Evaluation of NKp46 expression and cytokine production of decidual NK cells in women with recurrent pregnancy loss.

Purpose: NKp46, a receptor on NK cells, is involved in cytotoxicity and cytokine production. The authors aimed to evaluate the effect of NKp46 on decidual NK (dNK) cells during pregnancy and whether it can be a marker for immunological abnormalities in women with recurrent pregnancy loss (RPL). Methods: Flow-cytometric analysis was made to assess NKp46 expression and intracellular cytokine production of dNK cells. The proportion of NKp46+ dNK cells was analyzed among RPL patients who aborted karyotypically normal pregnancies and those who either aborted karyotypically abnormal pregnancies or without genetic studies, and controls who were going through the induced abortion. Results: The %NKp46+ and %NKp46bright dNK cells were significantly lower in the RPL women who aborted karyotypically normal pregnancies than in the control group. The %NKp46bright dNK cells were significantly correlated with the NK1/NK2 ratio of dNK cells. The %NKp46+ dNK cell cutoff for RPL with immunological abnormalities was determined by the ROC curve analysis. In women with the low %NKp46+ dNK, NK1/NK2 ratios were significantly higher than those with the high. Conclusion: RPL patients with an immunological abnormality have decreased NKp46 expression and NK1 shift in dNK cells. NKp46 expression could be a marker for RPL of immunological abnormalities.

Effects of leuprorelin for the treatment of recurrent gynecological cancer by assessment including self-administered quality-of-life questionnaire.

AIM: To investigate the effects of leuprorelin using a self-administered quality-of-life (QOL) questionnaire in patients with recurrent gynecological cancer. METHODS: Records of patients who received 3.75 mg leuprorelin every 4 weeks for the treatment of recurrent gynecological cancer were retrospectively reviewed. The physical domain of the QOL questionnaire, Care Notebook, was used to assess physical symptoms. Symptom deterioration was defined as a ≥10-point increase in baseline score; otherwise, symptoms were defined as controlled. Radiological and serological responses were evaluated according to the 2011 Gynecological Cancer Intergroup criteria. RESULTS: From 2007 to 2015, 25 patients were administered leuprorelin for the treatment of epithelial ovarian cancer, granulosa cell tumor, endometrial cancer, endometrial stromal sarcoma and clear cell cervical cancer (in 13, 3, 6, 2 and 1 patients, respectively). Twenty patients had received a median of three lines (range 1-12 lines) of chemotherapy. Ten patients had progressive disease during their previous round of chemotherapy. Twenty patients completed the questionnaire every 4 weeks. Following leuprorelin treatment for 8 weeks, the symptom and disease control rates were 65% (13/20) and 44% (11/25), respectively. Two patients, one each with granulosa cell tumor and endometrial cancer, had stable disease at 6 months. Among the 20 patients who completed the QOL questionnaire, symptom control and disease control at 8 weeks showed a significant correlation (P = 0.016). CONCLUSION: Leuprorelin had minimal anticancer activity. The physical domain of the QOL questionnaire could be used to assess effects of hormonal treatment.

Co-expression of activating and inhibitory receptors on peritoneal fluid NK cells in women with endometriosis.

The detailed mechanism underlying endometriosis development remains unclear; few reports have suggested the involvement of immune and genetic factors. This study aims to investigate the role of NK cells in endometriosis by analyzing the co-expression of activating (NKp46, NKG2C, and NKG2D) and inhibitory receptors (NKG2A and CD158a) on NK cells and their subsequent cytokine production in the peritoneal fluid (PF). Sixty-two patients were enrolled for this study from Hyogo Medical University between February 2018 and April 2022. Results showed that the proportions of CD56+/NKp46+, CD56dim/NKp46＋, NKG2C＋/NKp46＋, and NKG2D＋/NKp46＋ NK cells were significantly lower in the endometriosis group than those in the control group. Meanwhile, within the peritoneal endometriosis (n = 21) and deep infiltrating endometriosis (n = 11) groups, the co-expression of NKG2D＋/NKp46＋ and CD16＋/NKp46＋. Additionally, the abundance of IFN-γ-producing NK cells was significantly increased in the endometriosis group compared to controls, and a significant negative correlation was noted between NKp46 expression on NK cells and type 1 cytokine (IFN-γ and TNF-α) production. Taken together, the findings of this study indicate that NK cell cytotoxicity in endometriosis is reduced due to changes in NKp46 expression, as well as activating receptors co-expressed with NKp46. Consequently, NK cells do not eliminate endometrial cells in the abdominal cavity, resulting in the production of TNF-α and IFN-γ.

Weight-Loss Interventions and Levonorgestrel Intrauterine System Implantation for Early-Stage Endometrial Cancer and Atypical Endometrial Hyperplasia to Reduce Perioperative Risk of Severely Obese Patients.

Endometrial cancer (EC) and atypical endometrial hyperplasia (AEH) are associated with obesity, which increases the perioperative morbidity and surgical difficulties in laparoscopic and robotic surgery. Weight-loss interventions (WLIs) are likely to reduce morbidity; however, delayed surgery may cause cancer progression. To minimize the tumor progression, levonorgestrel intrauterine system (LNG-IUS) with minimal side effects was used until the planned surgery. During 2016 and 2021, we conducted preoperative management of WLI using LNG-IUS for seven highly obese women with a body mass index (BMI) ≥35 kg/m2 who had AEH and EC with Grade 1 and no myometrial invasion on magnetic resonance imaging. In three of the seven patients, the BMI decreased by more than 5. Two patients with AEH achieved remission after LNG-IUS placement and requested conservative management. Five patients with EC underwent laparoscopic hysterectomy, without perioperative complications.

Co-expression of NKp46 with activating or inhibitory receptors on, and cytokine production by, uterine endometrial NK cells in recurrent pregnancy loss.

NKp46 (CD335) is one of the activating receptors expressed on NK cells and its expression is decreased in patients with reproductive failure. However, the reasons remain unknown. In this study, we aimed to clarify the significance of decreased NKp46 expression in reproductive failure. Uterine endometrial samples collected from 39 patients with recurrent pregnancy loss (RPL) were assigned to high- or low-risk groups based on an 18 % ratio of CD16+/CD56dim NK cells in uterine endometrial NK (uNK) cells. We analyzed the expression of NKp46 and other activating or inhibitory receptors on, and intracellular cytokine production by NK cells using multicolor flow cytometry. The numbers of NKp46+/CD16- NK, NKp46+/NKG2C- NK, IL-4+/CD56+ NK, and IL-10+/CD56+ NK cells were significantly decreased, whereas that TNF-α+/CD56+ NK cells was significantly increased in the high-risk group, when compared with the low-risk group (P < 0.05 for all). The ratios of TNF-α/IL-4, IFN-γ/IL4, TNF-α/IL-10, and IFN-γ/IL10 cytokine production in uNK cells were significantly increased in the high-risk when compared with the low-risk group (P < 0.05, for all). It is suggested that low expression of activating receptors on NKp46 uNK cells is more prevalent in high-risk women.

NK cells that differ in expression of NKp46 might play different roles in endometrium.

NKp46 is a natural cytotoxicity receptor expressed by NK cells and its expression is decreased in reproductive failure patients. NKp46 can be subdivided into NKp46dim and NKp46bright according to different fluorescence staining intensities. We investigated the role of the NKp46 receptor in determining the reproductive outcomes. Uterine endometrium was collected from 34 women with reproductive failure and divided into the pregnant and failed groups based on the results of a pregnancy reaction test during a 1-year follow-up period. NKp46 receptor and other activating or inhibitory receptors expressed on NK cells as well as intracellular cytokine production by NK cells were analyzed by multicolor flow cytometry. In the failed group, the percentage of NKp46dim NK cells (P < 0.05) was significantly higher and percentages of NKp46bright NK cells (P < 0.01) and CD16-/CD56bright NK cells (P < 0.05) were significantly lower than those in the pregnant group. NKp46dim NK cells were significantly and positively correlated with CD16+/NKp46dim NK cells; NKp46bright NK cells were significantly and positively correlated with CD16-/NKp46bright NK cells. CD16+/NKp46dim NK cells were significantly and positively correlated with IFN-γ- and/or TNF-α-producing NK cells; CD16-/NKp46bright NK cells were significantly and positively correlated with TGF-ß1-producing NK cells. We suggest that the NKp46 receptor plays different roles in reproduction based on the different fluorescence intensities associated with NK cells, i.e. NKp46dim NK cells are involved in killing cells, whereas NKp46bright NK cells are involved in cytokine production, indicating that NKp46 could be a predictive marker to see a tolerate condition for embryos.

Pelvic endometriosis and natural killer cell immunity.

Endometriosis is a chronic disease that commonly affects women in their reproductive age. It has been reported that the infertility due to endometriosis is largely caused by pelvic adhesion, oocyte damage, and so on. There are several causes of endometriosis including bacterial infections, immunological abnormalities, epigenetics, and aberrant DNA methylation. The natural killer (NK) cells present in the peritoneal fluid express CD16 and CD56. They also express NK cell inhibitory receptors and activating receptors and usually work to eliminate endometrial cells in the retrograde menstruation. However, in women with endometriosis, the changes in these receptors and production of cytokines by NK cells cause the onset and progression of endometriosis. In this review, we have focused on the role of NK cells in pelvic endometriosis and presented the immunological abnormalities in endometriosis including the possibility of future treatment.