Oral dydrogesterone versus micronized vaginal progesterone for luteal phase support: a double-blind crossover study investigating pharmacokinetics and impact on the endometrium.

STUDY QUESTION: How do plasma progesterone (P) and dydrogesterone (D) concentrations together with endometrial histology, transcriptomic signatures, and immune cell composition differ when oral dydrogesterone (O-DYD) or micronized vaginal progesterone (MVP) is used for luteal phase support (LPS)? SUMMARY ANSWER: Although after O-DYD intake, even at steady-state, plasma D and 20αdihydrodydrogesterone (DHD) concentrations spiked in comparison to P concentrations, a similar endometrial signature was observed by histological and transcriptomic analysis of the endometrium. WHAT IS KNOWN ALREADY: O-DYD for LPS has been proven to be noninferior compared to MVP in two phase III randomized controlled trials. Additionally, a combined individual participant data and aggregate data meta-analysis indicated that a higher pregnancy rate and live birth rate may be obtained in women receiving O-DYD versus MVP for LPS in fresh IVF/ICSI cycles. Little data are available on the pharmacokinetic (PK) profiles of O-DYD versus MVP and their potential molecular differences at the level of the reproductive organs, particularly at the endometrial level. STUDY DESIGN, SIZE, DURATION: Thirty oocyte donors were planned to undergo two ovarian stimulation (OS) cycles with dual triggering (1.000 IU hCG + 0.2 mg triptorelin), each followed by 1 week of LPS: O-DYD or MVP, in a randomized, cross-over, double-blind, double-dummy fashion. On both the first and eighth days of LPS, serial blood samples upon first dosing were harvested for plasma D, DHD, and P concentration analyses. On Day 8 of LPS, an endometrial biopsy was collected for histologic examination, transcriptomics, and immune cell analysis. PARTICIPANTS/MATERIALS, SETTING, METHODS: All oocyte donors were <35 years old, had regular menstrual cycles, no intrauterine contraceptive device, anti-Müllerian hormone within normal range and a BMI ≤29 kg/m2. OS was performed on a GnRH antagonist protocol followed by dual triggering (1.000 IU hCG + 0.2 mg triptorelin) as soon as ≥3 follicles of 20 mm were present. Following oocyte retrieval, subjects initiated LPS consisting of MVP 200 mg or O-DYD 10 mg, both three times daily. D, DHD, and P plasma levels were measured using liquid chromatography-tandem mass spectrometry. Histological assessment was carried out using the Noyes criteria. Endometrial RNA-sequencing was performed for individual biopsies and differential gene expression was analyzed. Endometrial single-cell suspensions were created followed by flow cytometry for immune cell typing. MAIN RESULTS AND THE ROLE OF CHANCE: A total of 21 women completed the entire study protocol. Subjects and stimulation characteristics were found to be similar between groups. Following the first dose of O-DYD, the average observed maximal plasma concentrations (Cmax) for D and DHD were 2.9 and 77 ng/ml, respectively. The Cmax for D and DHD was reached after 1.5 and 1.6 h (=Tmax), respectively. On the eighth day of LPS, the first administration of that day gave rise to a Cmax of 3.6 and 88 ng/ml for D and DHD, respectively. For both, the observed Tmax was 1.5 h. Following the first dose of MVP, the Cmax for P was 16 ng/ml with a Tmax of 4.2 h. On the eighth day of LPS, the first administration of that day showed a Cmax for P of 21 ng/ml with a Tmax of 7.3 h. All 42 biopsies showed endometrium in the secretory phase. The mean cycle day was 23.9 (±1.2) in the O-DYD group versus 24.0 (±1.3) in the MVP group. RNA-sequencing did not reveal significantly differentially expressed genes between samples of both study groups. The average Euclidean distance between samples following O-DYD was significantly lower than following MVP (respectively 12.1 versus 18.8, Mann-Whitney P = 6.98e-14). Immune cell profiling showed a decrease of CD3 T-cell, γδ T-cell, and B-cell frequencies after MVP treatment compared to O-DYD, while the frequency of natural killer (NK) cells was significantly increased. LIMITATIONS, REASONS FOR CAUTION: The main reason for caution is the small sample size, given the basic research nature of the project. The plasma concentrations are best estimates as this was not a formal PK study. Whole tissue bulk RNA-sequencing has been performed not correcting for bias caused by different tissue compositions across biopsies. WIDER IMPLICATIONS OF THE FINDINGS: This is the first study comparing O-DYD/MVP, head-to-head, in a randomized design on a molecular level in IVF/ICSI. Plasma serum concentrations suggest that administration frequency is important, in addition to dose, specifically for O-DYD showing a rapid clearance. The molecular endometrial data are overall comparable and thus support the previously reported noninferior reproductive outcomes for O-DYD as compared to MVP. Further research is needed to explore the smaller intersample distance following O-DYD and the subtle changes detected in endometrial immune cells. STUDY FUNDING/COMPETING INTEREST(S): Not related to this work, C.Bl. has received honoraria for lectures, presentations, manuscript writing, educational events, or scientific advice from Abbott, Ferring, Organon, Cooper Surgical, Gedeon-Richter, IBSA, and Merck. H.T. has received honoraria for lectures, presentations, manuscript writing, educational events, or scientific advice from Abbott, Ferring, Cooper Surgical, Gedeon-Richter, Cook, and Goodlife. S.M. has received honoraria for lectures, presentations, educational events, or scientific advice from Abbott, Cooper Surgical, Gedeon-Richter, IBSA, and Merck and Oxolife. G.G. has received honoraria for lectures, presentations, educational events, or scientific advice from Merck, MSD, Organon, Ferring, Theramex, Gedeon-Richter, Abbott, Biosilu, ReprodWissen, Obseva, PregLem, Guerbet, Cooper, Igyxos, and OxoLife. S.V.-S. is listed as inventor on two patents (WO2019115755A1 and WO2022073973A1), which are not related to this work. TRIAL REGISTRATION NUMBER: EUDRACT 2018-000105-23.

Leptin is an endogenous protective protein against the toxicity exerted by tumor necrosis factor.

Tumor necrosis factor (TNF) is a central mediator of a number of important pathologies such as the systemic inflammatory response syndrome. Administration of high TNF doses induces acute anorexia, metabolic derangement, inflammation, and eventually shock and death. The in vivo effects of TNF are largely mediated by a complex network of TNF-induced cytokines and hormones acting together or antagonistically. Since TNF also induces leptin, a hormone secreted by adipocytes that modulates food intake and metabolism, we questioned the role of leptin in TNF-induced pathology. To address this question, we tested mouse strains that were defective either in leptin gene (ob/ob) or in functional leptin receptor gene (db/db), and made use of a receptor antagonist of leptin. Ob/ob and db/db mice, as well as normal mice treated with antagonist, exhibited increased sensitivity to the lethal effect of TNF. Exogenous leptin afforded protection to TNF in ob/ob mice, but failed to enhance the protective effect of endogenous leptin in normal mice. We conclude that leptin is involved in the protective mechanisms that allow an organism to cope with the potentially autoaggressive effects of its immune system.

A mediator role for metallothionein in tumor necrosis factor-induced lethal shock.

Tumor necrosis factor (TNF) is a proinflammatory cytokine, which is centrally involved in several inflammatory disorders. Administration of TNF leads to a potentially lethal systemic inflammatory response syndrome (SIRS). We observed that (a) mice lacking functional genes for metallothionein 1 and 2 (MT-null) were protected compared with wild-type controls (P = 0.0078), and (b) mice overexpressing MT-1 (MT-TG) were more sensitized for the lethal effect of TNF than control mice (P = 0.0003), indicating a mediating role for MT in TNF induced SIRS. As MT is involved in the body zinc homeostasis, we tested whether zinc-deprivation or -supplementation alters the response to TNF. Although zinc-depletion strongly sensitized (P = 0.036), and pretreatment with zinc sulfate (ZnSO4) conferred protection against the deleterious effects of TNF (P < 0.0002), it was also found that the protection provided by zinc is independent of MT. Our observation that hsp70 is strongly induced in jejunum after ZnSO4 treatment, suggests a contribution of hsp70 in the protection against TNF. In addition, ZnSO4 cotreatment allowed complete regression of inoculated tumors with TNF and interferon gamma, leading to a significantly better survival (P = 0.0045).

A neuroendocrine tumour of the sphenoid sinus and nasopharynx: a case report.

It is rare for neuroendocrine tumours to originate in the sphenoid sinus and the nasopharynx. Neuroendocrine tumours can be classified into typical carcinoids, atypical carcinoids and small cell neuroendocrine carcinomas. Here we report the case of a 48-year-old man with a typical carcinoid tumour of the nasopharynx and sphenoid sinus. This is a very rare diagnosis, and only a few cases of a typical carcinoid in this region have been described in the literature.

Analysis of third body particles generated during total knee arthroplasty: is metal debris an issue?

PURPOSE: There is a concern amongst knee surgeons that during total knee arthroplasty (TKA) certain particles could be generated which might become left inside the knee, and which could become a possible cause of third body wear. Especially during the sawing process, when an oscillating saw is used through slots in a cutting block, there is a potential cause for metal debris generation. So far however, no data exist to substantiate and quantify the amount of metal debris left in situ after TKA, and it was the purpose of this study to evaluate this. METHODS: In seven consecutive patients undergoing primary cemented TKA, we measured the amount of debris that was present at the end of the operation immediately before closure. The debris was retrieved using pulsed irrigation with 1 l of normal saline, which was then collected and centrifuged. Obtained pellets were subsequently washed and chemically treated to quantify the different components present in the debris. RESULTS: Overall an average amount of 134.9 mg (range 73.6-198.0 mg) debris was retrieved. The debris contained on average 75.8 mg of bone particles (range 41.2-109.3 mg), 57.2 mg (range 31.2-83.9 mg) of cement particles, and 1.96 mg (range 0-7.2 mg) of metal particles. On average the total amount of debris consisted for 56.5% of bony fragments, 42% cement fragments and 1.5% metal particles. CONCLUSION: Even despite precise surgical technique including pressurized irrigation, a significant amount of debris is still present after TKA. The debris consists predominantly of bone and cement particles. The presence of metal debris is limited, and contributes only 1.5% to the total amount.

A role for leptin in the systemic inflammatory response syndrome (SIRS) and in immune response, an update.

Leptin was originally identified as an adipocyte-derived cytokine with a key role in the regulation of the energy balance. Subsequent research revealed that leptin's biological action is not restricted to its effects on appetite and food intake, but instead has a much more pleiotropic character. There is now ample evidence that leptin has important functions in reproduction, hematopoiesis, HPA-axis endocrinology and angiogenesis. In this review we have focused on the effects of leptin in the antigen-specific immunity and in the inflammatory effector system.

Leptin: linking adipocyte metabolism with cardiovascular and autoimmune diseases.

Leptin was originally discovered as an adipocyte-derived hormone involved in the central control of body weight and energy homeostasis. It is now clear that leptin is a pleiotropic cytokine, with activities on many peripheral cell types. These findings may help explain the surprising role of leptin in pathophysiological processes. Recent evidence suggests that leptin contributes to atherosclerosis and to the increased risk of cardiovascular disease in obese people. Leptin also appears to be involved in T-cell-dependent immunity and possibly in the development and maintenance of certain autoimmune diseases. Here, we review the role of leptin in cardiovascular and autoimmune diseases, and also briefly address the potential therapeutic use of leptin antagonists.

A role for leptin in the systemic inflammatory response syndrome (SIRS) and in immune response.

Leptin was originally identified as an adipocyte-derived cytokine with a key role in the regulation of the energy balance. Subsequent research has, however, revealed that leptin's biological action is not restricted to its effects on appetite and food intake, but rather has a much more pleiotropic character. Evidence is now accumulating that it has important functions in reproduction, hematopoiesis, HPA-axis endocrinology and angiogenesis. In this review, we have focused on the effects of leptin in the immune system, which can be found in both the antigen-specific immunity and in the inflammatory effector system.

Analysis of Tyr to Phe and fa/fa leptin receptor mutations in the PC12 cell line.

Weight regulation through body-fat content and energy homeostasis, is regulated mainly through the actions of leptin. Herein, we analyse the effect of mutations in the mouse leptin receptor using the PC12 pheochromocytoma cell line as a model system. Both the induction of pancreatitis associated protein 1 and metallothionein-II, two leptin regulated genes in PC12, was evaluated. Tyr to Phe mutations in the cytoplasmic tail of the mouse leptin receptor confirmed the critical role of Tyr1138 (a YxxQ motif) and STAT-3 activation for induction of leptin-induced genes in PC12. In addition, the Tyr985Phe mutation showed enhanced responsiveness to leptin, which was even more pronounced in combination with Tyr1077Phe. The short isoform of the leptin receptor showed complete loss of stimulation of both genes. In contrast, a leptin receptor devoid of all Tyr residues in its cytoplasmic tail was still capable of a limited induction of the PAP 1 gene. A mutant mouse leptin receptor containing the fa/fa mutation showed constitutive signalling and impaired responsiveness to leptin. Treatment with the adenylate cyclase activator forskolin alone, in the absence of leptin was sufficient to obtain full induction of both genes.

Murine M cells express annexin V specifically.

The specialized epithelium covering the lymphoid follicles of Peyer's patches in the gut mediates transcytosis of antigens to the underlying immune cells, mainly through the membranous, or M, cells. At present, the molecular processes involved in the mucosal immune response, and in antigen transport across the follicle-associated epithelium (FAE) and M cells, are poorly understood. To characterize FAE and M cells, we compared the gene expression profiles of small intestine FAE and villus epithelium (VE) in BALB/c mice by microarray analysis; 91 genes were found to be up-regulated and four down-regulated at least two-fold (p<0.01) in the FAE. The differential expression of a subset of these genes was shown to be confirmed by quantitative RT-PCR. Using immunohistochemistry on BALB/c Peyer's patches, cathepsin H and clusterin expression was increased in the FAE compared to the VE. Moreover, we demonstrated M cell-specific expression of annexin V, which has recently been reported to be important in endocytic transport and membrane scaffolding, suggesting that annexin V has a function in M cell-mediated transcytosis.

Identification and expression analysis of leptin-regulated immediate early response and late target genes.

Using PC12 cells as an in vitro model system, we have identified a series of transcripts induced through activation of the leptin receptor. On the basis of kinetic studies, two distinct gene sets could be discerned: signal transducer and activator of transciption-3 (STAT-3), suppressor of cytokine signalling-3 (SOCS-3), MT-II (metallothionein-II), the serine/threonine kinase fibroblast-growth-factor-inducible kinase (Fnk) and modulator recognition factor (MRF-1), which are immediate early response genes, and pancreatitis-associated protein I (PAP I), squalene epoxidase, uridine diphosphate glucuronosyltransferase and annexin VIII, which are late induced target genes. At late time points a strong co-stimulation with beta-nerve growth factor or with the adenylate cyclase activator forskolin was observed. To assess the validity of the PC12-cell model system, we examined the effect of leptin administration on the gene transcription of STAT-3, MT-II, Fnk and PAP I in vivo. Leptin treatment of leptin-deficient ob/ob mice increased the STAT-3, SOCS-3, MT-II and Fnk mRNA, and MT-I protein levels in liver, whereas, in jejunum, expression of PAP I mRNA was down-regulated. Furthermore, administration of leptin to starved wild-type mice enhanced the expression of MT-II and Fnk mRNA in liver, but decreased MT-II and PAP I mRNA expression in jejunum. These findings may help to explain the obese phenotype observed in some colonies of MT-I- and MT-II-null mice and/or the observation that leptin protects against tumour-necrosis-factor toxicity in vivo.