Science Library Category:

Mitochondrial Encephalopathy

B-lymphocytes from a population of children with autism spectrum disorder and their unaffected siblings exhibit hypersensitivity to thimerosal.
Published: 2013

Research has determined there is a subgroup of the population that has hypersensitivity to the toxicity of thimerosal yet thimerosal containing vaccines are administered to all without consideration to this important fact. We can ban peanuts from schools because a subpopulation is allergic to them, so why is thimerosal still contained in our vaccines?


Sharpe MA, Gist TL, Baskin DS. J Toxicol. 2013;2013:801517. doi: 10.1155/2013/801517. Epub 2013 Jun 9.


Two medications (valproate and thalidomide) have been definitively shown to be causative with regards to autism spectrum disorder (ASD). Both of these medications share a common trait of inhibiting cell proliferation. Thus, these researchers set out to determine if thimerosal can inhibit cell proliferation using doses of thimerosal which reflect the concentrations that infants are exposed to via vaccinations. The design of this experiment was chosen to be able to distinguish between shared or different in utero environments among families with an ASD member. To accomplish this goal, B-cells were collected from, ASD individuals, their unaffected fraternal twins representing a shared in utero environment, and their unaffected nontwin siblings. In the same manner, B-cells were collected from control families with no history of ASD which were matched for age/sex/ethnicity and compared to ASD families. It was determined that there is a hypersensitivity to thimerosal among a subpopulation of ASD families. The target of thimerosal toxicity is the mitochondria and cell proliferation was inhibited at a dose that was lower than that required to cause cell death.  Among the hypersensitive population, the dose of thimerosal that could inhibit cell proliferation was found to be only 40% of that needed to inhibit proliferation in the control group. Whether a twin or sibling was hypersensitive was dependent on having another family member with hypersensitivity. This finding implies there is a genetic component to thimerosal hypersensitivity. Among the ASD families with hypersensitivity oxidative stress was determined to be the contributing factor. Poor antioxidant status, high lactate levels, and elevated markers of oxidative stress are a common finding among individuals with ASD. In 2008 the case of Hannah Poling was awarded compensation under the United States National Vaccine Injury Compensation Program. It was claimed that her vaccines induced a mitochondrial encephalopathy that resulted in autism. Since the mitochondria is the most significant target of thimerosal toxicity, it is particularly poignant to know that a lowering of antioxidant status by any other additional conditions such as infections or co-exposure to other toxins would further sensitize mitochondria to the damaging effects of thimerosal. These researchers state that their work, “…supports a multi-insult model of ASD causation where many individuals have the genetic background that makes them vulnerable to a particular type of insult at a particular time in their brain development…”. Just like valproate and thalidomide which are the only 2 accepted causative agents for ASD, this research has demonstrated that thimerosal is also capable of inhibiting cell proliferation.