Altered intravenous drug disposition in people living with cystic fibrosis: A meta‐analysis integrating top‐down and bottom‐up data

Cystic fibrosis (CF) has been linked to altered drug disposition in various studies. However, the magnitude of these changes, influencing factors, and underlying mechanisms remain a matter of debate. The primary aim of this work was therefore to quantify changes in drug disposition (top‐down) and the pathophysiological parameters known to affect pharmacokinetics (PKs; bottom‐up). This was done through meta‐analyses and meta‐regressions in addition to theoretical PK simulations. Volumes of distribution and clearances were found to be elevated in people living with CF. These increases were larger in studies which included patients with pulmonary exacerbations. Differences in clearance were smaller in more recent studies and when results were normalized to body surface area or lean body mass instead of body weight. For the physiological parameters investigated, measured glomerular filtration rate and serum cytokine concentrations were found to be elevated in people living with CF, whereas serum albumin and creatinine levels were decreased. Possible pathophysiological mechanisms for these alterations relate to renal hyperfiltration, increases in free fraction, and inflammation. No differences were detected for cardiac output, body fat, fat free mass, hematocrit, creatinine clearance, and the activity of drug metabolizing enzymes. These findings imply that, in general, lower total plasma concentrations of drugs can be expected in people living with CF, especially when pulmonary exacerbations are present. Given the potential effect of CF on plasma protein binding and the variability in outcome observed between studies, the clinical relevance of adapting existing dosage regimens should be evaluated on a case‐by‐case basis.

P–429 Calcium analysis and embryonic development of in vitro matured oocytes from transgender men

Study question

Can oocytes isolated from transgender men after oophorectomy support embryonic development?

Summary answer

Embryo developmental arrest at 4–8cell stage (day 3 embryos) indicates poor quality of in vitro matured oocytes from transgender men.

What is known already

Gender affirming surgery for transgender men leads to permanent infertility, as it involves bilateral oophorectomy. Current approaches for fertility preservation, such as oocyte freezing following ovarian hyperstimulation, may interfere with the wanted masculine characteristics and enhance gender dysphoria. In vitro matured oocytes (IVM) isolated following oophorectomy have been proposed as a source of potential gametes to ensure fertility preservation for transgender men with a child wish. From previous studies, it has been shown that these oocytes are able to undergo maturation and display normal spindles, but their competence to be fertilized and support embryonic development has not been addressed yet.

Study design, size, duration

We evaluated the quality of in vitro matured oocytes isolated from ovaries of transgender men by applying calcium imaging and monitoring fertilization and embryonic development following intracytoplasmic sperm injection (ICSI). Ovaries were collected in cold (4oC) or warm (37oC) medium, to investigate the best collection procedure. So far, results from four transgender men have been included. Participants/materials, setting, methods: Ovaries from four transgender men undergoing testosterone treatment were collected after oophorectomy in cold or warm medium. Cumulus oocyte complexes (COCs) were isolated and cultured in maturation medium for 48hrs. Mature oocytes were injected with donated sperm and assessed either by calcium imaging, measuring the total calcium release following injection, or following embryonic development. Donated in vitro matured oocytes, germinal vesicle(GV) or metaphase I(MI) origin, from other patients undergoing IVF treatment were used as controls.

Main results and the role of chance

In total, 179 COCs were collected from ovaries (n = 8) of four transgender men. From the COCs collected in warm medium, 73/105(69%) survived and 33/73(45%) reached metaphase II (MII). Of 21 MII injected with sperm, 13/21(62%) fertilized, 9/21(43%) formed 2 pronuclei (PN), 8/9(89%) reached the 2-cell stage, 3/9(33%) reached 4–8cell stage but arrested. From 74 COCs isolated in cold medium, 57/74(77%) survived and 28/57(49%) matured. Of the 11 MII injected with sperm, 7/11(64%) fertilized, 6/11(54%) formed 2PN, 6/6(100%) reached the 2-cell stage, 4/6(67%) reached 4–8cell but arrested. In the control group, 10/13 oocytes injected with the same sperm sample, were normally fertilized (77%), 8/10(80%) reached the 2-cell stage, 7/10(70%) reached the 4–8cell stage and 4/10(40%) became blastocysts. From the warm, cold and control conditions, respectively 12,14 and 17 MII oocytes were used for calcium imaging. The product of amplitude and frequency of calcium peaks, representing total calcium release, was calculated. Oocytes showed an average release of 0.66AU and 1.69AU for the warm and cold condition, respectively. The average value for control oocytes was 2.19AU.

Limitations, reasons for caution

One major limitation of our study is the lack of ovaries from cis women as control group. Our control oocytes originated from women undergoing IVF treatment and have undergone ovarian stimulation. Furthermore, the number of oocytes analysed and number of patients per group was limited and is being increased.

Wider implications of the findings: Our data indicate that in vitro matured oocytes from transgender men ovaries display poor quality, as demonstrated by the poor embryonic development. In the future, we will apply nuclear transfer technology as a mean to overcome embryonic developmental arrest in this group of oocytes.

Trial registration number

Not applicable

Ovarian stimulation during assisted reproduction treatment: a comparison of recombinant and highly purified urinary human FSH. On behalf of The Feronia and Apis study group

This randomized, single-blind, multicentre, multinational study compared recombinant human FSH (rhFSH, Gonal-F) with highly purified urinary human FSH (uhFSH, Metrodin HP) in women undergoing ovarian stimulation for IVF/intracytoplasmic sperm injection (ICSI). Following desensitization in a long gonadotrophin-releasing hormone (GnRH) agonist protocol, patients received s.c. Gonal-F or Metrodin HP, at a fixed dose of 150 IU, until there was adequate follicular development. Of 496 women randomized, 232 and 231 in the Gonal-F and Metrodin HP groups respectively received human chorionic gonadotrophin (HCG). The duration of FSH treatment was significantly shorter with Gonal-F than with Metrodin HP (11.6 +/- 1.9 days versus 12. 4 +/- 2.7 days; P < 0.0001) and significantly fewer ampoules were required (mean 22.6 +/- 5.0 versus 24.3 +/- 5.1, P < 0.0002). There were, however, significantly more follicles > or =10 mm in diameter with Gonal-F (15.6 +/- 8.2 versus 13.6 +/- 7.1, P < 0.01) and oocytes retrieved (13.1 +/- 7.7 versus 11.4 +/- 7.6, P < 0.002). Although no statistical difference in pregnancy rate was recorded, patients receiving Gonal-F had a higher pregnancy rate per cycle than patients given Metrodin HP (25.1 versus 20.1%). Moderate to severe ovarian hyperstimulation syndrome occurred in 2.8 and 1.2% of Gonal-F and Metrodin HP patients respectively (not significant). In conclusion, FSH stimulation in combination with a long GnRH agonist protocol is effective in inducing multiple follicular development and embryos with a high implantation potential. However, Gonal-F is clearly more effective than Metrodin HP in inducing multifollicular development.