4. Uncoupling of ATP-mediated calcium signaling and dysregulated interleukin-6 secretion in dendritic cells by nanomolar thimerosal. (2006)

Goes number 4; Taylor number 4

Goth SR, Chu RA, Gregg JP, Cherednichenko G, Pessah IN. Uncoupling of ATP-mediated calcium signaling and dysregulated interleukin-6 secretion in dendritic cells by nanomolar thimerosal. Environ Health Perspect. 2006 Jul;114(7):1083-91.

http://www.ncbi.nlm.nih.gov/pubmed/16835063

Molarity is an expression of the amount of a substance in the total volume of solution.  A nanomolar amount is 10⁻⁶ mol/m^3,  or 0.000000001.  

This study used a mouse (murine) cell line of nervous tissue (myeloid) and exposed the cells to a very minute amount of thimerosal, which 

A press release on the study pointed out

"Our findings do not directly implicate thimerosal as a single causative agent for triggering neurodevelopmental disorders such as autism," Pessah said. "There is growing evidence that autism is several disorders that we now refer to as just one. There is also growing evidence that some children with autism have unique immune cell composition and responses to antigens. The results of our work provide a framework to test the hypothesis that the genetic background of some individuals may render them especially susceptible to thimerosal."

Other experts also advise drawing no final conclusions regarding thimerosal and autism based on these outcomes.

"These findings should be interpreted cautiously. Although they suggest that thimerosal may affect dendritic cell function, the pathophysiological consequences of thimerosal remain unclear," said David A. Schwartz, a physician and director of the National Institute of Environmental Health Sciences.

Since cell functions can differ across organisms, Pessah will next study dendritic cells isolated from the blood of children with and without autism to confirm if the intercellular changes are the same in humans.

The study has not yet been replicated either in mice or in human cells. Does this study "demonstrate that vaccines can cause autism"? The study is certainly provocative, but there are four countervailing points:

1. the incidence of autism has continued to go up since 2002, when almost all pediatric vaccines becamse thimerosal-free 
2. The very large-scale studies comparing children who had received thimerosal-containing vaccines to children who had recieved thimerosal-free vaccines (Hvid in Denmark, Madsen in Denmark) and other large-scale studies (Verstraeten in US, Price in the US
3. The FDA ruling on the safety of thimerosal (September 2006)
4. The finding of the Vaccine Court that rejected thimerosal as causal in autism. (March 2010).

Does this study "demonstrate that vaccines can cause autism"?  No.  It demonstrates that very minute doses of thimerosal change mouse dendritic cells in a specific way that has not been connected to autism.