OBJECTIVES: A relationship between autism and gastrointestinal (GI) immune 
dysregulation has been postulated based on incidence of GI complaints as well as 
macroscopically observed lymphonodular hyperplasia and microscopically 
determined enterocolitis in pediatric patients with autism. To evaluate GI 
immunity, we quantitatively assessed levels of proinflammatory cytokines, 
interleukin (IL)-6, IL-8, and IL-1beta, produced by intestinal biopsies of 
children with pervasive developmental disorders.
METHODS: Fifteen patients, six with pervasive developmental disorders and nine 
age-matched controls, presenting for diagnostic colonoscopy were enrolled. 
Endoscopic biopsies were organ cultured, supernatants were harvested, and IL-6, 
IL-8, and IL-1beta levels were quantified by ELISA. Tissue histology was 
evaluated by blinded pathologists.
RESULTS: Concentrations of IL-6 from intestinal organ culture supernatants of 
patients with pervasive developmental disorders (median 318.5 pg/ml, 
interquartile range 282.0-393.0 pg/ml) when compared with controls (median 436.9 
pg/ml, interquartile range 312.6-602.5 pg/ml) were not significantly different 
(p = 0.0987). Concentrations of IL-8 (median 84,000 pg/ml, interquartile range 
16,000-143,000 pg/ml) when compared with controls (median 177,000 pg/ml, 
interquartile range 114,000-244,000 pg/ml) were not significantly different (p = 
0.0707). Concentrations of IL-1beta (median 0.0 pg/ml, interquartile range 
0.0-94.7 pg/ml) when compared with controls (median 0.0 pg/ml, interquartile 
range 0.0-60.2 pg/ml) were not significantly different (p = 0.8826). Tissue 
histology was nonpathological for all patients.
CONCLUSIONS: We have demonstrated no significant difference in production of 
IL-6, IL-8, and IL-1beta between patients with pervasive developmental disorders 
and age-matched controls. In general, intestinal levels of IL-6 and IL-8 were 
lower in patients with pervasive developmental disorders than in age-matched 
controls. These data fail to support an association between autism and GI 
inflammation.