Ken Friedman stated in a video just posted by ME-CFSCommunity.com that "... there are a number of biomarkers that are almost ready to be used to be able to diagnose Chronic Fatigue Syndrome." As best I understand, the main ME/CFS biomarker approaches are aimed at identifying: - Genomic Abnormalities - Immunological Abnormalities - Exercise-Response Abnormalities - Brain Imaging Abnormalities QUESTION 1. Does anyone know what, exactly, is needed for recognition of a biomarker? Kochs Postulates stipulate formal criteria that must be satisfied in order to establish a causal relationship between a microbe and a disease is there an equivalent framework for establishing the validity of proposed biomarkers? The topic of biomarkers was peripherally addressed in a recent article in Nature (Biomarkers: portents of malignancy, Nature 471 ppS19-21, 24th March 2011). It asserts the following: - To be useful on its own, a biomarker needs to have a sensitivity of at least 90% and a specificity of at least 90%; - Multiple biomarkers could be used in combination. Referring to 7 proposed biomarkers for lung cancer, the authors write Together these biomarkers are expected to yield a better risk assessment than one type alone I don't know whether these assertions are generally accepted. QUESTION 2. Does anyone know what sorts of biomarkers our researchers are trying to create? I gather that there are various sorts of biomarkers that are used by the medical community, including those used as: - A stand-alone diagnostic test; - A diagnostic tool, but without being a stand-alone diagnostic test; - A means of establishing how advanced a disease might be in a particular patient (ie for staging); - A predictor of prognosis / disease development in a particular patient; or - A means of monitoring a patients response to a treatment. (Consequently, sometimes it is desirable for a biomarker to yield a binary (yes or no) outcome, as in the case of diagnosis; whereas sometimes a binary outcome would be unsatisfactory (eg in monitoring the course of a degenerative disease, or in monitoring whether a treatment is leading to improvement).) Are the ME-CFS researchers looking for biomarkers all seeking a diagnostic test? A single marker or a set of multiple-markers? A binary or quantitatively graded measure? etc etc QUESTION 3. Do you share Professor Friedman's confidence? I have a sneaky suspicion that the bar will be set unusually high for ME/CFS; that it would take a very clear-cut test in order to be widely accepted.