Question

I have a new and very thorough GP who has decided to thoroughly re-assess my state of health. So he arranged for a number of blood tests – some of which are not usually used to diagnose ME/CFS but are referred to in the investigation section of the MEA purple book. Everything is normal – apart from me having an ANA positive result with a low antibody titre. What does this mean? Should I be concerned?

Answer

The ANA blood test measures the level of what are called antinuclear antibodies in the blood. This is a type of antibody that is made by the body’s immune system and can occur in what are called autoimmune diseases that often involve some form of inflammation. Examples include lupus/ SLE, rheumatoid arthritis, antiphospholipid syndrome and Sjogren’s syndrome – all of which have symptoms that can overlap with ME/CFS, and may be misdiagnosed as ME/CFS. So, an ANA test can be positive in a range of conditions – which ought to be excluded by your doctor taking a very careful clinical history, a full physical examination and possibly arranging some further blood tests.

However, an ANA test can also be positive in perfectly healthy people and with some types of medication. As you may know, low levels of various autoantibodies, including ANA, are also sometimes found in people with ME/ CFS. This is why the term ‘autoimmune component’ is sometimes used in terminology for ME/CFS. Where the ANA level is low, and there is no reason to link it to a specific cause, all that may be required is to repeat the test at intervals and continue to review the situation.

For example – I am in contact with someone at the moment who developed mild joint pains, had a slightly raised ANA but did not have any other laboratory or clinical evidence of an ANA-related condition. An anti-inflammatory drug was prescribed and the symptoms settled down and the ANA level returned to normal.

I think you need to discuss the result of your test with your doctor, ask why they think the ANA level is raised and how this is going to be managed. If there are any concerns that it may be related to another medical condition you could be referred to a hospital physician or an immunologist for further assessment.

More information

• For more information about the ANA test visit Lab Tests Online.
• The ME Association has produced a detailed booklet all about blood tests including those used to confirm a diagnosis of ME/CFS by excluding other possible causes for symptoms.
• We also have a free summary of the 2021 NICE Clinical Guideline, and recommend that people with ME/CFS familiarise themselves with the recommendations and discuss those that are relevant with their GP, ME/CFS Specialist Service, or Social Care service provider (as appropriate). The Guideline also includes recommended tests that should be performed as part of the diagnostic process.