OBJECTIVE: The expression of transcription factors involved in early pituitary development, such as PROP1 and POU1F1, has been detected in pituitary adenoma tissues. In this study, we sought to characterize the transcriptional profiles of PROP1, POU1F1, and TBX19 in functioning and nonfunctioning pituitary adenomas in an attempt to identify their roles in tumorigenesis and hormone hypersecretion. METHODS: RT-qPCR analyses were performed to assess the transcriptional pattern of PROP1, POU1F1, TBX19, and hormone-producing genes in tissue samples of corticotrophinomas (n = 10), somatotrophinomas (n = 8), and nonfunctioning adenomas (n = 6). RESULTS: Compared with normal pituitary tissue, POU1F1 was overexpressed in somatotrophinomas by 3-fold. PROP1 expression was 18-fold higher in corticotrophinomas, 10-fold higher in somatotrophinomas, and 3-fold higher in nonfunctioning adenomas. TBX19 expression was 27-fold higher in corticotrophinomas. Additionally, the level of TBX19 mRNA positively correlated with that of pro-opiomelanocortin (r = 0.49, p = 0.014). CONCLUSIONS: Our data demonstrate that PROP1 is overexpressed in pituitary adenomas, mainly in corticotrophinomas. Together with previously published data showing that patients who harbor PROP1 loss-of-function mutations present a progressive decline in corticotrope function, our results support a role for PROP1 in pituitary tumor development and in the maintenance of cell lineages committed to corticotrophic differentiation.

OBJETIVO: Avaliamos retrospectivamente os valores da 17OHP ajustados para o peso ao nascimento para melhorar a eficiência da triagem neonatal. SUJEITOS E MÉTODOS: 67.640 recém-nascidos com amostras coletadas entre 2-7 dias de vida. Uma segunda amostra foi solicitada na presença de testes com valores da 17OHP > 20 ng/mL. 17OHP dosada pelo método DELFIA- B024-112 e correlacionada com o peso ao nascimento: G1 < 1.500 g, G2 1.501-2.000 g, G3 2.000-2.500 g e G4 > 2.500 g. Pontos de corte da 17OHP foram determinados para cada grupo usando os percentis 97,5th, 99th, 99,5th e 99,8th. RESULTADOS: Falso-positivos ocorreram em 5% dos resultados com o ponto de corte > 20 ng/mL, dos quais 69% eram prematuros. Sete recém-nascidos apresentaram deficiência da 21-hidroxilase e, exceto em um, os valores da 17OHP foram > 120 ng/mL. Somente o valor da 17OHP do 99,8th apresentou maior valor preditivo positivo (2%) e menor índice de falso-positivos. CONCLUSÕES: Sugerimos o valor da 17OHP do 99,8th ajustado para o peso ao nascimento para se reduzir a taxa de resultados falso-positivos da triagem neonatal.

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.