Hi, all. Dr. Paul Cheney has given me permission to post his comments about a you-tube video that was made about his poster presentation at the recent XMRV Workshop at the U.S. NIH earlier this month. It's O.K. to repost these comments, so long as they are attributed to Dr. Cheney. Best regards, Rich "A poster presentation by me made at the 1st International XMRV meetings held at the NIH in early September, 2010 was partially summarized by a U-tube video (see http://www.youtube.com/watch?v=gkgEQ...layer_embedded). While the video was in many respects very well done and brings needed attention to CFS and its link to XMRV, there are several errors and misrepresentations made about the poster and what it actually said or implied. "My biggest problem with this U-tube video was the emphasis on "heart failure" as opposed to heart dysfunction or "LV diastolic dysfunction" which predisposes to orthostatic intolerance rather than death by heart failure which is very rare in my select cohort. My poster never said heart failure was associated with CFS. However, we do know that broadly defined diastolic heart failure does not typically occur until age 72 or later so what will happen to my patients when they get into their 70's is up in the air, assuming they are not treated with things like CSF's before then. There is also the semantic question of how heart failure is defined. If it is defined by organ failure and usually death within 5 years, I don't see this and is likely very rare in the age brackets I see with CFS with an average age of 49. If it is defined by organ dysfunction including heart, GI tract, exercise intolerance, heat intolerance and brain problems etc. produced by low cardiac output then you could use the term heart failure due to diastolic dysfunction in much of my practice. Death by such a functional definition is, however, rare compared to the heart failure patients admitted to hospitals with normal ejections fractions and deemed diastolic heart failure. Such a diagnosis is very lethal over the next five years with only a third alive after five years and virtually all are quite disabled and will remain so. "Another problem is the "8 of 16 family members" positive for XMRV. The poster actually says 50% of healthy family controls or exposure controls (N=8) were positive. The U-tube video assumed that there were 8 positives when in fact 8 were tested and 4 were positive. 6 of 8 were healthy family members of CFS cases and 2 of 8 were CFS exposure controls and not family members. However, when we get the serology data back, I think the number of family members infected will be higher than 50% and the N value will climb well beyond 16 so this correction may soon be mute. "I think the U-tube video misses the very important point that the cancer rate is much higher (47%) in the non-CFS, first order family members than in the CFS cases themselves. This will be the big story going forward as to how you answer the question of why this is so. Is CFS a compensatory response to reduce serious disease and early death? I will say that Dr. Jason's assertion (or perhaps it is only the U-tube's assertion) that death occurs 25 years before they should have died is a fallacy as that number is drawn from the average age of all those who actually "died" and not a large group of CFS cases. In addition, perhaps a third of deaths occur by suicide in the young CFS cases and that will skew that number of 25 years before their time. "The U-tube's final assertion that XMRV is a killer is somewhat exaggerated, at least in CFS. It certainly can be a killer but the U-tube video paints the death rate as much higher than it really is in CFS. In their defense, XMRV is a killer but more-so in the non-CFS but infected cohort which I think will be much larger than CFS itself and drives many cancers to be very aggressive with much higher death rates than would otherwise occur (see Singh et al, PNAS, 2009). XMRV may also be driving the epidemic of diastolic heart failure now seen in those over 70 and most die quickly within five years once admitted to hospitals for heart failure (see Owan et al, NEJM, 2006). XMRV may well be a killer, but the paradox is that not as much a killer in CFS unless perhaps they reach age 72 or above but that is near our present human life expectancy. The most interesting question of all is how did they live that long with such a killer virus and with such severe disability comparable to heart failure?" Paul Cheney, M.D.