Immune function in autistic children.

Background: There have been reports that some children with autistic spectrum disorders have abnormal immune function. However, data in this area remain scarce and conflicting.

Objective: To evaluate the immune function of a series of autistic children in the context of this proposed association.

Methods: We prospectively collected data on 24 autistic children who, between January 1, 1996, and September 30, 1998, were referred unsolicited to an immunology clinic. We examined the clinical history and evaluated immunoglobulin levels; specific antibody titers to diphtheria, tetanus, and Haemophilus influenzae; T- + B-cell numbers; T-cell proliferation; and complement studies.

Results: Seven of the 24 children had a history of recurrent infections. Only 2 patients had immunoglobulin levels that were outside the age-adjusted reference ranges, 1 of whom was subsequently diagnosed as having common variable immune deficiency. All the patients had normal in vitro T-cell function and complement study results, and only 2 of 24 patients had subtle derangements in T-cell numbers. Elevated levels of IgE were found in 5 patients, which correlated with a clinical history of atopy. Low diphtheria or tetanus antibody levels were found in 12 patients, but in 11 of these, vaccination status was not up-to-date.

Conclusions: Most of the autistic children studied had normal immune function, suggesting that routine immunologic investigation is unlikely to be of benefit in most autistic children and should be considered only when there is a history suggestive of recurrent infections.