High prevalence of serum folate receptor autoantibodies in children with autism spectrum disorders.

BACKGROUND: Supplementation of folic acid by pregnant mothers is thought to lower the risk of autism spectrum disorders (ASDs) in the offspring. Folic acid is taken up by cells via receptors with high affinity for folate and reduced folic acid derivatives. However, this is blocked by the presence of folate receptor autoantibodies (FRAA). Cerebral FRAA have been detected with high frequency in children with ASDs, suggesting the existence of a link between folic acid uptake and disease aetiology. METHODS: We investigated the frequency of FRAA in serum samples from 40 children with ASDs and 42 gender- and age-matched children with typical development (TD). Serum FRAA concentrations were measured by enzyme-linked immunosorbent assay. RESULTS: We found a significant difference in the frequency of serum FRAA in the two study cohorts. Serum FRAA were present in 77.5% (31/40) of children with ASDs compared with 54.8% (23/42) of TD children (p = 0.03746, Fischer's exact test). Thus, serum FRAA are more prevalent in children with ASDs than in TD children. CONCLUSIONS: Our data suggest that children with ASDs may have defects in folic acid absorption that play a role in the onset of ASDs.

A Model for Predicting Significant Hyperbilirubinemia in Neonates From China.

OBJECTIVES: To develop and validate a predischarge risk stratification model by using transcutaneous bilirubin (TcB) values and clinical factors to predict significant postdischarge hyperbilirubinemia in healthy term and late preterm Chinese neonates. METHODS: In a prospective cohort study, 8215 healthy term and late preterm neonates in 8 hospitals in China underwent TcB measurement at <168 hours of age. TcB percentiles were calculated and used to develop an hour-specific nomogram, and 9 empirically weighted items were used to derive a prediction model. A risk stratification model was developed by combining the TcB nomogram with clinical risk scores to predict significant hyperbilirubinemia, defined as a postdischarge bilirubin level that exceeded the hour-specific recommended threshold value for phototherapy. Data from another 13,157 neonates were used to validate the model. RESULTS: A TcB nomogram for every 12 hours of the studied interval was constructed from the development set. Gestational age, male gender, history of previous neonate who received phototherapy, bruising, feeding mode, weight loss, and early discharge were predictors of postdischarge significant hyperbilirubinemia. The combination of the TcB nomogram and clinical risk score provided the best prediction of significant hyperbilirubinemia with an area under the curve of 0.95 (95% confidence interval: 0.94-0.95) in the development data set and 0.94 (95% confidence interval: 0.93-0.94) in the validation data set. A risk stratification model with 6 distinct risk levels was developed and validated. CONCLUSIONS: A risk classification model, combining discharge transcutaneous bilirubin values and clinical risk factors, separated term and late preterm Chinese neonates into 6 risk classes for the timely follow-up of postdischarge hyperbilirubinemia detection.