Although there are associations linking autism with prenatal rubella, cytomegalovirus, syphilis, and varicella, the etiology of the autistic state remains obscure. Host defense against the etiologic agents postulated to be responsible for the autism-associated syndromes is believed to be primarily of the cell-mediated type. In this preliminary study, cellular immune function was assessed in vitro by phytohemagglutinin (PHA) stimulation of lymphocyte cultures. Twelve autistic children and 13 control subjects were compared. The autistic group exhibited a depressed lymphocyte transformation response to PHA when compared to the control subjects (p less than .01).

Previous studies have implicated a brainstem dysfunction in the syndrome of autism. This study matched six autistic children with six normal children by age and sex to evaluate brainstem evoked response (BSER) to auditory stimuli. An evaluation of pure tone audiometric threshold showed no evidence of impairment; however, the electrophysiologic responses differed for the autistic and control groups. The BSER of the autistic children was remarkable for showing increased latency and markedly increased variability. The findings from this study add additional evidence of a brainstem dysfunction in autistic children, while the electrophysiologic variability supports the hypothesis of perceptual inconstancy.

A case of intrauterine cytomegalovirus infection with onset of autistic symptoms apparently after 6 months of age is reported. Physicians who find autistic symptoms in very young children might include cytomegalovirus in their differential to document the presence or absence of a correlation.