Intro
Adenomyosis is a common gynecologic disease in premenopausal and late reproductive age women. Frequent symptoms include progressive dysmenorrhea, chronic pelvic pain, dyspareunia, abnormally heavy menstrual bleeding, and interval menstrual bleeding. The severity and frequency of the symptoms correlate with the extent and depth of the ectopic endometrium in the myometrium, which follows the endometriosis pathology and progression of the disease ( 1 ). Generally, diffuse globular enlargement is the common sign of adenomyosis and the size of uterus is typically not larger than 12 weeks gravid size. This enlargement of the uterus is due to invasion of the myometrium by endometrial glands only be made at histopathology following hysterectomy.
Currently, the etiology and pathology of adenomyosis
have yet to be elucidated, however, many theories have been
proposed; for example, the invagination of basalis endometrium
into the myometrium and the subsequent inflammation.
Adenomyosis uteri repetitively exhibit exaggerated
and non-synchronized uterine contractions, which induce a
micro-fracture at the endometrial-myometrial junction zone
(EMJZ). This micro-trauma at EMJZ causes the displacement
of endometrium into the surrounding myometrium,
where the myometrial cells proliferate and undergo metaplasia,
resulting in the thickening of EMJZ ( 3 , 4 ). The aberrant
immunologic activity in adenomyosis is seen by immunohistochemistry
with an increase in the number of infiltrating macrophages. These could activate T and B cells to produce
antibodies and cytokines that may destroy the EMJZ ( 5 ).
Macrophages transform from the circulatory monocyte cells
and serve many functions including phagocytosis, antibodydependent
cell-mediated cytotoxicity, and presenting antigens
to lymphocytes. Natural killer (NK) cells, on the other
hand, are cytotoxic lymphocytes that play a role in innate
immune response. They can remove infected cells without
recognition, and thus the killing process is an immediate response
to virus-infected cells and tumor formation ( 6 , 7 ).
Abnormal immune responses appear to play a role in adenomyosis.
Expression of human leukocyte antigen (HLA)
class II is recognized as the first step in the activation of
macrophages and/or T lymphocytes by presenting foreign
antigens to these cells. HLA class II expression is shown to
be increased in the glandular cells of eutopic and ectopic
endometrium of adenomyosis ( 6 , 7 ). At this point, the definitive
treatment for adenomyosis is hysterectomy ( 5 ), but
it is not the treatment of choice for patients who wish to
remain fertile. Oral contraceptive pills, high doses of progestin,
levonorgestrel-releasing intrauterine device (LNGIUD),
gonadotropin releasing hormone agonist (GnRH-a),
and danazol are hormonal treatment options for both adenomyosis
and endometriosis ( 1 ). The use of pre-operative
GnRH agonists in patients with myomas, endometriosis
and adenomyosis was tested by Khan et al. ( 8 ). They
found a decrease in MCP-1 level, as well as a reduction
in the number of macrophages in endometrial and myometrial
layers of patients with adenomyosis compared to
an untreated group. Progestin is considered a good choice
for long-term treatment of adenomyosis because it causes
minimal side effects. The administration of a progestin, depending
on the dose, may not cause a hypoestrogenic state.
Four generations of synthetic progestogens are now available to clinicians. A new progestin called dienogest (DNG) ( 17a-cyanomethyl-17b-hydroxyestra-4, 9-dien bioavailability and strong progestational effect due to its high selectivity to the progesterone receptor. It has been reported as one of the progestogens employing the strongest action on the endometrium ( 10 ). Its half-life is 9-10 hours, and it is approximately 90% secreted by the kidneys. The therapeutic dose of DNG for treatment of endometriosis is 2 mg daily providing a blood level of 10-7 mol/L. Although the blood level of dienogest after oral administration is very low, the symptoms of endometriosis can be cured ( 9 ). Dienogest has been shown to slightly increase the number and macrophages ( 11 ). The objective of our study was to investigate the effect of DNG on immune cells focusing on macrophages and NK cells in women with adenomyosis.
Results
Twenty-four elibible patients were enrolled and randomly
divided into treated and untreated groups. There
were no dropouts after treatment of dienogest for 28-35
days, therefore, complete data from 24 participants were
available for analysis ( Fig .1 ). The demographic characteristics
of the participants; for example, age, BMI, indication
for and type of surgery were not significantly
different ( Table 1 ). The number of participants with proliferative
and secretory menstrual phases in the DNG and
untreated groups were not statistically different.
Study design for the effects of dienogest on macrophages and natural
killer cells in adenomyosis clinical trials.
Demographic data of women with adenomyosis
BMI; Body mass index, AUB; Abnormal uterine bleeding, and NSAIDs; Nonsteroidal antiinflammatory
drug.
NK cell infiltration, as shown by CD57-positive brown spots ( Fig .2 ), was significantly increased in glands in
treated versus untreated groups [P=0.005, median (range
25, 75%), 4.37 (0.31, 14.68) vs. 0 (0, 0)] ( Fig .2D ), but
not in stroma of the endometrium of the treated group
[P=0.416, median (range 25, 75%), 21.87 (10, 68.81), 10
(8.75, 15.93)] ( Fig .2F , Table 2 ). NK cells were confirmed
by double immunostaining for CD57 and CD56 (Fig.2G,
H). Macrophage infiltration, as demonstrated by CD68-
positive brown spots ( Fig .3 ), was also increased, but was
not statistically significant in treated versus untreated
groups [P=0.055, median (range 25, 75%), 4.37 (0, 9.06),
0 (0, 1.56)] ( Fig .3D , Table 2 ).
Macrophage and natural killer (NK) cell infiltration in endometrial glands and stroma in endometrial tissue in adenomyosis patients
Data as presented as [median (range 25-75%)].
Immunohistochemistry staining for CD57 in eutopic and ectopic endometrium. The accumulation of CD57 is indicated by a
dark brown coloration in the nucleus; all nuclei were counter-stained with hematoxylin. A. Ectopic endometrium in myometrium
of adenomyosis women in untreated group, B. Ectopic endometrium in myometrium of adenomyosis women in dienogest-treated
group, C. Endometrial gland in endometrium of untreated group, D. Endometrial gland in endometrium of dienogest-treated group,
E. Endometrial stroma in endometrium of untreated group, F. Endometrial stroma in endometrium of dienogest-treated group, G.
Double staining for CD57 and CD56 in endometrium, and H. Double staining for CD57 and CD56 in myometrium.
Infiltration of macrophages and NK cells in the myometrium
of women with adenomyosis was also investigated. No
differences were seen between DNG-treated and untreated
groups (Figes .2 , 3 , Table 3 ).
The uterine endometrial thickness was more significantly
reduced after DNG treatment for 30 ± 2.76 days
(mean ± SD) when compared to the untreated group [median
(25, 75%), 37.5 (33.37, 60.12), 94.5 (67.75, 143.25),
respectively] (P=0.021).
Macrophage and natural killer (NK) cells infiltration in ectopic endometrium in myometrial tissue in adenomyosis patients
Data as presented as [median (range 25-75%)].
Immunohistochemistry staining for CD68 in eutopic and ectopic endometrium. The accumulation of CD68 is indicated by a
dark brown coloration in the nucleus and all nuclei were counter-stained with hematoxylin. A. Ectopic endometrium in myometrium
of adenomyosis women in untreated group, B. Ectopic endometrium in myometrium of adenomyosis women in dienogest-treated
group, C. Endometrial gland in endometrium of untreated group, D. Endometrial gland in endometrium of dienogest-treated group,
E. Endometrial stroma in endometrium of untreated group, and F. Endometrial stroma in endometrium of in denogest-treated group.
This randomized controlled trial compared the numbers
of infiltrating macrophages and NK cells in the eutopic
and ectopic endometrium in women with adenomyosis
after either one month of treatment with DNG or no
treatment. The results showed that oral DNG increased
the number of NK cell infiltration in glandular structure
of eutopic endometrium but not in ectopic endometrium.
However, no differences were observed in the number of
macrophages and NK cells in stromal tissue of eutopic endometrium
or ectopic endometrial tissue of the two study
groups. This suggests that progestin has a direct effect on
endometrium in addition to its systemic effect, thus may
improve local immunity in the endometrium.
The histopathological characterization of adenomyosis
is similar to endometriosis, except for the site of endometriotic
lesions. Immune dysfunction and inflammation
play significant roles in both endometriosis and adenomyosis.
Various immune alterations occur in endometriosis
that are also present in adenomyosis. We noted an increase
in the number and activity of macrophages secreting proinflammatory
cytokines interleukin-1 (IL-1) and tumor
necrosis factor (TNF) in women with endometriosis. It
has been shown that patients with adenomyosis have both
HLA-DR and HLA-G expression in eutopic and ectopic
endometrium ( 7 , 14 ). The expression of HLA-G corresponding
to major histocompatibility complex (MHC)
class I increases the survival of endometrial cells from
the host’s immunosurveillance ( 13 ). Ota and Igarashi ( 7 )
and Ota et al. ( 15 ) reported an increased number of macrophages
in ectopic and eutopic endometrium in women
with adenomyosis. Recently, Zhihong et al. ( 16 ) did a prospective
case-control study by collecting the endometrial
tissue from patients with adenomyosis during the implantation
window after ovarian stimulation, and then performed
immunohistochemistry and real time-polymerase
chain reaction (RT-PCR). The results showed an increase
in cytokine IL-6, monocyte chemoattractant protein-1
(MCP-1) and the number of macrophages. MCP-1, which
is produced by uterine NK cells is a cytokine that induces
the migration of immune cells to target tissue.
NK cells play a role in destroying viruses and tumor
cells but not normal host cells. The killing activity depends
on the activity of killer cell inhibitory receptors
(KIRs) and MHC molecules ( 17 ). The reduction of NK
cell activity in peripheral blood and peritoneal fluid has
been shown in endometriosis ( 18 , 19 ). The NK cell cytotoxicity
may also be reduced in eutopic endometrium in
adenomyosis, because the expression of CD94a (surface
marker for KIR) is increased in the endometrium versus
the myometrium in women with adenomyosis ( 17 ).
There are a few classical NK cells CD56+CD16+ in both
eutopic and ectopic endometrium in adenomyosis ( 20 ).
Here, we used CD57-a terminally sulfated carbohydrate
epitope (glucuronic acid 3-sulfate)-to identify NK cells.
This marker identifies the final stage of NK cell maturation.
Therefore, these matured CD57+ NK cells may have
strong cytotoxic activity, but weak proliferative property
( 21 ). Additionally, we verified NK cells via dual immunohistochemistry
staining for CD56 and CD57.
Several previous studies have demonstrated progesterone
and progestin-modulated immune responses ( 22 - 26 ).
The cyclical change of progestin in endometriums of nonpregnant
women suggested hormone regulation, specifically
progesterone ( 27 ). Our results showed that DNG increased
the number of mature NK cells at the glandular
epithelium of eutopic endometrium, which is comparable
to Klinger’s findings. Oral combined contraceptive pills
containing DNG have been demonstrated to increase the
number of lymphocytes, monocytes and granulocytes in
patients treated for one cycle ( 22 ). A similar result was
seen in an animal study, where administration of DNG in
rats with endometrial tissue auto-transplantation slightly
increased the NK cell activity and number in peritoneal
fluid cells and spleen cells ( 11 ).
Progestin treatment including megestrol acetate for endometrial
hyperplasia and endometrial cancer-induced
immune suppression can increase the number and activity
of NK cells and other immune cells ( 24 ). NK cells
are the important immune cell type in the gestational
decidua. The regulation of uterine NK cells by progesterone
and progestin are well-known during pregnancy
( 27 , 28 ). However, the role of uterine NK cells remains
unclear. Many are present during implantation, and they
may be involved in the implantation mechanism ( 23 ). The
potential role of uterine NK cells is that it supports the
preparation of uterus for embryo implantation by producing
many cytokines. Moreover, Le Bouteiller and Piccinni
( 27 ) found that uterine NK cells in early decidua could
kill target cells, for example, infected maternal decidual
cells, supporting the local immune responses to uterine
infection ( 23 , 27 , 29 ). Therefore, DNG administration in
patients with adenomyosis may improve the implantation
process and protect the fetus from infection to pregnancies
that occur after discontinuation of treatment.
Different types of progestin may affect immune responses
differently ( 23 , 30 ). However, there is no direct
comparative study on the effect of different progestins
on NK cells. This would be an interesting topic for further
studies. Progesterone recruites uterine NK cells by
increasing the chemokine C-X-C motif ligand (CXCL)10
and CXCL11, which has been demonstrated in an in vitro
study using an endometrial organ culture system ( 31 ). In
addition, hormone replacement therapy has been shown
to change NK cell activity ( 32 ). In this study, DNG enhanced
the NK cell number only at the glandular structure
of the endometrium. There was no increase in NK
cell numbers in stromal tissue of eutopic endometrium or
in the ectopic endometrium. In the study conducted by
Mehasseb et al. ( 33 ), they examined the expression pattern
of progesterone receptor (PR)-A and PR-B and foci
lesion of adenomyosis by immunohistochemistry in the
endometrium of control and adenomyosis subjects. The
expression of both PRs was lower in the stroma, and the inner and outer myometrium in the adenomyotic samples
compared to glands. Therefore, the differential effect of
DNG on various tissues may have been mediated by differential
expression of PRs on adenomyotic tissue and eutopic
endometrium.
DNG did not affect macrophage infiltration on eutopic
and ectopic endometrium or on the myometrium from
patients with adenomyosis. The effect of DNG on macrophage
infiltration was different from that of GnRHa
shown by Khan et al. ( 8 ). GnRHa decreased the infiltration
of CD68-expressing cells in the endometrium of
women with endometriosis and adenomyosis. It is possible
that the local actions of DNG and GnRHa on endometriosis
or adenomyosis lesions were different. The
highlight of our study is that, patients were randomly assigned
to two study groups by block randomization with a
block size of 4. There was an equal number of participants
in each study group and the cohorts had homogeneous
features. This maintained the balance of the study groups
and reduced selection bias. In this study we had aimed to
investigate the effect of progestin on mature NK cells by
immunohistochemistry, which indirectly reflect NK cell
cytotoxicity. However, further studies on functional NK
cells and other characteristics of NK cells, i.e. proliferation
or apoptosis, are still needed.
Conclusions
Progestin DNG administration causes an increase in
uterine mature NK cells in glandular structure of eutopic
endometriumn in patients with adenomyosis. The immunomodulating
effect of progestin on adnenomyosis may
be beneficial for implantation and fetal protection to pregnancies
occurring after treatment. The enhancing effect of
progestin on NK cells is differentially expressed depending
on the site of immune infiltration.
Materials Methods
A randomized control trial study was conducted from 1 February 2015 to 31 May 2016 at the Department of Obstetrics and Gynecology, Faculty of Medicine, Ramathibodi Hospital, Mahidol University, Bangkok, Thailand. The study was approved by the Ethical clearance Committee on human rights related to researches involving human subjects ( pro women aged 20-50 years, suffering from dysmenorrhea with or without hypermenorrhea, undergoing either abdominal hysterectomy or laparoscopic hysterectomy for adenomyosis, and diagnosed adenomyosis by ultrasonography. The exclusion criteria were patients who had used i. Pill or oral exogenous hormones for 3 months or ii. GnRH agonist or depot medroxyprogesterone acetate injection for 6 months before surgery. Twenty-four eligible patients were recruited into the study. The ultrasonographic diagnostic criteria for adenomyosis included a globular shape with diffuse uterine enlargement, myometrial anterior-posterior asymmetry, poorly described areas in the myometrium, a heterogeneous myometrial echotexture, sub-endometrial echogenic linear striations with or without small myometrial cysts, or hemorrhagic foci within the heterotopic endometrial layer ( 12 ). The sample size was calculated according to measurement outcomes and the mean number of NK cells and macrophages from Khan’s study with ple size was 12 for each arm. Therefore, a total of 24 subjects were needed for this present study.
The subjects were divided into two groups via block randomization
with a block size of 4. A group of 12 patients received
2 mg/day dienogest for 28-35 days before surgery, and
the other 12 underwent operation without prescribing the drug
(control group). The phase of the menstrual cycle was determined
by the subjects’ last menstrual period and confirmed
by endometrial histology. Patients with liver disease, kidney
disease, autoimmune disease, coagulopathy, endometriotic
cysts, or under hormonal therapy were excluded. Exclusion of
patients with pelvic endometriosis was not possible; therefore,
it was the potential limitation for the present study.
The myometrial tissue had gross features of adenomyosis, that is, hypertrophic swirls of smooth muscle separating duller prominent trabeculated patterns and gray foci of endometrium. The tissue was excised in 1cmx1cmx1cm dimentions immediately after hysterectomy. The endometrial tissue sample was also collected in block pattern size 1 cm×1 cm×1 cm from the myometrial layer. All collected sections of the samples were then prepared for subsequent histopathological and immunohistochemical studies.
Immunohistochemical analysis was performed with anti-
CD68 antibody for macrophages and anti-CD57 and anti-
CD56 for NK cells. Both primary rabbit monoclonal antibodies
clone PGM-1 and clone 123C3.D5 against CD68
and CD57, respectively, were from DAKO (Glostrup,
Denmark), and the primary mouse monoclonal antibody
clone NK-1 against CD56 was from Thermo Fisher Scientific (Waltham, USA). Primary antibodies CD68, CD57,
and CD56 were used at a dilutions of 1:100, 1:150, and
1:2400, respectively. The 3-μm thick paraffin-embedded
tissue sections were deparaffinized in xylene and then rehydrated.
Slides were incubated for 60 minutes at 60°C
and treated with Bond Dewax Solution (Leica Biosystems,
Bannockburn, IL). Epitope retrieval was performed by
incubating the slides in Bond Epitope Retrieval Solution
for 20 minutes at 100°C. Immunohistochemical analysis
was performed using the Bond Polymer Refine Detection
kit (Leica Biosystems, Bannockburn, IL), a 3-step indirect
immunoperoxidase technique. Briefly, primary antibody
was applied for 45 minutes at room temperature. Peroxide
block (3% hydrogen peroxide) was then applied for
5 minutes and rinsed with Bond Wash Solution. Post Primary
Polymer was applied for 9 minutes. Polymer Poly-
HRP IgG was applied for 7 minutes and rinsed with Bond
Wash Solution and deionized water, then diaminobenzidine
chromogen was applied for 4 minutes. Slides were counterstained
with hematoxylin for 5 minutes. Appendix tissue
was used as positive control. The negative control showed
an absence of specific staining ( 12 ).
The number of CD68 and CD57 brown spots were counted
in 20 different fields (200×200 microns) for each person
(magnification: ×200) under light microscopy. The number of
CD68 and CD57 positive cells were calculated and expressed as the mean positive cells per mm 2.Theresultsineachbiopsy er who did not know the patient’s history. Double-labeling immunohistochemical method for CD57 and CD56 was also performed. The primary antibody anti-CD57 was the first antibody
identified by diaminobenzidine chromogen, while the primary antibody anti-CD56 was the second antibody identified
by mixed red refine chromogen. The procedure was
similar to the described protocol above including deparaffinization, epitope retrieval and a 3-step indirect immunoperoxidase technique. However, before counterstaining each slide with hematoxylin, the second antibody (anti-CD56 primary antibody) was applied for 40 minutes at room temperature. Post Primary Polymer AP was applied for 20 minutes. Polymer Poly-AP IgG was applied for 20 minutes and rinsed with Bond Wash Solution and deionized water before the Mixed were then counterstained with hematoxylin for 5 minutes.
Each parameter is presented as either the mean ± SD or
medians (25, 75%) depending on the distribution of data. The
clinical characteristics were compared by chi-square test or
student’s t test for differences between two groups. The differences
in numbers of macrophages and NK cells between
the two groups were analyzed by the non-parametric Mann-Whitney U-test; a value of P<0.05 was considered statistically
significant. The data were analyzed by IBM SPSS Statistics
for Windows, version 19.0 (Armonk, NY: IBM Corp).
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