Pilot neonatal screening program for congenital central hypothyroidism : Improving detection L Prieto, D Barslavsky, V mendez, R Enacan, A Keselman, l Gruñeiro pependieck, I Bergada, A Chiesa.

V MENDEZ; L GRUÑEIRO PAPENDIECK,; D BRASLAVSKY; L PRIETO, ; A KESELMAN, ; R ENACAN,; A CHIESA. ; I BERGADA,

Buenos Aires

Congreso; XXVI Congreso de la Sociedad Latinoamericana de Endocrinologia Pediatrica; 2016

Sociedad Latinoamericana de Endocrinologia Pediatrica

Background: A recent pilot study from our Institution waslaunched for the diagnosis of congenital central hypothyroidism(CCH) in full term newborns. Based on T4 [cutoff (CO) of ?2.3SDS] and TSH (CO ≥10 mU/L) determinations in dried blood filterpaper samples (DBS) at maternity discharge, patients were recalledand thoroughly evaluated clinically and biochemically torule out CCH.After 67,719 screened samples, 4 CCH newborns were detected(1:16930). Additionally, 27 neonates with transient hypothyroxinemiadue to severe neonatal illnesses and 14 thyroid hormonetransport defects were observed. Nevertheless, whether milderforms of CCH present with higher levels of T4 in the neonatal periodremains uncertain.We therefore aim to improve sensitivity, setting a higher COlevel of lesser suspicion while keeping the previous one for the urgentrecall. However, this would imply lower specificity increasingthe recall of healthy babies. In the less suspected population, a secondDBS would be required to confirm hypothyroxinemia beforeundergoing further evaluation. This study aimed to provide referencevalues of T4 in filter paper samples adapted to age during thefirst month of life to adequately interpret the results in the next stepof our screening program for CCH. Material and methods.T4 was measured with DELFIA FIA method in 832 DBS fromfull term healthy newborns, 509 in the second week, 177 in thethird week, 101 in fourth week and 45 in the fifth week of life.Results: T4 levels μg/dl are shown below.Conclusion: These levels of T4 in DBS provide the normal referencesin full terms needed to set a proper CO, an essential toolfor the early detection of milder forms of CCH. Further observationswill clarify if this new screening strategy proposed is reliableand cost effective.