Antenatal corticosteroids and newborn screening for congenital adrenal hyperplasia

Congenital Adrenal Hyperplasia-Current Insights in Pathophysiology, Diagnostics, and Management

Congenital adrenal hyperplasia (CAH) is a group of autosomal recessive disorders affecting cortisol biosynthesis. Reduced activity of an enzyme required for cortisol production leads to chronic overstimulation of the adrenal cortex and accumulation of precursors proximal to the blocked enzymatic step. The most common form of CAH is caused by steroid 21-hydroxylase deficiency due to mutations in CYP21A2. Since the last publication summarizing CAH in Endocrine Reviews in 2000, there have been numerous new developments. These include more detailed understanding of steroidogenic pathways, refinements in neonatal screening, improved diagnostic measurements utilizing chromatography and mass spectrometry coupled with steroid profiling, and improved genotyping methods. Clinical trials of alternative medications and modes of delivery have been recently completed or are under way. Genetic and cell-based treatments are being explored. A large body of data concerning long-term outcomes in patients affected by CAH, including psychosexual well-being, has been enhanced by the establishment of disease registries. This review provides the reader with current insights in CAH with special attention to these new developments.

Congenital Adrenal Hyperplasia Due to Steroid 21-Hydroxylase Deficiency: An Endocrine Society Clinical Practice Guideline

Objective

To update the congenital adrenal hyperplasia due to steroid 21-hydroxylase deficiency clinical practice guideline published by the Endocrine Society in 2010.

Conclusions

The writing committee presents updated best practice guidelines for the clinical management of congenital adrenal hyperplasia based on published evidence and expert opinion with added considerations for patient safety, quality of life, cost, and utilization.

Bringing GC-MS profiling of steroids into clinical applications

Abnormalities of steroid biosynthesis and excretion are responsible for the development and prevention of endocrine disorders, such as metabolic syndromes, cancers, and neurodegenerative diseases. Due to their biochemical roles in endocrine system, qualitative and quantitative analysis of steroid hormones in various biological specimens is needed to elucidate their altered expression. Mass spectrometry (MS)-based steroid profiling can reveal the states of metabolites in biological systems and provide comprehensive insights by allowing comparisons between metabolites present in cells, tissues, or organisms. In addition, the activities of many enzymes related to steroid metabolism often lead to hormonal imbalances that have serious consequences, and which are responsible for the progress of hormone-dependent diseases. In contrast to immunoaffinity-based enzyme assays, MS-based methods are more reproducible in quantification. In particular, high-resolution gas chromatographic (GC) separation of steroids with similar chemical structures can be achieved to provide rapid and reproducible results with excellent purification. GC-MS profiling therefore has been widely used for steroid analysis, and offers the basis for techniques that can be applied to large-scale clinical studies. Recent advances in analytical technologies combined with inter-disciplinary strategies, such as physiology and bioinformatics, will help in understanding the biochemical roles of steroid hormones. Therefore, comprehensive analytical protocols in steroid analysis for different research purposes may contribute to the elucidation of complex metabolic processes relevant to steroid function in many endocrine disorders, and in the identification of diagnostic biomarkers.

Congenital adrenal hyperplasia: an update in children

PURPOSE OF REVIEW

Congenital adrenal hyperplasia (CAH) in children, the majority of which is due to 21-hydroxylase deficiency, represents a group of disorders in which there is impaired cortisol synthesis and abnormalities in adrenal hormonal profiles. There continues to be debate regarding the optimal management of and treatment for these children. This review will highlight the most recent advances in neonatal screening for CAH, as well as the timeliest recommendations for the treatment and management of 21-hydroxylase deficiency, both the classic and nonclassic forms of the disorder.

RECENT FINDINGS

Substantive advancements have been made with regard to neonatal screening for CAH, allowing for earlier diagnosis, while minimizing the morbidity and mortality associated with delayed detection. Although the achievement of normal growth and development remains the ultimate goal of treatment, recent studies have provided further insight into the management and refinement of therapy in these children.

SUMMARY

The optimal management and treatment for children with CAH is still unclear. Although there have been recent advances in the diagnosis and treatment of this group of disorders, there is still much to learn in order to optimize therapy for these individuals.

The effects of gestational age and birth weight on false-positive newborn-screening rates

OBJECTIVE

Newborn-screening false-positive rates (FPRs) are disproportionately increased in preterm infants. The objective of this study was to determine variation in newborn screening FPRs according to birth weight and gestational age. Our secondary objective was to examine the effect of postnatal age on FPRs in preterm infants.

METHODS

The Ohio State Newborn Screening Program Database was analyzed to determine the overall and birth weight-specific FPRs for 18 analytes. Data were stratified into birth weight categories (<1000 g, 1000-1499 g, 1500-2499 g, 2500-3999 g, and >4000 g). In addition, to examine the effect of postnatal age on FPRs, we examined the 2 analytes with the highest FPRs, thyrotropin with back-up thyroxine and 17-hydroxyprogesterone, in infants whose gestational age was <32 weeks, determined on the basis of postnatal age at screening.

RESULTS

Data from 448 766 neonates were reviewed. Infants with very low birth weight (VLBW) comprised 1.9% of the study cohort, but accounted for 18% of false-positive results. For 14 of 18 analytes studied, FPRs increased with decreasing birth weight/gestational age and were significantly increased in infants with VLBW compared with infants who weighed 2500 to 3999 g (P < .001). Thyrotropin/back-up thyroxine and 17-hydroxyprogesterone accounted for 62% of total false-positive results in VLBW infants. When blood specimens were collected at a postnatal age of ≥ 48 hours in infants born at <32 weeks, a 44% relative reduction in 17-hydroxyprogesterone false-positive results was detected.

CONCLUSIONS

False-positive newborn-screening rates are disproportionately increased in VLBW infants. FPRs may be reduced by delaying screening of <32 weeks' gestation, preterm infants until 24 to 48 hours' postnatal age.

Congenital adrenal hyperplasia due to steroid 21-hydroxylase deficiency: an Endocrine Society clinical practice guideline

OBJECTIVE

We developed clinical practice guidelines for congenital adrenal hyperplasia (CAH).

PARTICIPANTS

The Task Force included a chair, selected by The Endocrine Society Clinical Guidelines Subcommittee (CGS), ten additional clinicians experienced in treating CAH, a methodologist, and a medical writer. Additional experts were also consulted. The authors received no corporate funding or remuneration.

CONSENSUS PROCESS

Consensus was guided by systematic reviews of evidence and discussions. The guidelines were reviewed and approved sequentially by The Endocrine Society's CGS and Clinical Affairs Core Committee, members responding to a web posting, and The Endocrine Society Council. At each stage, the Task Force incorporated changes in response to written comments.

CONCLUSIONS

We recommend universal newborn screening for severe steroid 21-hydroxylase deficiency followed by confirmatory tests. We recommend that prenatal treatment of CAH continue to be regarded as experimental. The diagnosis rests on clinical and hormonal data; genotyping is reserved for equivocal cases and genetic counseling. Glucocorticoid dosage should be minimized to avoid iatrogenic Cushing's syndrome. Mineralocorticoids and, in infants, supplemental sodium are recommended in classic CAH patients. We recommend against the routine use of experimental therapies to promote growth and delay puberty; we suggest patients avoid adrenalectomy. Surgical guidelines emphasize early single-stage genital repair for severely virilized girls, performed by experienced surgeons. Clinicians should consider patients' quality of life, consulting mental health professionals as appropriate. At the transition to adulthood, we recommend monitoring for potential complications of CAH. Finally, we recommend judicious use of medication during pregnancy and in symptomatic patients with nonclassic CAH.

Neonatal screening for congenital adrenal hyperplasia

Congenital adrenal hyperplasia (CAH) caused by steroid 21-hydroxylase deficiency occurs in 1:16,000-1:20,000 births. If not promptly diagnosed and treated, CAH can cause death in early infancy from shock, hyponatremia and hyperkalemia. Affected girls usually have ambiguous genitalia but boys appear normal; therefore, newborn babies are commonly screened for CAH in the US and many other countries. By identifying babies with severe, salt-wasting CAH before they develop adrenal crises, screening reduces morbidity and mortality, particularly among affected boys. Diagnosis is based on elevated levels of 17-hydroxyprogesterone, the preferred substrate for steroid 21-hydroxylase. Initial testing usually involves dissociation-enhanced lanthanide fluorescence immunoassay that has a low positive predictive value (about 1%), which leads to many follow-up evaluations that have negative results. The positive predictive value might be improved by second-tier screening using DNA-based methods or liquid chromatography followed by tandem mass spectrometry, but these methods are not widely adopted. Cost estimates for such screening range from US$20,000 to $300,000 per life-year saved. In babies with markedly abnormal screen results, levels of serum electrolytes and 17-hydroxyprogesterone should be immediately determined, but the most reliable way to diagnose CAH is measurement of levels of steroid precursors after stimulation with cosyntropin.

17-Hydroxyprogesterone in premature infants as a marker of intrauterine stress

AIMS

Amniotic infection (AI) and preeclampsia (PE), which are commonly the reason for prematurity, inflict stress of different duration on immature fetuses. Whether chronic stress, as reflected by intrauterine growth retardation, influences the level of 17-OH progesterone (17-OHP), was not previously examined.

METHODS

We analyzed 17-OHP and TSH levels during neonatal screenings in the first hours of life of 90 premature infants born between 25 and 33 weeks of gestation in infants with AI (n=37) or with PE (n=53). Control of acute stress parameters was derived from umbilical arterial cord blood pH and base excess (BE).

RESULTS

Mean 17-OHP levels of infants born to mothers with PE were 85.7 nmol/L compared to 54.6 nmol/L (P<0.001) in AI infants. 17-OHP was even higher when intrauterine growth restriction was present (99.8 nmol/L). Antenatal steroids and mode of delivery did not significantly affect 17-OHP levels.

CONCLUSIONS

Stress of relatively long duration, as in cases of PE, leads to a significant increase of 17-OHP level in preterm infants. The postnatal 17-OHP level may be considered as a measure for severity of intrauterine stress and might be used as an individualized indicator for earlier intensive care.

Newborn screening levels of 17-hydroxyprogesterone in very low birth weight infants and the relationship to chronic lung disease

OBJECTIVES

17-Hydroxyprogesterone (17-OHP), an intermediary hormone in cortisol synthesis, has been shown to be elevated in premature infants. However, the relationship between levels of 17-OHP with chronic lung disease (CLD) have not been extensively explored. The objective of this study was to determine whether there is an association between CLD and levels of 17-OHP in a population of very low birth weight infants.

STUDY DESIGN

Cohort study of very low birth weight infants cared for at a single level 3 NICU during a 3-year period from July 2001-July 2004, n=435. Infants had a minimum of one screen for 17-OHP. 17-OHP was measured on the 5th day of life and at 2-4 weeks of life as part of the State of Delaware Newborn Screening Program. Statistical analysis included chi-squared, Pearson correlation, and logistic regression.

RESULTS

Levels of 17-OHP were higher at the time of the 1st screen compared to the 2nd screen (42.2 +/- 36.7 vs 23.5 +/- 32.3 ng/ml, respectively, p = 0.01). After controlling for potential confounding variables, gestational age and prenatal steroids were independently associated with 17-OHP. However, logistic regression analysis showed no association between a 1 log increase in levels of 17-OHP with the outcomes of CLD (odds ratio 1.7, 95% CI 0.7-3.8), or death and/or CLD (odds ratio 2.1, 95% CI 0.9-4.8).

CONCLUSIONS

In our population of very low birth weight infants elevated levels of 17-OHP were not associated with the development of CLD.

Effect of single and multiple courses of prenatal corticosteroids on 17-hydroxyprogesterone levels: implication for neonatal screening of congenital adrenal hyperplasia

Measurement of 17-hydroxyprogesterone (17-OHP) from filter-paper blood is widely used to screen for congenital adrenal hyperplasia (CAH). However, in pregnancies with an expected preterm delivery, prenatal treatment with steroids to induce pulmonary maturation could suppress the fetal adrenals and interfere with this screening. In 160 infants who were born between 25 and 35 wk of gestation, we measured 17-OHP in filter-paper blood at 72-96 h and compared the values between those who had not received antenatal steroids (n=50) and those who had (n=110). A single course of steroids was two 12-mg injections of betamethasone given within a 24-h interval: 30 infants received a half single course, 45 received a full single course, and 35 received multiple courses. Results are expressed as medians (25th percentile; 75th percentile). Blood 17-OHP differed significantly among groups: 23.7 (14.2; 30.7) nmol/L, 26.1 (15.0; 50.1) nmol/L, 20.1 (13.8; 29.1) nmol/L, and 14.9 (9.5; 26.2) nmol/L (for, respectively, no steroid, half a single course, a full single course, and multiple courses; p <0.05, multiple comparisons with the Kruskal-Wallis test). However, only infants who were treated with multiple antenatal courses of steroids had lower blood 17-OHP than those who were untreated (p <0.05 with the Mann-Whitney U test). In multiple regression analysis, steroid treatment and intrauterine growth retardation were significant negative predictors of blood 17-OHP, whereas respiratory distress syndrome was a significant positive predictor (multiple R=0.50, p <0.001). Multiple courses of steroids in preterm infants decrease 17-OHP values by approximately 30% in filter-paper blood, thus raising the risk of false-negative results in screening programs for CAH.

Factors influencing levels of 17-hydroxyprogesterone in very low birth weight infants and the relationship to death and IVH

OBJECTIVES

17-Hydroxyprogesterone, an intermediary hormone in cortisol synthesis, has been shown to be elevated in premature infants. However, the relationship between levels of 17-hydroxyprogesterone with death and intraventricular hemorrhage has not been extensively explored. The objective of this study was to determine the factors influencing 17-hydroxyprogesterone and determine if there is an association between intraventricular hemorrhage, mortality, and levels of 17-hydroxyprogesterone in a population of very low birth weight infants.

STUDY DESIGN

Cohort study of very low birth weight infants cared for at a single level 3 NICU during a 1-year period from July 2001 to July 2002. Infants had a minimum of one screen for 17-hydroxyprogesterone and one cranial sonogram. 17-Hydroxyprogesterone was measured on the fifth day of life and at 2 to 4 weeks of life as part of the State of Delaware Newborn Screening Program. Statistical analysis included chi(2), Pearson correlation, multiple-linear regression, and logistic regression.

RESULTS

Levels of 17-hydroxyprogesterone were higher at the time of the first screen compared to the second screen (28.3+/-25.6 vs 17.0+/-18.0 ng/ml, p=0.01), respectively. After controlling for potential confounding variables, gestational age, T(4), and prenatal steroids were all independently associated with 17-hydroxyprogesterone. However, logistic regression analysis showed no association between a 1 log increase in levels of 17-hydroxyprogesterone with the outcomes of death (odds ratio 1.8, 95% CI 0.6 to 5.6), severe IVH (0.7, 0.3 to 1.7), and death and/or severe intraventricular hemorrhage (0.9, 0.4 to 2.1).

CONCLUSIONS

In our population of very low birth weight infants, low gestational age, low T(4), and prenatal steroids were all associated with an elevation in levels of 17-hydroxyprogesterone. High levels of 17-hydroxyprogesterone were not associated with death and/or severe IVH. Our data indicate that factors such as gestational age and antenatal steroids must be considered when interpreting 17-hydroxyprogesterone results from newborn screening.