Negative XMRV study - blood/brain/semen of Autistic Individuals

[alex3619]

Hi everyone. Several have commented that this is a question of fact, not opinion, or something to that effect.

I concur with that. XMRV either is or is not real. I think we already have the answer to that - it is real.

XMRV either is or is not in most ME/CFS patients. I will only be convinced that it is not present if they start doing biopsies and stop using nested PCR as the primary tool.

XMRV either is or is not causing ME/CFS, whether directly or indirectly. This will be the tough one, I think if it is causal we will prove it by successfully treating us long before we fully understand the pathology.

These issues are a matter of fact. The science is about finding what the facts are, and failed investigations are much more likely than successful ones when operating at the limits of current technology.

Bye
Alex

 

[free at last]

It may not be about scorecards, as was mentioned, but the WPIs results on blinded known samples in phase 3 ( known is the only sticking point i can think of ) should still tell us a lot about the WPIs consistency, against the consistency of the science paper figures. if they get most right i belive they will be validated. if they do not, it will to a degree argue against the figures in the science study, how can it not ? thats not score cards, its accurate detection rates we are talking about. I for one hope they get most right

 

[Cort]

XMRV Not In Autism Patient's Blood, Semen or Brains

An autism connection was made pretty early in the XMRV saga but XMRV was not found in the blood, semen or after death - in autopsy samples of people with autism.

However XMRV turns out - it sure has spurred alot of excitement in a lot of areas.

PLoS One. 2011 Feb 23;6(2):e16609.
Lack of Infection with XMRV or Other MLV-Related Viruses in Blood, Post-Mortem Brains and Paternal Gametes of Autistic Individuals.

Lintas C, Guidi F, Manzi B, Mancini A, Curatolo P, Persico AM.
Laboratory of Molecular Psychiatry and Neurogenetics, University Campus Bio-Medico, Rome, Italy.
Abstract

BACKGROUND: Autistic spectrum disorder (ASD) is characterized by impaired language, communication and social skills, as well as by repetitive and stereotypic patterns of behavior. Many autistic subjects display a dysregulation of the immune system which is compatible with an unresolved viral infection with prenatal onset, potentially due to vertical viral transmission. Recently, the xenotropic murine leukemia virus-related virus (XMRV) has been implicated in chronic fatigue syndrome (CFS) and in prostate cancer by several, though not all studies.

METHODOLOGY/PRINCIPAL FINDINGS: We assessed whether XMRV or other murine leukemia virus (MLV)-related viruses are involved in autistic disorder. Using nested PCR targeted to gag genomic sequences, we screened DNA samples from: (i) peripheral blood of 102 ASD patients and 97 controls, (ii) post-mortem brain samples of 20 ASD patients and 17 sex- and age-matched controls, (iii) semen samples of 11 fathers of ASD children, 25 infertile individuals and 7 fertile controls. No XMRV gag DNA sequences were detected, whereas peripheral blood samples of 3/97 (3.1%) controls were positive for MLV. CONCLUSIONS|

SIGNIFICANCE: No MLV-related virus was detected in blood, brain, and semen samples of ASD patients or fathers. Hence infection with XMRV or other MLV-related viruses is unlikely to contribute to autism pathogenesis.

 

[alex3619]

Hi Cort, the science presented could well be correct, and still have incorrect implications. Autism is probably a heterogenous condition. If you take a cohort of autistic patients, and test for XMRV, you might well find little or none of it. I don't want to discuss the issue of whether or not the test was able to reliably find XMRV at this time. This is a cohort comment.

The WPI on the other hand start with families with XMRV positives. XMRV is claimed to be already there. They then note high prevalence of both autism and XMRV, and often in the same person. The cohort selection process is totally different.

My take is that either view could be more or less right. An interesting possibility, however, is that both are right. If XMRV is only one of a vast range of causative agents, then both investigations would be likely to get the results we see.

I expect to see similar results with other heterogenous conditions, including MS, and maybe even ME/CFS. A cause is not the same as the cause. There might be multiple causes with ill defined diseases.

Bye
Alex

 

[cigana]

There's that 3.something % showing up in controls again.

 

[Jemal]

There's already a 3 page thread on this study by the way:
http://forums.aboutmecfs.org/showth...udy-blood-brain-etc-of-autitistic-individuals

 

[Cort]

Hi Cort, the science presented could well be correct, and still have incorrect implications. Autism is probably a heterogenous condition. If you take a cohort of autistic patients, and test for XMRV, you might well find little or none of it. I don't want to discuss the issue of whether or not the test was able to reliably find XMRV at this time. This is a cohort comment.

The WPI on the other hand start with families with XMRV positives. XMRV is claimed to be already there. They then note high prevalence of both autism and XMRV, and often in the same person. The cohort selection process is totally different.

My take is that either view could be more or less right. An interesting possibility, however, is that both are right. If XMRV is only one of a vast range of causative agents, then both investigations would be likely to get the results we see.

I expect to see similar results with other heterogenous conditions, including MS, and maybe even ME/CFS. A cause is not the same as the cause. There might be multiple causes with ill defined diseases.

Bye
Alex

Good point Alex Thanks.

 

[Cort]

There's already a 3 page thread on this study by the way:
http://forums.aboutmecfs.org/showth...udy-blood-brain-etc-of-autitistic-individuals

Whoops! They got that up early! It just showed up in Pubmed. Thanks