not required”. How the atlas works →
The first block is for the primary paper and is the citation you should use in research work. The atlas-snapshot line only applies if you are specifically referring to this atlas’s reading of the paper on the date shown.
Primary citation
Simpson, L O (1989). Nondiscocytic erythrocytes in myalgic encephalomyelitis.. The New Zealand medical journal. https://pubmed.ncbi.nlm.nih.gov/2927808/
BibTeX
@article{mecfsatlas-simpson-1989-nondiscocytic-erythrocytes,
author = {Simpson, L O},
title = {Nondiscocytic erythrocytes in myalgic encephalomyelitis.},
journal = {The New Zealand medical journal},
year = {1989},
note = {PubMed: 2927808},
url = {https://www.mecfsatlas.com/evidence/simpson-1989-nondiscocytic-erythrocytes},
}Atlas snapshot reference
ME/CFS Atlas. Generator v1 / Scanner v1.4 / policy v0.1. Accessed 2026-05-27. https://www.mecfsatlas.com/evidence/simpson-1989-nondiscocytic-erythrocytes
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