The effect of prednisolone on endometrial uterine NK cell concentrations and pregnancy outcome in women with reproductive failure. A retrospective cohort study.

This retrospective study of prospectively collected data examines the effect of prednisolone therapy on raised uterine Natural Killer cell (uNK) concentrations and pregnancy outcomes in women with recurrent miscarriage (RM) and recurrent implantation failure (RIF) after IVF/ICSI treatment. 136 women diagnosed with RRF who had a timed midluteal endometrial biopsy taken for uNK cell analysis were included. Women with high uNK cell concentrations (n = 45) were treated with prednisolone (10 mg/day) for one month, after which a second biopsy was taken for repeat uNK cell analysis. Women for whom prednisolone caused a decrease in uNK cell concentrations continued on prednisolone until 12 weeks of pregnancy. Pregnancy outcomes (live birth, miscarriage and implantation rates) and pregnancy complications were compared for women who received prednisolone and those who did not. Results showed that the prevalence of high uNK cells was 33.1%. Prednisolone significantly decreased the uNK cell concentration (P < 0.001), however reduction to normal limits was achieved in only 48.3% of patients. There was no difference in any of the pregnancy outcomes or complications between women who had received prednisolone and those who had not. In conclusion, this study showed a relatively high prevalence of raised uNK cells in women with recurrent reproductive failure and confirmed the effect of prednisolone on reducing uNK cell concentrations. We found however no evidence for a significant beneficial effect for prednisolone therapy on pregnancy outcomes. Until the results of an adequately powered RCT become available however, these findings should be considered preliminary.

Standardisation of uterine natural killer (uNK) cell measurements in the endometrium of women with recurrent reproductive failure.

Considerable work is being carried out on endometrial NK cells to determine whether they play a role in successful pregnancy outcome. In addition there is debate about whether measurements of uNK should be included in the clinical assessment for women with recurrent implantation failure or recurrent miscarriage. A hindrance to taking this forward is the fact that the density of uNK cells reported by different centres is very different. The aim of this study was to determine the reason for these differences and to develop a standardised method. Three centres participated in the study. Each centre exchanged five formalin fixed, wax embedded sections of endometrium from five women. Sections were immunostained for CD56. Images were taken of 10 random fields at ×400 magnification; total stromal and uNK cells were counted using Image J. Results were expressed as % positive uNK cells and the variation in counts obtained in each centre was compared. After initial analysis a standardised protocol was agreed and the process repeated. Significant variation was seen in the counts obtained after initial analysis (Centre A vs.B, mean difference=-0.72 P<0.001; A vs.C mean difference=-0.47 P<0.001; B vs.C, mean difference=0.25 P=0.085). Analysis suggested that differences may be due to duration of tissue fixation, the embedding and sectioning processes, selection of areas for assessment, definition of immunopositive cells and inclusion or exclusion of blood vessels. Adoption of a standardised protocol reduced the variation (Centre A vs.B mean difference=-0.105 P=0.744; A vs.C mean difference=0.219 P=0.150; B vs.C mean difference=0.32 P=0.031). Use of a standardised method is needed to establish a normal range for uNK cells and to develop a meaningful clinical test for uNK cell measurements.

Peritoneal fluid concentrations of matrix metalloproteinase-9, tissue inhibitor of metalloproteinase-1, and transforming growth factor-beta in women with pelvic adhesions.

OBJECTIVE: To establish whether the concentration of matrix metalloproteinase-9 (MMP-9), tissue inhibitor of metalloproteinase-1 (TIMP-1), and transforming growth factor-beta (TGF-beta) is influenced by the presence or absence of adhesions, and whether the concentration of these mediators vary throughout the menstrual cycle. DESIGN: Prospective case-control study. SETTING: Women undergoing laparoscopy in a university hospital in the United Kingdom. PATIENT(S): Women undergoing laparoscopy for benign gynecological conditions. INTERVENTION(S): Samples of peritoneal fluid were collected at diagnostic laparoscopy in one group, and at laparoscopy and serially during the first 48 hours after laparoscopic adhesiolysis in a second group. We correlated the concentrations of mediators in serially sampled peritoneal fluid during the 48 hours following laparoscopic adhesiolysis to the adhesion formation and reformation found during second-look laparoscopy. MAIN OUTCOME MEASURE(S): The concentrations of MMP-9, TIMP-1, and TGF-beta in peritoneal fluid. RESULT(S): MMP-9 concentration was lower in the follicular phase than the luteal phase of the menstrual cycle. MMP-9 concentration was significantly lower in women with pelvic adhesions than in women with a normal pelvis. The MMP-9/TIMP-1 ratio is significantly higher in women with significant adhesions at second-look laparoscopy compared to women with minimal or no adhesions. CONCLUSION(S): The components of extracellular matrix remodeling may play an important part in the adhesion formation/reformation process.

Do uterine natural killer cell numbers in peri-implantation endometrium predict hypertensive disorder in pregnancy in women with a history of reproductive failure?

The aim of this study was to investigate whether or not increased uterine natural killer (uNK) cell numbers in the peri-implantation endometrium are associated with an increased risk of hypertensive disorders in a subsequent pregnancy. This is a retrospective study including 80 women with a history of unexplained recurrent miscarriage or recurrent implantation failure. Precisely timed endometrial biopsies were obtained from women 7-9 days after the luteinising hormone surge. uNK cells were immunostained for CD56+ and expressed as a percentage of total stromal cells. Patients were defined as having a high uNK cell count if the percentage of total stromal cells was more than 13.9%. Five out of 29 (17.2%) women in the high uNK cell count group and 5 out of 51 (9.8%) women in the normal uNK cell count group developed gestational hypertension. Pre-eclampsia was diagnosed in 2 (6.9%) patients in the high uNK cell count group and 1 (2.0%) patient from the normal uNK cell count group. There was no significant difference in the incidence of either gestational hypertension (P=0.483) and pre-eclampsia (P=0.296) between groups. The overall incidence of hypertensive disease in women with high uNK cell count (24.1%) was two times higher than women with normal uNK cell count (11.8%), but it was not statistically significant (P=0.208). An increased uNK cells count in the peri-implantation period in a cycle prior to conception did not appear to significantly increase the likelihood of hypertensive disease of pregnancy.

Expression of integrins in the endometrium of women with recurrent miscarriage.

Immunostaining intensity for alpha(1), alpha(4), alpha(v)beta(3), and beta(3) was assessed by H score in timed peri-implantation endometrium from 21 women with unexplained recurrent miscarriage and 16 healthy fertile women. No significant difference in H scores in gland epithelium, luminal epithelium, stroma, or blood vessels was observed between the two groups, suggesting that alpha(1), alpha(4), alpha(v)beta(3) and beta(3) integrins are expressed normally in the endometrium of women with unexplained recurrent miscarriage.

Evidence-based investigations and treatments of recurrent pregnancy loss.

OBJECTIVE: To give an overview of currently used investigations and treatments offered to women with recurrent pregnancy loss (RPL) and, from an evidence-based point of view, to evaluate the usefulness of these interventions. DESIGN: Ten experts on epidemiologic, genetic, anatomic, endocrinologic, thrombophilic, immunologic, and immunogenetic aspects of RPL discussed methodologic problems threatening the validity of research in RPL during and after an international workshop on the evidence-based management of RPL. CONCLUSION(S): Most RPL patients have several risk factors for miscarriage, and an extensive investigation for all major factors should always be undertaken. There is an urgent need for agreement concerning the thresholds for detecting what is normal and abnormal, irrespective of whether laboratory tests or uterine abnormalities are concerned. A series of lifestyle factors should be reported in future studies of RPL because they might modify the effect of laboratory or anatomic risk factors. More and larger randomized controlled trials, including trials of surgical procedures, are urgently needed, and to achieve this objective multiple centers have to collaborate. Current meta-analyses evaluating the efficacy of treatments of RPL are generally pooling very heterogeneous patient populations and treatments. It is recommended that future meta-analyses look at subsets of patients and treatment protocols that are more combinable.