Laboratory predictions of infantile autism based on 5-hydroxytryptamine efflux from blood platelets and their correlation with the rimland E-2 score

Experiments were conducted to determine the possibility of predicting a diagnosis of autism on the basis of an abnormally high release of¹⁴C-5-hydroxy-tryptamine from 5-HT loaded blood platelets of children. Such increased 5-HT release was previously reported by the authors for blood platelets of children diagnosed as autistic according to the Rimland E-2 score. The platelets of 10 psychotic children (including a number of subjects diagnosed as autistic by the E-2 score) were examined without knowledge of the diagnosis, in order to determine whether the biochemical results correlated with the E-2 score. On the basis of experimental data it was possible to predict that six children were autistic and four were nonautistic psychotics. According to the E-2 score, seven children were autistic and three nonautistic psychotics. The authors conclude that there is a correlation between a diagnosis of infantile autism by the E-2 score and enhanced release of radioactive 5-HT from 5-HT-loaded blood plateletsin vitro.This research was supported in part by National Institutes of Health Grant RR 00 284 and National Institute of Mental Health Grant HD 08429.