When The New York Times reported on a possible link between a virus called XMRV and chronic fatigue syndrome, many readers had questions.

Dr. Nancy G. Klimas, who serves on the board of the International Association for Chronic Fatigue Syndrome, responds to readers' questions about fibromyalgia, H.I.V., cystitis and chronic fatigue syndrome. Dr. Klimas is a director of the department of immunology of the University of Miami School of Medicine and director of research for clinical AIDS/H.I.V. research at the Miami Veterans Affairs Medical Center.

H.I.V. and Chronic Fatigue Syndrome

QUESTION:

One thing I don't notice here is comments by people with both H.I.V. and chronic fatigue syndrome. People with H.I.V. have long lived with the fear of not being able to speak openly of their difficulties. And medications are no picnic and no sure cure. People with H.I.V. have learned that, when you think you're finally understood and supported, don't be fooled - you're not. You're only feared and looked down on.

But living with C.F.S. and being in agony, losing everything else in life that meant anything - and also not being able to get any medical help or be understood about it - that really hurts worse. The two together must be a nightmare almost too unbearable to continue to live with.
Kim

ANSWER:

Interesting points. H.I.V. is a tough illness; I have cared for H.I.V. patients since 1983 and lost more than 1,000 to AIDS before the effective therapies came out in 1994.

Since then, most H.I.V./AIDS patients are in much better health, though they have suffered through the medical learning curve as we learned about common and rare drug toxicities, and the pharmaceutical industry developed easier treatment regimens requiring fewer pills. In 1994, our Veterans Administration H.I.V. in-patient unit averaged 38 full beds; right now, I have one patient in the hospital for H.I.V.-related problems.

H.I.V. and C.F.S. can coexist in an individual, but the combination does not meet the case definition for chronic fatigue syndrome, which requires the exclusion of coexisting illnesses that could explain fatigue. Still, I find myself providing consults on H.I.V. patients with profound fatigue - they are so uncommon that the local H.I.V. doctors refer them to my clinic. I can almost always find a cause for the profound fatigue. Reactivation of the cytomegalovirus, or CMV, infection is a common explanation, even in those who have excellent CD4 counts. Symptoms of fatigue in these patients may also be related to chronic active hepatitis.

If - and this is a big if - XMRV turns out to be a big player in C.F.S., one would expect 3 percent to 4 percent of the H.I.V. population to have the virus as well, and that would put them at risk of viral reactivation of XMRV. But, since many H.I.V. patients are on antiretroviral drugs and if some of those medications were also active against the XMRV virus, it might not actually result in a C.F.S.-like illness.

I raised the issue of case definitions above. Remember that when scientists define an illness, they do so to go after the group that has the illness, trying to exclude as many similar illnesses as possible.

Before we had a blood test to identify patients infected with H.I.V., for example, AIDS was defined as an illness affecting men 18 to 65 years old who had opportunistic infections. When H.I.V. was discovered and a reliable blood test to identify the virus was established, the case definition changed to include women and children, and doctors could define an asymptomatic H.I.V. illness. But it took that narrow initial circle to find a bug that caused the illness.

So while today's C.F.S. case definition clearly will exclude some people with the illness, including those afflicted with other illnesses at the same time, it is meant as a research tool.

A Canadian sponsored international working group has developed another clinical case definition of C.F.S. that was meant for clinical use. The case definition usefully separates symptoms into autonomic, inflammatory and endocrine categories.

There is also a pediatric case definition for chronic fatigue syndrome.

Fibromyalgia and Chronic Fatigue Syndrome

QUESTION:

I have been diagnosed with fibromyalagia and C.F.S. for nearly eight years. My question is: Is it possible that fibromyalgia is just the infant stages of myalgic encephalomyelitis/C.F.S.? It seems the longer you have F.M., the worse it gets and the symptoms are more in tune with C.F.S. as it progresses.
Stacey, Salt Lake City

ANSWER:

It is very likely that under the umbrella of the chronic fatigue syndrome diagnosis there are several subgroups of the illness. The two largest are the postviral syndrome onset of C.F.S., and the slower onset of fibromyalgia that evolves into a C.F.S. illness. Several research groups are studying the biology of these two types of onset. One group in Spain has developed a diagnostic test based on patterns of gene activation that seems to distinguish between these two groups; they presented their work at an international meeting last spring. It is important that researchers look at subgroups, as it is likely the treatment approaches for each may be quite different.

Even within fibromyalgia, there may be subgroups of patients. Dr. Andrew Holman published a study several years ago suggesting that a subgroup of fibromyalgia patients had enough cervical arthritis or bony abnormalities to in effect bruise the spinal cord in certain positions. Dr. Holman suggested that these patients should be treated more like patients who had spinal cord injuries, using medicines that calmed overactive nerve fibers and reduced inflammation. One of the three approved medications for fibromyalgia - pregabalin (Lyrica) - does act in this fashion.

Your own insight into your illness is very helpful. The connections that link fibromyalgia and C.F.S. are not well understood. It will take studies that follow patients over time and that watch for factors that mediate changes for the good or bad to really get at what is going on.

At the University of Miami, we have a study called the "good day, bad day" study, which hunts for the biomarkers that predict a relatively good day or relatively bad day in patients with C.F.S. We see study subjects four times over 18 months and measure everything under the sun (well, mostly immune and endocrine measures). For more information, contact lgarcia2@med.miami.edu.

Fibromyalgia, Myalgic Encephalomyelitis and Chronic Fatigue

QUESTION:

I'd like to know if Dr. Klimas believes that M.E. is both C.F.S. and fibromyalgia combined, and if she believes that any treatments created for M.E./C.F.S. would also alleviate the suffering of fibromyalgia? Or does she believe fibro is a totally different illness, even though most of the time, U.S. patients are diagnosed with both initially, or else partway into the expression of one or the other as a presenting illness.
Nerdse

ANSWER:

Myalgic encephalomyelitis, or M.E., was defined by British investigators as the more extreme end of the chronic fatigue syndrome spectrum. The term is used in a number of countries instead of the term chronic fatigue syndrome and implies brain inflammation and muscle pain.

Muscle pain occurs in both C.F.S./M.E., as well as in fibromyalgia. Whether brain inflammation also occurs is more controversial. There are neuroimaging studies that support the concept of neurologic abnormalities in C.F.S./M.E., particularly studies that look at blood flow. More recently, studies by Dr. Shungu and colleagues looking at brain lactate levels suggest that cortical blood flow issues result in a reduced ability to clear the toxin lactate. This might act directly on the brain, explaining the cognitive function findings, or it may result in local inflammation, also causing symptoms relating to the region of the brain affected.

Fibromyalgia seems to occur as a result of a ramped up pain signaling pathway in the brain. Sixty percent of C.F.S./M.E. patients also have fibromyalgia, so the two conditions seem to be related.

A Link Between Cystitis and Chronic Fatigue?

QUESTION:

I'm wondering if interstitial cystitis could also be associated with XMRV infection. Is any one looking into this?
Stephanie Bergweiler

QUESTION:

I have a history of Crohn's disease, Sjogren's syndrome, interstitial cystitis and then got C.F.S. When I started meeting others with C.F.S., many had Sjogren's and interstitial cystitis. Last night I spoke to a woman with R.A., interstitial cystitis and C.F.S. Have you seen constellations like this, and if so, do you have any explanation?
Andy

ANSWER:

Both interstitial cystitis and fibromyalgia overlap with C.F.S. Right now we have to use the case definitions of each to make a diagnosis, as none have a diagnostic blood test that is well accepted. It is possible to have all three of these conditions at once. Fibromyalgia is more common than the other two, and about 60 percent of C.F.S. patients also have fibromyalgia.