Ovarian response prediction in GnRH antagonist treatment for IVF using anti-Müllerian hormone.

STUDY QUESTION: What is the clinical value of anti-Müllerian hormone (AMH) for the prediction of high or low ovarian response in controlled ovarian stimulation for IVF using GnRH antagonist treatment? SUMMARY ANSWER: AMH as a single test has substantial accuracy for ovarian response prediction in GnRH antagonist treatment for IVF, with a higher accuracy for predicting a high response than for low response. WHAT IS KNOWN ALREADY: The role of AMH and other patient characteristics in ovarian response prediction has been studied extensively in long GnRH agonist protocols; however, little information is available regarding the clinical value in GnRH antagonists. STUDY DESIGN, SIZE, DURATION: This is an observational (retrospective) substudy as part of an ongoing cohort study. A total of 487 patients scheduled for IVF/ICSI between 2006 and 2011 were included in the study. PARTICIPANTS/MATERIALS, SETTING, METHODS: Patients with a regular cycle who underwent their first IVF/ICSI cycle with GnRH antagonist treatment while receiving a starting dose of 150 or 225 IU recombinant FSH were included in the study. Patients were divided into three subgroups according to the following ovarian response categories: high (>15 oocytes or cycle cancellation), normal (4-15 oocytes) and low (<4 oocytes or cycle cancellation). Serum samples collected prior to IVF treatment were used to determine serum AMH levels. MAIN RESULTS AND THE ROLE OF CHANCE: According to the predefined ovarian response categories, 58 patients were classified as high, 326 as normal and 101 as low responders, and the ongoing pregnancy rates did not differ among groups (19.0, 22.1 and 16.8%, respectively, P = 0.9). For the prediction of high response, AMH had an area under the receiver-operating characteristic curve (AUC) of 0.87. Both female age and BMI had lower accuracy (AUC 0.66 and 0.58, respectively). For low response prediction, again AMH had a better accuracy (AUC 0.79) than female age and BMI (AUC 0.59 and 0.56, respectively). In a multivariate model, including the factors age, AMH, BMI, smoking, type and duration of subfertility, only BMI added some predictive value to AMH for both high and low response prediction. Clinical test characteristics demonstrated that using a specificity of ∼90%, the detection rate of AMH for high and low response, corresponding with a test cut-off of 4.5 and 0.8 µg/l, was ∼60 and ∼45%, respectively. LIMITATIONS, REASONS FOR CAUTION: The impact of the antral follicle count (AFC) on ovarian response prediction in GnRH antagonists was not assessed; however, previously studies demonstrated that for GnRH antagonists, AMH has a better accuracy than AFC. WIDER IMPLICATIONS OF THE FINDINGS: The current study demonstrates that AMH is an adequate predictor for both high and low response in GnRH antagonist cycles, showing a similar accuracy to GnRH agonists, as reported previously. The optimization and individualization of GnRH antagonist protocols may be improved by using an AMH-tailored approach. STUDY FUNDING/COMPETING INTERESTS: This study was funded by the Academic Institutional Resources of the Department of Reproductive Medicine of the UMC Utrecht. O.H., M.J.C.E, E.W.G.L and H.L.T. have nothing to declare. N.S.M. has received fees and/or grant support from the following companies (in alphabetic order): Anecova, Ferring, Informa, Merck Serono and MSD. B.C.J.M.F. has received fees and/or grant support from the following companies (in alphabetic order); Childhealth, CVON, Ferring, Ova-Science, PregLem, Roche and Watson laboratories. F.J.B. has received fees and/or grant support from the following companies (in alphabetic order); Merck Serono and MSD. TRIAL REGISTRATION NUMBER: www.clinicaltrials.gov, Protocol ID 13-109.

Genome-wide association study of monoamine metabolite levels in human cerebrospinal fluid.

Studying genetic determinants of intermediate phenotypes is a powerful tool to increase our understanding of genotype-phenotype correlations. Metabolic traits pertinent to the central nervous system (CNS) constitute a potentially informative target for genetic studies of intermediate phenotypes as their genetic underpinnings may elucidate etiological mechanisms. We therefore conducted a genome-wide association study (GWAS) of monoamine metabolite (MM) levels in cerebrospinal fluid (CSF) of 414 human subjects from the general population. In a linear model correcting for covariates, we identified one locus associated with MMs at a genome-wide significant level (standardized ß=0.32, P=4.92 × 10(-8)), located 20 kb from SSTR1, a gene involved with brain signal transduction and glutamate receptor signaling. By subsequent whole-genome expression quantitative trait locus (eQTL) analysis, we provide evidence that this variant controls expression of PDE9A (ß=0.21; P unadjusted=5.6 × 10(-7); P corrected=0.014), a gene previously implicated in monoaminergic transmission, major depressive disorder and antidepressant response. A post hoc analysis of loci significantly associated with psychiatric disorders suggested that genetic variation at CSMD1, a schizophrenia susceptibility locus, plays a role in the ratio between dopamine and serotonin metabolites in CSF. The presented DNA and mRNA analyses yielded genome-wide and suggestive associations in biologically plausible genes, two of which encode proteins involved with glutamate receptor functionality. These findings will hopefully contribute to an exploration of the functional impact of the highlighted genes on monoaminergic transmission and neuropsychiatric phenotypes.

LC-MS/MS in clinical chemistry: Did it live up to its promise?: Consideration from the Dutch EQAS organisation.

BACKGROUND: Over the past decade the use of LC-MS/MS has increased significantly in the hospital laboratories. Clinical laboratories have switched from immunoassays to LC-MS/MS methods due to the promise of improvements in sensitivity and specificity, better standardization with often non-commutable international standards, and better between-laboratory comparison. However, it remains unclear whether routine performance of the LC-MS/MS methods have met these expectations. METHOD: This study examined the EQAS results, from the Dutch SKML, of serum cortisol, testosterone, 25OH-vitaminD and cortisol in urine and saliva over 9 surveys (2020 to first half of 2021). RESULTS: The study found a significant increase in the number of compounds and in the number of results measured in the different matrices, with LC-MS/MS over a period of eleven years. In 2021, approximately 4000 LC-MS/MS results were submitted (serum: urine: saliva = 58:31:11%) compared to only 34 in 2010. When compared to the individual immunoassays, the LC-MS/MS based methods for serum cortisol, testosterone and 25OH-vitaminD showed comparable but also higher between-laboratory CVs in different samples of the surveys. For cortisol, testosterone and 25OH-vitaminD the median CV was 6.8%, 6.1% and 4.7% respectively for the LC-MS/MS compared to 3.9-8.0%,4.5-6.7%, and 7.5-18.3% for immunoassays. However, the bias and imprecision of the LC-MS/MS was better than that of the immunoassays. CONCLUSION: Despite the expectation that LC-MS/MS methods would result in smaller between-laboratory differences, as they are relatively matrix independent and better to standardize, the results of the SKML round robins do not reflect this for some analytes and may be in part explained by the fact that in most cases laboratory developed tests were used.

Reference ranges for analytes of thyroid function in children.

Promptly detecting pediatric thyroid dysfunction requires age-appropriate reference ranges for serum thyroid-stimulating hormone (TSH), serum free thyroxine (FT4), and serum free triiodothyronine (FT3). We sought to establish such ranges, employing the widely-used Immulite® 2000 automated immunoluminometric assays in a large population. We assayed the analytes according to manufacturer's instructions in serum samples from 359 male and 297 female university hospital patients, aged between newborn to 18 years, without evidence of thyroid or pituitary dysfunction. As data were not normally distributed, the reference ranges were assumed to lie between the 2.5th and 97.5th percentiles. Curves for age-related changes in the reference ranges were calculated using the linearity, median and skewness method. TSH, FT4, and FT3 reference ranges showed a wide spread immediately after birth, rapidly decreasing within the first 2 years of life. Reference range width was fairly stable after about age 4 years. However, from that time, the ranges' lower and upper limits steadily declined, essentially reaching (FT3) or approximating (TSH, FT4) healthy adult values by age 18 years. Age-specific reference ranges should be used when measuring TSH, FT4, and FT3 in children. During very early life, values of these analytes range widely, making it challenging to interpret measurements in infants, and, especially, newborns.

Heterophile antibodies rarely influence the measurement of thyroglobulin and thyroglobulin antibodies in differentiated thyroid cancer patients.

The aim of the study was to determine the impact of heterophile antibodies on the measurement of serum thyroglobulin (Tg), thyroglobulin recovery, and thyroglobulin antibody levels in differentiated thyroid carcinoma patients. We studied serum samples of 201 individual patients that were followed in our hospital for differentiated thyroid carcinoma and 52 control samples. Samples were split; half were treated by incubating the sample for 1 h in HAB-blocking tubes, the remainder was left untreated. Subsequently thyroglobulin and thyroglobulin antibody levels were measured in both the blocked and untreated samples. A difference between the two samples was considered significant if the blocked sample deviated from the untreated one by more than 2.77 times the standard deviation for the method. In the measurement of Tg, 2 patients showed a moderate, but significant lowering of Tg levels after blocking treatment, but not so great as to affect clinical management. None of the 52 controls showed heterophile antibody interference in thyroglobulin measurement. Neither in DTC patients, nor in controls was any possible heterophile antibody interference encountered. And in all thyroid carcinoma patients, and in all but one controls, no interference was found in the thyroglobulin antibody measurement. All in all a possible heterophile antibody interference was found in 3/759 tests (0.4%). We can assume that heterophile antibody interference is not a factor to be reckoned with in the daily practice of Tg measurement in the treatment and follow-up of differentiated thyroid carcinoma patients.

Endometrial secretion analysis identifies a cytokine profile predictive of pregnancy in IVF.

BACKGROUND: The study of human endometrial-embryonic interactions is complicated by the disruptive impact of endometrial sample collection on the process of implantation itself. Endometrial secretion analysis is a novel technique, non-disruptive to implantation. The primary aim of this prospective cohort study was to explore whether a cytokine profile predictive of implantation and clinical pregnancy can be identified in endometrial secretions aspirated immediately prior to embryo transfer following IVF. METHODS: Endometrial secretions, aspirated immediately prior to embryo transfer from 210 women undergoing IVF, were analyzed using a multiplex immunoassay for 17 soluble regulators of implantation, namely interleukin (IL)-1beta, IL-5, IL-6, IL-10, IL-12, IL-15, IL-17, IL-18, tumor necrosis factor (TNF)-alpha, interferon (IFN)-gamma, macrophage migration inhibitory factor, eotaxin, IFN-gamma-inducible 10 kDa protein (IP-10), monocyte chemo-attractant protein-1 (MCP-1), Dickkopf homolog 1, heparin-binding epidermal growth factor and vascular endothelial growth factor (VEGF). In order to detect implantation, daily urine samples were collected after embryo transfer, and human Chorionic Gonadotropin (hCG) concentrations were analyzed by an immunoassay. RESULTS: Multivariable logistic regression analysis revealed significant associations (negative and positive association, respectively) between MCP-1 (P = 0.005) and IP-10 (P = 0.037) levels and implantation, and between IL-1beta (P = 0.047) and TNF-alpha (P = 0.023) levels and clinical pregnancy. The predictive value for pregnancy of IL-1beta and TNF-alpha was observed to be equivalent and additive to that of embryo quality. CONCLUSIONS: Endometrial secretion cytokine profiling offers a novel, non-disruptive approach to study the role of the endometrium in human embryo implantation and identifies a profile which appears to be conducive to clinical pregnancy. CLINICAL TRIAL REGISTRATION: www.clinicaltrials.gov (nCT00264992).

Low bone mineral density in adult patients with moderate to severe atopic dermatitis.

BACKGROUND: Atopic dermatitis (AD) is a chronic inflammatory skin disease commonly treated with topical corticosteroids. The inflammatory nature of this disorder and the use of topical corticosteroids represent potential risk factors for bone loss. OBJECTIVES: The aim was to assess the prevalence of osteoporosis and osteopenia in adult patients with moderate to severe AD. In addition, the associations between topical/oral corticosteroid use and bone mineral density (BMD) and between disease activity and BMD were studied. PATIENTS AND METHODS: We studied 125 adult patients with moderate to severe AD. Using dual-energy X-ray absorptiometry, BMD was measured at lumbar spine and hips. The cumulative dose of topical and oral corticosteroids was calculated from pharmacy prescription records. Lifestyle parameters were collected by a questionnaire. Biochemical parameters of bone metabolism and disease activity [serum concentration of thymus and activation-regulated chemokine (TARC) levels] were also measured. RESULTS: Osteoporosis was documented in six patients (4.8%) and osteopenia in 41 patients (32.8%); 30.4% of the patients had a Z-score

Value of diagnostic radioiodine scintigraphy and thyroglobulin measurements after rhTSH injection.

UNLABELLED: Measurements of thyroglobulin (Tg) levels 72 h after administration of recombinant human thyrotropin (rhTSH) are recommended by the manufacturer in the follow-up of patients with differentiated thyroid carcinoma (DTC). In our department, Tg measurements are performed both 24 h and 72 h after administration of rhTSH, together with 72 h post rhTSH 131I whole body scintigraphy (WBS). The OBJECTIVE of this study is to compare the diagnostic usefulness of Tg measurements 24 and 72 h after rhTSH administration, and 131I WBS. PATIENTS AND METHODS: 181 patients were included who had been referred to our Nuclear Medicine Department for follow-up after 131I ablation of DTC. Tg measurements 24 h (Tg24) and 72 h (Tg72) after rhTSH, and 131I WBS, were done in all patients. The lower detection limit of Tg was 0,2 microg/l. RESULTS: 47 patients (26%) had detectable Tg levels: in 4/47 cases (8%) only Tg24 was detectable (always <1 microg/l), and in 6/47 cases (11%), only Tg72 was detectable. In 10/47 patients with detectable Tg-levels, Tg24 and Tg72 tested equally. In 27/47 cases, Tg24 was lower, and in 10/47 higher, than Tg72. Two patients with one or two positive Tg-test results also had a positive 131I WBS. In 8 patients (14%) only the 131I WBS was positive; an anatomical substrate for such a Tg-negative positive WBS was confirmed in only 2 patients. CONCLUSION: Tg-measurement 72 hours after rhTSH injection reveals all clinically relevant detectable Tg-levels. Diagnostic 131I scintigraphy may be omitted, even in high-risk patients.

Elevated plasma corticotrophin-releasing hormone levels in veterans with posttraumatic stress disorder.

Posttraumatic stress disorder (PTSD) is associated with alterations in corticotrophin-releasing hormone (CRH) secretion. Plasma CRH levels, which are easily acquired, might serve as a predictor of hypothalamic CRH levels. Assessment of plasma CRH, adrenocorticotrophin hormone (ACTH), and cortisol levels in 31 veterans with PTSD, 30 traumatized veterans without PTSD matched on age, year, and region of deployment (traumacontrols), and 28 age-matched healthy controls (HCs) was carried out. Plasma CRH levels were higher in PTSD patients compared to both HCs (p=0.005) and traumacontrols (p=0.007). This led to our conclusion, that elevated plasma CRH levels are specifically related to PTSD and not to exposure to traumatic stress during deployment.

Enhanced cortisol suppression in response to dexamethasone administration in traumatized veterans with and without posttraumatic stress disorder.

BACKGROUND: While enhanced cortisol suppression in response to dexamethasone is one of the most consistent biological findings in posttraumatic stress disorder (PTSD), the relative contribution of trauma exposure to this finding remains unclear. METHODS: Assessment of diurnal salivary cortisol levels and 1600 h salivary cortisol before and after oral administration of 0.5mg dexamethasone in veterans with PTSD, veterans without PTSD (trauma controls) and healthy controls. Assessment of 1600 h plasma cortisol, ACTH and corticotrophin binding globulin (CBG) in response to dexamethasone in PTSD patients and trauma controls. RESULTS: Both PTSD patients and trauma controls demonstrated significantly more salivary cortisol suppression compared to healthy controls. Salivary cortisol, plasma cortisol and ACTH suppression as well as CBG levels did not differ between PTSD patients and trauma controls. PTSD patients showed a reduced awakening cortisol response (ACR) compared to healthy controls that correlated significantly with PTSD symptoms. No significant differences were observed in ACR between PTSD patients and trauma controls. CONCLUSIONS: These data suggest that enhanced cortisol suppression to dexamethasone is related to trauma exposure and not specifically to PTSD. The correlation between the ACR and PTSD severity suggests that a flattened ACR may be a result of clinical symptoms.

Intracavitary deposits on Essure® hysteroscopic sterilization devices: A case report.

OBJECTIVE: To study the composition of intracavitary deposits on Essure® hysteroscopic sterilization devices. DESIGN: Case report. SETTING: Reproductive Medicine and Gynecology department of a University Hospital. PATIENTS: A 39 years old patient presenting with a request for surgical removal of Essure® sterilization devices. Diagnostic hysteroscopy showed a crystal like white deposit attached to one of the devices. INTERVENTION: Diagnostic hysteroscopy and surgical removal of Essure® devices was performed. The deposits were collected and infrared spectroscopy analysis was performed. MAIN OUTCOME MEASURE: Chemical composition of the deposits attached to the device. RESULTS: Infrared spectroscopy of the material showed patterns conclusive with calcite (calcium carbonate, CaCO3). CONCLUSION: Until now, it is not clear if there is a relationship between reported complaints and formation of calcite deposits on Essure®. CAPSULE: Infrared spectroscopy of deposits on Essure® devices showed a pattern conclusive with calcite. The relationship between reported complaints and the formation of calcite deposits on Essure® remains unclear.

A quantitative comparison of anti-Müllerian hormone measurement and its shifting boundaries between two assays.

OBJECTIVE: Anti-Müllerian hormone (AMH), a quantitative marker of ovarian reserve, is used for both clinical and research purposes in the field of reproductive medicine. Numerous AMH assays have been developed. Among other factors, the lack of large-scale comparisons of the various assays hinders the universal interpretation of AMH levels. Moreover, little is known of the practical performance of highly sensitive assays compared with conventional assays with regard to the very low AMH levels found in women nearing menopause. This study aimed to compare the measurements of the Gen II (Beckman Coulter) assay with those of the highly sensitive picoAMH (AnshLabs) assay. METHODS: This cross-sectional study included 1985 premenopausal women who completed the second visit of the population-based Doetinchem Cohort Study, with a mean age of 42±7years. AMH levels were measured with the Gen II and picoAMH assays. Passing-Bablok and Bland Altman analyses were performed and differences in the proportion of detectable samples were assessed. RESULTS: The results from the Gen II and picoAMH assays were highly correlated, with a Spearman correlation coefficient of 0.91. The Passing-Bablok regression formula was picoAMH=0.01+1.69*GenII, meaning that on average picoAMH levels were 69% higher than Gen II levels. Of the 670 samples with an undetectable AMH value with the Gen II assay, AMH could be detected in 78% with the picoAMH assay, at a median concentration [interquartile range] of 0.05 [0.01-0.14] ng/mL. CONCLUSION: These results indicate that, despite a high correlation, there is a large relative difference between results of the Gen II and picoAMH assays. The use of a highly sensitive AMH assay is likely to result in a large increase in the proportion of samples with detectable levels. This may enable research into women's health across the menopausal transition and research into the potential clinical benefits of distinguishing between women with very low ovarian reserve.

Peripheral blood gene expression profiles linked to monoamine metabolite levels in cerebrospinal fluid.

The blood-brain barrier separates circulating blood from the central nervous system (CNS). The scope of this barrier is not fully understood which limits our ability to relate biological measurements from peripheral to central phenotypes. For example, it is unknown to what extent gene expression levels in peripheral blood are reflective of CNS metabolism. In this study, we examine links between central monoamine metabolite levels and whole-blood gene expression to better understand the connection between peripheral systems and the CNS. To that end, we correlated the prime monoamine metabolites in cerebrospinal fluid (CSF) with whole-genome gene expression microarray data from blood (N=240 human subjects). We additionally applied gene-enrichment analysis and weighted gene co-expression network analyses (WGCNA) to identify modules of co-expressed genes in blood that may be involved with monoamine metabolite levels in CSF. Transcript levels of two genes were significantly associated with CSF serotonin metabolite levels after Bonferroni correction for multiple testing: THAP7 (P=2.8 × 10-8, ß=0.08) and DDX6 (P=2.9 × 10-7, ß=0.07). Differentially expressed genes were significantly enriched for genes expressed in the brain tissue (P=6.0 × 10-52). WGCNA revealed significant correlations between serotonin metabolism and hub genes with known functions in serotonin metabolism, for example, HTR2A and COMT. We conclude that gene expression levels in whole blood are associated with monoamine metabolite levels in the human CSF. Our results, including the strong enrichment of brain-expressed genes, illustrate that gene expression profiles in peripheral blood can be relevant for quantitative metabolic phenotypes in the CNS.

Hypothyroidism during immunotherapy with interleukin-2 is associated with antithyroid antibodies and response to treatment.

PURPOSE: We investigated whether the association of interleukin-2 (IL-2) with hypothyroidism is related to the presence of thyroid autoantibodies, dose of IL-2, and clinical effectiveness of treatment, and reviewed the literature. PATIENTS AND METHODS: Sixteen cancer patients were treated with high-dose recombinant, continuous infusion IL-2 (18 x 10(6) IU/m2/d) and lymphokine-activated killer (LAK) cells. One patient previously treated for a toxic goiter with radioactive iodine was analyzed separately. Thyroid function and levels of thyroid antibodies were determined regularly. RESULTS: Seven of 15 patients (47%) became hypothyroid with high serum thyrotropin (TSH) levels within 60 to 120 days after the start of treatment; five responded favorably to treatment (one complete remission [CR], four partial remissions [PRs]), compared with none of the other eight patients. Two hypothyroid patients developed antimicrosomal antibodies (AMAs), one showed a further increase of antithyroglobulin antibodies (TgAbs), and six developed TgAbs. Only one of eight euthyroid patients developed slightly elevated TgAb levels. Development of hypothyroidism correlated significantly with a favorable response to treatment (r = .76, P = .001). The patient, treated with radioactive iodine, also became hypothyroid with high levels of TSH and development of AMAs and TgAbs. No difference was found between the hypothyroid and euthyroid patients in mean cumulative dose of IL-2 administered within the first 60 days or total treatment period, or with the relative dose-intensity. No other autoantibodies were found and patients had normal corticotropin (ACTH) stimulation tests. CONCLUSION: The likelihood of developing (transient) hypothyroidism is higher in patients who respond to IL-2 treatment. The development of antithyroid antibodies suggests that IL-2 treatment triggers autoreactive B-cell clones or that cellular and/or cytokine-mediated thyroid destruction leads to activation of autoreactive B-cell clones.

Melanogenesis in cultured melanocytes can be substantially influenced by L-tyrosine and L-cysteine.

We investigated the effect of varying concentration of 1-tyrosine and 1-cysteine in culture medium on melanin production by human skin melanocytes (skin phototype II/III). In addition to the analyses of dopa oxidase activity and total melanin, pheomelanin production in the cells was assessed by high-performance liquid chromatography determinations of pheomelanin degradation products, 3-aminotyrosine and 4-amino-3-hydroxyphenylalanine. As another marker for pheomelanin, melanosomal sulfur was determined by the use of X-ray microanalysis. With varying concentration of both amino acids, profound changes in the pigmentation patterns of the melanocytes were observed. A high concentration of 1-tyrosine (0.2 mM) was always connected with increased pigmentation. In combination with a low 1-cysteine content we saw an increase in tyrosinase activity and the highest melanin content. At high concentrations of both 1-tyrosine and 1-cysteine, the melanocytes showed reduced tyrosinase activity and they produced notably more pheomelanin. In case of the pheomelanin measurements by high-performance liquid chromatography and the sulfur detection with X-ray microanalysis, strongly increased concentrations were found when cells were maintained in high 1-tyrosine medium as compared with those grown with low 1-tyrosine. This was especially true for the combination with low 1-cysteine showing that the 1-tyrosine content of the medium strongly influences not only the eumelanin but also the pheomelanin production in the cultured melanocyte. It can be concluded that variations in the concentrations of 1-tyrosine and 1-cysteine in culture medium can be used to regulate the melanogenetic phenotype under in vitro conditions.

Temperature-dependent cortisol distribution among the blood compartments in man.

This study was conducted to investigate the effect of temperature on the amount of cortisol bound to the erythrocytes and the distribution of cortisol in whole blood at various temperatures. The amount of cortisol bound to the erythrocytes was determined in a way that did not disturb the equilibrium distribution of cortisol between plasma and erythrocytes. Total and free cortisol concentrations in plasma and the amount of cortisol bound to the erythrocytes were determined at 20, 30, 37, and 40 C in the blood of six healthy persons. The amount of cortisol bound to the erythrocytes showed a perfect linear relation with the free cortisol concentration and was independent from the temperature. The average ratio of the erythrocyte-associated and free cortisol was 2.38 +/- 0.06. Computer simulations of the distribution of cortisol among the blood compartments showed that the free and loosely bound fraction (albumin and erythrocytes) was highly temperature dependent: at 30 C, this fraction was 3-5 times lower than at 37 C. It was demonstrated by computer simulation that changes in the concentration of cortisol-binding globulin had an effect on the fractional distribution of cortisol among the blood components. These shifts in the cortisol distribution, between the erythrocyte and the plasma compartment, can also be the cause of apparently high or low free and total plasma cortisol concentrations. Differences up to 25% in the free cortisol concentration can be observed. We conclude that the erythrocyte-associated cortisol fraction is relatively undervalued but can serve as an important transport vehiculum and storage compartment for cortisol. This fraction can have a considerable effect on the total plasma and free cortisol concentration when strict temperature control during sample handling is not considered.

The influence of reduced liver blood flow on the pharmacokinetics and pharmacodynamics of recombinant tissue factor pathway inhibitor.

OBJECTIVES: Recombinant tissue factor pathway inhibitor (rTFPI) has been shown to be an effective treatment in animal models of sepsis and is under investigation for human use. Reduced liver blood flow during septic shock may substantially alter the pharmacokinetics of rTFPI because clearance of rTFPI approaches liver blood flow. The aim of this study was to examine the effect of exercise-induced reduction in liver blood flow on the pharmacokinetics and pharmacodynamics of rTFPI. METHODS: This was a two-way, open-label, randomized crossover study in eight healthy male volunteers. The subjects in both treatment groups received a continuous intravenous infusion of rTFPI (0.2 mg/kg/h) concurrently with intravenous sorbitol (50 mg/min) for 4 hours. Sorbitol was used as a biomarker for liver blood flow. The subjects were randomized to remain supine or to exercise on a bicycle ergometer for 30 minutes starting at the beginning of the third hour of the infusion. RESULTS: Exercise reduced liver blood flow (mean +/- SEM) from 1.44 +/- 0.06 L/min to 0.40 +/- 0.03 L/min. The average clearance of rTFPI decreased from 0.73 +/- 0.04 L/min in the supine position to 0.25 +/- 0.02 L/min during exercise. This decrease in rTFPI clearance resulted in an 80% (95% confidence interval [CI], 60% to 102%) increase in plasma rTFPI levels during exercise. The average maximal prothrombin time and activated partial thromboplastin time values during exercise were 1.4 (95% CI, 0.4 to 2.5) and 4.4 (95% CI, 2.7 to 6.1) seconds higher compared with the supine steady-state level. CONCLUSIONS: Reduction in liver blood flow by exercise markedly increased rTFPI concentrations and induced a slight but variable prothrombin time and activated partial thromboplastin time increase at the rTFPI dose studied.

A potential role for the mast cell in the pathogenesis of idiopathic osteoporosis in men.

Osteoporosis is increasingly being recognized in men. Secondary causes are often implicated, but the mechanism of bone loss remains unclear in about a third of patients. The mast cell is a complex cell that stores a number of factors known to affect bone metabolism. Patients with systemic mastocytosis often demonstrate osteoporosis and bone marrow mast cells may be increased in osteoporotic postmenopausal women. We address the possible role of the mast cell in the pathophysiology of male osteoporosis by studying the relationship between bone marrow infiltration with mast cells and the 24 h urine excretion of N-methylhistamine, and the severity of osteoporosis in 48 consecutive men with idiopathic osteoporosis (bone mineral density Z score of <-1 and/or at least one prevalent vertebral fracture). Secondary causes for osteoporosis were excluded and none of the patients had systemic manifestations of enhanced mast cell activity. A widely variable number of morphologically normal mast cells were counted in toluidine blue-stained sections from 42 of 46 evaluable bone marrow biopsies. In 4 of the 42 biopsies (9%), clusters of abnormal mast cells were identified. These four patients were the only ones who also demonstrated increased 24 h urine excretion of N-methylhistamine. There was a significant positive relationship between mast cell number and the 24 h urine excretion of N-methylhistamine reflecting mast cell activity (p = 0.0001), and this latter measurement correlated negatively with bone mineral density (BMD) at the lumbar spine (p < 0.001). We identified clinically important bone marrow cell infiltration with pathologic mast cells in the absence of systemic manifestations of mast cell hyperactivity as an additional secondary cause for osteoporosis in some 9% of men with idiopathic osteoporosis, and found urinary excretion of N-methylhistamine to be above the upper limit of the normal laboratory reference range diagnostic for this cause of secondary osteoporosis. The more continuous spectrum in the relationship between mast cell activity and BMD supports a potential role for this cell in the pathogenesis of idiopathic male osteoporosis.

Supplementation with antioxidant micronutrients and chemotherapy-induced toxicity in cancer patients treated with cisplatin-based chemotherapy: a randomised, double-blind, placebo-controlled study.

Cisplatin-induced toxicities are mainly caused by the formation of free radicals, leading to oxidative organ damage. Plasma concentrations of antioxidants decrease significantly during cisplatin chemotherapy for cancer. Forty-eight cancer patients treated with cisplatin-based chemotherapy were randomised in a double-blind manner to receive either supplementation with vitamin C, vitamin E and selenium dissolved in a beverage or to receive a placebo beverage. Primary outcome measures were the amount of nephrotoxicity and ototoxicity induced by cisplatin. No significant differences were found between the two study groups with respect to these primary outcome measures. However, patients who achieved the highest plasma concentrations of the three antioxidant micronutrients had significantly less loss of high-tone hearing. In addition, significant correlations were found between the reduced/oxidised vitamin C ratio and malondialdehyde (MDA), markers of oxidative stress, and cisplatin-induced ototoxicity and nephrotoxicity. The lack of protection against cisplatin-induced toxicities in patients in the intervention arm may be related to poor compliance and/or inadequate supplementation. Supplementation with a higher dose (intensity) and in combination with other antioxidants should be investigated further.

LPS-induced IL-10 production in whole blood cultures from chronic fatigue syndrome patients is increased but supersensitive to inhibition by dexamethasone.

Several causes have been held responsible for the chronic fatigue syndrome (CFS), including an altered hypothalamus-pituitary-adrenal gland (HPA)-axis activity, viral infections and a reduced Th1 activity. Therefore, it was investigated whether the regulation of IL-10 is different in CFS. LPS-induced cytokine secretion in whole blood cultures showed a significant increase in IL-10 and a trend towards a decrease in IL-12 as compared with healthy controls. In patients and controls, IL-12 secretion was equally sensitive to suppression by dexamethasone, whereas IL-10 secretion appeared more sensitive in CFS-patients. In controls, IL-10 and IL-12 secretion were inversely correlated with free serum cortisol (r=-0.492, p<0.02 and r=-0.434, p<0.05, respectively). In CFS, such an inverse correlation was found for IL-12 (r=-0.611, p<0.02) but not for IL-10 (r=-0.341, ns). These data are suggestive for a disturbed glucocorticoid regulation of IL-10 in CFS.