Oxidative stress

Bell tied the relatively new idea of XMRV to the concept of oxidative stress as another potential cause of ME/CFS. Oxidative stress is the term for bodily damage caused by free radicals (the "evil" molecules implicated in everything from simple infections to cancer and heart attack). Oxidative stress also reduces energy at the cellular level in the mitochondria, or energy factories, whose function is impaired in this illness (see our article Mitochondrial Dysfunction, Post-Exertional Malaise and CFS/ME). Bell described this part of his theory as follows:

  1. Oxidative stress causes aging.
  2. Patients have high oxidative stress.
  3. In patients, oxidative stress from ME/CFS is added to oxidative stress from aging, causing a double-whammy.

The notion of accelerated aging might ring a bell for patients. Bell stated that "Patients will say, 'I feel like I'm 95. My grandmother is 97, and she's more active than I am.’ This raises the question: Can you, at age 40, be a really old person?"

Anyone who's watched the labored gait of a 40-year-old patient, or seen one try to carry heavy packages, would answer yes.

Bell noted that XMRV could lead to infection with or without oxidative stress; if oxidative stress was involved, it would cause an increase in cytokines, disrupt the function of mitochondria, and injure natural-killer cells. Because all these phenomena are characteristic of ME/CFS, oxidative stress is a natural suspect in the causation of the disease.

Like other pathogens, XMRV is also a natural candidate, because the illness so often begins with an acute viral onset. "My bias is that this disease has a discrete cause," Bell said. Having seen so many people who were fine one day and sick the next, "I'm very biased about that; something happened that made patients sick," he said. Is it likely that many people have been infected with XMRV, and that some don't know it? Bell thinks it likely. "People are working on this like mad," Bell said, "but at this point they're working quietly."