Measurement of late-night salivary cortisol with an automated immunoassay system.

BACKGROUND: Measurement of late-night salivary cortisol concentrations is increasingly used as a screening test in suspected Cushing's syndrome. Cortisol concentrations are typically extremely low in late-night samples and discordant assay-specific reference ranges have been reported. Therefore, the aim of our study was to assess the analytical performance of the first automated cortisol immunoassay specified for salivary measurements and to establish late-night sampling reference-range data for this test. METHODS: Salivary cortisol was measured using the Roche Cobas Cortisol assay (Roche Diagnostics). Five salivary pools in different concentration ranges were used to assess the inter-assay imprecision of this test in a two-centre evaluation protocol including two reagent lots. Linearity was tested by serial dilution. Salivary samples were obtained at 23:00 h from 100 apparently healthy volunteers using a commercially available salivary sampling device (Salivette, Sarstedt). A subset of 20 samples was used for method comparison with isotope dilution liquid chromatography-tandem mass spectrometry. RESULTS: Inter-assay coefficients of variation (n=20) between 11.6% and 40.4% were found for mean cortisol concentrations between 12.9 and 2.6 nmol/L, with an estimated functional sensitivity of approximately 5.0 nmol/L. The test also gave linear results in the lowest concentration range between 1.0 and 8.3 nmol/L. Mean late-night salivary cortisol of 5.0 nmol/L was found for healthy individuals; the absolute range was 1.4-16.7 nmol/L, and the 95th percentile was 8.9 nmol/L. Substantially lower concentrations were found with isotope dilution LC-MS/MS compared to immunoassay results (mean concentrations 1.8 and 4.4 nmol/L, respectively). CONCLUSIONS: The automated assay investigated was found to offer acceptable analytical performance in the very low concentration range required for late-night salivary cortisol, despite a very short turn-around time. Using this assay, late-night salivary cortisol concentrations below 8.9 nmol/L are typically found in healthy volunteers.

Gender-specific differences in sex hormones and cytokines in patients undergoing major abdominal surgery.

PURPOSE: Experimental and clinical evidence suggests that gender has a profound influence on outcome after inflammatory hits caused by such events as trauma. We conducted this prospective clinical study to evaluate the influence of gender on the release of pro- and anti-inflammatory cytokines in the circulation and after lipopolysaccharide (LPS) ex vivo stimulation. We also measured the course of sex hormones in the acute phase response after surgery and assessed their correlation with cytokine release. METHODS: We measured the serum concentrations of interleukin (IL)-6, IL-8, IL-10, tumor necrosis factor-alpha (TNF-alpha), testosterone, estradiol, prolactin, procalcitonin, and sex hormone-binding globulin, as well as the release of IL-6, TNF-alpha, and IL-10 after LPS ex vivo stimulation of whole blood in 26 patients without complications after major or minor abdominal surgery. RESULTS: There was a gender-specific pattern of decreasing testosterone concentrations in men and increasing testosterone concentrations in women. Increasing estradiol concentrations were seen in both men and women. The ex vivo-stimulated and systemic IL-6, IL-8, IL-10, and TNF-alpha cytokine release was not gender specific. There was a marked prolactin peak after the induction of anesthesia before the commencement of surgery. CONCLUSION: In contrast to the release of pro- and anti-inflammatory cytokines, sex hormones show a gender-specific pattern during the acute phase response 1 week after abdominal surgery.

Significance of a common single nucleotide polymorphism in exon 10 of the follicle-stimulating hormone (FSH) receptor gene for the ovarian response to FSH: a pharmacogenetic approach to controlled ovarian hyperstimulation.

The p.N680S sequence variation of the follicle-stimulating hormone (FSH) receptor gene was previously shown to influence the ovarian response to FSH in normo-ovulatory women undergoing controlled ovarian hyperstimulation. In this prospective, randomized, controlled study, we tested whether the same daily dose of FSH results in lower levels of oestradiol in women homozygous for the p.N680S sequence variation, and whether the difference can be overcome by higher FSH doses. Women undergoing controlled ovarian hyperstimulation for in vitro fertilization or intracytoplasmic sperm injection and homozygous for the wild-type or for the p.N680S FSH receptor were randomly assigned to group I (Ser/Ser, n=24), receiving an FSH dose of 150 U/day, or group II (Ser/Ser, n=25), receiving an FSH dose of 225 U/day. In group III (Asn/Asn, n=44), the FSH dose was 150 U/day. Age and basal FSH levels were not different between groups. At ovulation induction, total FSH doses were comparable in group I (1631+/-96 U) and group III (1640+/-57 U) but significantly higher in group II (2421+/-112 U) (P<0.001). Peak oestradiol levels on the day of human chorionic gonadotrophin (hCG) administration were significantly lower in group I (5680+/-675 pmol/l) compared to group III (8679+/-804 pmol/l) (P=0.028). Increasing the FSH dose from 150 to 225 U/day overcame the lower oestradiol response in women with Ser/Ser (group II, 7804+/-983 pmol/l). In women undergoing controlled ovarian hyperstimulation, the p.N680S sequence variation results in lower oestradiol levels following FSH stimulation. This lower FSH receptor sensitivity can be overcome by higher FSH doses.