American scientists in the latest study published in the Proceedings of the National Academy of Sciences (PNAS) show that there is a relationship between Chronic Fatigue Syndrome and the mouse retrovirus. For now, however, this view is controversial – writes the portal Science Now.
A study by scientists from the National Institutes of Health (NIH), the US Food and Drug Administration (FDA) and Harvard University looked for signs of a virus called XMRV in samples from 37 patients diagnosed with Chronic Fatigue Syndrome (CFS). ). Anthony Komaroff, a Harvard Medical School specialist dealing with this disease, gathered them in the mid-90s. Traces of the presence of the virus were found in as many as 32 samples out of 37 (82%) tested, but only in three out of 44 samples from routine health checks (6,8%). As NIH virologist and study co-author Harvey Alter said, it is not known whether the virus causes the disease or the reverse.
As Science writes, XMRV – more vividly known as the xenotropic murine leukemia virus – has already been linked to prostate cancer once. This link is currently being intensively researched.
In a publication last year in Science, a team led by Judy Mikovits of the Whittemore Peterson Institute for Neuro-Immune Disease (WPI) in Reno, Nevada, reported that they found traces of a viral infection in 67 percent of the respondents. patients with CFS compared with 3,4%. patients undergoing routine checkups. On the other hand, four other publications showed no association or any evidence of XMRV infection in humans. The last one, by scientists from the US Centers for Disease Control and Prevention (CDC), tried to find out how government laboratories could have produced completely different results on this issue. Skeptics on the matter also argue that murine DNA may have been mixed up in the Mikovits laboratory. In support of their thesis, they have a work of virologists with the FDA created under the direction of Shyh-Ching Lo. The team looked for traces of the mice’s mitochondrial DNA in the samples and found nothing.
According to Science, when the publication of the CDC was suspended because it clashed with the results of other studies, the team working on the XMRV and CFS dependencies launched an additional check to validate the data. Alter, who was the third additional reviewer of the published work, stated that it was necessary to aid this matter. For example, new samples were taken from 8 patients and found 15 years later that they were still infected with the virus, as would be expected from a retrovirus, Science Alter said.
However, scholars shared their assessment of the results of the new study. Steve Monroe, co-author of the controversial CDC study, calls the analysis of XMRV’s association with Chronic Fatigue Syndrome robust. Reinhard Kurth, former director of the Robert Koch Institute in Germany, who studied CDC samples and found no signs of the virus, agrees but remains skeptical.
Robin Weiss, a virologist at Imperial College London (ICL) says he has seen too many proposed human retroviruses that have not survived through close study, including the viruses that were identified in 1999 as causing lichen and arthritis and turned into harmless rabbit virus.
Science also notes that skeptics also say it is hard to conclude that recent research supports Mikovits’ thesis. XMRV is a mouse xenotropic virus, which means that it can infect animals other than mice. The researchers in a study published in PNAS admit that the viral sequences are different and similar to polytropic viruses, which led them to adopt a term similar to the murine leukemia virus. As ICL retrovirologist Myra McClure, co-author of one of three studies that showed no link between the virus and CFS, notes, the team found a virus other than Mikovits syndrome. By contrast, Celia Witten, director of the FDA’s Office of Cellular, Tissue and Gene Therapies, concludes that the virus is broadly most similar to XMRV, confirming the Mikovits team’s findings. Her team found many genetic differences in this virus, which means that these differences are not the most important.
Currently, a working group, coordinated by the National Heart, Lung, and Blood Institute (NHLBI), is expected to address the most shocking question: why some laboratories found the virus in healthy and sick, while others did not find it at all. Perhaps geographic factors played a role – all the studies where nothing was found were from Europe. The choice of patients was also important – diagnosis and selection criteria were different each time. As part of the research, Blind sample tests with virus and tests of blank samples where nothing was detected. The researchers also believe that changing the reagents and samples will reveal where the difference in results came from. As Science Reinhard Kurth said, the matter will probably be clarified by Christmas. (PAP)