Statewide screening helped detect infant T-cell lymphopenia

Testing the DNA from a statewide blood screening program for infants in Wisconsin was able to identify infants with T-cell lymphopenia, a disease in which early detection is important.

Researchers from Wisconsin conducted a study to examine if determining the number of T-cell receptor excision circles using DNA extracted from dried blood spots on newborn blood screening cards could detect T-cell lymphopenia in a statewide screening program. Between January and December 2008 all infants born in Wisconsin were screened for the disease by quantitating the number of T-cell receptor excision circles contained in a portion of the newborn blood screening cards with the cut-off number being T-cell receptor excision circles values of less than 25/mcL.

During the trial 71,000 infants were screened. Seventeen aged at least 37 weeks old had at least one abnormal T-cell receptor excision circles assay. Eleven had samples analyzed to enumerate T-cells. Eight infants had confirmed T-cell lymphopenia.

The researchers suggested that these results provide support for state screening program for severe T-cell lymphopenia, with the incidence of primary and secondary immunodeficiencies identified by the T-cell receptor excision circles assay exceeding the required incidence of disease to institute screening, and the T-cell receptor excision circles assay being relatively inexpensive.

“In conclusion, the Wisconsin screening program demonstrates the feasibility of the T-cell receptor excision circles assay performed on newborn blood screening cards to identify infants with primary and secondary forms of T-cell lymphopenia,” the researchers wrote.

Routes JM. JAMA. 2009;302:2465-2470.