He's not heavy metal poisoned, he's my brother.

A new study out today titled: Cultured lymphocytes from autistic children and non-autistic siblings up-regulate heat shock protein RNA in response to thimerosal challenge.

Sounds bad right? These guys took immune cells from kids with autism and their non-ASD siblings, infected the cells with Epstein Barr Virus, kept the cells alive in a laboratory, exposed the cells to thimerosal, and they saw an upregulation in RNA for HEAT SHOCK proteins.
HEAT and SHOCK! Scary stuff.

The first thing I noticed is that Steven Walker is the first author listed. If his name sounds familiar it's because he was in the news recently for "independently" confirming the presence of the Measles Virus in gut tissue from autistic children. Odd that he'd be interested in thimerosal and MMR but anything to help autistic kids I guess.

A little about Heat Shock Proteins (HSPs)
Heat Shock Proteins are so named because they are produced when cells are subjected to stress which includes the shock of heat, also cold, and many other stressful conditions. They are more accurately known as stress proteins and chaperonins since they are responsible for seeing that proteins behave themselves, fold properly, and do what they are supposed to. Here's a good overview of some of the basics of HSPs.
HSPs come in many different flavors and are usually referred to by their molecular weights. (i.e. HSP-60, HSC-70, etc.)

So Walker, et al. found that when these cells were exposed to 10 μM ethyl mercury there was an upregulation of several different HSPs. That's a pretty high concentration of mercury they used and far more than would be found in the bloodstream following vaccination. The materials and methods section lists thimerosal but for some reason the abstract calls it ethyl mercury.

The authors also wanted to find out what happened when they exposed autistic lymphocytes to zinc, or zinc chloride in this case.

Well the good news is that the cells responded exactly as expected. The thimerosal caused an upregulation in HSPs and the ZnCl2 caused an upregulation in metallothioneins. More good news, or bad if the authors were expecting otherwise, the lymphocytes from siblings responded in a similar fashion. Unfortunately it doesn't appear that they included a non-ASD and non-sibling control group but at least we know that lymphocytes from autistic children react to thimerosal just like lymphocytes form their brothers and sisters, at least as measured with these methods.

The differences in gene expression following zinc exposure was more compelling than the thimerosal data but the authors are forced to conclude:

The comparison of microarray results from individual samples yielded some compelling trends between gene expression responses following treatment with either zinc or thimerosal: however the between-individual (autistic and non-autistic siblings) gene expression changes did not appear to yield striking differences.

And in the discussions section the authors appear reluctant to close the door on the possibility that a larger study might reveal something of significance.

Although in this small sample size there were no differential responses between the autistic and non-autistic sibling, a larger number of individual samples (biological replicates)must be examined to determine with certainty the relevance of this observation. What was apparent from these experiments, when data from the siblings were combined and then analyzed based on treatment, was that the functional genomic responses to the two metals were quite distinct

The main conclusion we are able to draw from this study is that lymphocytes, be they from autistic or non-autistic children, respond to zinc chloride differently than thimerosal.

Excuse me while I yawn