| Inclusion Criteria | Exclusion criteria |
|---|---|
| Aged 18-60 years | Recent (in the preceding 3 months) use of drugs known to alter immune function (e.g. azathioprine, cyclosporine, methotrexate, steroids), use of anti-viral medications, or vaccination (e.g. ‘flu). |
| ME/CFS cases must have a clinical diagnosis using CCC and/or CDC 1994 criteria. | History of acute or chronic infectious diseases such as hepatitis B and C, tuberculosis, HIV (but not herpes virus or other retrovirus infection). |
| MS cases must have a confirmed diagnosis made by an NHS consultant according to the NICE guideline | Other severe illnesses (e.g. cancer). |
| Informed consent given | Psychiatric diagnosis (e.g. schizophrenia or severe mood disorder, such as current severe depression). |
| Pregnant women and those within 12 months’ post-partum and/or currently lactating. | |
| For MS cases, conditions other than MS that could explain their chronic fatigue. | |
| For “healthy controls”, current or past fatiguing illness and/or other major morbidity. |