|Year : 2019 | Volume
| Issue : 2 | Page : 191-194
Peripheral blood level of natural killer cells in pregnant women with recurrent spontaneous abortion during the 6–12 weeks gestation
Sung-Guk Kim, Mi-Yong Paek, Il Gyong Ko
Department of Obstetrics and Gynecology, Pyongyang Medical College, Kim Il Sung University, Pyongyang, Democratic People's Republic of Korea
|Date of Submission||07-Feb-2019|
|Date of Decision||02-Oct-2019|
|Date of Acceptance||11-Nov-2019|
|Date of Web Publication||16-Dec-2019|
Dr. Sung-Guk Kim
Department of Obstetrics and Gynecology, Pyongyang Medical College, Kim Il Sung University, Pyongyang
Democratic People's Republic of Korea
Source of Support: None, Conflict of Interest: None
Background and Aim: The study was performed to confirm the clinical characteristics and peripheral blood level of natural killer (NK) cells as a diagnostic index in women with recurrent spontaneous abortion (RSA) comparing with normal pregnant women. Materials and Methods: Consultation with all patients was conducted to obtain the number and timing of previous miscarriages and signs and symptoms of abortion progress. Assessment of peripheral blood NK cell level was performed by flowcytometric analyses. Results: Women with RSA have brown-colored vaginal bleeding and history of more than three consecutive miscarriage, while the percentage of peripheral blood NK cell within blood lymphocytes was more than 18.1%. Conclusion: In the current study, RSA patients (6–12 weeks') showed significantly higher level of peripheral blood NK cells (>18.1%) compared to that of normal gravidas. Further studies are required to clarify the precise mechanism how NK cells affect the progression of healthy pregnancy and investigate clinical evidence whether therapies to lower the level of NK cells can decrease the rate of RSA.
Keywords: 6–12 weeks, consecutive miscarriage, natural killer cell, peripheral blood, recurrent spontaneous abortion
|How to cite this article:|
Kim SG, Paek MY, Ko IG. Peripheral blood level of natural killer cells in pregnant women with recurrent spontaneous abortion during the 6–12 weeks gestation. Arch Med Health Sci 2019;7:191-4
|How to cite this URL:|
Kim SG, Paek MY, Ko IG. Peripheral blood level of natural killer cells in pregnant women with recurrent spontaneous abortion during the 6–12 weeks gestation. Arch Med Health Sci [serial online] 2019 [cited 2022 Jan 28];7:191-4. Available from: https://www.amhsjournal.org/text.asp?2019/7/2/191/273069
| Introduction|| |
Recurrent spontaneous abortion (RSA) is defined by the occurrence of two or more consecutive failed pregnancies.,, Spontaneous abortions are mostly caused by chromosomal abnormalities in embryos, and anatomic uterine defects appear to predispose women to reproductive difficulties.,,,,,,, Mechanisms of unexplained reproductive failure (infertility and RSA) involve immune-mediated pathways, including the presence of a predominant T-helper (Th) 1-Type immunity during pregnancy, a decrease in T-regulatory cells and an increase in natural killer (NK) cells.,, These phenomena can occur locally, at the site of implant, and can be observed also in the peripheral blood.,, It has been shown that the interaction between human leukocyte antigen (HLA) molecules and NK cells is the checkpoint of the regulation of the NK cell activity at the maternal–fetal interface. NK cells are innate immune effectors that are able to exert a cytolytic activity against infected and tumor cells and to produce immunomodulatory cytokines without HLA restriction or prior sensitization. Peripheral blood NK cells comprise about 10%–12% of blood lymphocytes and are strikingly suppressed in normal early pregnancy.
On the other hand, NK cells constitute the predominant leukocyte population present in the endometrium at the time of implantation and in early pregnancy. Decidual NK cells (dNK) are a specific CD16-cell subset that includes selective expression of CD9, galectin-1, and glycodelin, with regulatory effects on T-cells., Since peripheral NK cells downregulate dNK under the influence of estrogen and progesterone levels, both the hormonal status and the NK cytokines contribute to the shift toward a Th2 response that characterizes normal pregnancy.
In 1981, Taylor first described about human immunotherapy with white blood cells and Beer reported the efficacy of immunotherapy with husband white blood cells in treatment for RSA women.,,,,, As the incidence of clinically evident abortion is approximately 15%, the probability of three times of consecutive pregnancy losses could be estimated as 0.34%., However, the incidence of recurrent abortion is 1%–5% of all pregnancy. Moreover, the probability of abortion after three times of previous abortion is 26.2%–60.0%.,,,,,, The study was performed to confirm characters of the medical symptoms and the percentage of peripheral blood NK cell within blood lymphocytes with the RSA during the pregnancy 6–12 weeks. When these factors are high, it is of high possibility of the RSA.
| Materials and Methods|| |
One hundred and twelve pregnant women with RSA who were admitted to the Pyongyang Maternity Hospital since January 2009–July 2011 were involved in study group, and thirty normal pregnant women with no history of RSA and no sign of imminent abortion in pregnancy of 6–12 weeks were involved in control group. Three cases with luteal insufficiency, 2 cases with uterine fibroids, 1 case with positive Rh, 1 case with uterine anomaly, 3 cases with antiphospholipid syndrome, and 1 case with thyroid disorder were excluded. All the patients with RSA were confirmed to have fetal heartbeat by ultrasound examination.
As shown in [Table 1], 70 cases (62.5%) were 25–29 years, accounted for the majority of all patients.
- Consultation with all patients were conducted to obtain the number and timing of previous miscarriages, subjective symptoms, and objective signs of abortion progress
- Assessment of peripheral NK cell level was performed by flowcytometric analyses.
- One milliliter of peripheral blood was sampled in sterile test tube preprocessed with ethylenediaminetetraacetic acid K2 so that it would not be clotted
- Fifty microliters of the blood were added to the Falcon test tube with cap which was previously added with 10 μl of CD56-labeled fluorescence antibody solution, and then incubated in dark room for 15 min
- Then, 1 ml of FACS Lysing solution was added to the tube, which was then incubated in dark room for 10 min and then centrifuged at 1500 rpm for 5 min
- Supernatant was disposed, and then 500 μl of suspension was agitated to make cell suspension, which was then assessed to evaluate the ratio of NK cells in total lymph cells.
Statistical analysis was performed by Student t-test for numerical values and Chi-square test for proportional values.
| Results|| |
1. Pregnant women with RSA has history of regular bleeding, little morning sickness, lower back or lower abdomen pain, and vaginal bleeding of brown color [Table 2], [Table 3], [Table 4], [Table 5].
|Table 5: Levels of peripheral blood natural killer cells with the recurrent spontaneous abortion during the pregnancy 6~12 weeks|
Click here to view
Regularity of miscarriage timing
As shown in [Table 2], 96 cases (85.7%) had regular miscarriages, which accounted for the majority of all patients.
Presence of morning sickness
[Table 3] showed that 20 cases (17.9%) had morning sickness and 92 cases (82.1%) had no sickness, and majority of patients had no morning sickness.
Subjective symptoms of miscarriage
As shown in [Table 4], 4 patients (3.6%) with RSA had lower back pain, 11 patients (9.8%) lower abdominal pain and black red bleeding, and 81 patients (72.3%) brown bleeding with no pain, which was the most frequent symptom.
2. Levels of peripheral blood NK cells with the RSA during the pregnancy 6–12 weeks.
As shown in [Table 5], peripheral blood NK cell level was 23.8% ± 5.5% in pregnant women with RSA, which was significantly higher than those (8.9% ± 2.8%) in normal pregnant women (P< 0.01). Moreover, the NK cell levels in all normal pregnant women were lower than 18%, while 105 patients (93.7%) had NK cells higher than 18%.
| Discussion|| |
We analyzed NK cell levels in all the women enrolled.,,,,,,,, We found that the RSA women had significantly higher NK cell levels than controls. These results are in accordance with other studies comparing the percentage of peripheral blood NK cells in RSA women versus controls.,,,,,
It is possible that elevated NK cell levels represent an evidence of such broadly based immune system activation, and they may characterize women with RSA according to alloimmune mechanisms of the pregnancy failure.,, The result of our research suggested that the assessment of the percentage of peripheral blood NK cell may play as diagnostic tool in women with RSA. We described that NK cell percentage may be a useful test to differentiate women with RSA and fertile controls.
The cutoff value of NK cell percentage obtained in our study population resulted in accordance with data in the literature. According to the threshold value for abnormal NK cell levels, we observed that the prevalence of women with abnormal NK levels was, as expected, higher among the RSA women with the respect to the comparison group.
As the incidence of clinically-evident abortion is approximately 15%, the probability of three times of consecutive pregnancy losses could be estimated as 0.34%., However, the incidence of recurrent abortion is 26.2%–60.0%., We determined clinical and NK cell level features in patients with RSA. This result suggests that these parameters could be used to estimate high risk of miscarriage.
More studies are needed to confirm the role of NK cell assessments as a prognostic test for women with reproductive failure.
| Conclusion|| |
In this study, we have assessed the levels peripheral NK cells in early-trimester recurrent abortion patients (6–12 weeks' gestation) in our country and compared with that of literature. In the current study, RSA patients (6–12 weeks') showed significantly higher peripheral blood NK cells (>18.1%) compared to that of normal gravidas. Although this study has confirmed the relationship between elevated levels of peripheral NK cells and the incidence of RSA, further studies are required to clarify the precise mechanism how NK cells affect the progression of normal pregnancy. Furthermore, clinical evidence whether therapies to lower the level of NK cells can decrease the rate of RSA should also be investigated.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
| References|| |
Hofmeyr GJ, Joffe MI, Bezwoda WR, van Iddekinge B. Immunologic investigation of recurrent pregnancy loss and consequences of immunization with husbands' leukocytes. Fertil Steril 1987;48:681-4.
Toth B, Jeschke U, Rogenhofer N, Scholz C, Würfel W, Thaler CJ, et al.
Recurrent miscarriage: Current concepts in diagnosis and treatment. J Reprod Immunol 2010;85:25-32.
Rai R, Regan L. Recurrent miscarriage. Lancet 2006;368:601-11.
Coulam CB. Immunotherapy for recurrent spontaneous abortion. Early Pregnancy 1995;1:13-26.
Carrington B, Sacks G, Regan L. Recurrent miscarriage: Pathophysiology and outcome. Curr Opin Obstet Gynecol 2005;17:591-7.
Chen L, Hu R. Thyroid autoimmunity and miscarriage: A meta-analysis. Clin Endocrinol (Oxf) 2011;74:513-9.
Chen L, Quan S, Ou XH, Kong L. Decreased endometrial vascularity in patients with antiphospholipid antibodies-associated recurrent miscarriage during midluteal phase. Fertil Steril 2012;98:1495-5020.
Dal Lago A, Vaquero E, Pasqualetti P, Lazzarin N, De Carolis C, Perricone R, et al.
Prediction of early pregnancy maternal thyroid impairment in women affected with unexplained recurrent miscarriage. Hum Reprod 2011;26:1324-30.
Higuchi K, Aoki K, Kimbara T, Hosoi N, Yamamoto T, Okada H, et al.
Suppression of natural killer cell activity by monocytes following immunotherapy for recurrent spontaneous aborters. Am J Reprod Immunol 1995;33:221-7.
Somkuti SG. Obstetrics and Gynecology Board Review – Pearls of Wisdom. 3th
. ed. McGraw-Hill Companies; 2008. p. 573-80.
Triggianese P, Perricone C, Perricone R, De Carolis C. Prolactin and natural killer cells: Evaluating the neuroendocrine-immune axis in women with primary infertility and recurrent spontaneous abortion. Am J Reprod Immunol 2015;73:56-65.
Dosiou C, Giudice LC. Natural killer cells in pregnancy and recurrent pregnancy loss: Endocrine and immunologic perspectives. Endocr Rev 2005;26:44-62.
Yuan J, Li J, Huang SY, Sun X. Characterization of the subsets of human NKT-like cells and the expression of th1/Th2 cytokines in patients with unexplained recurrent spontaneous abortion. J Reprod Immunol 2015;110:81-8.
Zhu LY, Chen X, Xu ZZ, Xu L, Mao T, Zhang H, et al.
Changes and clinical significance of peripheral blood helper T lymphocyte and natural killer (NK) cells in unexplained recurrent spontaneous abortion (URSA) patients after abortion and successful pregnancy. Clin Exp Obstet Gynecol 2015;42:62-6.
Beer AE, Kwak JY, Ruiz JE. Immunophenotypic profiles of peripheral blood lymphocytes in women with recurrent pregnancy losses and in infertile women with multiple failedIn vitro
fertilization cycles. Am J Reprod Immunol 1996;35:376-82.
Emmer PM, Nelen WL, Steegers EA, Hendriks JC, Veerhoek M, Joosten I, et al.
Peripheral natural killer cytotoxicity and CD56(pos) CD16(pos) cells increase during early pregnancy in women with a history of recurrent spontaneous abortion. Hum Reprod 2000;15:1163-9.
Baltadzheiva D, Penkova K, Stamenov G, Dimitrova D, Michailova A. Expression of activating and inhibitory receptors on peripheral blood natural killer cell subsets of women with reproductive failures. Akush Ginekol (Sofiia) 2010;49:12-7.
Hosseini S, Zarnani AH, Asgarian-Omran H, Vahedian-Dargahi Z, Eshraghian MR, Akbarzadeh-Pasha Z, et al.
Comparative analysis of NK cell subsets in menstrual and peripheral blood of patients with unexplained recurrent spontaneous abortion and fertile subjects. J Reprod Immunol 2014;103:9-17.
Beer AE, Quebbeman JF, Ayers JW, Haines RF. Major histocompatibility complex antigens, maternal and paternal immune responses, and chronic habitual abortions in humans. Am J Obstet Gynecol 1981;141:987-99.
Ntrivalas EI, Kwak-Kim JY, Gilman-Sachs A, Chung-Bang H, Ng SC, Beaman KD, et al.
Status of peripheral blood natural killer cells in women with recurrent spontaneous abortions and infertility of unknown aetiology. Hum Reprod 2001;16:855-61.
Triggianese P, Perricone C, Conigliaro P, Chimenti MS, Perricone R, De Carolis C, et al.
Peripheral blood natural killer cells and mild thyroid abnormalities in women with reproductive failure. Int J Immunopathol Pharmacol 2016;29:65-75.
Taylor C, Faulk WP. Prevention of recurrent abortion with leucocyte transfusions. Lancet 1981;2:68-70.
Practice Committee of the American Society for Reproductive Medicine. Evaluation and treatment of recurrent pregnancy loss: A committee opinion. Fertil Steril 2012;98:1103-11.
Christiansen OB, Steffensen R, Nielsen HS, Varming K. Multifactorial etiology of recurrent miscarriage and its scientific and clinical implications. Gynecol Obstet Invest 2008;66:257-67.
Cunningham FG, Leveno KJ, Bloom SL, Spong CY, Dashe JS, Hoffman BL, et al
. (eds). Williams Obstetrics. 24th
ed. New York: McGraw-Hill; 2014.
Dakhly DM, Bayoumi YA, Sharkawy M, Gad Allah SH, Hassan MA, Gouda HM, et al.
Intralipid supplementation in women with recurrent spontaneous abortion and elevated levels of natural killer cells. Int J Gynaecol Obstet 2016;135:324-7.
Gharesi-Fard B, Zolghadri J, Foroughinia L, Tavazoo F, Samsami Dehaghani A. Effectiveness of leukocyte immunotherapy in primary recurrent spontaneous abortion (RSA). Iran J Immunol 2007;4:173-8.
Schorge JO. Williams Gynecology. New York: McGraw-Hill Companies; 2008.
Lin X, Lin D, Liu J, Bao Y, Luo Z, Fang J, et al.
Declined natural killer cells emerging in women with unexplained recurrent spontaneous abortion and further reducing after medical therapy. Clin Lab 2016;62:2241-7.
Perricone C, De Carolis C, Giacomelli R, Zaccari G, Cipriani P, Bizzi E, et al.
High levels of NK cells in the peripheral blood of patients affected with anti-phospholipid syndrome and recurrent spontaneous abortion: A potential new hypothesis. Rheumatology (Oxford) 2007;46:1574-8.
Shimada S, Takeda M, Nishihira J, Kaneuchi M, Sakuragi N, Minakami H, et al.
Ahigh dose of intravenous immunoglobulin increases CD94 expression on natural killer cells in women with recurrent spontaneous abortion. Am J Reprod Immunol 2009;62:301-7.
Gao L, Zhang JP, Chen H, Zhang SN, Chen LB, Tan JP, et al.
Characteristics of immune cell changes before and after immunotherapy and their clinical significance in patients with unexplained recurrent spontaneous abortion. Genet Mol Res 2014;13:1169-78.
Gharesi-Fard B, Zolghadri J, Kamali-Sarvestani E. Effect of leukocyte therapy on tumor necrosis factor-alpha and interferon-gamma production in patients with recurrent spontaneous abortion. Am J Reprod Immunol 2008;59:242-50.
Carp H. Recurrent pregnancy loss: Towards more accurate diagnosis and treatment. Isr Med Assoc J 2001;3:528-32.
Chaichian S, Shoaee S, Saremi A, Pedar S, Firouzi F. Factors influencing success rate of leukocyte immunization and anti-paternal antibodies in spontaneous recurrent miscarriage. Am J Reprod Immunol 2007;57:169-76.
Taylor CG, Faulk WP, McIntyre JA. Prevention of recurrent spontaneous abortions by leukocyte transfusions. J R Soc Med 1985;78:623-7.
Saito S. The causes and treatment of recurrent pregnancy loss. J Japan Med Assoc 2009;52:97-102.
[Table 1], [Table 2], [Table 3], [Table 4], [Table 5]