Newborn Screening for Severe Combined Immunodeficiency: Experience at a New York City Academic Medical Center
Saturday, March 3, 2018
South Hall A2 (Convention Center)
Rebecca Koransky, Abigail Leathe, Sairaman Nagarajan, Yesim Demirdag
RATIONALE: The New York state newborn screening program has included Severe Combined Immunodeficiency (SCID) in their panel since 2010. T cell receptor excision circles (TREC) < 200 copies/μl are considered abnormal. We hypothesize that patients referred to our medical center for TREC levels <200 will have other diagnoses besides SCID and that TREC levels will correlate with CD3 counts.

METHODS: An electronic chart review was conducted for 45 patients referred to New York – Presbyterian/Morgan Stanley Children’s Hospital with TREC levels < 200 between 7/2013 and 3/2017. Laboratory and clinical data were recorded for each patient. Columbia University IRB approved the study.

RESULTS: We identified 6 patients with a primary immunodeficiency, DiGeorge Syndrome was the most common etiology. Secondary immunodeficiency was diagnosed in 14 patients, the most common etiology was thymectomy with cardiac surgery. We also identified 18 premature patients, 1 patient with a genetic syndrome, and 6 idiopathic cases. There was a nearly significant correlation between TREC levels and CD3 counts (p = .055). Interestingly, there was no correlation between TREC levels and percentage of CD45RA T cells (p = .35).

CONCLUSIONS: Low TREC levels can be seen in a variety of disorders, confirming the need for physician evaluation in referred patients. We identified one patient with Gorlin Syndrome, which to our knowledge has not previously been associated with T cell lymphopenia. We found that TREC levels did not correlate with CD45RA T cell counts as we were expecting, but this may be due to small sample size and timing of laboratory testing.