Phoenix Rising - Cort Johnson's Column
...Presenting complex chronic fatigue syndrome (ME/CFS) research in a way we can all understand.
The Pathogen Question - A Short Overview
by Cort Johnson
The Pathogen Question. There may be no issue in chronic fatigue syndrome (ME/CFS) more complex or confusing than the role pathogens play in this disease. The disease often starts with some sort of infection but standard follow up pathogen tests are usually negative. Pathogen and immune research dominated the research agenda in the 1990s but dropped off greatly as research efforts brought sometimes intriguing but hardly jaw-dropping results; certainly there was little that appeared to be substantial enough to explain a disease as severe as this one. The underwhelming results resulted in a shift in federal funding priorities from the immune system to identifying the multi-systemic abnormalities found in the disease.
Immune Research - If pathogens can’t be found directly, they can often be inferred by tests indicating that an on-going immune response in present. Researchers particularly look for high levels of powerful immune messengers called cytokines which travel through the blood activating the different components of the immune system. Chronic fatigue syndrome (ME/CFS) patients do show signs of immune activation and/or immune abnormalities (unusual RNase L activity, NK cell dysfunction etc.) but the significance of these abnormalities has been unclear to the traditional medical community.
Several of the abnormalities involve segments of the immune system which are relatively ‘new’ to science (RNase L) or which previously have not been deemed particularly important (NK cells). What researchers really wanted to see were blatant problems with T-cells or cytokines. Chronic fatigue syndrome (ME/CFS) cytokine studies have had mixed results, however; except for early in the disease, when many CFS patients are in the throes of infection, ME/CFS patients do not show the startling cytokine up regulation seen in many infectious diseases.
Still, chronic fatigue syndrome (ME/CFS) patients' symptoms (fatigue, muscle and joint pain, sore throat, swollen lymph nodes) and the immune studies suggest immune activation is occurring. Dr. Chia believes ME/CFS patients' symptoms are caused by an inflammatory response but that the specific agents of that response – whether they are cytokines, chemokines or others - have not been elucidated. (We will see in an upcoming issue of Phoenix Rising that the Whittemore-Peterson Neuro-immune Institute is attempting to identify a unique immune signature in a subset of ME/CFS patients.).
Hidden From View - If pathogens are at the heart of this disease they will be unusual in either their type, or where they are found, or the kind of activity they engage in. Indeed each current theory focusing on pathogens in this disease assumes that they must be hidden in some way. HHV-6A, for instance, is not only difficult to detect but is found in a part of the body – the central nervous system – that is almost impossible to directly access. Dr. Chia suggests that enteroviruses in chronic fatigue syndrome (ME/CFS) could have an unusual structure and/or are located in a part of the body (gastrointestinal system) that pathologists rarely examine.
The question of whether a hidden chronic infection is present in ME/CFS has gained more currency as pathogen detection techniques have improved. Some researchers are looking for and finding more evidence of pathogen activity in ME/CFS and the Whittemore Peterson Neuro-Immune Institute is using highly sophisticated tests in an attempt to document the immune abnormalities present in at least a subset of ME/CFS patients.
Still, how important a role pathogens play in this disease is very much up in the air. Different research groups tend to find abundant evidence of ‘their pathogen’ but not others – an unsettling situation for patients. Studies and anecdotal reports do indicate that antiviral therapies can work very well – at least for a time – in some patients, but there is little talk at present of a cure.
The researchers studying pathogens in ME/CFS are basically on their own; mostly without federal funding, they’ve had to raise the money on their own (Dr. Chia), rely on state and private funding (Dr. Peterson) or get help from drug companies (Dr. Lerner, Dr. Montoya) and other foundations (Dr. Montoya, Dr. Peterson). Will this small group of researchers unlock the key to this disease? Only time will tell.
For more information on pathogens in ME/CFS and an interview with Dr. Chia visit Phoenix Rising: A Guide to Chronic Fatigue Syndrome