Autism Studies and Related Medical Conditions, January 2009 - TACA

chromatography linked tandem mass spectrometric (LC/MS/MS) method was
used to determine the levels of SAA metabolites in peripheral blood mononuclear
cells obtained from 11 healthy controls and 31 autistic children. Improved
detection sensitivity and selectivity of the LC/MS/MS method allowed accurate
quantification using small samples. Results show that leukocytes from autistic
children contained significantly lower concentrations of S-adenosylmethionine (-
35%; p = 0.01), and elevated levels of intracellular homocysteine content
(+80%; p=0.003). Additionally, the levels of intracellular total cysteine and
glutathione (GSH) were reduced by 39% (p=0.004) and 25% (p=0.01),
respectively. These autism-associated changes were leukocyte specific in that no
significant alterations in SAA metabolite concentrations were detected in the
plasma samples. Our results provide novel evidence for altered metabolism in
immune cells; furthermore, this data suggest the involvement of inflammation in
autism. Dietary differences between controls and patients, however, remain a
potential confounder.
Sweeten, T. L., D. J. Posey, et al. (2003). "High blood monocyte counts and neopterin
levels in children with autistic disorder." Am J Psychiatry 160(9): 1691-3.
OBJECTIVE: Leukocyte counts and plasma neopterin levels were determined in
autistic children and matched healthy comparison subjects. METHOD: Blood from
31 autistic children and 28 age- and gender-matched healthy comparison
subjects was analyzed for numbers of neutrophils, eosinophils, basophils,
lymphocytes, monocytes, and total leukocytes and for plasma neopterin levels.
RESULTS: The monocyte count and neopterin level were significantly higher in
the autistic children than in the comparison subjects. CONCLUSIONS: These
results suggest that the immune system may be activated in some children with
autism.
Sweeten, T. L., D. J. Posey, et al. (2004). "High nitric oxide production in autistic
disorder: a possible role for interferon-gamma." Biol Psychiatry 55(4): 434-7.
BACKGROUND: Neuroimmune regulation abnormalities have been implicated in
the pathophysiology of autistic disorder. Nitric oxide (NO) is involved in immune
reactivity and is known to affect brain neurodevelopmental processes. Recent
evidence indicates that NO, and cytokines involved in NO production, may be
high in children with autism. The purpose of this study was to verify that plasma
NO is high in children with autism and determine whether this elevation is
related to plasma levels of cytokines involved in NO production. METHODS: The
metabolites of NO, nitrite, and nitrate (NOx), along with the cytokines interferongamma
(IFN-gamma), tumor necrosis factor-alpha, and interleukin-1beta, were
measured in plasma of 29 children with autism (mean age +/- SD = 6.1 +/- 2.8
years) and 27 age- and gender-matched healthy comparison subjects using
commercially available assay kits. RESULTS: Plasma levels of NOx were
significantly higher in the autistic subjects (p =.006); plasma levels of the
cytokines did not differ between groups. NOx and IFN-gamma levels were
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