OK, that's interesting.
One tell-tale sign that a given disease may involve autoimmunity is when several of its comorbid illnesses (the other illnesses that are frequently found to co-occur with the disease) are autoimmune.
In the case of ME/CFS, this disease has quite a few comorbid conditions that frequently co-occur with it, and several of these comorbidities are autoimmune, or suspected to be autoimmune, namely the following ME/CFS comorbidities: POTS, orthostatic hypotension, Sjögren's syndrome, Hashimoto's.
I don't know offhand what the common comorbidities of Lyme disease are, but if one or more of these comorbid diseases found in Lyme were autoimmune, it would provide suggestive evidence that Lyme might involve autoimmunity.
Does anyone know of any studies which have identified the common comorbidities of Lyme disease?
Incidentally, finding autoimmune aspects to a disease does not rule out the idea that an ongoing chronic infection may be driving the autoimmunity.
For example, in the case of the autoimmune disease of type I diabetes, this involves an autoimmune attack on and destruction of the beta cells in the pancreas which secrete insulin. Now in type I diabetes, patients have been found to be infected with coxsackievirus B — the same virus that is found in ME/CFS patients.
There is ongoing research to try to determine whether this coxsackievirus B infection may be the cause of the autoimmunity in type I diabetes (though at this stage, the
evidence for coxsackievirus B driving the autoimmunity is not very strong).