Do infections lead to lasting changes in immune or metabolic function that lead to symptoms, or is the pathogen still present? This #OMFScienceWednesday, OMF discusses recently funded research into addressing this central question in ME / CFS.
Do infections lead to lasting changes in immune or metabolic function that lead to symptoms, is the pathogen still present, or could it be both? OMF recently funded research into addressing this central question in ME / CFS pathology.
Some viruses replicate using RNA, while other viruses replicate using DNA instead. Several pathogens that have been associated with ME / CFS onset are DNA viruses, including herpesviruses (HHV6, HHV7, EBV), cytomegalovirus, parvovirus B19, and adenovirus. While there is good evidence that these viruses can trigger ME / CFS, studies are inconsistent as to whether the pathogens persist past onset.
The Stanford Genome Technology Center under Dr Ron Davis partnered with Dr Eric Delwart at the Blood Systems Research Institute to examine patients’ blood for microorganisms.
By comparing the DNA sequences of the microorganisms they found to the DNA of all known microorganisms, the researchers could find if patients had elevated levels of any known microbe. Scientists can even identify organisms no one has ever studied before, finding close DNA relatives to microorganisms by scanning for partial matches. However, they found no unusual microorganisms, or evidence that there was a significant difference in microorganism population between patients and healthy controls.
Next, the scientists looked for cell-free DNA. Cell-free DNA is genetic material that once belonged to a patient’s own cells, or DNA that used to belong to bacteria, fungi, or viruses. When pathogens die and break down in the patient’s body, fragments of their DNA are released into the bloodstream to be eliminated. Some pathogens are challenging to detect if the infection is mostly confined to a particular organ or tissue; however, by relying only on fragments and not on whole, healthy pathogens, cell-free DNA analysis can identify an infection growing anywhere in the body.
When the scientists looked for DNA viruses, there was no difference in overall levels of DNA viruses in patients and controls.
Examining cell-free RNA to look for RNA viruses, such as enterovirus — notably studied by John Chia in association with ME / CFS onset — is more challenging, due to the fact that cell-free RNA is less stable. The Stanford Genome Technology Center is currently developing technology that will allow them to look for RNA viruses in the ME / CFS population.
If the analysis of microorganisms reveals a particular pattern of common pathogens, it may be possible to employ as part of a diagnostic algorithm. If a lingering infection is causing or contributing to ME / CFS symptoms in a subset of patients, it may be possible to address with targeted therapies.
Read our previous post about viruses in ME / CFS: here
Would you like to learn more about pathogens in ME / CFS? What’s a topic you’d like to see more about in a future post? Let us know in the comments below!