Reference intervals for follicle-stimulating hormone, luteinizing hormone and prolactin in children and young adults on the bioMérieux Mini-Vidas system

Sex Differences in Serum Prolactin Levels in Children and Adolescents on Antipsychotics: A Systematic Review and Meta-Analysis

BACKGROUND

Serum prolactin levels are influenced by sex, physical development and medications among other factors. Antipsychotics usually increase serum prolactin levels in both adults and younger patients, but no study has reviewed the potential association between sex and vulnerability for developing hyperprolactinemia among children and adolescents.

OBJECTIVE

Systematic review and meta-analysis of serum prolactin levels in children and adolescents on antipsychotic treatment for any psychiatric diagnosis to determine the effect of sex.

METHODS

A systematic search was performed in MEDLINE/PubMed/Web of Science and Cochrane databases for randomized controlled trials of antipsychotics in children and adolescents reporting serum prolactin levels by sex.

RESULTS

Of 1278 identified records, seven studies were included, comparing different single antipsychotics to placebo (risperidone N=4; lurasidone N=1; olanzapine N=1; queriapine N=1). Both male and female children and adolescents on antipsychotics presented a significant increase in prolactin levels relative to subjects receiving a placebo. (Male: 16.53 with 95% CI: 6.15-26.92; Female: 26.97 with 95% CI: 9.18-44.75). The four studies using risperidone had similar findings (Male: 26.49 with 95% CI: 17.55-35.43; Female: 37.72 with 95% CI: 9.41-66.03). In the direct comparison between sexes, females showed greater increases in prolactin, but the differences were not statistically significant.

CONCLUSION

Serum prolactin levels are increased in children and adolescents of both sexes on antipsychotics, with females showing a slightly greater increase than males. Further research is needed to clarify the influence of sex and pubertal status on prolactin levels in children and adolescents taking antipsychotics.

Chronic valproate treatment influences folliculogenesis and reproductive hormones with possible ameliorating role for folic acid in adult albino rats

Sodium Valproate (VPA) is known to have deleterious consequences on ovarian function and folliculogenesis. Folic acid (FA) is associated with the quality of many parameters in folliculogenesis. Therefore, we aimed to investigate the effects of chronic Valproate administration on ovarian morphology, folliculogenesis, reproductive hormones, and the possible protective effect of Folic acid supplementation. Forty adult female albino rats were divided into four groups and treated orally for 90 days as follows: Control group received distilled water; FA group received (folic acid 400 μg/day); VPA group received (Na Valproate 200 mg/kg/day) and VPA + FA group received (Na Valproate 200 mg/kg/day + folic acid 400 μg/day). In addition, ovaries were processed for routine histology and immunohistochemistry (TGFβ1 and PCNA) and reproductive hormones levels were measured. Results showed a significant decrease in number of follicles in VPA group, while atretic follicles increased compared with control group (P < 0.001). Interestingly, the number of follicles significantly increased in VPA + FA group compared with VPA group (P < 0.001). Also, number of atretic follicles significantly decreased in the VPA + FA group compared to the VPA group. Histochemistry score decreased for TGFβ1 and PCNA staining in VPA group compared with control group (P < 0.01). Moreover, Valproate demonstrated a significant increase in testosterone levels in VPA group than control group (P < 0.001). However, VPA group demonstrated a significant decrease in levels of estradiol, progesterone, FSH and LH levels compared with control group. These changes were partially improved in VPA + FA group. In conclusion, FA co-treatment can modulate ovarian follicular and hormonal disturbances induced by valproate, which needs further investigations to identify the precise mechanisms.

Comparison of VIDAS and radioimmunoassay methods for measurement of cortisol concentration in bovine serum

Radioimmunoassay (RIA) is the “gold standard” method for evaluation of serum cortisol concentration. The VIDAS cortisol test is an enzyme-linked fluorescent assay designed for the MiniVidas system. The aim of this study was to compare the VIDAS method with RIA for measurement of bovine serum cortisol concentration. Cortisol concentrations were evaluated in 40 cows using both VIDAS and RIA methods, the latter as the reference method. A paired Student's t-test, Pearson's correlation analysis, Bland-Altman plot, and Deming regression analysis were used to compare the two methods. There was no statistically significant difference between mean serum cortisol concentrations measured by VIDAS or RIA methods (P = 0.6570). Both methods were able to detect significant differences in mean low and high cortisol concentrations (P < 0.00014 RIA and P < 0.0016 VIDAS). The correlation coefficient was low, but a Bland-Altman plot and Deming regression analysis show neither constant nor proportional error. The VIDAS method produced slightly higher values than RIA, but the difference was small and in no case did the mean value move the normal range. Results suggest that VIDAS method is suitable for the determination of bovine serum cortisol concentration in studies of large numbers of animals.

Complex Biological Pattern of Fertility Hormones in Children and Adolescents: A Study of Healthy Children from the CALIPER Cohort and Establishment of Pediatric Reference Intervals

BACKGROUND

Pediatric endocrinopathies are commonly diagnosed and monitored by measuring hormones of the hypothalamic-pituitary-gonadal axis. Because growth and development can markedly influence normal circulating concentrations of fertility hormones, accurate reference intervals established on the basis of a healthy, nonhospitalized pediatric population and that reflect age-, gender-, and pubertal stage–specific changes are essential for test result interpretation.

METHODS

Healthy children and adolescents (n = 1234) were recruited from a multiethnic population as part of the CALIPER study. After written informed parental consent was obtained, participants filled out a questionnaire including demographic and pubertal development information (assessed by self-reported Tanner stage) and provided a blood sample. We measured 7 fertility hormones including estradiol, testosterone (second generation), progesterone, sex hormone–binding globulin, prolactin, follicle-stimulating hormone, and luteinizing hormone by use of the Abbott Architect i2000 analyzer. We then used these data to calculate age-, gender-, and Tanner stage–specific reference intervals according to Clinical Laboratory Standards Institute C28-A3 guidelines.

RESULTS

We observed a complex pattern of change in each analyte concentration from the neonatal period to adolescence. Consequently, many age and sex partitions were required to cover the changes in most fertility hormones over this period. An exception to this was prolactin, for which no sex partition and only 3 age partitions were necessary.

CONCLUSIONS

This comprehensive database of pediatric reference intervals for fertility hormones will be of global benefit and should lead to improved diagnosis of pediatric endocrinopathies. The new database will need to be validated in local populations and for other immunoassay platforms as recommended by the Clinical Laboratory Standards Institute.

Reference intervals on the Abbot Architect for serum thyroid hormones, lipids and prolactin in healthy children in a population-based study

Pediatric reference intervals for thyroid hormones, prolactin and lipids are of high clinical importance as deviations might indicate diseases with serious consequences. In general, previous reference intervals are hampered by the inclusion of only hospital-based populations of children and adolescents. The study included 694 children, evenly distributed from 6 months to 18 years of age. They were recruited as volunteers at child care units and schools. All subjects were apparently healthy and a questionnaire on diseases and medications was filled out by parents and by the older children. TSH, free T4, free T3, total cholesterol, LDL, HDL, triglycerides and prolactin were analyzed on Abbott Architect ci8200. Age- and gender-related 2.5 and 97.5 percentiles were estimated. The thyroid hormone levels were similar to previous data for the Abbott Architect platform, but exhibited differences from studies performed with other methods. Prolactin displayed wide reference ranges, but relatively small age-related changes, and a marginal difference between sexes during adolescence. Reference intervals for lipids in the different age groups are known to vary geographically. Levels of LDL and total cholesterol were higher than those reported for children in Canada, but lower than those reported for children in China. The study gives age- and gender- specific pediatric reference intervals, measured with modern methods for a number of important analytes. The results presented here differ from previously recommended reference intervals. In many earlier studies, retrospective hospital-based reference intervals, which may include various sub-groups have been presented. By non-hospital studies it is possible to avoid some of these biases.

Comparison of the VIDAS and IMMULITE-2000 methods for cortisol measurement in canine serum

BACKGROUND

Serum cortisol concentration is often measured in dogs for the diagnosis and monitoring of adrenal disease. An enzyme-linked fluorescent assay (VIDAS method) on the MiniVidas analyzer has been validated for the measurement of cortisol concentration in human serum and could have applications for canine samples.

OBJECTIVE

The aim of this study was to compare canine cortisol results obtained using the VIDAS method with those obtained using the IMMULITE-2000 immunoassay, which has previously been validated for canine serum.

METHODS

The concentration of cortisol in 40 canine serum samples was determined concurrently with the VIDAS and IMMULITE methods, the latter as the reference method. Pearson's correlation coefficient, linear, and Deming regression analyses and Bland-Altman analysis were used to compare the 2 methods. Acceptability of the new method was judged using a medical decision chart (MEDx chart).

RESULTS

Cortisol concentrations obtained with the IMMULITE method ranged from 23.1 to 1380 nmol/L. Correlation (r=.977) and simple linear regression (slope=1.0722, confidence interval [CI] 0.996-1.148; intercept=-4.799, CI -42.838 to 33.240) revealed no proportional or constant error. Based on Deming regression and a Bland-Altman plot the 2 methods gave comparable results. The MEDx chart indicated that performance of the new method was good at decision limits of 40, 132, and 480 nmol/L.

CONCLUSION

Results of the VIDAS method were comparable to those of the IMMULITE-2000 reference method such that the VIDAS may be used as an alternative assay to evaluate serum cortisol concentration in dogs for the diagnosis of adrenal disease.