Effect of gender, birth weight and gestational age on serum 17-hydroxyprogesterone concentration and distribution among neonates in Saudi Arabia

The adjustment of 17-hydroxyprogesterone cut-off values for congenital adrenal hyperplasia neonatal screening by GSP according to gestational age and age at sampling

Background Congenital adrenal hyperplasia (CAH) screening is facing great challenges because of a high false-positive rate and a low positive predictive value (PPV). We established and optimized 17-hydroxyprogesterone (17-OHP) cut-off values for CAH neonatal screening using a genetic screening processor (GSP) according to gestational age (GA), birth weight (BW) and age at sampling. Methods The 17-OHP concentrations in dried blood spots were measured by time-resolved immunofluorescence and were grouped in terms of GA, BW and age at sampling for 48,592 newborns. The 99.5th percentile was used to set an initial cut-off value as a reference. Results Significant differences in 17-OHP concentrations were observed among newborns with different GAs and BWs. A significant difference was observed among different sampling age groups. Finally, we defined new multitier cut-off concentrations based on GA and age at sampling. Application of the new cut-off values resulted in a 30% reduction of the positive rate and a 40% increase of the PPV. Conclusions GA, BW and sampling age time influenced the concentrations of 17-OHP. The efficiency of congenital adrenal hyperplasia screening can be substantially improved by adjusting the multitier cut-off value according to GA and age at sampling.

Evaluation of factors associated with elevated newborn 17-hydroxyprogesterone levels

BACKGROUND

Measurement of 17-hydroxyprogesterone (17-OHP) in dried blood spots has been widely used as a newborn screening tool for congenital adrenal hyperplasia (CAH). Various maternal and neonatal factors can result in falsely high values of 17-OHP. There is a paucity of Indian studies in this regard because routine evaluation of newborn 17-OHP levels as a screening program is not widely practiced in India. Hence, this study was undertaken to evaluate the influence of various maternal and neonatal factors on newborn 17-OHP levels. The aim of the study was to determine the effect of various maternal and neonatal factors on the newborn 17-OHP values.

METHODS

Retrospective data related to a total of 3080 newborn 17-OHP values and clinical characteristics were collected for 3 years (2013-2015). The data were analyzed to determine the influence of various factors on 17-OHP values.

RESULTS

The mean value of 17-OHP in our study was 5.486±3.96 ng/mL. Gender and mode of delivery did not significantly affect the 17-OHP levels. The levels were significantly higher in preterm and low birth weight babies as compared to term babies and babies with normal birth weight. Stress factors like pregnancy induced hypertension (PIH), early onset sepsis (EOS), neonatal seizures and birth asphyxia significantly increase the neonatal 17-OHP levels.

CONCLUSIONS

The levels of 17-OHP in newborns was measured around day 3 of life are very sensitive to the influence of gestational age, birth weight and presence of stress factors like maternal PIH, birth asphyxia, neonatal sepsis and neonatal seizures and should be interpreted cautiously.

The influence of seasonality and manufacturer kit lot changes on 17α-hydroxyprogesterone measurements and referral rates of congenital adrenal hyperplasia in newborns

Newborn screening for congenital adrenal hyperplasia (CAH) is performed by measuring the concentration of 17α-hydroxyprogesterone (17-OHP) in dried blood spots. Unfortunately, the level of 17-OHP varies due to multiple factors, and therefore, the false positive rate for the test is a challenge. We analyzed screening data from 2007 to 2015 to determine the effect of seasonal changes and manufacturer kit lot changes on 17-OHP values and on numbers of infants referred. Data from screening 2.2 million infants over a 9-year period indicates that in the NYS during the colder months, daily mean 17-OHP values are higher, more retests are performed, and more infants are referred even though fewer infants are born. The practice of using fixed cutoffs for referring infants for CAH leads to more false positive results in colder months. In addition, there was an overall 10% increase in the daily mean 17-OHP values from the 2 years before and after a manufacturer kit lot change that occurred in November 2013, suggestive of a functional change in the kit at that time.

CONCLUSION

Newborn screening programs should be cognizant of seasonal temperature variations and (un)anticipated manufacturer kit changes because they may affect 17-OHP values and CAH referral rates. What is Known: • Newborn screening for congenital adrenal hyperplasia is generally performed by measuring 17α-hydroxyprogesterone (17-OHP) levels in dried blood spots. • 17-OHP concentrations are affected by gestational age/weight of infant when specimen is collected, specimen collection time after birth, as well as race and sex of infant. What is New: • Seasonal temperature variations and unanticipated manufacturer kit changes affect 17-OHP levels and consequently referral rates in programs that use fixed cutoffs. • Daily mean 17-OHP is generally higher when the ambient temperature is lower.

Newborn screening for congenital adrenal hyperplasia in New York State

From 2007 to 2014 the New York State (NYS) Newborn Screening (NBS) program screened 2 million newborns for congenital adrenal hyperplasia (CAH). The data was analyzed to determine factors that affect 17α-hydroxyprogesterone levels and assist in developing algorithm changes that would improve the positive predictive value of the methodology being used. The concentration of 17-OHP in dried blood spots was measured using the AutoDELFIA Neonatal 17-OHP kit (Perkin Elmer, Turku, Finland). During the 8 year period of this study 2476 babies were referred, 105 babies were diagnosed with CAH (90 with the salt-wasting (SW), 8 with simple virilizing (SV), 5 with non-classical CAH, and 2 with another enzyme deficiency) and, 14 with possible CAH. Three false negative cases with SV-CAH were reported to the program. Of the total 108 known cases, 74 (69%) infants were detected by newborn screening in the absence of clinical information, or, known family history. The incidence of CAH in NYS is 1 in 18,170 with a ratio of SW to SV of 8.2:1. The incidence of CAH is lower in Black infants than in White, Hispanic and Asian infants. Despite a lower mean birth weight, female infants have a lower mean 17-OHP value than male infants and are under-represented in the referred category. As per other NBS programs the false positive rate is exacerbated by prematurity/low birth weight and by over-early specimen collection.

Newborn screening for congenital adrenal hyperplasia in Cuba: six years of experience

BACKGROUND

Since 2005, a newborn screening program for congenital adrenal hyperplasia (CAH) by measuring 17-alpha-hydroxyprogesterone (17OHP) in dried blood spots was introduced in Cuba.

METHODS

The hormone was measured by the 17OHP Neonatal UMELISA method, in samples collected on the 5th day as average. Confirmatory test was performed to those neonates with 17OHP values above 55 nmol/l. Some perinatal factors that can influence on 17OHP levels were studied.

RESULTS

From January 2005 to December 2010, 621,303 newborns were screened and 39 CAH cases were detected. Coverage of the program reached 98%. The incidence of CAH in Cuba was 1:15,931, similar to that reported by other programs. A recall for suspected CAH was performed in 10,799 cases (1.74%). Therapy in classical CAH patients was started at the mean age of 22 days. 17OHP levels were significantly higher in newborns with lower birth-weight (BW) and/or gestational age (GA). In addition, 17OHP values were affected by the gender, twin status or mode of delivery.

CONCLUSIONS

In Cuba, the nationwide newborn screening program has allowed the early detection of CAH. The use of an optimized cut-off level for BW or GA could lead to a reduction in the percentage of recalled babies.

Serum 17 alpha hydroxyprogesterone in normal full term and preterm vs sick preterm and full term newborns in a tertiary hospital

OBJECTIVES

To determine the variables affecting serum 17 hydroxyprogesterone (17OHP) in neonates born at a tertiary hospital in Mumbai, India.

METHODS

Serum 17OHP was measured in peripheral venous blood between 3rd to 5th day of life by competitive radioimmunoassay and on follow up at 3 mo of age. Serum 17OHP was compared among four groups [full term healthy(FT), full term stressed(FS), preterm healthy(PT), preterm stressed(PS)] by non-parametric tests (Kruskal Wallis (KW) test and Mann- Whitney (MW) test). Pearson's test was used to correlate natural log of serum 17OHP (ln17OHP) with variables like gestational age, birth weight, stress factor, sex, antenatal administration of glucocorticoids to mothers, Apgar score at 5 min and mode of delivery. Linear regression analysis was done using significant variables in Pearson's test to determine best predictors of ln17OHP.

RESULTS

The initial median (number of cases, inter-quartile range) serum 17OHP (ng/ml) for the four groups was as follows; FT 8.4 (33, 6-13); PT 20 (36, 11-29.5); FS 34 (29, 26-45) and PS 58 (24, 40.75-76.5) [total N = 122 newborns, p = 0.001]. Pearson's test showed that gestational age, birth weight, stress factor, Apgar score were negatively correlated with 17OHP whereas stress factor, mode of delivery, use of antenatal steroids in mothers were significantly positively correlated. However, stress factor emerged as the most important significant positive predictor (multiple R = 0.643, P = <0.0001). On follow up at 3 mo age, the median 17OHP (N = 73 newborns) had significantly decreased to normal level.

CONCLUSION

Stress due to neonatal illnesses like meconium aspiration, sepsis, birth asphyxia, etc. significantly elevate serum 17OHP and may lead to false positives in newborn screening for congenital adrenal hyperplasia.

17alpha-hydroxyprogesterone and cortisol serum levels in neonates and young children: influence of age, gestational age, gender and methodological procedures

To determine the influence of age, gestational age, gender and methodological protocol on serum 17OHP and cortisol concentrations. 17OHP in non-extracted (NE) and extracted (E) sera was measured by RIA in 319 full-term (FT) (1 d-5 yr) infants, 38 pre-term (PT) and in 19 neonates with classical CAH at diagnosis. 17OHP (NE- and E-) decreased with age in normal children. The extraction procedure significantly reduced 17OHP by eliminating interfering steroids in children < 1 year. Sexual dimorphism was only observed in NE-17OHP. 17OHP in PT was always higher than in FT up to 2 months of age (p < 0.001). Neither NE- nor E-17OHP in CAH overlapped with those of FT or PT (p < 0.001) allowing to omit the extraction procedure to confirm CAH diagnosis. Cortisol levels were within normal range in neonates with CAH, thus not adding useful information about adrenal function. Chronological and gestational age, gender, and extraction for 17OHP measurement are important factors to know when assessing adrenal function during the first year of life.

Newborn screening for congenital adrenal hyperplasia has reduced sensitivity in girls

OBJECTIVES

To characterize Wisconsin-born infants with 21-hydroxylase deficiency-congenital adrenal hyperplasia (21-OH-D-CAH) who were not identified by the newborn screening for 21-OH-D-CAH, and to examine male and female screening 17-hydroxyprogesterone (17-OHP) levels.

STUDY DESIGN

Information on infants with false-negative results was gathered. Results of the Wisconsin newborn screening for 21-OH-D-CAH from January 1, 2000, to June 30, 2003, were analyzed to detect possible differences between male (n=119,842) and female (n=114,951) infants.

RESULTS

Six of 7 female infants with false-negative results had genital masculinization, and 4 of 8 infants with false-negative results had laboratory evidence of salt-wasting. None died, had a salt-wasting crisis, or was assigned the wrong sex. A significant difference in the mean 17-OHP levels between male (17.5 ng/mL) and female (15.4 ng/mL) infants (P <.0001) was detected. The sensitivity of newborn screening for female infants was 60%, compared with 80% for male infants.

CONCLUSIONS

Male and female infants have significantly different mean 17-OHP levels on newborn screening, and female infants comprise most of the infants with false-negative results. Although health professionals should not assume that newborn screening for 21-OH-D-CAH is a means of identifying all affected infants, the primary goals of newborn screening for CAH (prevention of salt-wasting crises and sex misassignment) are fulfilled.

Rapid second-tier molecular genetic analysis for congenital adrenal hyperplasia attributable to steroid 21-hydroxylase deficiency

BACKGROUND

Neonatal screening for steroid 21-hydroxylase (CYP21) deficiency is performed to identify congenital adrenal hyperplasia (CAH). The immunologic assay for 17alpha-hydroxyprogesterone (17-OHP) has a high rate of false positives. We assessed the potential for increasing the specificity for CAH by use of a second step involving analysis of the CYP21 gene.

METHODS

Between January 1999 and December 2003, a total of 810,000 newborns were screened. Of these, 7920 had to be retested because their 17-OHP values were above the cutoff of the assay. Sixty-one had positive 17-OHP values in their recall samples and were diagnosed as having CAH. We used a rapid assay for common mutations of the CYP21 gene to analyze these 61 samples. In a prospective study, 198 consecutive samples that had increased 17-OHP and 100 samples that had normal 17-OHP concentrations were genotyped.

RESULTS

Fifty-nine of 61 cases diagnosed as having CAH were confirmed genetically as CYP21 deficiencies. One patient had a 3beta-hydroxysteroid dehydrogenase deficiency, and one patient carried no CYP21 mutations. The 198 increased 17-OHP results were designated as false positives after immunologic testing of recall samples. None of these samples exhibited the genetic pattern consistent with CYP21 deficiency.

CONCLUSIONS

If samples with increased 17-OHP values were screened genetically, the number of retests would decrease by approximately 90%, but the overall sensitivity of CAH screening would remain the same. Adding a second-tier genetic step would require a modest increase in costs, but is counterbalanced by fewer recalls, less clinical follow-up, and a reduction in unnecessary worry for families.