The presence of gestational diabetes is associated with increased detection of anti-HLA-class II antibodies in the maternal circulation

Analysis, validation, and discussion of key genes in placenta of patients with gestational diabetes mellitus

Gestational diabetes mellitus (GDM) is a common complication during pregnancy, which can have harmful health consequences for both the mother and the fetus. Given the placenta's crucial role as an endocrine organ during pregnancy, exploring and validating key genes in the placenta hold significant potential in the realm of GDM prevention and treatment. In this study, differentially expressed genes (DEGs) were identified from two databases, GSE70493 and PRJNA646212, and verified by reverse transcription-quantitative polymerase chain reaction (RT-qPCR) in placenta tissues. DEGs expression was detected in normal or high-glucose-treated HTR8/SVneo cells. We also investigated the relationship between DEGs and glucose levels in GDM patients. By selecting the intersection of the two databases, we screened 20 DEGs, which were validated in GDM patients. We observed an up-regulation of SLAMF, ALDH1A2, and CHI3L2, and a down-regulation of HLA-E, MYH11, HLA-DRB5, ITGAX, GZMB, NAIP, TMEM74B, RANBP3L, PAEP, WT-1, and CEP170. We conducted further investigations into the expression of DEGs in HTR8/SVneo cells exposed to high glucose, revealing a significant upregulation in the expression of SERPINA3, while the expressions of HLA-E, BCL6, NAIP, PAEP, MUC16, WT-1, and CEP170 were decreased. Moreover, some DEGs were confirmed to have a positive or negative correlation with blood glucose levels of GDM patients through correlation analysis. The identified DEGs are anticipated to exert potential implications in the prevention and management of GDM, thereby offering potential benefits for improving pregnancy outcomes and long-term prognosis of fetuses among individuals affected by GDM.

Genomics and Epigenomics of Gestational Diabetes Mellitus: Understanding the Molecular Pathways of the Disease Pathogenesis

One of the most common complications during pregnancy is gestational diabetes mellitus (GDM), hyperglycemia that occurs for the first time during pregnancy. The condition is multifactorial, caused by an interaction between genetic, epigenetic, and environmental factors. However, the underlying mechanisms responsible for its pathogenesis remain elusive. Moreover, in contrast to several common metabolic disorders, molecular research in GDM is lagging. It is important to recognize that GDM is still commonly diagnosed during the second trimester of pregnancy using the oral glucose tolerance test (OGGT), at a time when both a fetal and maternal pathophysiology is already present, demonstrating the increased blood glucose levels associated with exacerbated insulin resistance. Therefore, early detection of metabolic changes and associated epigenetic and genetic factors that can lead to an improved prediction of adverse pregnancy outcomes and future cardio-metabolic pathologies in GDM women and their children is imperative. Several genomic and epigenetic approaches have been used to identify the genes, genetic variants, metabolic pathways, and epigenetic modifications involved in GDM to determine its etiology. In this article, we explore these factors as well as how their functional effects may contribute to immediate and future pathologies in women with GDM and their offspring from birth to adulthood. We also discuss how these approaches contribute to the changes in different molecular pathways that contribute to the GDM pathogenesis, with a special focus on the development of insulin resistance.

Decreased serum human leukocyte antigen-G levels are associated with gestational diabetes mellitus

AIM

This study was designed to determine serum human leukocyte antigen-G (HLA-G) levels and establish whether serum HLA-G level is related with gestational diabetes mellitus (GDM).

METHODS

Twenty-five GDM patients aged between 24 and 34 years and 24 healthy pregnant women aged between 22 and 33 years were included in this study. Health status of subjects was determined by medical history, physical, and obstetric examinations. Absence of family history for Type 2 diabetes mellitus, absence of diagnosis or clinical evidence of any major disease, and absence of medication use altering glucose metabolism constituted the inclusion criteria. GDM cases who are at their 24-28 weeks of pregnancy and who have not been using any oral hypoglycemic agents were included in GDM group. Control group consisted of healthy pregnant women at their 24-28 weeks of pregnancy.

RESULTS

Women with GDM had significantly lower levels of serum HLA-G than controls. HLA-G levels were negatively correlated with all parameters of glucose metabolism including insulin (r = - 0.14; p = 0.338), fasting blood glucose (r = - 0.220; p = 0.129), 1-h oral glucose tolerance test (OGTT) blood glucose (r = - 0.18; p = 0.271), 2-h OGTT blood glucose (r = - 0.314; p = 0.172), homeostasis model assessment (r = - 0.226; p = 0.119), HbA1C (r = -0.342; p = 0.108), and WBC (r = -0.149; p = 0.307). There was a negative correlation between HLA-G and BMI (r = -0.341; p = 0.016).

CONCLUSION

Decreased circulating HLA-G level is found to be associated with insulin resistance and GDM, in this study.

First trimester secreted Frizzled-Related Protein 4 and other adipokine serum concentrations in women developing gestational diabetes mellitus

Background

The aim of this study was to evaluate whether soluble frizzled-related protein 4 (sFRP4) concentration in the first trimester of pregnancy is individually, or in combination with Leptin, Chemerin and/or Adiponectin, associated with the development of gestational diabetes (GDM).

Methods

In a nested case-control study, 50 women with GDM who spontaneously conceived and delivered a live-born infant were matched with a total of 100 uncomplicated singleton control pregnancies based on body mass index (± 2 kg/m²), gestational age at sampling (exact day) and maternal age (± 2 years). In serum samples, obtained between 70–90 days gestational age, sFRP4, Chemerin, Leptin and Adiponectin concentrations were determined by ELISA. Statistical comparisons were performed using univariate and multi-variate logistic regression analysis after logarithmic transformation of the concentrations. Discrimination of the models was assessed by the area under the curve (AUC).

Results

First trimester sFRP4 concentrations were significantly increased in GDM cases (2.04 vs 1.93 ng/ml; p<0.05), just as Chemerin (3.19 vs 3.15 ng/ml; p<0.05) and Leptin (1.44 vs 1.32 ng/ml; p<0.01). Adiponectin concentrations were significantly decreased (2.83 vs 2.94 ng/ml; p<0.01) in GDM cases. Further analysis only showed a weak, though significant, correlation of sFRP4 with Chemerin (R² = 0.124; p<0.001) and Leptin (R² = 0.145; p<0.001), and Chemerin with Leptin (R² = 0.282; p<0.001) in the control group. In a multivariate logistic regression model of these four markers, only Adiponectin showed to be significantly associated with GDM (odds ratio 0.12, 95%CI 0.02–0.68). The AUC of this model was 0.699 (95%CI 0.605–0.793).

Conclusion

In the first trimester of pregnancy, a multi-marker model with sFRP4, Leptin, Chemerin and Adiponectin is associated with the development of GDM. Therefore, this panel seems to be an interesting candidate to further evaluate for prediction of GDM in a prospective study.

Th2-Immune Polarizing and Anti-Inflammatory Properties of Insulin Are Not Effective in Type 2 Diabetic Pregnancy

Background

The implication of the immune system in the physiopathology of pregnancy complicated by diabetes has been reported. Here, we investigated the effects of insulin treatment on the frequencies of immune cell subpopulations as well as T cell-derived cytokines in type 2 diabetic (T2D) pregnancy compared to gestational diabetes mellitus (GDM).

Methods

Fifteen (15) women with GDM, twenty (20) insulin-treated T2D pregnant women, and twenty-five (25) pregnant controls were selected. Immune cell subpopulation frequencies were determined in blood using flow cytometry. The proliferative capacity of T cells was performed, and serum and cell culture supernatant cytokine levels were also quantified.

Results

The frequencies of total CD3+ and CD4+ T cells and nonclassical monocytes significantly increased in insulin-treated T2D pregnant women compared to pregnant controls. The proportions of CD4+ T cells as well as B cells were significantly higher in women with GDM than in pregnant controls. GDM was associated with high frequencies of total CD3+ and CD4+ T cells and B cell expansion, suggesting a concomitant activation of cellular and humoral immunity. Concomitantly, Th1/Th2 ratio, determined as IFN-γ/IL-4, was shifted towards Th1 phenotype in women with GDM and insulin-treated T2D pregnant women. Besides, isolated T cells elicited similar proliferative capacity in the three groups of women. Insulin-treated T2D pregnant women and women with GDM exhibited a low serum IL-10 level, without any change in the number of Treg cells.

Conclusion

Our study showed that, despite insulin treatment, pregnant women with T2D displayed a proinflammatory status consistent with high proportions of CD3+ and CD4+ T cells, upregulation of Th1 cytokines, and low IL-10 production, suggesting a reduced immune-suppressive activity of regulatory T cells. However, GDM, although associated with proinflammatory status, has shown increased humoral immunity consistent with high proportion of CD19+ B cells. Thus, the lack of response to insulin in diabetes during pregnancy and clinical implications of these immunological parameters deserves further investigations.

Identification of hub-methylated differentially expressed genes in patients with gestational diabetes mellitus by multi-omic WGCNA basing epigenome-wide and transcriptome-wide profiling

Gestational diabetes mellitus (GDM), defined as dysglycaemia that is detected during pregnancy for the first time, has become a global health burden. GDM was found to be correlated to epigenetic changes, which would cause abnormal expression of placental genes. In the present study, we performed multi-omic weighted gene coexpression network analysis (WGCNA) to systematically identify the hub genes for GDM using both epigenome- and transcriptome-wide microarray data. Two microarray datasets (GSE70493 and GSE70494) were downloaded from the Gene Expression Omnibus (GEO) database. GEO2R was used to screen differentially expressed genes (DEGs) and differentially methylated genes (DMGs) between normal and GDM samples, separately. The results of WGCNA found that 15 modules were identified and the MEblack module had a significantly negative correlation with GDM (r = -.28, P = .03). GO enrichment analysis by BinGO of the MEblack module showed that genes were primarily enriched for the presentation of antigen processing, regulation of interferon-α production and interferon-γ-mediated signaling pathway. By comparing the DEGs, DMGs and hub genes in the coexpression network, we identified five hypermethylated, lowly expressed genes (ABLIM1, GRHL1, HLA-F, NDRG1, and SASH1) and one hypomethylated, highly expressed gene (EIF3F) as GDM-related hub DMGs. Moreover, the expression levels of ABLIM1, GRHL1, HLA-F, NDRG1, and SASH11 in the GDM patients and healthy controls were validated by a real-time quantitative polymerase chain reaction. Finally, gene set enrichment analysis showed that the biological function of cardiac muscle contraction was enriched for four GDM-related hub DMGs (ABLIM1, GRHL1, NDRG1, and SASH1). Analysis of this study revealed that dysmethylated hub genes in GDM placentas might affect the placental function and thus, take part in GDM pathogenesis and fetal cardiac development.

Analysis of key genes and their functions in placental tissue of patients with gestational diabetes mellitus

BACKGROUND

This study was aimed at screening out the potential key genes and pathways associated with gestational diabetes mellitus (GDM).

METHODS

The GSE70493 dataset used for this study was obtained from the Gene Expression Omnibus database. Differentially expressed genes (DEGs) in the placental tissue of women with GDM in relation to the control tissue samples were identified and submitted to protein-protein interaction (PPI) network analysis and subnetwork module mining. Functional enrichment analyses of the PPI network and subnetworks were subsequently carried out. Finally, the integrated miRNA-transcription factor (TF)-DEG regulatory network was analyzed.

RESULTS

In total, 238 DEGs were identified, of which 162 were upregulated and 76 were downregulated. Through PPI network construction, 108 nodes and 278 gene pairs were obtained, from which chemokine (C-X-C motif) ligand 9 (CXCL9), CXCL10, protein tyrosine phosphatase, receptor type C (PTPRC), and human leukocyte antigen (HLA) were screened out as hub genes. Moreover, genes associated with the immune-related pathway and immune responses were found to be significantly enriched in the process of GDM. Finally, miRNAs and TFs that target the DEGs were predicted.

CONCLUSIONS

Four candidate genes (viz., CXCL9, CXCL10, PTPRC, and HLA) are closely related to GDM. miR-223-3p, miR-520, and thioredoxin-binding protein may play important roles in the pathogenesis of this disease.

Longitudinal assessment of HLA and MIC-A antibodies in uneventful pregnancies and pregnancies complicated by preeclampsia or gestational diabetes

The significance of antibodies directed against paternal epitopes in the context of obstetric disorders is discussed controversially. In this study anti-HLA and anti-MIC-A antibodies were analysed in sera of women with uneventful pregnancy (n = 101), preeclampsia (PE, n = 55) and gestational diabetes (GDM, n = 36) using antigen specific microbeads. While two thirds of the women with uneventful pregnancy or GDM were HLA and MIC-A antibody positive in gestational week 11 to 13 with a modest increase towards the end of pregnancy, women with PE showed an inverse kinetic: 90% were HLA antibody positive in gestational week 11 to 13 and only 10% showed HLA reactivities at the end of the pregnancy. HLA antibody binding strength was more pronounced in gestational week 14 to 17 in patients with PE compared to women with uneventful pregnancy (maximum median fluorescence intensity of the highest ranked positive bead 7403, IQR 2193–7938 vs. 1093, IQR 395–5689; p = 0.04) and was able to predict PE with an AUC of 0.80 (95% CI 0.67–0.93; p = 0.002). Our data suggest a pathophysiological involvement of HLA antibodies in PE. HLA antibody quantification in early pregnancy may provide a useful tool to increase diagnostic awareness in women prone to develop PE.

Microarray analysis of differentially expressed genes and their functions in omental visceral adipose tissues of pregnant women with vs. without gestational diabetes mellitus

Increasing evidence has shown that insulin resistance in omental visceral adipose tissue (OVAT) is a characteristic of gestational diabetes mellitus (GDM). The present study aimed to identify differentially expressed genes (DEGs) and their associated functions and pathways involved in the pathogenesis of GDM by comparing the expression profiles of OVATs obtained from pregnant Chinese women with and without GDM during caesarian section. A total of 935 DEGs were identified, including 450 downregulated and 485 upregulated genes. In the gene ontology category cellular components, the DEGs were predominantly associated with functions of the extracellular region, while receptor binding was predominant in the molecular function category and biological process terms included antigen processing and presentation, extracellular matrix organization, positive regulation of cell-substrate adhesion, response to nutrients and response to dietary excess. Functional enrichment and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment were performed and a functional interaction network was constructed. Functions of downregulated genes included antigen processing and presentation as well as cell adhesion molecules, while those of upregulated genes included transforming growth factor (TGF)-β-signaling, focal adhesion, phosphoinositide-3 kinase-Akt-signaling, P53 signaling, extracellular matrix-receptor interaction and regulation of actin cytoskeleton pathway. The five main pathways associated with GDM were antigen processing and presentation, cell adhesion molecules, Type 1 diabetes mellitus, natural killer cell-mediated cytotoxicity and TGF-β signaling. These pathways were included in the KEGG pathway categories of ‘signaling molecules and interaction’, ‘immune system’ and ‘inflammatory response’, suggesting that these processes are involved in GDM. The results of the present study enhanced the present understanding of the mechanisms associated with insulin resistance in OVATs of GDM.

Epigenome-wide and transcriptome-wide analyses reveal gestational diabetes is associated with alterations in the human leukocyte antigen complex

Background

Gestational diabetes mellitus (GDM) affects approximately 10 % of pregnancies in the United States and increases the risk of adverse health outcomes in the offspring. These adult disease propensities may be set by anatomical and molecular alterations in the placenta associated with GDM.

Results

To assess the mechanistic aspects of fetal programming, we measured genome-wide methylation (Infinium HumanMethylation450 BeadChips) and expression (Affymetrix transcriptome microarrays) in placental tissue of 41 GDM cases and 41 matched pregnancies without maternal complications from the Harvard Epigenetic Birth Cohort. Specific transcriptional and epigenetic perturbations associated with GDM status included alterations in the major histocompatibility complex (MHC) region, which were validated in an independent cohort, the Rhode Island Child Health Study. Gene ontology enrichment among gene regulation influenced by GDM revealed an over-representation of immune response pathways among differential expression, reflecting these coordinated changes in the MHC region. This differential methylation and expression may be capturing shifts in cellular composition, reflecting physiological changes in the placenta associated with GDM.

Conclusions

Our study represents the largest investigation of transcriptomic and methylomic differences associated with GDM, providing comprehensive insight into how GDM shapes the intrauterine environment, which may have implications for fetal (re)programming.

Electronic supplementary material

The online version of this article (doi:10.1186/s13148-015-0116-y) contains supplementary material, which is available to authorized users.

The role of regulatory T cell (Treg) subsets in gestational diabetes mellitus

Physiological changes during normal pregnancy are characterized by an inflammatory immune response and insulin resistance. Therefore, we hypothesize that gestational diabetes mellitus (GDM) may be caused by an inappropriate adaption of the maternal immune system to pregnancy. In this study we examined the role of regulatory T cell (Treg) differentiation for the development of GDM during pregnancy. We used six-colour flow cytometric analysis to demonstrate that the total CD4(+) CD127(low+/-) CD25(+) forkhead box protein 3 (FoxP3(+)) T(reg) pool consists of four different T(reg) subsets: naive CD45RA(+) T(regs), HLA-DR(-) CD45RA(-) memory T(regs) (DR(-) T(regs)) and the highly differentiated and activated HLA-DR(low+) CD45RA(-) and HLA-DR(high+) CD45RA(-) memory T(regs) (DR(low+) and DR(high+) T(regs)). Compared to healthy pregnancies, the percentage of CD4(+) CD127(low+/-) CD25(+) FoxP3(+) T(regs) within the total CD4(+) T helper cell pool was not different in patients affected by GDM. However, the suppressive activity of the total CD4(+) CD127(low+/-) CD25(+) T(reg) pool was significantly reduced in GDM patients. The composition of the total T(reg) pool changed in the way that its percentage of naive CD45RA(+) T(regs) was decreased significantly in both patients with dietary-adjusted GDM and patients with insulin-dependent GDM. In contrast, the percentage of DR(-) -memory T(regs) was increased significantly in patients with dietary-adjusted GDM, while the percentage of DR(low+) and DR(high+) memory T(regs) was increased significantly in patients with insulin-dependent GDM. Hence, our findings propose that alterations in homeostatic parameters related to the development and function of naive and memory T(regs) may cause the reduction of the suppressive capacity of the total T(reg) pool in GDM patients. However, as this is an exploratory analysis, the results are only suggestive and require further validation.

Characterization of the fetal blood transcriptome and proteome in maternal anti-fetal rejection: evidence of a distinct and novel type of human fetal systemic inflammatory response

BACKGROUND

The human fetus is able to mount a systemic inflammatory response when exposed to microorganisms. This stereotypic response has been termed the 'fetal inflammatory response syndrome' (FIRS), defined as an elevation of fetal plasma interleukin-6 (IL-6). FIRS is frequently observed in patients whose preterm deliveries are associated with intra-amniotic infection, acute inflammatory lesions of the placenta, and a high rate of neonatal morbidity. Recently, a novel form of fetal systemic inflammation, characterized by an elevation of fetal plasma CXCL10, has been identified in patients with placental lesions consistent with 'maternal anti-fetal rejection'. These lesions include chronic chorioamnionitis, plasma cell deciduitis, and villitis of unknown etiology. In addition, positivity for human leukocyte antigen (HLA) panel-reactive antibodies (PRA) in maternal sera can also be used to increase the index of suspicion for maternal anti-fetal rejection. The purpose of this study was to determine (i) the frequency of pathologic lesions consistent with maternal anti-fetal rejection in term and spontaneous preterm births; (ii) the fetal serum concentration of CXCL10 in patients with and without evidence of maternal anti-fetal rejection; and (iii) the fetal blood transcriptome and proteome in cases with a fetal inflammatory response associated with maternal anti-fetal rejection.

METHOD OF STUDY

Maternal and fetal sera were obtained from normal term (n = 150) and spontaneous preterm births (n = 150). A fetal inflammatory response associated with maternal anti-fetal rejection was diagnosed when the patients met two or more of the following criteria: (i) presence of chronic placental inflammation; (ii) ≥80% of maternal HLA class I PRA positivity; and (iii) fetal serum CXCL10 concentration >75th percentile. Maternal HLA PRA was analyzed by flow cytometry. The concentrations of fetal CXCL10 and IL-6 were determined by ELISA. Transcriptome analysis was undertaken after the extraction of total RNA from white blood cells with a whole-genome DASL assay. Proteomic analysis of fetal serum was conducted by two-dimensional difference gel electrophoresis. Differential gene expression was considered significant when there was a P < 0.01 and a fold-change >1.5.

RESULTS

(i) The frequency of placental lesions consistent with maternal anti-fetal rejection was higher in patients with preterm deliveries than in those with term deliveries (56% versus 32%; P < 0.001); (ii) patients with spontaneous preterm births had a higher rate of maternal HLA PRA class I positivity than those who delivered at term (50% versus 32%; P = 0.002); (iii) fetuses born to mothers with positive maternal HLA PRA results had a higher median serum CXCL10 concentration than those with negative HLA PRA results (P < 0.001); (iv) the median serum CXCL10 concentration (but not IL-6) was higher in fetuses with placental lesions associated with maternal anti-fetal rejection than those without such lesions (P < 0.001); (v) a whole-genome DASL assay of fetal blood RNA demonstrated differential expression of 128 genes between fetuses with and without lesions associated with maternal anti-fetal rejection; and (vi) comparison of the fetal serum proteome demonstrated 20 proteins whose abundance differed between fetuses with and without lesions associated with maternal anti-fetal rejection.

CONCLUSION

We describe a systemic inflammatory response in human fetuses born to mothers with evidence of maternal anti-fetal rejection. The transcriptome and proteome of this novel type of fetal inflammatory response were different from that of FIRS type I (which is associated with acute infection/inflammation).

Beneficial or harmful effect of antipaternal human leukocyte antibodies on pregnancy outcome? A systematic review and meta-analysis

PROBLEM

During pregnancy, antibodies are induced that target the paternal human leukocyte antigens of the semi-allogeneic fetus. The level and presence of these antibodies have been reported increased as well as decreased for a variety of pregnancy complications; the clinical relevance and consequences of these antibodies are not very clear. Therefore, the objective of this review is to determine whether the presence of antipaternal antibodies influences pregnancy outcome.

METHOD

We performed a systematic search of studies that described the effect of antipaternal antibodies on pregnancy complications. The primary outcome was the risk ratio for HLA class I and class II antibodies on pregnancy complications. Furthermore, we calculated the risk for first- and third-trimester complications.

RESULTS

The seventeen studies that were selected for meta-analysis showed high level of statistical and clinical heterogeneity. In the meta-analysis, we found no significant effect of HLA class I or class II antibodies on pregnancy outcome.

CONCLUSION

No consistent conclusions can be drawn from the meta-analysis. Discrepancies in the meta-analysis are the result of different screening techniques, varying time points of screening, and use of incorrect control groups. Furthermore, more detailed analyses of the characteristics and specificity of the antibodies involved are essential.

Secondary recurrent miscarriage and H-Y immunity

BACKGROUND

Approximately half recurrent miscarriage (RM) cases remain unexplained after standard investigations. Secondary RM (SRM) is, in contrast to primary RM, preceded by a birth, which increases the transfer of fetal cells into the maternal circulation. Mothers of boys are often immunized against male-specific minor histocompatibility (H-Y) antigens, and H-Y immunity can cause graft-versus-host disease after stem-cell transplantation. We proposed the H-Y hypothesis that aberrant H-Y immunity is a causal factor for SRM.

METHODS

This is a critical review of the H-Y hypothesis based on own publications and papers identified by systematic PubMed and EMBASE searches.

RESULTS

SRM is more common after the birth of a boy and the subsequent live birth rate is reduced for SRM patients with a firstborn boy. The male:female ratio of children born prior and subsequent to SRM is 1.49 and 0.76 respectively. Maternal carriage of HLA-class II alleles presenting H-Y antigens to immune cells is associated with a reduced live birth rate and increased risk of obstetric complications in surviving pregnancies in SRM patients with a firstborn boy. In early pregnancy, both antibodies against HLA and H-Y antigens are increased in SRM patients compared with controls. Presence of these antibodies in early pregnancy is associated with a lower live birth rate and a low male:female ratio in subsequent live births, respectively. Births of boys are also associated with subsequent obstetric complications in the background population.

CONCLUSIONS

Epidemiological, immunogenetic and immunological studies support the hypothesis that aberrant maternal H-Y immune responses have a pathogenic role in SRM.

Diabetes related autoimmunity in gestational diabetes mellitus: is it important?

Some GDM women show autoantibody positivity during and after pregnancy and pancreatic autoantibodies can appear for the first time in some patients after delivery. Autoantibody positivity is often accompanied by a high frequency of DR3 and DR4 alleles, which are classically related to the development of type 1 diabetes and, although not all studies agree on this point, by an immunological imbalance expressed by the behaviour of the lymphocyte subpopulation, which can be seen as diabetic anomalies overlapping with the immunological changes that occur during pregnancy. It is worth emphasizing that such patients may develop classical type 1 diabetes during and/or after their pregnancy or they may evolve, often some years after their pregnancy, into cases of latent autoimmune diabetes of adulthood (LADA). Autoimmune GDM accounts for a relatively small number of cases (about 10% of all GDM) but the risk of these women developing type 1 diabetes or LADA is very high, so these patients must be identified in order to prevent the severe maternal and fetal complications of type 1 diabetes developing in pregnancy, or its acute onset afterwards. Since women with autoimmune GDM must be considered at high risk of developing type 1 diabetes in any of its clinical forms, these women should be regarded as future candidates for the immunomodulatory strategies used in type 1 diabetes.

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.

O papel do complexo principal de histocompatibilidade na fisiologia da gravidez e na patogênese de complicações obstétricas

Este trabalho tem por objetivo discutir a estrutura e função dos Antígenos Leucocitários Humanos (HLA), seus métodos de detecção, nomenclatura e os mecanismos imunopatológicos que o associam com a fisiologia da gestação e morbidades obstétricas. Sabe-se que o equilíbrio imunológico entre mãe e concepto é imprescindível na manutenção da gravidez. Moléculas do HLA - notadamente o HLA-G expresso na interface materno-fetal - exercem função importante na tolerância imunológica materna, evitando rejeição fetal e algumas complicações obstétricas. Além disso, o HLA permeia diversas etapas do desenvolvimento conceptual como clivagem, formação do trofoblasto e implantação. Para revisão, foram pesquisados os bancos de dados MEDLINE e LILACS, utilizando os descritores: "HLA antigens"; "pregnancy"; "embryonic development"; "pregnancy complication"; "abortion, habitual"; "pre-eclampsia". O conhecimento sobre a influência do HLA na gravidez é necessário para melhor manejo da gestação e patologias obstétricas auto-imunes, favorecendo intervenções precoces e terapêutica específica, reduzindo a morbimortalidade materna e perinatal.

Indications of anti-HY immunity in recurrent placental abruption

PROBLEM

Placental abruption is a potential life-threatening condition for both the fetus and the mother, being significantly more common in pregnancies with male fetuses. The pathogenesis of placental abruption remains unknown. However, some recent reports point toward a maternal immune response against the fetus as a possible mechanism. No data exist concerning special characteristics of patients suffering recurrent placental abruptions.

METHOD OF STUDY

Identification of all patients with recurrent placental abruption in a retrospective review of 881 consecutive Caucasian women seen in our tertiary centre for recurrent pregnancy losses between 1986 and 2005. The HLA, DRB1, DRB3, 4, 5 and DQB1 genotypes of patients were compared with relevant controls.

RESULTS

Eight patients were identified with recurrent placental abruption. The patients had a total of 22 abruptions; 18 (82%) in which the fetus died. Seven patients (88%) had first-born boys, and 15 abruptions (68%) involved male fetuses. All patients with a first-born boy, except one, had HLA-class II alleles known to restrict CD4+ T-cell responses against male-specific minor histocompatibility (HY)-antigens (HLA-DRB1*15, HLA-DRB3*0301 and HLA-DQB1*05). Haplotypes with these HLA-alleles constituted 64% of the patients' haplotypes compared to 28% of those of the controls (p=0.009). Furthermore, 43% of the patients were homozygous for these haplotypes compared to 5% of controls (p=0.023).

CONCLUSION

We have found that recurrent placental abruption is exclusively almost preceded by the birth of a boy and the majority of patients have HLA-class II known to restrict CD4 T-cell reactions against HY-antigens. This indicates that maternal immunological responses against HY-antigens play a role in recurrent placental abruption.