XMRV Nytt 22 september 2011: Amerikanske helsemyndigheter kan ikke validere eller bekrefte at XMRV/P-MLVs er en trussel for blodforsyning eller link til ME

Amerikanske helsemyndigheter  22 september 2011 kan ikke verken validere eller bekrefte de tidligere funnene som assosierer retroviruset XMRV og dens trofiske varianter. En ny studie antyder at XMRV og relaterte gammaretrovirus ikke er en trussel for blodforsyningen og at det ikke er funnet link mellom ME/CFS og retrovirus.

Dette er å lese i pressemeldingen:

XMRV and related viruses not confirmed in blood of healthy donors or chronic fatigue syndrome patients

HHS-funded research was part of efforts to determine whether these viruses could affect safety of blood supply

A study supported by the U.S. Department of Health and Human Services could not validate or confirm previous research findings that suggested the presence of one of several viruses in blood samples of people living with chronic fatigue syndrome. The new study also could not find the viruses in blood samples of healthy donors who were previously known to not have the viruses.

The HHS-supported study examined the validity of testing techniques intended to detect the presence of several viruses, xenotropic murine leukemia virus-related virus (XMRV) or related polytropic murine leukemia viruses (P-MLVs). Such follow-up studies are standard in science to determine whether earlier findings are accurate. The new findings suggest earlier results may have resulted from laboratory error, either contamination or false positive test results.

The initial reports of a link between XMRV and chronic fatigue syndrome prompted HHS to investigate how well tests detect XMRV/P-MLVs, and the prevalence and potential transmission of these viruses in the blood supply. If the viruses had been proven to be present in patients with chronic fatigue syndrome or healthy donors, concerns were raised that these viruses could put the blood supply at risk. The new results were published online on Thursday, Sept. 22, 2011 in Science Express.

“The results of this study, along with other recent findings, reassure us that these viruses do not pose a threat to the safety of the nation’s blood supply,” said Susan B. Shurin, M.D., acting director of the National Heart, Lung, and Blood Institute (NHLBI) of the National Institutes of Health. “These data add to the mounting evidence that there is no need to screen blood donors for them at the present time.”

In the new study, blood samples were taken from healthy donors and from 14 patients with chronic fatigue syndrome who had previously tested positive for XMRV or P-MLV, and samples from another person who had tested positive for XMRV but who did not have chronic fatigue syndrome. The study also used blood samples from healthy volunteers whose blood tests previously had shown no signs of XMRV/P-MLV.

The samples were blinded with no indication as to their source, and sent to nine laboratories. The study involved laboratories supported by several HHS agencies along with Abbott Laboratories, Abbott Park, Ill., GenProbe Inc., San Diego, and the Whittemore Peterson Institute (WPI), Reno, Nev.

The nine laboratories tested identical sets of the new blood samples for the XMRV/P-MLV nucleic acid, for replication of the virus (whether it reproduced itself in cells), and for antibodies to the viruses. Two labs, which previously had reported the association of XMRV with chronic fatigue syndrome, reported the presence of XMRV for some samples. However, the labs reported similar rates of finding XMRV in samples from patients with chronic fatigue syndrome and from healthy donors who were known to not have XMRV. Additional tests run in the same and other laboratories on the same samples did not find XMRV, strongly suggesting that these persons were negative for XMRV/ P-MLVs. This would be a sign that the few observed positive results represented false positives — that is, the results indicated the condition was present when it actually was not.

To investigate the validity of testing techniques and to determine XMRV’s potential impact on the blood supply, HHS formed the Blood XMRV Scientific Research Working Group in December 2009. The NHLBI leads the working group, which includes other HHS agencies including the Office of the Assistant Secretary for Health, NIH’s National Cancer Institute (NCI) and the NIH Clinical Center, as well as the Centers for Disease Control and Prevention and the Food and Drug Administration. The current study is based on the working group’s efforts to determine the best way to test blood samples for the virus.

Researchers used 11 nucleic acid, five antibody, and three culture assays to determine the assays’ abilities to detect XMRV/P-MLVs. The study also checked for evidence of contamination with mouse DNA, because XMRV or its predecessors may be present in some mouse strains and cell lines.

In 2009, WPI researchers had reported a possible link between XMRV and chronic fatigue syndrome. In June 2010, the AABB, a nonprofit U.S. blood banking association, recommended that collection centers discourage people with chronic fatigue syndrome from donating blood.

However, within the last year, evidence emerged suggesting that contamination in the laboratory was potentially responsible for detection of XMRV in some blood samples from patients with chronic fatigue syndrome. To ensure that this did not compromise results in the new study, extensive efforts were undertaken to avoid laboratory contamination and contamination of samples.

The Blood Systems Research Institute, San Francisco, including Graham Simmons, Ph. D., the paper’s lead author, compiled the blood samples and distributed them to participating laboratories. The following labs and investigators were responsible for testing the sample panels:

  • Abbott (Two labs: Molecular Laboratory and Diagnostic Laboratory) — John Hackett Jr., Ning Tang
  • CDC — William M. Switzer, Walid Heneine
  • FDA — Indira K. Hewlett, Jiangqin Zhao
  • FDA — Shyh-Ching Lo/ Harvey Alter, NIH Clinical Center, Bethesda, Md.
  • Gen-Probe, Inc. — Jeffrey M. Linnen, Kui Gao
  • NCI — Mary F. Kearney/John M. Coffin, Tufts University, Boston
  • NCI — Francis W. Ruscetti
  • WPI — Judy A. Mikovits, Max A. Pfost

W. Ian Lipkin, M.D., of Columbia University’s Mailman School of Public Health, is currently leading a separate study that is testing fresh blood samples from 150 people living with chronic fatigue syndrome and 150 similar but healthy people. Through this effort, organizers will process, blind, and send samples to laboratories at the FDA, the CDC, and the WPI for testing for the presence of XMRV, MLV or related viruses.

If one of the participating laboratories finds that a sample is virus positive, further tests will be conducted to determine the validity of the result. If one participating laboratory finds a positive sample but another laboratory does not, the same samples can be shipped again, with a new blinded code, to be retested. It is hoped that the results from this study will be available by the end of 2011.

For more information or to schedule an interview with an NHLBI expert, contact the NHLBI Office of Communications at 301-496-4236 or nhlbi_news@nhlbi.nih.gov. To interview an NCI expert, contact NCI Office of Media Relations at 301-496-6641 or ncipressofficers@mail.nih.gov.

Part of the National Institutes of Health, the National Heart, Lung, and Blood Institute (NHLBI) plans, conducts, and supports research related to the causes, prevention, diagnosis, and treatment of heart, blood vessel, lung, and blood diseases; and sleep disorders. The Institute also administers national health education campaigns on women and heart disease, healthy weight for children, and other topics. NHLBI press releases and other materials are available online at www.nhlbi.nih.gov.

NCI leads the National Cancer Program and the NIH effort to dramatically reduce the burden of cancer and improve the lives of cancer patients and their families, through research into prevention and cancer biology, the development of new interventions, and the training and mentoring of new researchers. For more information about cancer, please visit the NCI Web site at www.cancer.gov or call NCI’s Cancer Information Service at 1-800-4-CANCER (1-800-422-6237).

About the National Institutes of Health (NIH): NIH, the nation’s medical research agency, includes 27 Institutes and Centers and is a component of the U.S. Department of Health and Human Services. NIH is the primary federal agency conducting and supporting basic, clinical, and translational medical research, and is investigating the causes, treatments, and cures for both common and rare diseases. For more information about NIH and its programs, visit www.nih.gov.

***

XMRV kontaminering funnet av Silverman og Das Gupta. Abstrakt er å lese i Science 22 september 2011

A reexamination by Silverman and Das Gupta of the samples they used shows that some of the CFS peripheral blood mononuclear cell (PBMC) DNA preparations are contaminated with XMRV plasmid DNA.

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3 kommentarer om “XMRV Nytt 22 september 2011: Amerikanske helsemyndigheter kan ikke validere eller bekrefte at XMRV/P-MLVs er en trussel for blodforsyning eller link til ME

  1. En skal kanskje være klar over at dette dreier seg om to ulike publikasjoner, som bedre og godt er forklart av vernon her: http://www.research1st.com/2011/09/22/study-summaries/

    Del 1: Delvis tilbaketrekkelse av Lombardi et al: som dreier seg om deler av den orginale Lomardi et al (2009) tilbaketrekkes på grunn av at det som står beskrevet av Silverman og Das Gaupta dreier seg om at de positive prøvene er en kontaminering av ett såkalt XMRV VP62 plasmid DNA og dermed så ja er de positive prøvene ikke naturlig forekommende XMRV.

    This work by Silverman and Das Gupta indicates the source of XMRV in the CFS patient samples as the original full-length XMRV plasmid rather than naturally occurring XMRV. They reached this conclusion based on the fact that they easily amplified portions of the plasmid DNA that is not naturally occurring DNA. This partial retraction of data from the Science 2009 paper, signed by all of the authors on the original paper, casts further doubt on the validity of the original report and the likelihood that naturally occurring XMRV is associated with CFS. The editors of Science have indicated that they are discussing “next steps” with the authors and that they stand by the Expression of Editorial Concern published in May.

    brevet eller skrivet i Science er ett åttesiders skriv som har titel: “False Positive”

    Del 2: pressemeldingen som kommer fra «bloodworking gruop», som ble nedsatt av de amerikanske helsemyndigheter som etter Lomardi et al fant at det var kontroller som var positive (ca 4%). Dette arbeidet har vært i flere faser og det som nå er konklusjonen etter at omfattende prøver av både positive og kontroller har blitt sendt ved flere labs i blindet testing, er at testingen kom ut negativ. Siste fase blir dermed ikke gjennomført og helsemyndighetene konkluderer med at XMRV og andre relaterte P-MLVs ikke er en trussel mot blodforsyningen og dermed vil heller ikke blodet bli screenet (undersøkt) av blodgivere.

    Hvorvidt dette har konsekvender for ME og føre-var-prinsippet er vel ganske så uklart ennå. Anbefalinger fra statene vil nok være gjeldene for andre lands holdninger – hva og når den beslutningen tas.

  2. Hva sier Mikovits og hvorfor bare delvis tilbaketrekking av rapporten?

    Meanwhile, the authors of the 2009 Science paper have determined that some of the samples they used for DNA testing were contaminated with XMRV plasmid DNA. As a result, they are retracting the data associated with those tests but continue to stand by the validity of the other two assays they performed – one to detect antibodies against the virus and the other to test for viral replication. Mikovits says they had discussions with editors at Science about whether the DNA contamination threatened the validity of the rest of the paper, and all agreed that it did not.

    In fact, the retraction has done nothing to dampen Mikovits’ support for her original
    conclusion: that a gamma-retrovirus like XMRV is present in a disproportionate number of chronic fatigue patients. But she does acknowledge that with the DNA sequence data now in question, the identity of the virus they found in chronic fatigue patient samples is unclear. In fact, Mikovits says this could account for some of the controversy: researchers that based their assays on that sequence data may well turn up empty handed, she says, but that doesn’t rule out the presence of a related retrovirus.

    Meanwhile, virus hunter Ian Lipkin of Columbia University in New York is heading up another multi-laboratory effort to bring some resolution to the matter. That project, which will also involve independent testing by multiple laboratories, is critical for chronic fatigue research, says Mitkovits: «Nobody has collected such well controlled and defined samples before.» She anticipates that her lab will receive samples for testing in the coming weeks.

    kilde: http://blogs.nature.com/news/2011/09/embattled_chronic_fatigue_stud_1.html

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