Endometrial lymphoid tissue: an immunohistological study

Expression of the Costimulatory Molecule B7-H4 in the Decidua and Placental Tissues in Patients with Placental Abruption

B7 homolog 4 protein (B7-H4), a member of the B7 family, is a immunomodulatory membrane protein. The aim of the study was to evaluate the expression of this protein in the decidua and placental tissues in case of placental abruption (PA) compared to cases of retained placental tissue (RPT) and controls. Tissue samples were obtained from 47 patients with PA, 60 patients with RPT, and 41 healthy controls. The samples were stained for B7-H4 expression, analyzed by an expert pathologist, and a semi-quantitative scale was applied. A statistical analysis revealed that the expression of B7-H4 was significantly higher in the decidua in PA samples compared to samples from patients with RPT (p-value < 0.001) and healthy controls (p-value < 0.001). The expression of B7-H4 in the placental chorionic villus was significantly higher in PA samples in relation to samples from healthy controls (p-value < 0.001) but not in relation to RPT samples (p-value = 0.0853). This finding suggests that B7-H4 might play an important role in mechanisms restoring reproductive tract homeostasis. Further research is necessary in regard to the role of B7-H4 in PA.

The role of endometrial B cells in normal endometrium and benign female reproductive pathologies: a systematic review

STUDY QUESTION

What are the similarities and differences in endometrial B cells in the normal human endometrium and benign reproductive pathologies?

SUMMARY ANSWER

Endometrial B cells typically constitute <5% of total endometrial CD45⁺ lymphocytes, and no more than 2% of total cells in the normal endometrium, and while their relative abundance and phenotypes vary in benign gynaecological conditions, current evidence is inconsistent.

WHAT IS KNOWN ALREADY

B cells are vitally important in the mucosal immune environment and have been extensively characterized in secondary lymphoid organs and tertiary lymphoid structures (TLSs), with the associated microenvironment germinal centre. However, in the endometrium, B cells are largely overlooked, despite the crucial link between autoimmunity and reproductive pathologies and the fact that B cells are present in normal endometrium and benign female reproductive pathologies, scattered or in the form of lymphoid aggregates (LAs). A comprehensive summary of current data investigating B cells will facilitate our understanding of endometrial B cells in the endometrial mucosal immune environment.

STUDY DESIGN, SIZE, DURATION

This systematic review retrieved relevant studies from four databases (MEDLINE, EMBASE, Web of Science Core Collection and CINAHL) from database inception until November 2021.

PARTICIPANTS/MATERIALS, SETTING, METHODS

The search strategy combined the use of subject headings and relevant text words related to ‘endometrium’, ‘B cells’ and B-cell derivatives, such as ‘antibody’ and ‘immunoglobulin’. Non-benign diseases were excluded using cancer-related free-text terms, and searches were limited to the English language and human subjects. Only peer-reviewed research papers were included. Each paper was graded as ‘Good’, ‘Fair’ or ‘Poor’ quality based on the NEWCASTLE-OTTAWA quality assessment scale. Only ‘Good’ quality papers were included.

MAIN RESULTS AND THE ROLE OF CHANCE

Twenty-seven studies met the selection criteria and were included in this review: 10 cross-sectional studies investigated B cells in the normal endometrium; and 17 case–control studies compared the characteristics of endometrial B cells in control and benign female reproductive pathologies including endometritis, endometriosis, infertility, abnormal uterine bleeding, endometrial polyps and uterine fibroids. In all studies, B cells were present in the endometrium, scattered or in the form of LAs. CD20⁺ B cells were more abundant in patients with endometritis, but the data were inconsistent as to whether B-cell numbers were increased in endometriosis and patients with reproductive pathologies.

LIMITATIONS, REASONS FOR CAUTION

Although only ‘good’ quality papers were included in this systematic review, there were variations in patients’ age, diagnostic criteria for different diseases and sample collection time among included studies. Additionally, a large number of the included studies only used immunohistochemistry as the identification method for endometrial B cells, which may fail to provide an accurate representation of the numbers of endometrial B cells.

WIDER IMPLICATIONS OF THE FINDINGS

Histological studies found that endometrial B cells are either scattered or surrounded by T cells in LAs: the latter structure seems to be under hormonal control throughout the menstrual cycle and resembles TLSs that have been observed in other tissues. Further characterization of endometrial B cells and LAs could offer insights to endometrial B-cell function, particularly in the context of autoimmune-associated pathologies, such as endometriosis. Additionally, clinicians should be aware of the limited value of diagnosing plasma cell infiltration using only CD138.

STUDY FUNDING/COMPETING INTEREST(S)

This study was funded by Finox Biotech. The authors have no conflicts of interest to declare.

PROSPERO REGISTRATION NUMBER

This systematic review was registered in PROSPERO in January 2020 (PROSPERO ID: CRD42020152915).

Evaluation of Mucosal Humoral and Cellular Immune Responses to HIV in External Secretions and Mucosal Tissues

The mucosal immune systems of the genital and intestinal tracts as the most frequent sites of HIV-1 entry, display remarkable immunological differences from the systemic immune compartment which must be considered in the evaluation of humoral and cellular immune responses to HIV-1. Marked differences in the fluids from the genital and intestinal tracts and in plasma with respect to the Ig isotypes, their levels, molecular forms and distinct effector functions must be taken into consideration in the evaluation and interpretation of humoral immune responses. Because of the low levels and highly pronounced variation in Ig content, HIV-1-specific antibody concentrations should be always related to the levels of total Ig of a given isotype. This practice will avoid inevitable differences due to the small volumes of collected fluids and sample dilution during the collection and processing of samples from external secretions. Furthermore, appropriate controls and immunochemical assays should be used to complement and confirm results generated by ELISA, which is prone to false positivity. In the evaluation of antibody-mediated virus neutralization in external secretions, precautions and rigorous controls must be used to exclude the effect of innate humoral factors. The evaluation of cell-mediated immune responses in mucosal tissues is difficult due to the low yields of cells obtained from tissue biopsies or cytobrush scrapings. Furthermore, tissue biopsies of, for example rectal mucosa, provide information pertinent exclusively to this local site, which due to the differences in distribution of cells of different phenotypes, do not provide information generalized to the entire intestinal tract. Importantly, studies concerning the kinetics of cellular responses are difficult to perform due to the limited availability of samples or to the inability of obtaining frequent repeated tissue biopsies. For sampling the female genital tract parallel collection of menstrual and peripheral blood yields high numbers of cells that permit their detailed phenotypic and functional analyses. In contrast to tissue biopsies, this non-traumatic collection procedure, results in high cell yields and repeated monthly sampling permits extensive and parallel functional studies of kinetics and unique characteristics of HIV-1-specific cellular responses in the female genital tract and peripheral blood.

Menstrual cycle distribution of uterine natural killer cells is altered in heavy menstrual bleeding

Heavy menstrual bleeding (HMB) affects 30% of women of reproductive age and significantly interferes with quality of life. Altered endometrial vascular maturation has been reported in HMB and recurrent miscarriage, the latter associated with increased uterine natural killer (uNK) cell numbers. This study compared endometrial leukocyte populations in controls and women with HMB. Formalin-fixed paraffin-embedded endometrial biopsies from controls (without endometrial pathology) and HMB were immunostained for CD14 (macrophages), CD56 (uNK cells), CD83 (dendritic cells), FOXP3 (regulatory T cells/Tregs), CD3 and CD8 (T cells). Leukocyte numbers were analysed as a percentage of total stromal cells in five randomly selected fields of view in the stratum functionalis of each sample. In control women across the menstrual cycle, 2-8% of total stromal cells were CD3(+) cells, 2-4% were CD8(+) T cells and 6-8% were CD14(+) macrophages. Compared with controls, CD3(+) cells were reduced during the mid-secretory phase (4%, P<0.01) and increased in the late secretory phase (12%, P=0.01) in HMB. CD83(+) dendritic cells and FOXP3(+) Tregs were scarce throughout the menstrual cycle in both groups. In controls, 2% of stromal cells in proliferative endometrium were CD56(+) uNK cells, increasing to 17% during the late secretory phase. In HMB, CD56(+) uNK cells were increased in the proliferative (5%, P<0.01) and early secretory (4%, P<0.02) phases, but reduced (10%, P<0.01) in the late secretory phase. This study demonstrates dysregulation of uNK cells in HMB, the functional consequence of which may have an impact on endometrial vascular development and/or endometrial preparation for menstruation.

The Role of Uterine NK Cells in Normal Reproduction and Reproductive Disorders

The human endometrium contains a substantial population of leucocytes which vary in distribution during the menstrual cycle and pregnancy. An unusual population of natural killer (NK) cells, termed uterine NK (uNK) cells, are the most abundant of these cells in early pregnancy. The increase in number of uNK cells in the mid-secretory phase of the cycle with further increases in early pregnancy has focused attention on the role of uNK cells in early pregnancy. Despite many studies, the in vivo role of these cells is uncertain. This chapter reviews current information regarding the role of uNK cells in healthy human pregnancy and evidence indicating their importance in various reproductive and pregnancy problems. Studies in humans are limited by the availability of suitable tissues and the limitations of extrapolation from animal models.

Regulation of mucosal immunity in the female reproductive tract: the role of sex hormones in immune protection against sexually transmitted pathogens

The immune system in the female reproductive tract (FRT) does not mount an attack against human immunodeficiency virus (HIV) or other sexually transmitted infections (STI) with a single endogenously produced microbicide or with a single arm of the immune system. Instead, the body deploys dozens of innate antimicrobials to the secretions of the FRT. Working together, these antimicrobials along with mucosal antibodies attack viral, bacterial, and fungal targets. Within the FRT, the unique challenges of protection against sexually transmitted pathogens coupled with the need to sustain the development of an allogeneic fetus, has evolved in such a way that sex hormones precisely regulate immune function to accomplish both tasks. The studies presented in this review demonstrate that estradiol (E2 ) and progesterone secreted during the menstrual cycle act both directly and indirectly on epithelial cells, fibroblasts and immune cells in the reproductive tract to modify immune function in a way that is unique to specific sites throughout the FRT. As presented in this review, studies from our laboratory and others demonstrate that the innate and adaptive immune systems are under hormonal control, that protection varies with the stage of the menstrual cycle and as such, is dampened during the secretory stage of the cycle to optimize conditions for fertilization and pregnancy. In doing so, a window of STI vulnerability is created during which potential pathogens including HIV enter the reproductive tract to infect host targets.

Estradiol regulation of constitutive and keratinocyte growth factor-induced CCL20 and CXCL1 secretion by mouse uterine epithelial cells

PROBLEM

Estradiol can directly affect epithelial cells or indirectly affect epithelial cells via stromal fibroblast secretion of growth factors, such as keratinocyte growth factor (KGF). The purpose of the present study was to determine whether estradiol regulates constitutive as well as KGF-induced uterine epithelial cell secretion of CCL20 and CXCL1.

METHOD OF STUDY

Freshly isolated and polarized uterine epithelial cells from Balb/c mice were cultured with estradiol in the presence or absence of KGF. CCL20 and CXCL1 were measured by ELISA.

RESULTS

Estradiol inhibited CCL20 secretion by freshly isolated and polarized uterine epithelial cells in the presence or absence of KGF. Unexpectedly, it enhanced KGF-induced CXCL1 secretion beyond that seen with KGF alone. Estradiol increased CXCL1 secretion at 24 hr and inhibited CCL20 at 48 hr. The effects of estradiol are specific in that progesterone, cortisol, dihydrotestosterone, and aldosterone had no effect on either CCL20 or CXCL1 secretion. The inhibitory effect of estradiol on CCL20 secretion was reversed with ICI 182,780, an estrogen receptor antagonist, indicating that this effect is estrogen receptor mediated.

CONCLUSIONS

Our data indicate that estradiol is important in regulating the effects of KGF on mouse uterine epithelial cell secretion of CCL20 and CXCL1.

Menstrual blood as a potential source of endometrial derived CD3+ T cells

Studies of T cell-mediated immunity in the human female genital tract have been problematic due to difficulties associated with the collection of mucosal samples. Consequently, most studies rely on biopsies from the lower female genital tract or remnant tissue from hysterectomies. Availability of samples from healthy women is limited, as most studies are carried out in women with underlying pathologies. Menstruation is the cyclical sloughing off of endometrial tissue, and thus it should be a source of endometrial cells without the need for a biopsy. We isolated and phenotyped T cells from menstrual and peripheral blood and from endometrial biopsy-derived tissue from healthy women to determine the types of T cells present in this compartment. Our data demonstrated that T cells isolated from menstrual blood are a heterogeneous population of cells with markers reminiscent of blood and mucosal cells as well as unique phenotypes not represented in either compartment. T cells isolated from menstrual blood expressed increased levels of HLA-DR, αEβ7 and CXCR4 and reduced levels of CD62L relative to peripheral blood. Menstrual blood CD4+ T cells were enriched for cells expressing both CCR7 and CD45RA, markers identifying naïve T cells and were functional as determined by antigen-specific intracellular cytokine production assays. These data may open new avenues of investigation for cell mediated immune studies involving the female reproductive tract without the need for biopsies.

Limitations of the criteria used to diagnose histologic endometritis in epidemiologic pelvic inflammatory disease research

While endometrial neutrophils and plasma cells are criteria used to diagnose histologic endometritis in epidemiologic pelvic inflammatory disease (PID) research, plasma cell misidentification and nonspecificity may limit the accuracy of these criteria. Herein, we examined: (1) the identification of endometrial plasma cells with conventional methyl green pyronin-based methodology versus plasma cell-specific (CD138) immunostaining, (2) the prevalence of endometrial plasma cells among women at low risk for PID, and (3) endometrial leukocyte subpopulations among women diagnosed with acute or chronic histologic endometritis by conventional criteria. We observed an absence of CD138+ cells in 25% of endometrial biopsies in which plasma cells had been identified by conventional methodology, while additional immunohistochemical analyses revealed indistinguishable inflammatory infiltrates among women diagnosed with acute or chronic endometritis by conventional criteria. Among women considered at lower risk for PID development, flow cytometric analyses detected plasma cells in 30% of endometrial biopsy specimens, suggesting that these cells, even when accurately identified, only nonspecifically identify upper genital tract inflammatory processes. Combined, our findings underscore the limitations of the criteria used to diagnose histologic endometritis in PID-related research and suggest that satisfactory understanding of PID pathogenesis, treatment, and prevention is hindered by continued use of these criteria.

Endometrial leukocyte subpopulations associated with Chlamydia trachomatis, Neisseria gonorrhoeae, and Trichomonas vaginalis genital tract infection

OBJECTIVE

The objective of the study was to characterize endometrial inflammation associated with common genital tract pathogens.

STUDY DESIGN

The design of the study was the immunohistochemical characterization of the endometrial leukocyte subpopulations from 37 controls and 45 women infected with Chlamydia trachomatis, Neisseria gonorrhoeae, or Trichomonas vaginalis.

RESULTS

Compared with uninfected women, endocervical infection with C trachomatis, N gonorrhoeae, or T vaginalis was associated with significant increases in endometrial T cells, B cells, plasma cells, and polymorphonuclear leukocytes. Even more substantial increases in T cell, B cell, and plasma cell numbers were detected among women infected endocervically and endometrially with C trachomatis.

CONCLUSION

Because lower genital tract C trachomatis, N gonorrhoeae, or T vaginalis infections were associated with comparable increases in the same endometrial leukocyte subpopulations, our results suggest the underappreciated involvement of T vaginalis in upper genital tract inflammatory processes. The more robust inflammatory infiltrate associated with C trachomatis endometrial ascension may offer insight into host inflammatory responses associated with pelvic inflammatory disease development.

Interaction between endometrial epithelial cells and blood leucocytes promotes cytokine release and epithelial barrier function in response to Chlamydia trachomatis lipopolysaccharide stimulation

Chlamydia trachomatis infection is currently the most common cause of infection-related sterility in women. However, it remains largely unknown how uterine epithelial cells interact with recruited leucocytes in response to C. trachomatis infection in the female genital tract. To study the defence mechanism of the endometrium against C. trachomatis infection, we established an in vitro co-culture of EEC (endometrial epithelial cells) and PBL (peripheral blood leucocytes) isolated from mice and investigated the immune response of these cells upon C. trachomatis LPS (lipopolysaccharide) challenge using a cytokine antibody array and RT-PCR (reverse transcription-PCR). Our results showed that upon C. trachomatis LPS stimulation, proinflammatory cytokines/chemokines, such as TNF-alpha, IL-1beta, MIPs (macrophage inflammatory proteins), IL-12p40p70, KC, GCSFs (granulocyte colony stimulating factors), IL-6 and TIMPs (tissue inhibition metalloproteinases) are up-regulated and/or released from EEC-PBL co-culture. Further, the TER (transepithelial resistance), measured by the Isc (short-circuit current) technique was significantly increased in EEC/PBL co-cultured cells and also when stimulated with C. trachomatis LPS compared with EEC alone. These changes appear to be mediated by the change in cytokine-induced expression of tight junction-related protein ZO-1. The present results demonstrated that the epithelial-immune cross-talk could promote the release of proinflammatory cytokines and enhance the barrier function of the endometrium against C. trachomatis infection in the female reproductive tract.

Sex hormone regulation of innate immunity in the female reproductive tract: the role of epithelial cells in balancing reproductive potential with protection against sexually transmitted pathogens

The immune system in the female reproductive tract (FRT) does not mount an attack against HIV or other sexually transmitted infections (STI) with a single endogenously produced microbicide or with a single arm of the immune system. Instead, the body deploys dozens of innate antimicrobials to the secretions of the female reproductive tract. Working together, these antimicrobials along with mucosal antibodies attack many different viral, bacterial and fungal targets. Within the FRT, the unique challenges of protection against sexually transmitted pathogens coupled with the need to sustain the development of an allogeneic fetus have evolved in such a way that sex hormones precisely regulate immune function to accomplish both tasks. The studies presented in this review demonstrate that estradiol and progesterone secreted during the menstrual cycle act both directly and indirectly on epithelial cells and other immune cells in the reproductive tract to modify immune function in a way that is unique to specific sites throughout the FRT. As presented in this review, studies from our laboratory and others demonstrate that the innate immune response is under hormonal control, varies with the stage of the menstrual cycle, and as such is suppressed at mid-cycle to optimize conditions for successful fertilization and pregnancy. In doing so, a window of STI vulnerability is created during which potential pathogens including HIV enter the reproductive tract to infect host targets.

Role of cytokines in endometrium and at the fetomaternal interface

Cytokines were first recognized as factors involved in the immune responses. However, emerging evidence suggests that cytokines serve as the unanimous language through which cells in organ systems as diverse as hypothalamus to endometrium communicate. Evidence for the participation of these factors in the normal function of the endometrium and uteroplacental unit and development of the embryo is being recognized. This review will highlight the significant insight gained over the past several years for the role of cytokines in the field of reproductive biology. Major emphasis will be placed on interleukins, tumour necrosis factor-α, transforming growth factors, colony stimulating factors and interferon-gamma.

Seminal plasma—Immunomodulatory potential in men with normal and abnormal sperm count

OBJECTIVES

Seminal plasma elicits recruitment of immune cells into the cervix. It increases in mice in vivo and in humans in vitro the endometrial epithelial expression of those cytokines and growth factors, which play an essential role in implantation. To analyse if the stimulatory effect of seminal plasma correlates to the quality of the sperm count, the immunomodulatory potential of seminal plasma of fertile and infertile men was studied.

STUDY DESIGN

Seminal plasma from 34 volunteers with normal sperm count und from 28 men with oligozoospermia or asthenozoospermia was studied. Firstly, the concentrations of IL-6, IL-8, VEGF, TNFalpha, IL-1beta, TGFbeta1 und G-CSF were analysed by ELISA. Secondly, the immunomodulatory potential was studied by bioassays. Bioassays were set-up by isolation of peripheral mononuclear blood cells (PMBC), sensitized by stimulation with LPS. The assays were incubated with seminal plasma of both patient groups and secretion of IL-6, IL-8 and TNFalpha was analysed by ELISA.

RESULTS

IL-6, IL-8, VEGF, TNFalpha, IL-1beta, TGFbeta1 and G-CSF were detected in seminal plasma. The bioassays revealed a significant increase of IL-6 and IL-8 and a decrease of TNFalpha by incubation with seminal plasma. The concentrations of all factors and the stimulatory and inhibitory potential of seminal plasma from men with oligozoospermia, asthenozoospermia and normozoospermia were not significantly different in ELISA- and bioassays.

CONCLUSION

The experiments revealed a similar immunomodulatory potential of seminal plasma from men with normal and abnormal sperm counts, suggesting that male infertility is probably not caused by differences in the activity of seminal plasma.

My approach to the interpretation of endometrial biopsies and curettings

A major proportion of the workload in many histopathology laboratories is accounted for by endometrial biopsies, either curettage specimens or outpatient biopsy specimens. The increasing use of pipelle and other methods of biopsy not necessitating general anaesthesia has resulted in greater numbers of specimens with scant tissue, resulting in problems in assessing adequacy and in interpreting artefactual changes, some of which appear more common with outpatient biopsies. In this review, the criteria for adequacy and common artefacts in endometrial biopsies, as well as the interpretation of endometrial biopsies in general, are discussed, concentrating on areas that cause problems for pathologists. An adequate clinical history, including knowledge of the age, menstrual history and menopausal status, and information on the use of exogenous hormones and tamoxifen, is necessary for the pathologist to critically evaluate endometrial biopsies. Topics such as endometritis, endometrial polyps, changes that are induced by hormones and tamoxifen within the endometrium, endometrial metaplasias and hyperplasias, atypical polypoid adenomyoma, adenofibroma, adenosarcoma, histological types of endometrial carcinoma and grading of endometrial carcinomas are discussed with regard to endometrial biopsy specimens rather than hysterectomy specimens. The value of ancillary techniques, especially immunohistochemistry, is discussed where appropriate.

Expression of Toll-like receptors (TLR) and responsiveness to TLR agonists by polarized mouse uterine epithelial cells in culture

The objective of the present study was to examine the expression of Toll-like receptors (TLRs) by mouse uterine epithelial cells and to determine if stimulation of the expressed TLR induces changes in cytokine and/or chemokine secretion. Using RT-PCR, the expression of TLRs 1-6 by mouse uterine epithelial cells was demonstrated, with TLRs 7-9 expressed only periodically. In the absence of pathogen-associated molecular patterns, polarized uterine epithelial cells constitutively secrete interleukin (IL) 1A, cysteine-cysteine ligand (CCL) 2, IL6, granulocyte-macrophage colony-stimulating factor 2 (CSF2), tumor necrosis factor A (TNFA), CSF3, and IL8 in vitro, with levels of cytokines/chemokines secreted into the apical compartment being significantly greater than those released into the basolateral compartment. When added to the apical surface for 48 h before analysis, the TLR2-agonist Pam3Cys-Ser-(Lys)4 and TLR1/6-agonist peptidoglycan increased epithelial cell apical secretion of IL1A, CCL2, and IL6 and apical/basolateral bidirectional secretion of CSF2, TNFA, CSF3, and IL8 when compared to controls. The TLR3-agonist poly (I:C) significantly increased bidirectional secretion of CCL2, IL6, TNFA, and CSF2 and basolateral secretion of CSF3. Lastly, the TLR4-agonist lipopolysaccharide increased bidirectional secretion CCL2, CSF2, TNFA, CSF3, and IL8 and apical secretion of IL6. These results indicate that mRNAs for Tlr1 through Tlr6 are expressed by uterine epithelial cells and that treatment with specific TLR agonists alters the expression of key chemokines and proinflammatory cytokines that contribute to the defense of the uterus against potential pathogens.

Primary Burkitt lymphoma of the uterine corpus

This study reports the first well-documented case of sporadic Burkitt lymphoma arising in and confined to the uterine corpus in a 40-year-old woman who presented with vaginal bleeding. Endometrial curettings showed a diffuse infiltrate of medium sized lymphocytes with the characteristic morphologic and immunophenotypic features of Burkitt lymphoma. Fluorescence in-situ hybridization demonstrated the t(8;14)(q24;q32) translocation. There was no evidence of extra-uterine disease and the patient is alive without disease 10 months after hysterectomy and chemotherapy. This report demonstrates that Burkitt lymphoma can present as isolated, organ confined disease at unusual sites and with protean symptoms.

Lymphocytes and MHC class II positive cells in the female rabbit reproductive tract before and after ovulation

In this study, we identified lymphocytes and MHC class II positive (MHC-II+) cells in the reproductive tract of female rabbits both before and after ovulation. CD43+ T cells were frequently present in the mucosa of the oviduct, cervix, and vagina, but far fewer positive cells were seen in the endometrium. The induction of ovulation did not change the cell density in these regions. KEN-5+ T cells and MHC-II+ cells were also frequently seen in the mucosa of the oviduct, cervix, and vagina both before and after ovulation. However, in the uterus, there were very few positive cells before ovulation, but the number increased dramatically after ovulation. Associated with the increase of KEN-5+ T cells, IL-2 mRNA expression in the uterus also increased after ovulation, suggesting that the uterus experienced an increase of T-cell activation. IgM- and IgA-positive B cells were not commonly seen in the reproductive tract and the induction of ovulation did not alter this. Our results suggest that the reproductive tract of female rabbits has the capacity to mount an immune response and that the immune cell distribution of the rabbit reproductive tract has some distinctive features compared with that found in other species.

The molecular changes during placental detachment

OBJECTIVES

RCAS1 is a membrane protein that plays a role in the maintenance of maternal immune tolerance during pregnancy. The work presented here demonstrates the results of RCAS1 expression in placenta in cases of placental abruption and patients with retained placental tissue during the third stage of labor.

STUDY DESIGN

The placenta tissue samples were obtained during vaginal and cesarean delivery (derived from 117 pregnancies). Pregnant women were divided into four groups according to the onset of labor and the time of placental detachment in term labors. The samples were analyzed by the Western blot method. Statistical analysis was performed using the Shapiro-Wilk procedure. The Mann-Whitney test and Student's t-test were applied to compare the differences between parametric data.

RESULTS

The average relative amount of RCAS1 observed in those patients with retained placental tissue was statistically significantly higher than in the patients with placental abruption.

CONCLUSION

The differences observed in placental RCAS1 levels confirm the participation of this protein in the inhibition of maternal immune response during gestation. The present results also indicate that RCAS1 participates in the changes in the maternal immune system that take place during parturition and reinforce its potential involvement in the mechanism of placental abruption.

Immunohistochemical characterization of endometrial leucocytes in endometritis

AIMS

Leucocytes are a normal and variable component of the endometrial stromal cell population. The aim of this study was to characterize endometrial leucocytes in established cases of endometritis in order to determine whether there are objective characteristics of the leucocyte infiltrate which would allow its identification as part of an inflammatory process rather then the normal physiological leucocyte infiltrate.

METHODS AND RESULTS

We examined endometrial tissue from 79 cases of endometritis and 22 histologically normal controls. Leucocytes were characterized immunohistochemically for CD45, CD20, CD68, CD3 and CD56 and numbers were analysed semiquantitatively on a scale of 0-4. In many endometritis cases the overall number of leucocytes was increased. Furthermore, leucocytes were unusually distributed with a tendency to accumulate superficially beneath the endometrial surface. Whilst numbers of macrophages, T lymphocytes and endometrial granulated lymphocytes (uterine natural killer cells) did not differ between endometritis samples and controls, most endometritis cases contained a substantially increased number of B cells, which normally represent 1% or less of the endometrial leucocyte population. B lymphocytes were also observed in unusual locations such as intraepithelially and within glandular lumina.

CONCLUSIONS

These results suggest that immunohistochemical characterization of endometrial leucocytes may be helpful in establishing a diagnosis of endometritis in equivocal cases.

CCL20/macrophage inflammatory protein 3alpha and tumor necrosis factor alpha production by primary uterine epithelial cells in response to treatment with lipopolysaccharide or Pam3Cys

Having previously shown that CCL20/macrophage inflammatory protein 3alpha and tumor necrosis factor alpha (TNF-alpha) are released by polarized primary rat uterine epithelial cells (UEC) in response to Escherichia coli but not to Lactobacillus rhamnosus, we sought to determine if epithelial cells are responsive to pathogen-associated molecular patterns (PAMP), including lipopolysaccharide (LPS), lipoteichoic acid (LTA), and Pam(3)Cys, a bacterial lipoprotein analog. Epithelial cells were grown to confluence on Nunc cell culture inserts prior to apical treatment with PAMPs. In response to LPS, LTA, and Pam(3)Cys (EMC Microcollection GmbH, Tubingen, Germany), CCL20 levels increased (4- to 10-fold) while PAMPs caused increased TNF-alpha (1- to 4-fold) in the medium collected after 24 h of incubation. Both apical and basolateral secretion of CCL20 and TNF-alpha increased in response to PAMPs, but treatments had no effect on cell viability and integrity, as measured by transepithelial resistance. Time course studies of CCL20 and TNF-alpha release in response to Pam(3)Cys and LPS indicated that CCL20 release peaked between 2 and 4 h after treatment, whereas TNF-alpha release was gradual over the length of the incubation. Freeze-thaw and cell lysis experiments, along with actinomycin D studies, suggested that CCL20 and TNF-alpha are synthesized in response to PAMP stimulation. Taken together, these studies demonstrate that E. coli and selected PAMPs have direct effects on the production of CCL20 and TNF-alpha without affecting cell integrity. Since CCL20 is known to be both chemotactic and antimicrobial, the increase in apical and basolateral release by UEC in response to PAMPs suggests a new mechanism of innate immune protection in the female reproductive tract.

Specific Localization of Macrophages in Pregnant Bovine Caruncles

The objective of this study was to evaluate the distribution and phagocytotic function of macrophages in bovine caruncles during pregnancy. Pregnant Holstein caruncles obtained at a slaughterhouse and by Caesarean section just before the onset of parturition were used. Macrophages in these caruncles were observed immunohistochemically and histochemically. Macrophages were present in the parenchyma of caruncles throughout pregnancy. The macrophages were irregular in shape, and exhibited thin, long processes along the main and intermediate septa of caruncles. Macrophages increased as the gestation period progressed. Acid phosphatase activity of the macrophages appeared at 5-6 months of gestation and remained until the end of gestation period. In particular, macrophages showed strong acid phosphatase activity at the peripheral region of the caruncles just facing the chorionic villi. In addition, they were conglomerated in the hyperplastic prominences of caruncles. These results indicate that caruncle macrophages maintain the appropriate size and shape of each caruncle during pregnancy.

Primary extranodal marginal zone B-cell lymphoma of MALT type of the endometrium

BACKGROUND

Only one case of primary extranodal marginal zone B-cell lymphoma of the mucosa-associated lymphoid tissue (MALT) of the endometrium has been previously reported.

CASE

A 65-year old patient presented with postmenopausal bleeding. She was found to have endometrial polyps. The endometrial curettings showed a dense lymphoid infiltrate that was suggestive of a lymphoproliferative disorder. Histological examination of the total abdominal hysterectomy revealed primary extranodal marginal zone B-cell lymphoma (MALT-type lymphoma) of the endometrium. The diagnosis was supported by morphology, immunohistochemistry, and molecular analysis.

CONCLUSIONS

Extranodal MALT lymphoma of the endometrium is exceptionally rare although the female genital tract is rich in mucosa and the presence of MALT tissue has been previously described. The diagnosis of lymphoproliferative disorder in this case was initially made on endometrial curettings. Although most lymphoid aggregates within endometrial curettings are due to reactive conditions such as endometritis, the possibility of lymphoma must be kept in mind when dense lymphoid aggregates or atypical lymphoid cells are present in the curettings.

Lymphocytes and T lymphocyte subsets are regionally distributed in the female goat reproductive tract: influence of the stage of the oestrous cycle

The reproductive tract of the female is a part of the mucosal system which protects from pathogens invasion. We have analysed the presence and distribution of total lymphocytes, plasma cells (antibody secreting B cells) and T lymphocytes subsets in the reproductive tract of the female goat. The influence of the oestrous cycle on the densities of lymphocytes and plasma cells of the cervix and uterus horn was evaluated in sections prepared for conventional histology. Immunocytochemistry was used for the study of lymphocyte subsets by confocal microscopy and immunoperoxidase techniques. Present results show that the reproductive tract of the goat is a site rich in lymphocytes. These cells were found mingled with the epithelial cells of the endometrium and distributed throughout the stroma. Lymphocyte aggregates were observed in the stroma. Lymphocyte but not plasma cell number changed depending on the reproductive stage of the goats. The impact of the hormonal environment was different for the cervix and uterine horn. Immunocytochemistry studies evidenced the presence of cells displaying immunoreactivity for both CD 4+ and CD 8+ antibodies in the epithelial layer and stroma of the cervix and uterine horn. These cells were more numerous in the cervix and were also found infiltrating the luminal epithelia of endometrial glands. Overall, our results indicate that lymphocyte distribution is different in the cervix and the horn, and is influenced by the stage of the reproductive cycle. In summary, CD 4+ and CD 8+ T lymphocytes subsets could be found in the endometrium of both the cervix and uterine horn of the goat reproductive tract.

Reduced phagocytotic activity of macrophages in the bovine retained placenta

This study was carried out to investigate the distribution of immune cells in the bovine placenta during the postpartum period and to compare these cells between normal and retained placenta. Within 1 h after normal calving, biopsy samples of placentomes were collected from 10 cows. The occurrence of retention of fetal membranes was monitored for more than 8 h post-calving, and the samples obtained were divided into two groups: normally discharged and retained placenta (n = 5 each). Immunohistochemical procedures were utilized to detect macrophages and T lymphocytes. Numerous CD14-positive macrophages were found in the stroma of both normal placenta and retained placenta whereas only a few CD3-positive T lymphocytes were found in both cases. However, histochemical staining for acid phosphatase, a predominant lysozomal enzyme, revealed that almost all macrophages showed strong enzyme activity in the normally discharged placentas, whereas in retained placenta the activity of acid phosphatase was conspicuously decreased in intensity. These results indicate that there are functional differences in placental macrophages between normal and retained placenta.

Identification and implantation stage-specific expression of an interferon-alpha-regulated gene in human and rat endometrium

Implantation of the developing blastocyst is regulated by multiple effectors, such as steroid hormones, growth factors, and cytokines. To understand how these diverse signaling pathways interact to modulate uterine gene expression, we employed a gene expression screen technique to identify the molecules that are induced in the periimplantation rat uterus. Here we report the isolation of a complementary DNA representing a novel gene, interferon-regulated gene 1 (IRG1). This gene exhibits significant homology to interferon (IFN)-alpha/beta-inducible human genes p27 and 6-16, indicating that these genes may belong to the same family. Consistent with this finding, expression of IRG1 messenger RNA (mRNA) in rat uterus increased about 20-fold in response to IFNalpha. Uterine expression of IRG1 was also stimulated by estrogen and was partially inhibited by an antiestrogen, ICI 182,780. In pregnant rats, IRG1 expression was high on day 1, but declined on days 2 and 3. The level of IRG1 mRNA again rose transiently on day 4 immediately preceding implantation. In situ hybridization analysis localized the IRG1 mRNA expression in the endometrial epithelium and the surrounding stroma. Interestingly, the expression of p27, which shows high homology to IRG1, was strongly enhanced in human endometrium during the midsecretory phase of the menstrual cycle, overlapping the putative window of implantation. Both IRG1 and p27 mRNAs are therefore induced in the endometrium in an implantation stage-specific manner. We also observed a synergistic interaction between IFNalpha and estrogen receptor signaling pathways that led to maximal induction of p27 mRNA in Ishikawa cells. Although the functional roles of IRG1 and p27 remain unclear, we describe for the first time, identification of a gene family regulated by IFNalpha in both rodent and human uteri. More importantly, our studies reveal that a complex interplay between the steroid hormone and IFN pathways regulates the expression of these genes in the endometrium at the time of implantation.

Messenger ribonucleic acid encoding interferon-inducible guanylate binding protein 1 is induced in human endometrium within the putative window of implantation

The putative window of embryo implantation in the human opens between days 19--24 of the menstrual cycle. During this period, the endometrium undergoes distinctive structural and functional changes orchestrated by steroid hormones, growth factors, and cytokines to attain a receptive phase in which it acquires the ability to implant the developing embryo. A major challenge in the study of human reproduction is to identify the molecular signals that participate in the establishment of this critical receptive phase in the context of the natural cycle. Toward this goal, we analyzed human endometrial biopsies at various days of the menstrual cycle by employing messenger RNA (mRNA) differential display technique. We isolated several complementary DNAs representing genes that are either up- or down-regulated within the putative window of implantation. We identified one of these genes as that encoding interferon (IFN)-inducible guanylate-binding protein 1 (or GBP1), which possesses GTPase activity. Analysis of endometrial biopsies by Northern blotting and RT-PCR demonstrated that GBP1 mRNA is specifically induced at the midsecretory phase of the menstrual cycle. In situ hybridization analysis revealed that GBP1 mRNA expression is localized in the glandular epithelial cells as well as in the stroma in the immediate vicinity of the glands. We observed that treatment of human endometrial adenocarcinoma cell, Ishikawa, with IFN-gamma or IFN-alpha markedly induced the expression of GBP1 mRNA. IFN-gamma was, however, a more potent inducer of GBP1 than IFN-alpha. Consistent with this finding, the temporal profile of GBP1 expression during the menstrual cycle resembled that of IFN-gamma mRNA more closely than that of IFN-alpha, predicting a regulatory role of IFN-gamma in GBP1 expression in midsecretory human endometrium. Although the precise function of GBP1 in the receptive human uterus remains unclear, its unique expression overlapping the putative window of implantation suggests that it might serve as a useful marker of uterine receptivity in the human.

Primary endometrial T-cell lymphoma. A case report

Primary lymphomas of the female genital tract are rare. Most involve the cervix rather than the uterine corpus. All of those previously reported have been B-cell lymphomas, with the exception of 1 case report of an endometrial T-cell lymphoma in a Japanese woman. We report the case of a white woman from the United States with a diffuse large cell lymphoma of the endometrium, characterized as a peripheral T-cell type on the basis of immunophenotypic and molecular probe studies. Staging evaluation revealed tumor limited to the endometrium (stage IE). The patient underwent a total abdominal hysterectomy, bilateral salpingo-oophorectomy, and lymph node dissection and received 6 cycles of combination chemotherapy, after which she remained free of disease at last follow-up of 36 months. Unusual features of this lymphoma case are discussed, with emphasis on differential diagnosis and speculation on histogenesis. This case illustrates that, while most peripheral T-cell lymphomas are widely disseminated at presentation, those limited to a single extranodal site may have a favorable outcome akin to that associated with high-grade extranodal B-cell lymphomas of early stage.

Antigen-presenting cells in the human female reproductive tract: analysis of antigen presentation in pre- and post-menopausal women

PROBLEM

To determine whether cells in the female reproductive tract (FRT) are functionally capable of presenting antigen to T cells.

METHOD OF STUDY

Analysis was done by determining the proliferation of purified autologous T cells to antigen, following co-incubation with non-proliferating cell suspensions isolated from the uterus and prepared by enzymatic digestion of reproductive tract tissues from hysterectomy patients with benign disease.

RESULTS

All uterine preparations analyzed were functionally capable of presenting antigen; the ability to present antigen was independent of pre- and post-menopausal status. In contrast, some, but not all, tissues from the ovary, Fallopian tube, cervix, and vagina were capable of presenting antigen.

CONCLUSION

These results suggest that the human FRT is an inductive site for immune responses. Regulation of antigen presentation in the reproductive tract may be important for protection against sexually transmitted diseases.

Phenotypic analysis and proliferative responses of human endometrial granulated lymphocytes during the menstrual cycle

The in vivo function of the unusual population of CD56+ CD16- endometrial granulated lymphocytes (eGLs) in human endometrium is unknown; their increased numbers in the secretory phase of the menstrual cycle suggests that they may play a role in the immunobiology of nonpregnant endometrium. In the present study, the phenotype and proliferative responses of eGLs at various phases of the menstrual cycle were compared with those in early pregnancy. Endometrial GLs were highly purified (> 98% CD56+) using immunomagnetic separation, and the expression of cell surface antigens was examined in smears using a double immunohistochemical labeling technique. Proliferative responses to mitogens and interleukin 2 (IL-2) were assessed in hanging drops in 60-well Terasaki plates. There was low to no expression of CD3, CD8, CD16, HML-1, L-selectin, and CD25 (IL-2 receptor alpha) on CD56+ cells isolated from nonpregnant and pregnant endometrium. The expression of CD2, CD49a, and CD122 (IL-2 receptor beta, IL-2Rbeta), however, increased from the proliferative to the late secretory phase of the menstrual cycle. In contrast, CD11a, CD69, and CD49d expression was high and did not vary with menstrual cycle phase; CD49d levels were significantly reduced in early pregnancy. Unlike early-pregnancy eGLs, none of the CD56+ eGL cultures throughout the menstrual cycle displayed phytohaemagglutinin (PHA)-induced lymphoproliferation. In contrast, eGLs from nonpregnant endometrium in the presence of 5 or 100 U/ml IL-2 after 48- and 120-h incubation showed significant proliferative responses, as did eGL cultures from early pregnancy. A significantly reduced number of proliferative phase eGL cultures proliferated in response to IL-2 compared to secretory phase and early-pregnancy eGL cultures. The IL-2-induced proliferative responses of CD56+ eGLs were associated with increased IL-2Rbeta (CD122) expression. These findings demonstrate 1) differential eGL expression of CD2, CD49a, and CD122 during the menstrual cycle; 2) differential IL-2-induced eGL proliferative responses during the menstrual cycle; and 3) differences between eGLs from nonpregnant and pregnant endometrium in CD49d expression and their ability to respond to PHA.

HCG secretion by peripheral mononuclear cells during pregnancy

Peripheral mononuclear cells (MNC) in culture release a biologically active hCG. This effect is detectable during pregnancy with a maximum between the 9th and 16th wk. Peripheral MNC already secrete hCG between the 7th and 11th d after embryo transfer. The secretion of hCG is activated by the PKC-activator TPA. TPA induces hCG release into the medium, thus causing a decrease in intracellular hCG content. In contrast, db-cAMP inhibites hCG secretion into the medium. Protein synthesis inhibitors of transcription and translation suppress the production and secretion of hCG. Peripheral natural killer (NK) cells (CD56+/CD16+) and monocytes (CD14+) show the highest secretion rates. IL-1 beta, IL-4, IL-6, IL-10, TNF alpha, and GM-CSF stimulate, whereas IL-2 and INF gamma inhibit, the hCG secretion of mononuclear cells. Flow cytometric experiments with hCG antibody demonstrate a binding of hCG on the surface of monocytes more than lymphocytes. The binding capacity is improved during pregnancy. Different hCG bands are shown in the Western blot analysis. We could confirm the mRNA of beta hCG and alpha CG are in MNC as well in the placental control. Peripheral MNC, first and foremost NK cells and monocytes, produce and secrete hCG during pregnancy, which play an important role for the corpus luteum rescue during the early gestational age and possibly for the immunotolerance.

Interferon-alpha is a potent inhibitor of basic fibroblast growth factor-stimulated cell proliferation in human uterine cells

PROBLEM

Abnormal uterine bleeding is a significant health problem for many women and is the number-one reason for performing hysterectomy in the United States. Leiomyomas (uterine fibroids) are benign neoplasms that are a frequent cause of abnormal uterine bleeding. The goal of this study was to assess the effects of the anti-angiogenic cytokine, interferon (INF)-alpha, on the proliferation of both leiomyoma and normal uterine cells.

METHOD OF STUDY

Primary cultures of leiomyoma, myometrial, and endometrial stromal cells were established for in vitro study. The effects of INF-alpha (10, 100, and 1000 U/ml) were tested on serum-stimulated and basic fibroblast growth factor-stimulated cell proliferation using the [3H]thymidine incorporation assay.

RESULTS

INF-alpha was a potent inhibitor of cell proliferation for all three cell types, with endometrial stromal cells showing the greatest sensitivity. The antiproliferative effect did not appear to result from toxic effects on the cells.

CONCLUSION

INFs may prove to be useful therapeutic agents for the treatment of leiomyoma-related abnormal uterine bleeding.

IFN-γ Is Produced by Polymorphonuclear Neutrophils in Human Uterine Endometrium and by Cultured Peripheral Blood Polymorphonuclear Neutrophils

Cytokines present in the human uterus play an important role both in modulating immune responses to infectious challenge and in the establishment and maintenance of pregnancy. In particular, successful implantation and pregnancy is thought to require the establishment of a Th2 environment, while Th1 cytokines are associated with pregnancy loss and infertility. On the other hand, a Th1 response appears to be required for the resolution of acute infection. Using novel confocal microscopic analysis of fresh sections of human tissue, we have investigated the production of IFN-γ, a Th1 cytokine, in human endometria. Extracellular IFN-γ, mostly associated with matrix components, was located immediately beneath the luminal epithelium and along the glandular epithelium proximal to the lumen. As evidenced by intracellular staining, IFN-γ is produced by both stromal cells and intraepithelial lymphocytes through all stages of the menstrual cycle. Surprisingly, the stromal cell containing intracellular IFN-γ was identified as a polymorphonuclear neutrophil on the basis of its reactivity with a panel of mAbs and its nuclear morphology. We further found that polymorphonuclear neutrophils isolated from normal donors produce IFN-γ in response to stimulation with LPS, IL-12, and TNF-α. Taken together, these findings suggest that polymorphonuclear neutrophils are capable of producing IFN-γ both in vitro and in vivo, indicating that their role in shaping immune responses may be more extensive than previously thought. Furthermore, these studies strongly suggest that polymorphonuclear neutrophils play an important role in determining immune responsiveness within the female reproductive tract.

Mucosal immunity in the female genital tract

Immunoglobulin (Ig)-producing cells in mucosal tissues represent quantitatively the most important humoral immune system of the body. All exocrine tissue sites contain immunocytes (B-cell blasts and plasma cells) that mainly synthesize dimers and larger polymers of IgA (collectively called pIgA) with incorporated J chain. Such pIgA is actively transported to external secretions as secretory IgA (SIgA) by the polymeric Ig receptor (pIgR), a transmembrane epithelial glycoprotein also called the secretory component (SC). The same transport mechanism includes pentameric IgM to generate SIgM. Although the most active SIgA system occurs in the gut, secretory immunity also operates in the female genital tract, with considerable pIgA production in the cervical mucosa and fallopian tubes. The origin of these local IgA immunocytes remains undefined. In mice, both lymphoid tissue in the large bowel (GALT) and nasopharynx (NALT) have been suggested as inductive sites for B cells homing to the urogenital tract. It is well established that integrin alpha 4 beta 7 is used by primed lymphoid cells to enter the intestinal lamina propria through interactions with mucosal addressin cell adhesion molecule (MAdCAM)-1 expressed on venule endothelium. However, alpha 4 beta 7 does not appear to be an important homing molecule in the airways, and the same might be true for the urogenital tract; this could explain that high levels of IgA antibodies occur in cervicovaginal secretions of mice after nasal immunization. The endometrium can likewise perform pIgR-mediated external translocation of pIgA that in this tissue appears to be mainly derived from serum, partly under hormonal regulation. In addition, paracellular diffusion of serum-derived and locally produced IgG through epithelia is an important part of humoral immunity in the female genital tract.

Flow cytometric analysis of leukocytes in the human female reproductive tract: comparison of fallopian tube, uterus, cervix, and vagina

PROBLEM

The tissues of the human female reproductive tract (Fallopian tube, uterus, cervix, and vagina) may play different roles in the provision of mucosal immunity. The purpose of this study was to develop a uniform method suitable for quantitative comparison of the leukocytes from all these tissues.

METHOD OF STUDY

Tissues, typically 0.5-1.0 g, were dispersed by enzyme treatment. A flow cytometric gating procedure based on CD45-positivity and low far-red autofluorescence permitted unfractionated, freshly dispersed cells to be phenotyped with respect to T lymphocytes, B lymphocytes, macrophages, and granulocytes.

RESULTS

Reproductive tract tissues contain leukocytes that represent approximately 6-20% of the total number of cells, with the Fallopian tubes and uterus containing a higher proportion of leukocytes than the cervix and vagina. The uterine endometrium from post-menopausal women has fewer leukocytes than does uterine endometrium from pre-menopausal women. T lymphocytes are a major constituent (30-60%) of leukocytes from all tissues. The Fallopian tube contains granulocytes as another major constituent; granulocytes are significantly less numerous in the other tissues. All tissues contain B lymphocytes and macrophages as clearly detectable but minor components.

CONCLUSIONS

Three-color flow cytometry is an appropriate method for quantitative comparison of leukocytes from the different tissues of the female reproductive tract, during all phases of the menstrual cycle and within post-menopausal samples. Results indicate that the tissues differ from each other, particularly with respect to the large number of granulocytes in the Fallopian tubes.

Primary low-grade endometrial B-cell lymphoma

We describe three cases of primary low-grade B-cell lymphoma of the endometrium and contrast the histological, immunohistochemical, and molecular features with two examples of benign endometrial lymphoid infiltrates. The first case was an incidental finding in a curettage specimen, confirmed on a subsequent hysterectomy. The other two cases of lymphoma were incidental findings on hysterectomy procedures performed for prolapse and cervical dysplasia, respectively. All three lymphomas occurred in patients in their sixties; none formed gross tumors. Histologic examination revealed lymphoid nodules adjacent to endometrial glands. The lymphoid cells showed mild nuclear enlargement and slight irregularities of the nuclear contour. None of the three patients had evidence of disease outside the endometrium by physical examination, bone marrow biopsy, or sampling of pelvic lymph nodes. Immunohistochemistry demonstrated a B-cell phenotype of the lymphoid cells (CD20 positive, CD79a positive) with aberrant coexpression of the T-cell-associated marker CD43. Polymerase chain reaction (PCR) amplification of the VDJ region of the immunoglobulin heavy-chain was performed on DNA isolated from paraffin sections. These studies demonstrated a clonal proliferation of B-lymphocytes in two cases. In the third case, a faint band was found superimposed on a background smear, suggesting the presence of a B-cell clone. In contrast, the two examples of histologically benign lymphoid aggregates of the endometrium consisted predominantly of T cells with rare B-lymphocytes; there was no evidence of coexpression of CD43 by B-cells. The PCR amplification from the benign lymphoid aggregates did not support a clonal process. Primary lymphoid neoplasms of the endometrium are rare, and all cases described so far have been high-stage, high-grade neoplasms. To our knowledge, this is the first report of primary low-grade B-cell lymphoma of the endometrium, presumably arising from endometrial lymphoid tissue.

Local immune response in endometrial carcinomas

OBJECTIVE

To determine whether Langerhans cells act as antigen-presenting cells in endometrial carcinomas and their related lesions.

SAMPLES

Frozen endometrial samples were obtained from 13 women with normal menstrual cycles, 3 postmenopausal women, 11 women with hyperplasia (simple 4, complex 4 and atypical 3) and 32 women with endometrial carcinomas.

MAIN OUTCOME MEASURES

Langerhans cells (CD1), T lymphocytes (CD4 and CD8), B lymphocytes (CD22), natural killer (NK) cells (CD57) and HLA-DR were all quantitatively assessed in endometrial samples using immunohistochemical method.

RESULTS

The numbers of Langerhans, CD4+, CD8+ and B cells were higher in the secretory phase than in the proliferative endometrium. The CD8+ cells appeared to be more plentiful than the CD4+ cells. When compared with the proliferative endometrium, the numbers of Langerhans cells were higher in hyperplasias and carcinomas. Most of Langerhans cells were HLA-DR+, showing a strong correlation with CD4+ cells in carcinomas. This suggests that MHC class II antigen restricted lymphocytes in carcinomas are activated by HLA-DR+ Langerhans cells. However, epithelial expression of HLA-DR in carcinomas did not show on association with high numbers of Langerhans and CD4+ cells. No correlation was observed between Langerhans cells and clinicopathologic features of carcinomas. In contrast, the number of NK cells significantly decreased in noninvasive carcinomas but increased in Grade 3 tumours.

CONCLUSION

Based on the above findings, Langerhans cells are considered to act as antigen-presenting cells in carcinomas, but it was not shown that they were activated by epithelial expression of HLA-DR in carcinomas.

Lymphocyte subsets in the endometrium of patients with endometriosis throughout the menstrual cycle

PROBLEM

Comparison and characterisation of different lymphocyte subsets in the endometrium of endometriosis patients and in healthy women on every day of the menstrual cycle with special emphasis on the CD4:CD8 ratio in the endometrium.

METHOD

Immunohistochemical staining of 253 endometrial biopsies of infertile women with and without endometriosis with Anti-Leu4 (CD3), Anti-Leu3a (CD4), Anti-Leu2a (CD8), Anti-Leu7 and Anti-Human-B-cell (CD22) using the immune peroxidase reaction. Identification and counting of positive lymphocyte were performed on cryostat sections.

RESULTS

Endometrial lymphocyte subsets show equal quantity and distribution in endometriosis patients and in the control group. After a peak in the early proliferative phase the absolute number of T lymphocytes decreases while a predominance of T-suppressor/cytotoxic T lymphocytes (CD8) compared to T-helper/inducer lymphocytes (CD4) occurs towards the end of the menstrual cycle.

CONCLUSION

Endometrium as the potential parent epithelia of endometriosis lesions seems not to be altered in its lymphatic cell content compared to healthy women. Furthermore, endometrium is clearly characterised as part of the mucosa associated lymphatic tissue (MALT). T lymphocytes show specific quantitative changes due to different phases of the menstrual cycle.

Proliferative activity of the endometrium throughout the menstrual cycle in infertile women with and without endometriosis

OBJECTIVE

To assess whether changes in endometrial proliferation in patients with endometriosis contribute to ectopic endometrial implantation.

DESIGN

Endometrial biopsies from patients with endometriosis were stained immunohistochemically and compared with endometrium of a control group (n = 111). The newly developed monoclonal antibody Ki-S3 was used as a marker of cellular proliferation in surface and glandular epithelia and in stromal cells.

SETTING

Female Infertility Clinic, Research Centre of Obstetrics, Gynecology, and Perinatology, Moscow, Russia, and Institute of Pathology, Christian-Albrechts-University, Kiel, Germany.

PATIENTS

One hundred thirty-nine women with endometriosis and 111 women without endometriosis, all being infertile.

INTERVENTION

Collecting endometrial samples during diagnostic and therapeutic laparoscopy.

MAIN OUTCOME MEASURE

Number of proliferating cells in endometrial stroma, glandular, and surface epithelia.

RESULTS

Endometrial proliferation showed a characteristic cyclic dependency with greatest activity in the follicular phase. Although epithelial proliferation ceased completely during the luteal phase, the number of proliferating cells in the stroma increased again toward the end of the menstrual cycle after its maximum at ovulation. No significant differences could be found between both investigated groups.

CONCLUSIONS

Endometriosis is not due to an altered proliferative activity in eutopic endometrium. Proliferating stromal cells at the end of the menstrual cycle may reflect increasing numbers of immunocompetent cells. Endometrium of patients with endometriosis reveals almost the same cyclical changes as endometrium of patients without endometriosis does. Further attention to cells and cell-mediated reactions in the extrauterine milieu is required to elucidate the pathogenesis of endometriosis.

Immunohistochemical characterization of stromal leukocytes in ovarian endometriosis: comparison of eutopic and ectopic endometrium with normal endometrium

OBJECTIVE

To compare stromal leukocyte subpopulations in different phases of the menstrual cycle in eutopic and ectopic endometrium from women with ovarian endometriosis and in control endometrium.

DESIGN

Retrospective immunohistochemical study.

SETTING

Department of Pathology, Royal Victoria Infirmary, Newcastle-upon-Tyne, United Kingdom.

PATIENTS

Paraffin-embedded tissue blocks from 30 patients with endometriosis and 30 control blocks from patients undergoing hysterectomy for nonendometrial pathology were retrieved from archive files.

MAIN OUTCOME MEASURE

Quantitative assessment of defined stromal leukocyte subpopulations in eutopic, ectopic and control endometrium at different stages of the menstrual cycle.

RESULTS

In the proliferative and early secretory phases, ectopic endometrium contained elevated numbers of CD45+, CD3+, and CD43+ cells but reduced percentages of CD68+ macrophages. The proportions of granulated cells were reduced in ectopic endometrium throughout the cycle. No differences were noted between eutopic endometrium from women with endometriosis and control endometrium.

CONCLUSION

Differences between eutopic and ectopic leukocyte subpopulations with the exception of large granular lymphocytes may be due to the lack of cyclicity demonstrated by endometriotic lesions.

Lymphocyte subsets in the endometrium of genitally normal mares and mares susceptible to endometritis

The density and distribution of MHC Class II positive cells and subpopulations of lymphocytes were studied in the endometrium of genitally normal mares and mares susceptible to endometritis. In genitally normal mares, more MHC Class II positive cells were present in the epithelium and stratum compactum during oestrus than dioestrus. Significantly more CD4+ and CD8+ lymphocytes were present in the stratum compactum than in the stratum spongiosum. CD4+ lymphocytes were present in greater numbers than CD8+ lymphocytes in the stratum compactum but approximately equal numbers were present in the stratum spongiosum and in lymphoid aggregates. Occasional CD4+ and CD8+ cells were seen in the luminal and glandular epithelium. Infrequently, B cells were present in the endometrium and were not observed in the epithelium. Numbers of T and B cells did not appear to be affected by cycle stage. In mares with endometritis, the densities of CD4+, CD8+ and B cells were significantly increased. Large aggregates of lymphoid cells which contained approximately twice as many CD4+ cells as CD8+ cells were present in the endometrium of these mares and all 3 subclasses of lymphocyte were seen occasionally in luminal and glandular epithelium.

Immunohistochemical characterization of leukocytic subpopulations in chronic endometritis

Objective: We analyzed the histologic and immunohistochemical changes in the endometrial leukocytic subpopulations to determine which of them are characteristic of chronic endometritis.

Results: Endometrial biopsies from 25 cases of chronic endometritis and 35 controls were studied. Characteristic morphologic findings included the presence of a plasma cell infiltrate, and a prominent, albeit non-specific, lymphocytic infiltrate in all patients with endometritis. A neutrophilic infiltrate was also noted in 90% of the patients. Other non-specific histologic findings included occasional prominent lymphoid aggregates, stromal edema, hemorrhage, and necrosis and cystic dilation of some glands in endometria of patients with chronic endometritis. Endometrial immune cells were investigated immunohistochemically using antibodies to CD3 (pan-T), CD20 (pan-B, L26), and Ham-56 (macrophage). In control patients, endometrial immune cells were predominantly composed of CD3 and Ham-56 positive cells. CD20 positive cells comprised <2% of immune cells in control patients [mean: <2 cells/high power field (HPF)]. Large numbers of CD20 and CD3 lymphocytes were seen in endometria of patients with chronic endometritis. A semiquantitative analysis showed that the numbers of CD20 and CD3 positive cells in patients with chronic endometritis were increased 50- and 3-fold, respectively, when compared to those of control patients (mean B cells: 49 vs. 2 cells/HPF; mean T cells: 149 vs. 45 cells/HPF). CD20 positive cells were predominantly seen in subepithelial and periglandular aggregates. CD3 positive cells had a predominant stromal distribution and an occasional intra- or subepithelial localization. There was no difference in the number and distribution of Ham-56 positive cells in patients with or without endometritis.

Conclusions: These findings suggest that CD20 cells may have a significant role in the pathogenesis of chronic endometritis and that immunostaining for B and T lymphocytes could be used in confirming the diagnosis of endometritis or in diagnosing subclinical or progressing endometritis in which plasma cells could not be detected or are rarely identified.

Lymphocytes--their possible endocrine role in the regulation of fertility

PROBLEM

Peptide secretion by peripheral lymphocytes obtained from fertile and infertile women.

METHOD

LH, FSH, and prolactin were estimated in the serum and culture supernatants obtained from Con-A stimulated human lymphocytes by RIA.

RESULTS

The levels of LH, FSH and prolactin were low in the culture supernatants obtained from lymphocytes of infertile women, when compared with proven fertile women.

CONCLUSION

The results indicated impairment in endocrine functions of lymphocytes obtained from infertile women. This impairment in lymphocyte function could be one of the causes of infertility in these women.