Systemic Th1/Th2 Cytokine Responses to Paternal and Vaccination Antigens in Preeclampsia: No Differences Compared with Normal Pregnancy

Low Serum IL-17A in Pregnancy During Second Trimester Is Associated With an Increased Risk of Subclinical Hypothyroidism

Problem: Interleukin-17A (IL-17A) has a role in sustaining normal pregnancy. IL-17A is also associated with thyroid autoimmunity during pregnancy. This study sought to investigate whether IL-17A is a risk factor for thyroid dysfunction during pregnancy in women negative for thyroid autoantibodies. Methods of Study: The study comprised 216 pregnant women with negative thyroid peroxidase antibody (TPOAb) and thyroglobulin antibody (TGAb) during the second trimester who provided blood samples for serum IL-17A, thyroid autoantibodies and thyroid function tests. To further evaluate the ratio of CD4+IL-17A+ Th17 cells, we collected peripheral blood from 26 women with thyroid-stimulating hormone (TSH) levels ≤ 2.5 mIU/L and 26 pregnancy-week matched women with TSH levels >2.5 mIU/L, along with samples from 20 women with TSH levels ≤ 4 mIU/L and 20 pregnancy-week matched women with TSH levels >4 mIU/L. Results: The serum IL-17A levels and ratios of CD4+IL-17A+ cells were significantly lower in women with TSH > 2.5 mIU/L than in those with TSH ≤ 2.5 mIU/L (both P < 0.01). Similar lower differences were noted in women with TSH > 4 mIU/L than in those with TSH ≤ 4 mIU/L (both P < 0.01). Moreover, serum TSH correlated negatively with IL-17A levels (β = -0.195, P = 0.004), but positively with the week of gestation (β = 0.284, P < 0.001). Logistic regression indicated that a lower serum IL-17A level was a risk factor for TSH > 2.5 mIU/L [OR = 0.453 (0.298-0.689), P = 0.000] and TSH > 4.0 mIU/L [OR = 0.588 (0.385-0.899), P = 0.013]. Conclusion: A low serum IL-17A level during the second trimester is associated with an increased risk of TSH > 2.5 mIU/L and subclinical hypothyroidism.

The role of interleukins in preeclampsia: A comprehensive review

Preeclampsia is a multi-system hypertensive disorder of pregnancy, with significant rates of maternal and neonatal morbidity. It represents a major cause of preterm birth, as definitive treatment demands fetal delivery. Although its pathophysiology is complicated, placental hypoxia and endothelial dysfunction constitute established pathogenetic steps of the disease. Inflammation is considered to be a crucial mediator of preeclampsia process, as an imbalance between T_H 1, T_H 2, and T_H 17 immune responses is observed. The present review accumulates current knowledge about the contribution of interleukins in preeclampsia, summarizing the pathways through which each interleukin exerts its function in the disease. Also, the role of genetic polymorphisms is explored and the predictive efficacy of maternal serum interleukin levels is evaluated. Finally, recommendations about the safe interpretation of the outcomes, as well as guidance for future research, are provided.

Biomarkers of coagulation, inflammation, and angiogenesis are independently associated with preeclampsia

PROBLEM

Although preeclampsia has been associated with inflammation, coagulation, and angiogenesis, their correlation and relative contribution are unknown.

METHOD OF STUDY

About 114 women with preeclampsia, 31 with early onset (EOP) and 83 with late onset preeclampsia (LOP), and 100 normal pregnant controls were included. A broad panel of 32 biomarkers reflecting coagulation, inflammation, and angiogenesis was analyzed.

RESULTS

Preeclampsia was associated with decreased antithrombin, IL-4 and placental growth factor levels and with increased C3a, pentraxin-3, and sFlt-1 levels, with more marked differences in the EOP group. The Th1-associated chemokines CXCL10 and CXCL11 were significantly higher in the preeclampsia and EOP group than in controls, respectively. No correlations between the biomarkers were found in preeclampsia. Multivariate logistic regression tests confirmed the results.

CONCLUSIONS

Cytokines, chemokines and complement activation seem to be part of a Th1-like inflammatory reaction in preeclampsia, most pronounced in EOP, where chemokines may be more useful than cytokines as biomarkers. Biomarkers were not correlated suggesting partly independent or in time separated mechanisms.

Contribution of interferon-gamma receptor 1 gene polymorphisms to pre-eclampsia in China

PROBLEM

As gene polymorphisms of cytokines receptors have been found to significantly influence cell responses to cytokines, the aim of this study was to test the hypothesis that IFN-gamma receptor 1 (IFNGR1) gene polymorphisms may contribute to the pathogenesis of pre-eclampsia.

METHOD OF STUDY

One hundred and sixty-four pre-eclamptic patients (121 patients with mild pre-eclampsia and 43 patients with severe pre-eclampsia) and 171 controls were included. Polymorphisms of the IFNGR1 gene at positions -611, -270, +56 and +95 were genotyped with the matrix-assisted laser desorption/ionization time of flight mass spectrometry.

RESULTS

This study showed a positive association between -56C/C genotype (OR = 1.7; 95% CI = 1.1-2.7) and pre-eclampsia. Although the genotype frequencies (except for -56C/C) of the two polymorphisms were comparable between cases and controls, higher frequency of the -611A/-56C haplotype (OR = 1.450; 95% CI = 1.070-1.966) was noticed in patients versus controls. All patients and controls were homozygous for the -270T/T and +95T/T genotypes. Specifically, the frequency of the -56C allele (OR = 1.838; 95% CI = 1.127-2.995) was higher among patients with severe pre-eclampsia.

CONCLUSION

The IFNGR1 gene polymorphisms may contribute to the pathogenesis of pre-eclampsia in our population.

Functional changes of human peripheral B-lymphocytes in pre-eclampsia

PROBLEM

The aim of our study was to investigate the functional changes of human peripheral B-lymphocytes in healthy and pre-eclamptic pregnancies.

METHOD OF STUDY

Twenty patients with pre-eclampsia and 15 healthy third-trimester pregnant women were recruited in this study. Peripheral blood mononuclear cells (PBMCs) were isolated and directly stained with fluorescein isothiocyanate (FITC)-labeled anti-CD27 monoclonal antibody (mAb) and phycoerythrin (PE)-labeled anti-CD38 mAb. The percentages of the individual B-cell subsets were estimated out of total lymphocytes by flow cytometric analysis. Additionally, the enriched PBMCs were cultured with or without the stimulation of pokeweed mitogen (PWM) for 5 days. Then morphologic observation of plasma cells was analysed by Wright-Giemsa stain, and antibody-producing cells were detected by enzyme-linked immunospot assay.

RESULTS

The percentage of CD27(-)CD38(-) naïve B-cells and CD27(-)CD38(+) plasma cells did not differ between study groups (P > 0.05). The percentage of CD27(+)CD38(-) memory B-cells and CD27(+)CD38(+) plasma cell precursors increased in pre-eclamptic women compared with the controls (P < 0.05). Irrespective of whether the PBMCs were stimulated with or w/o PWM in vitro, the mean percentages of generated plasma cells were significantly higher in pre-eclamptic group than in the controls (P < 0.05). There were more antibody-producing cells in pre-eclamptic women following the activation of PWM than those in the controls (P < 0.01).

CONCLUSION

Our findings implicate that the functional changes of human circulating B-cells might contribute to the etiology of pre-eclampsia.

Maternal Serum Interleukin-10, Interleukin-2 and Interleukin-6 in Pre-Eclampsia and Eclampsia

PROBLEM

The aim of the study was to investigate and compare the concentrations of interleukin (IL)-2, IL-6, and IL-10 in serum of women with mild pre-eclampsia, severe pre-eclampsia, eclampsia, and normotensive pregnancy.

METHOD OF STUDY

A total of 69 consecutive cases, 38 mild pre-eclampsia, 20 severe pre-eclampsia, 11 eclampsia, and 20 normotensive controls were included in this study. Serum IL-2, IL-6, and IL-10 levels were determined using enzyme-linked immunosorbent assay method.

RESULTS

Gestational age (P = 0.210) and body mass index (P = 0.214) between the groups were similar. The mean concentration of serum IL-2 and IL-6 were not different between the groups (P = 0.261, P = 0.141 respectively). The median concentrations of serum IL-10 in patients with mild and severe pre-eclampsia were similar (P < 0.282) and was significantly lower than those of controls (P < 0.001) and patients with eclampsia (P < 0.001). In patients with eclampsia, the median concentration of IL-10 was significantly higher than that of all other groups (P < 0.001 for each comparison).

CONCLUSION

Pre-eclampsia is associated with a deficiency serum IL-10. High serum IL-10 is correlated with the presence of eclampsia.

Elevated serum levels of interleukin-15 and interleukin-16 in preeclampsia

A generalized inflammatory response has been considered to be the main pathology and has an important role in the pathogenesis of preeclampsia. The immune aberrations per se and immunomodulatory milieu present in serum need to be elucidated. The purpose of the current investigation was to characterize changes in serum levels of interleukin (IL)-15 and IL-16 in preeclampsia. Thirty-seven women with preeclampsia were recruited and 36 age- and gestational age-matched women with normal pregnancy served as control. Levels of IL-15 and IL-16 were detected with immune assays in all serum samples. We found that serum levels of IL-15 and IL-16 were significantly higher in preeclampsia than in normal pregnancy (p<0.001 for both). There were significant differences in serum IL-15 and IL-16 between mild and severe preeclampsia (p<0.01 for both). Our data corroborate the hypothesis of an increased inflammatory response in preeclampsia, as illustrated by the elevated serum levels of IL-15 and IL-16, suggesting their possible role in the pathogenesis of preeclampsia. These associations may offer insight into the pathophysiology of preeclampsia.

Inflammatory Changes in Preeclampsia: Current Understanding of the Maternal Innate and Adaptive Immune Response

Preeclampsia is characterized by generalized endothelial dysfunction as a result of an inappropriate maternal immune response against the fetus. It has been postulated that the adaptive immune system plays a key role in the etiology of preeclampsia by generating a pro-inflammatory Th1 type immune reaction. In this review, recent studies on Th1 and Th2 type cytokine mapping in preeclampsia are reviewed, as well as on the sources of pro-inflammatory cytokines and the role of regulatory cytokines and chemokines. In addition, we discuss the possible role of Toll-like receptors of the innate immune system in the pathophysiology of preeclampsia.

TARGET AUDIENCE

Obstetricians & Gynecologists, Family Physicians.

LEARNING OBJECTIVES

After completion of this article, the reader should be able to summarize the newer concepts related to the pathogenesis of preeclampsia and explain the role of the maternal immune system and the role of pro-inflammatory and regulatory cytokines and chemokines in the pathophysiology of the disease.

Indications of an altered immune balance in preeclampsia: A decrease in in vitro secretion of IL-5 and IL-10 from blood mononuclear cells and in blood basophil counts compared with normal pregnancy

It has been suggested that maladaptation of the maternal immune response during pregnancy might be a causal factor for preeclampsia. This study was designed to examine the systemic immune status at both the innate level and the adaptive level in pregnancies complicated by preeclampsia (n=15) and normal pregnancies (n=15). Spontaneous and in vitro-induced secretion of IL-5, IL-6, IL-10, IL-12, IL-13 and TNF-alpha, in response to paternal blood cells and the vaccination antigens purified protein derivate of tuberculin (PPD) and tetanus toxoid (TT), was detected in cell culture supernatants from blood mononuclear cells by ELISA. Preeclamptic women showed reduced numbers of basophil granulocytes in the blood (p=0.004) and lower spontaneous secretion of IL-5 from blood mononuclear cells (p=0.016). In addition, paternal antigen-induced secretion of IL-10 was decreased in preeclampsia compared with normal pregnancy (p=0.012). No further differences between preeclampsia and normal pregnancy were found for any stimuli or cytokines. The present findings of reduced basophil numbers and lower spontaneous in vitro secretion of IL-5 in preeclampsia compared with normal pregnancy indicate a decrease in systemic Th2 immunity in preeclampsia. Furthermore, the decrease in paternal antigen-induced secretion of the immunosuppressive cytokine IL-10 in preeclampsia indicates a fetus-specific decrease in immunosuppression mediated by blood mononuclear cells. Whether these systemic changes are a cause or a consequence of preeclampsia remains to be elucidated.