@2024 Afarand., IRAN

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ISSN: 2251-8215    Sarem Journal of Reproductive Medicine 2018;2(4):159-163

Background
Recurrent Spontaneous Abortion (RSA) is one of the problems that results in the lack of maintenance of ‎the fetus in mother and is characterized by three or more abortions before the 20th week of pregnancy ‎‎[1].‎ ‎
Previous Studies
‎... [2, 3]. Recent studies of repeated abortions with unspecified causes illustrate the imbalance in ‎regulatory mechanisms and suggest significant changes in immune cell pattern in these patients ‎compared to healthy women [4]. The study of Lee et al. on RSA patients has shown increase in pro-‎inflammatory response and auxiliary T cells (Th17) and decrease in regulatory responses of T cells ‎‎[5]. In addition, several studies indicate the lack of pattern of cell and cytokine pattern of natural killer ‎cells (NK), auxiliary T-1 (Th1) and T-2 (Th2) cells in RSA patients compared to healthy women with ‎successful pregnancy history [4 , 6]. Therefore, many research and therapeutic centers, with the ‎justification that alloimmunity may cause the disorder in balance and regulation of the immune system ‎of RSA patients and, as a result, cause abortion in these patients, carry out immunological treatment ‎such as lymphocyte therapy or IVG immunoglobulin injection (IVIG) to prevent the excretion of ‎embryos by induction of immunological toleration [7-10].‎ ‎... [11].The findings show that 20% of RSA cases are due to autoimmune factors [12]. ... [13, 14]. The ‎success of the pregnancy process is dependent on implantation and formation of placenta, and during ‎the first trimester of pregnancy, the oxygen pressure in the placenta increases to provide the oxygen ‎needed for the fetus, but this increase in pressure leads to an increase in the production of active ‎oxygen intermediates (ROS), and place the placenta in the oxidative stress condition [15]. Numerous ‎pairwise proteins, as the natural antioxidant, retain the placenta of destructive oxidative stress effects, ‎including peroxiredoxin 3 (Prx3 or PRDX3) and peroxiredoxin 4 (Prx4 or PRDX4). These proteins are ‎expressed by cytotrophoblast cells and play an important role in implantation and maintenance of the ‎placenta in oxidative stress conditions [16].‎ In recent years, researchers have focused on placenta as a key member in the management of ‎pregnancy and the maintenance of the fetus, and have studied the presence of antibodies against two ‎placenta proteins, peroxiredoxin-3 and peroxiredoxin-4, and have introduced these two antibodies as ‎autoimmune factors involved in RSA; However, these studies have been qualitative and the quantity ‎and exact amount of these two antibodies in RSA patients and normal women have not been evaluated ‎so far [17].‎
Aim(s)

Research type
This is a case-control study.‎
Research society, place and time
This study was carried out on two groups of patients referred to Sarem Hospital in Tehran, one with at ‎least 3 recurrent spontaneous abortions and another with no history of abortion and having at least ‎two living children.‎
Sampling method and number
The case group included 100 patients with a history of at least 3 recurrent spontaneous abortions. The ‎status of these patients was normal, in terms of karyotype, antiphospholipid antibodies, ‎anticardillipin, ANA, antithyroid antibodies, microbial infections (TORCH, HBV, HIV, EBV and CMV), ‎anatomical abnormalities, and normal hormone disorders. The control group consisted of 32 healthy ‎women without a history of abortion and had at least two alive children.‎
Used devices&materials
Patients' consent was obtained before the sampling and the informed consent form approved by the ‎morality committee of Sarem Hospital was completed by each of the volunteer patients. Then, 2 cc ‎blood samples were taken from the participants and the serum sample was kept at -20 C of the freezer ‎until complete collection of the samples.‎ For quantitative measurement of anti-peroxiredoxin -3 and anti-peroxiredoxin -4 antibodies, their ‎ELIZA kit was designed by coating the recombinant proteins of proxirdoxin-3 and proxirdoxin-4 ‎‎(Sigma-Aldrich, USA) in two distinct ELIZA plates (MaxiSorp; Nunc Co., Denmark), and the amount of ‎autoantibodies against these two placenta antigens were evaluated. As standard, certain amounts of ‎commercial monoclonal antibodies against these two proteins (Sigma-Aldrich, USA) were used and, ‎quantitatively, the amount of these autoantibodies was determined. Data was analyzed by SPSS ‎software. The Kolmogorov-Smirnov test was used to evaluate the normal distribution of data. Mann-‎Whitney U test was used to examine the significant difference between the groups. The results were ‎reported as median and interquartile range.‎
Findings by Text
The mean age of the control and case groups was 34.78 ± 1.13 and 31.61 ± 0.48 years, respectively. The ‎anti-peroxiredoxin-3 autoantibody level in the case group was 62.98 (33.72-204.46) pg / ml and in the ‎control group, it was 59.25 (45.02-97.77) pg / ml. The anti-peroxiredoxin-3 autoantibody level in these ‎two groups did not show any significant difference (p = 0.51; Fig. 1). In contrast, the anti-‎peroxiredoxin-4 autoantibody level was 34.91(17.87-98.45) pg /ml in the case group and it was 8.32 ‎‎(17.90-33.52) pg / ml (17.77 ± 4.59) in the control group, that there was a significant difference ‎between the two groups (p=0.0004; Figure 1).‎The serum level of anti-oxidoxin-3 autoantibodies was 0.538, which was not significantly different ‎from the reference line (which is equal to 0.50). The serum of antiperoxiredoxin-4 autoantibody level ‎was 0.67, which had a relative separation value (Fig. 2).‎The surface area under the curve (AUC) is the result of the sensitivity and test characteristic. The ‎borderline number of 124.8 was obtained from the analysis of the ROC curve of the anti-peroxiredoxin-‎‎4 serum autoantibody level above which was considered positive and the below of it was considered ‎as negative. Based on the obtained borderline number, the odds ratio or OR calculated for PRDX4 was ‎‎12.66 (Figure 3).‎
Main comparison to the similar studies
‎... [18]. The most well-known autoantibodies involved in pregnancy and abortion problems are ‎antiphospholipid antibodies [19]. ... [20]. Previous findings have reported the presence of multiple ‎autoimmune antibodies in recurrent abortions [21], although the question that what antibodies can ‎clearly predict pregnancy failure is still remained. The aPL antibody that is measurable in the ‎antiphospholipid syndrome (APS) is considered as an autoimmune antibody associated with recurrent ‎abortion, and according to recent reports and recent studies, about 10% of recurrent abortions occur ‎due to APS, which accounts for a significant proportion. APS can be primary or secondary, be ‎associated with lupus, and is associated with recurrent abortions [18]. Anti-oxidant V antibodies, ‎antiprothrombin antibodies, anti-nuclease, anti-lamina, anti-gliadina, and anti-transglutaminase ‎antibodies are other autoimmune antibodies that can have a deleterious effect on the placenta or ‎embryo, and lead to abortion [2, 18].‎ For the first time in 2005, the presence of autoantibody against Prx1 was reported in autoimmune ‎patients [22]. There is no other study on the role of peroxiredoxin anti-protein autoantibodies and their ‎association with abortion. Regarding the importance of Prx3 and Prx4 proteins in preserving the ‎placenta and the success of pregnancy, in this study, the serum of recurrent abortion patients was ‎evaluated for the detection of anti-autoantibody against these two proteins, and the findings showed ‎that there was no significant difference in the anti-peroxiredoxin-3 levels in RSA women compared ‎with healthy women. However, the level of anti-peroxiredoxin-4 antibodies in RSA women is ‎significantly higher than those of women in the control group. Therefore, anti-peroxiredoxin-4 ‎antibodies are produced in RSA women, which can justify the association between autoimmunity and ‎RSA, and the presence of these autoantibodies in the serum of these patients shows a new autoimmune ‎theory.‎ The important point in this study was that in the analysis of the ROC curve, the under curve for the ‎Prx4 region was acceptable (close to 0.7), indicating a relatively good suitability and practicality of the ‎test, and more importantly, the ratio of the obtained OR was high and It was noteworthy, which, of ‎course, would require a further study with a larger sample size, since OR = 12.66, and if confirmed ‎with a high sample size, it is clinically important. This odd ratio expresses that if people with Prx4 test ‎are positive, the incidence of recurrent spontaneous abortion is 12 times more likely than those with ‎negative tests.‎ ‎
Suggestions
Further study of these autoantibodies and its evaluation during pregnancy in RSA patients, as a ‎supplementary study, can be used as an immunologic risk factor for embryo in these patients and its ‎measurement can be used as a diagnostic test.‎
Limitations

Conclusions
The serum levels of placenta anti-peroxiredoxin-3 autoantibody in patients with recurrent abortions ‎and healthy women are not different, while serum levels of anti-peroxiredoxin-4 autoantibodies in ‎patients with a history of recurrent spontaneous abortions are higher than healthy women. ‎
Acknowledgments

Conflict of interest

Ethical Permissions
Patient satisfaction was obtained for participation in this study and the informed consent form ‎approved by the Committee on the Ethics of Sarem Hospital was completed by each of the volunteer ‎patients.
Funding Sources

TABLES and CHARTS

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