Weight-adjusted neonatal 17OH-progesterone cutoff levels improve the efficiency of newborn screening for congenital adrenal hyperplasia

Author(s)

Hayashi, Giselle ^{[1, 2]} ; Faure, Claudia ^[1] ; Brondi, Maria Fernanda ^[1] ; Vallejos, Carla ^[1] ; Soares, Daiana ^[1] ; Oliveira, Erica ^[1] ; Brito, Vinicius N. ^[2] ; Mendonca, Berenice B. ^[2] ; Bachega, Tania A. S. S. ^[2]

Affiliation

^[1] Assoc Pais & Amigos Excepc Sao Paulo APAE, Sao Paulo - Brazil

^[2] FMUSP, Lab Hormonios & Genet Mol LIM 42, Unidade Endocrinol Desenvolvimento, Disciplina Endocrinol, Sao Paulo - Brazil

• Document type: Journal article
• Source: Arquivos Brasileiros de Endocrinologia e Metabologia; v. 55, n. 8, p. 632-637, NOV 2011.
• Web of Science Citations: 11

Abstract

OBJECTIVE: To evaluate weight-adjusted strategy for levels of neonatal-17OHP in order to improve newborn screening (NBS) efficiency. SUBJECTS AND METHODS: Blood samples collected between 2-7 days of age from 67,640 newborns were evaluated. When N17OHP levels were > 20 ng/mL, and a second sample was requested. We retrospectively analyzed neonatal-17OHP levels measured by Auto DELFIA- B024-112 assay, grouped according to birth-weight: G1: < 1,500 g, G2: 1,501-2,000 g, G3: 2,000-2,500 g and G4: > 2,500 g. 17OHP cutoff values were determined for each group using the 97.5th, 99th, 99.5th and 99.8th percentiles. RESULTS: 0.5% of newborns presented false-positive results using the cutoff level > 20 ng/mL for all groups. Neonates of low birthweight made up 69% of this group. Seven full-term newborns presented congenital adrenal hyperplasia (CAH) and, except for one of them, 17OHP levels were > 120 ng/mL. Only the 99.8th percentile presented higher predictive positive value (2%), and lower rate of false-positives in all groups. CONCLUSIONS: We suggest the use of 99.8th percentile obtained by weight-adjusted N17OHP values of healthy newborns to reduce the rate of false-positive results in NBS. (AU)