The First Newborn Screening Study of T-Cell Receptor Excision Circle and κ-Deleting Recombination Excision Circle for Severe Combined Immunodeficiency in Korea: A Pilot Study

Purpose: Severe combined immunodeficiency (SCID) is the most serious form of primary immunodeficiency. Infants with SCID are susceptible to life-threatening infections. To establish newborn screening for SCID in Korea, we performed a screening test for T-cell receptor excision circle (TREC) and ${\kappa}$-deleting recombination excision circle (KREC) in neonates and investigated the awareness of SCID among their parents. Methods: Collections of dried blood spots from neonates and parent surveys were performed at the Samsung Medical Center and Cheil General Hospital & Women's Healthcare Center in Korea. The amplification crossing point (Cp) value <37.0 was defined as TREC/KRECpositive based on cutoff values from measuring multiplex real-time polymerase chain reaction. A Cp value >39.0 was defined as negative. Results: For TREC/KREC screening, 141 neonates were enrolled; 63 (44.7%) were male. One hundred forty neonates (99.3%) had positive TREC/KREC results at the time of the initial test; 82.3% and 75.9% were positive and 17.0% and 23.4% were weakly positive for TREC and KREC, respectively. In one neonate (0.7%), the initial TREC/KREC test result was negative. However, repeated tests obtained and confirmed a positive result. For an awareness survey, 168 parents were engaged. Only 2% of parents (3/168) knew that the newborn screening test for SCID had been introduced and performed in other countries. Eighty-four percent of parents (141/168) replied that nationwide newborn SCID screening should be performed in Korean newborns. Conclusions: In this study, newborn SCID screening was performed along with assessment of public awareness of the SCID test in Korea. The study results showed that newborn SCID screening can be readily applied for clinical use at a relatively low cost in Korea.

국내 최초 T-Cell Receptor Excision Circle과 κ-Deleting Recombination Excision Circle 신생아 선별검사에 관한 연구

목적: 중증복합면역결핍증(severe combined immunodeficiency [SCID])은 일차면역결핍증 중 가장 심각한 형태의 질병이다. 국내에서 SCID 선별검사를 확립하기 위하여, 신생아에게 T-cell receptor excision circle (TREC)/${\kappa}$-deleting recombination excision circle (KREC) 선별검사를 시행하고, 부모에게 인식도를 조사하였다. 방법: 혈액 검체에서 TREC/KREC을 multiplex 실시간중합효소연쇄반응으로 분석하였다. 부모에게 설문조사를 실시하였다. 결과: 141명의 신생아가 선별검사에 참여하였고, 140명(99.3%)이 첫 검사에서 TREC/KREC 양성이었으며, 한 명(0.7%)은 처음에 음성이었으나, 추후 양성으로 확인되었다. 인식도 조사에는 84% (141/168)는 SCID 선별검사가 국내에서도 시행되어야 한다고 답변했다. 결론: 본 연구에서는 국내에서 처음으로 신생아 SCID 선별검사와 인식도 시행되었으며, SCID 선별검사가 국내 임상에 적용될 수 있을 것으로 보인다.