Increased sHLA-G Is Associated with Improved COVID-19 Outcome and Reduced Neutrophil Adhesion

Human leukocyte antigen (HLA) is a group of molecules involved in inflammatory and infective responses. We evaluated blood sHLA-E and sHLA-G levels in hospitalized COVID-19 patients with respiratory failure and their relationship with clinical evolution, changes in endothelial activation biomarker profile, and neutrophil adhesion. sHLA-E, sHLA-G, and endothelial activation biomarkers were quantified by ELISA assay in plasma samples. Neutrophil adhesion to endothelium was assessed in the presence/absence of patients’ plasma samples. At admission, plasma levels of sHLA-G and sHLA-E were significantly higher in COVID-19 patients with respiratory failure compared to controls. COVID-19 clinical improvement was associated with increased sHLA-G plasma levels. In COVID-19, but not in control patients, an inverse correlation was found between serum sICAM-1 and E-selectin levels and plasma sHLA-G values. The in vitro analysis of activated endothelial cells confirmed the ability of HLA-G molecules to control sICAM-1 and sE-selectin expression via CD160 interaction and FGF2 induction and consequently neutrophil adhesion. We suggest a potential role for sHLA-G in improving COVID-19 patients’ clinical condition related to the control of neutrophil adhesion to activated endothelium.

Pregnancy and postpartum levels of circulating maternal sHLA-G in preeclampsia

Preeclampsia is a leading cause of maternal and offspring mortality and morbidity, and predicts increased future cardiovascular disease risk. Placental dysfunction and immune system dysregulation are likely key pathophysiological factors. Soluble human leukocyte antigen G (sHLA-G) may dampen the specific immune response towards placental trophoblasts. Previous studies have shown low sHLA-G levels in preeclampsia, but postpartum, levels are unknown. Furthermore, the relationship between sHLA-G and sFlt-1 and PlGF, placental function markers, is unknown. We hypothesized that low maternal sHLA-G during pregnancy would be associated with placental dysfunction, including preeclampsia, gestational hypertension, and dysregulated sFlt-1 and PlGF, and that sHLA-G would remain decreased following preeclampsia. We included 316 pregnant women: 58 with early-onset preeclampsia (<34 weeks' gestation), 81 with late-onset preeclampsia (≥34 weeks' gestation), 25 with gestational hypertension, and 152 normotensive controls. Postpartum (1 or 3 years), we included 321 women: 29 with early-onset preeclampsia, 98 with late-onset preeclampsia, 57 with gestational hypertension, and 137 who were normotensive during their index pregnancies. In pregnancy, plasma sHLA-G was significantly lower both in the early- and late-onset preeclampsia groups compared to controls. In women with preeclampsia or gestational hypertension, sHLA-G was inversely correlated with serum sFlt-1. Postpartum, plasma sHLA-G levels were significantly higher in women who had had early-onset preeclampsia compared to controls. Our results support that sHLA-G may be important for placental function. Unexpectedly, sHLA-G was elevated up to 3 years after early-onset preeclampsia, suggesting an excessively activated immune system following this severe preeclampsia form, potentially contributing to future cardiovascular disease risk.

Plasma levels of soluble HLA-G and cytokines in papillary thyroid carcinoma before and after thyroidectomy

BACKGROUND

Increasing evidence shows that chronic inflammation plays an important role in thyroid tumorigenesis. Cytokines as central mediators in inflammatory microenvironment can present both pro-tumour and anti-tumour effects and cytokine release may be influenced by soluble HLA-G (sHLA-G), an immune checkpoint molecule whose expression can also be induced by certain cytokines.

AIM

To understand the role of these soluble factors in papillary thyroid cancer (PTC).

METHODS

We evaluated plasma levels of sHLA-G and of 13 cytokines using ELISA and flow cytometry, respectively, in PTC patients at two time points: pre- and post-thyroidectomy; and control subjects.

RESULTS

Compared with controls, IL-6 levels were increased, while IL-1β, IFN-α and TGF-β1 levels were decreased in pre-thyroidectomy PTC patients. IFN-α and TGF-β1 efficiently discriminated patients from controls and were associated with extrathyroidal extension and lymph node metastasis, respectively. In addition, TNF and IL-13 were associated with male gender, lymph node metastasis and Hashimoto thyroiditis, and sHLA-G with tumour invasion. Compared with pre-thyroidectomy, IL-4, IL-10, TNF, IFN-α and TGF-β1 levels were increased in post-thyroidectomy.

CONCLUSION

There are significant changes in the cytokine profile after surgical removal of the thyroid tumour, and IFN-α e TGF-β1 showed to be promising cytokines for discriminating PTC patients from controls. We also found that different cytokines are associated with clinicohistopathological characteristics of PTC related to poor prognosis, suggesting that cytokines seem to play an important role in PTC development and management.

High plasma soluble levels of the immune checkpoint HLA-G molecule among bodybuilders

Introduction

Studies report that intense physical activity influences the down-regulation of immune function in athletes as well as the interaction between adipose tissue and the immune system.

Aim

This study aimed to compare the plasma soluble levels of the immune checkpoint HLA-G (sHLA-G) molecule with the fat mass and muscle mass index among 77 bodybuilders and 64 controls.

Results

The comparisons of the percentage of body fat (%BF) revealed that the groups of male and female bodybuilders showed a statistically significant reduction in the percentage of body fat when compared to their control group, (P <0.0001, for both comparisons). Regarding sHLA-G levels, the comparisons showed that the group of male bodybuilders had significantly higher sHLA-G levels compared to the group of female bodybuilders (P = 0.0011).

Conclusion

Our results showed that in bodybuilders with less body fat, the systemic levels of soluble HLA-G, an immunological molecule with recognized immunosuppressive function, are significantly higher and suggest that this immune mechanism may corroborate the immunosuppressive state in athletes undergoing intense and prolonged physical training.

Integrated analysis of DNA methylation profile of HLA-G gene and imaging in coronary heart disease: Pilot study

Aims

Immune endothelial inflammation, underlying coronary heart disease (CHD) related phenotypes, could provide new insight into the pathobiology of the disease. We investigated DNA methylation level of the unique CpG island of HLA-G gene in CHD patients and evaluated the correlation with cardiac computed tomography angiography (CCTA) features.

Methods

Thirty-two patients that underwent CCTA for suspected CHD were enrolled for this study. Obstructive CHD group included fourteen patients, in which there was a stenosis greater than or equal to 50% in one or more of the major coronary arteries detected; whereas subjects with Calcium (Ca) Score = 0, uninjured coronaries and with no obstructive CHD (no critical stenosis, NCS) were considered as control subjects (n = 18). For both groups, DNA methylation profile of the whole 5’UTR-CpG island of HLA-G was measured. The plasma soluble HLA-G (sHLA-G) levels were detected in all subjects by specific ELISA assay. Statistical analysis was performed using R software.

Results

For the first time, our study reported that 1) a significant hypomethylation characterized three specific fragments (B, C and F) of the 5’UTR-CpG island (p = 0.05) of HLA-G gene in CHD patients compared to control group; 2) the hypomethylation level of one specific fragment of 161bp (+616/+777) positively correlated with coronary Ca score, a relevant parameter of CCTA (p<0.05) between two groups evaluated and was predictive for disease severity.

Conclusions

Reduced levels of circulating HLA-G molecules could derive from epigenetic marks. Epigenetics phenomena induce hypomethylation of specific regions into 5'UTR-CpG island of HLA-G gene in CHD patients with obstructive non critical stenosis vs coronary stenosis individuals.

Soluble HLA-G expression levels and HLA-G/irinotecan association in metastatic colorectal cancer treated with irinotecan-based strategy

We here explore the soluble Human Leukocyte Antigen-G (sHLA-G) expression level as clinical biomarker in metastatic colorectal cancer (mCRC). To this aim the sHLA-G protein was measured in plasma samples of 40 patients with mCRC treated with the FOLFIRI (irinotecan (CPT-11) plus 5-fluorouracil (5-FU) and leucovorin (LV)) regimen. The results suggest a link between HLA-G levels and irinotecan (CPT-11) pharmacokinetic, leading to hypothesize a molecular interaction between sHLA-G and CPT-11. This interaction was confirmed experimentally by fluorescence spectroscopy. HLA-G is known to exist in a number of polymorphs that affect both the protein expression levels and its peptide-binding cleft. The interaction between HLA-G polymorphs and CPT-11 was explored by means of computational modelling, confirming the hypothesis that CPT-11 could actually target the peptide binding cleft of the most common HLA-G polymorphs.

HLA-G Ins/Del polymorphism and +3142C/G SNP are not related to neuromyelitis optica spectrum disorder (NMOSD) development, disability status or anti-aquaporin 4 presence in Brazilian patients

We analyzed the association of polymorphisms from the 3' untranslated region of the HLA-G gene in 70 neuromyelitis optica spectrum disorder (NMOSD) patients and 162 healthy controls. No associations were found between the polymorphisms in NMOSD when compared to healthy controls, serology of the anti-AQP4 NMOSD biomarker and Expanded Disability Status Scale (EDSS). In conclusion, the 3' untranslated region 14 bp Ins/Del and +3142C/G polymorphisms seem not to be associated with NMOSD susceptibility, autoantibody production, nor a neurological deficit in patients.

Influence of hormones on the immunotolerogenic molecule HLA-G: a cross-sectional study in patients with congenital adrenal hyperplasia

BACKGROUND

HLA-G is an immune checkpoint molecule, naturally expressed during pregnancy, playing a critical role in the tolerance of the fetal semi-allograft from the maternal immune system. While HLA-G expression levels are associated with progesterone, the influence of other hormones is still unclear. Congenital adrenal hyperplasia (CAH) represents an adequate model to study the hormonal influence on biomarkers as it leads to impaired cortisol biosynthesis and increased progesterone and androgens production due to 21-hydroxylase enzyme deficiency.

METHODS

In a cross-sectional study of CAH patients matched on sex and age with healthy control, the association between circulating levels of soluble HLA-G and hormones was assessed by use of non-parametric analyses tests. Multivariable linear regressions were performed on normalized data.

RESULTS

Overall, 83 CAH patients and 69 healthy controls were included. Among CAH patients, all were under glucocorticoid and 52 (62.6%) were under mineralocorticoid supplementation. Compared to controls, CAH patients had increased HLA-G levels (15 vs 8 ng/mL, P = 0.02). In controls, HLA-G level was independently associated with progesterone and estradiol (β = 0.44 (0.35-1.27) and -0.44 (-0.94, -0.26) respectively, both P values = 0.001). In CAH patients, HLA-G level was independently associated with mineralocorticoid supplementation dosage (β = 0.25 (0.04-0.41), P = 0.001) and estradiol (β = -0.22 (-0.57, -0.02), P < 0.001).

CONCLUSION

CAH patients had higher HLA-G levels than healthy controls. HLA-G level was positively associated with progesterone and corticosteroid supplementation, and negatively with estradiol. The association between mineralocorticoid, renin and HLA-G levels may suggest a role of the renin-angiotensin system in the expression of soluble HLA-G.

HLA-G and anti-HCV in patients on the waiting list for kidney transplantation

PURPOSE

Human leukocyte antigen (HLA)-G is a non-classic major histocompatibility complex HLA class I molecule. HLA-G may have tolerogenic properties which are linked to epigenetic-sensitive pathways. There is a correlation of sHLA-G levels and graft acceptance in transplantation studies. There are previous data on correlation of sHLA-G with graft rejection as well as with viral infections such as hepatitis C virus (HCV) in kidney transplanted patients. Here, we report the sHLA-G expression in patients on the waiting list for kidney transplantation, with and without anti-HCV compared to a control group.

METHODS

Serum of 67 patients on the waiting list for kidney transplantation (n = 43 with anti-HCV and n = 24 without anti-HCV) was analyzed. Among these patients, n = 39 were on the waiting list for the first transplantation, while n = 28 were patients who returned in the list. The control group included n = 23 blood donors with anti-HCV (n = 13) and without anti-HCV (n = 10).

RESULTS

The expression of sHLA-G was significantly lower in the control group (39.6 ± 34.1 U/ml) compared to both - patients on the waiting list for the first transplantation (62.5 ± 42.4 U/ml, p=0.031) and patients who returned in the list (76.7 ± 53.9 U/ml, p=0.006). No significant differences were observed in all anti-HCV positive groups. A positive linear correlation between sHLA-G and TNF-α, and patient age was observed.

CONCLUSIONS

Serum sHLA-G values were significantly increased in both - patients on the waiting list for the first transplantation and patients who returned in the list, as compared to control group. Our findings confirm the key tolerogenic role of sHLA-G levels as epigenetic-related marker for measuring the state of kidney allograft acceptance.

Evaluation of Soluble HLA-G Serum Level as Diagnostic Biomarker in Allergic Rhinitis Patients and its Association with Specific IgE Levels

About 30 % of people are affected by allergic rhinitis (AR). Allergic rhinitis is an inflammatory condition defined by a disturbance of immunoregulation generating an amplified T helper "Th-2" response. An inflammatory mechanism mediated by HLA-G is thought to be involved through initiation of Th2 cytokine profile releasing "interleukin IL-3, IL-4, and IL-10". We evaluated levels of soluble HLA-G "sHLA-G" and studied its association with "allergen specific IgE" in AR patients. Twenty-five AR patients and twenty healthy subjects were enrolled. sHLA-G levels (U/ml) were measured by an immunoenzymatic method, while specific IgE levels (IU/ml) of respiratory allergens were analyzed using immunoblotting assay. The results revealed that AR group has significantly higher serum sHLA-G levels than normal subjects, P < 0.001. There was a highly significant and positive correlation between sHLA-G levels and specific IgE levels of Alternaria alternate and Dermatophagoides pteronyssinus (P < 0.01). Besides, there was a significant (P < 0.05) positive correlation between sHLA-G levels and specific IgE levels of brich and mixed grasses. We concluded that serum sHLA-G level is significantly increased in AR patients and that serum sHLA-G level could be a diagnostic biomarker in AR patients for clinical severity assessment.

Prognostic value of tumor-stroma ratio combined with the immune status of tumors in invasive breast carcinoma

PURPOSE

Complex interactions occur between cancer cells and cells in the tumor microenvironment. In this study, the prognostic value of the interplay between tumor-stroma ratio (TSR) and the immune status of tumors in breast cancer patients was evaluated.

METHODS

A cohort of 574 breast cancer patients was analyzed. The percentage of tumor stroma was visually estimated on Hematoxylin and Eosin (H&E) stained histological tumor tissue sections. Immunohistochemical staining was performed for classical human leukocyte antigen (HLA) class I, HLA-E, HLA-G, markers for regulatory T (Treg) cells, natural killer (NK) cells and cytotoxic T-lymphocytes (CTLs).

RESULTS

TSR (P < .001) and immune status of tumors (P < .001) were both statistically significant for recurrence free period (RFP) and both independent prognosticators (P < .001) in which tumors with a high stromal content behave more aggressively as well as tumors with a low immune status. Ten years RFP for patients with a stroma-low tumor and high immune status profile was 87% compared to 17% of patients with a stroma-high tumor combined with low immune status profile (P < .001). Classical HLA class I is the most prominent immune marker in the immune status profiles.

CONCLUSIONS

Determination of TSR is a simple, fast and cheap method. The effect on RFP of TSR when combined with immune status of tumors or expression of classical HLA class I is even stronger. Both are promising for further prediction and achievement of tailored treatment for breast cancer patients.

Recipient HLA-G +3142 CC Genotype and Concentrations of Soluble HLA-G Impact on Occurrence of CMV Infection after Living-Donor Kidney Transplantation

The expression modulation of the immunosuppressive non-classical Human leukocyte antigen-G (HLA-G) molecule and its soluble isoforms is an immune evasion strategy being deployed by cytomegalovirus (CMV). The +3142 C>G single nucleotide polymorphism (SNP) located within the 3′ untranslated region (3′UTR) is of crucial importance for the regulation of HLA-G expression. Therefore, we analyzed the influence of the +3142 C>G HLA-G SNP on the occurrence of CMV infection in a cohort of 178 living-donor kidney recipients and their 178 corresponding donors. In addition, soluble HLA-G (sHLA-G) levels were quantified before and after transplantation. The presence of the HLA-G +3142 CC genotype in recipients, but not donors of our cohort as along with elevated sHLA-G levels (≥6.1 ng/mL) were associated with higher susceptibility to CMV infection after transplantation. Our results provided evidence that (i) HLA-G is implicated in the establishment of CMV after living-donor kidney transplantation and (ii) recipient HLA-G +3142 CC genotype and sHLA-G concentration levels could represent important predictive risk markers for CMV infection.

[Serum soluble HLA-G, soluble CD30 is correlated to the time after transplantation in renal transplant recipients]

Objective To investigate the expressions of serum soluble human leukocyte antigen G (sHLA-G) and soluble CD30 (sCD30) in renal transplant recipients at different time after transplantation, and explore the relationship between the expressions of serum sHLA-G, sCD30 and the time after renal transplantation. Methods Eleven kidney transplant recipients and 10 healthy donors were selected, in which the dynamic changes of serum sHLA-G and sCD30 were detected by ELISA before transplantation and 1 year after transplantation; 33 kidney transplant recipients with normal renal graft were selected and divided into three groups: 1-5 years, 5-10 years and 10 years post-transplantation. The expressions of serum sHLA-G and sCD30 in the recipients were tested over one year after transplantation. Results The level of serum sHLA-G before transplantation was not significantly different from that of the control group. There was no significant difference between pre-transplantation, 1 week and 1 month after transplantation. Serum sHLA-G level of renal transplant recipients at 3 months after transplantation was higher than that 1 month after transplantation. There was no significant change in serum sHLA-G level among 3, 6 and 12 months after transplantation. The level of serum sHLA-G in the group of transplant time >10 years was significantly higher than that in the group of transplant time ≤5 years. The serum sHLA-G level was significantly associated with the time after renal transplantation. The level of serum sCD30 before transplantation was higher than that in the control group and decreased in 1 week after transplantation. There were no significant differences in sCD30 level between 1, 3, 6, and 12 months after transplantation, and similarly, there were also no significant differences between the groups of transplant time ≤5 years, 5-10 years and 10 years after transplantation. The level of sCD30 was significantly associated with the time within 1 month after renal transplantation. Conclusion The serum sHLA-G in kidney transplant recipients with normal renal graft increased with the time after renal transplantation, while the serum sCD30 level was reduced within 1 month after renal transplantation.

Soluble human leukocyte antigen -G during pregnancy and infancy in Benin: Mother/child resemblance and association with the risk of malaria infection and low birth weight

Human leukocyte antigen (HLA) G is a tolerogenic molecule involved in the maternal-fetal immune tolerance phenomenon. Its expression during some infectious diseases leading to immune evasion has been established. A first study conducted in Benin has shown that the production of soluble HLA-G (sHLA-G) during the first months of life is strongly correlated with the maternal level at delivery and associated with low birth weight and malaria. However sHLA-G measurements during pregnancy were not available for mothers and furthermore, to date the evolution of sHLA-G in pregnancy is not documented in African populations. To extend these previous findings, between January 2010 and June 2013, 400 pregnant women of a malaria preventive trial and their newborns were followed up in Benin until the age of 2 years. Soluble HLA-G was measured 3 times during pregnancy and repeatedly during the 2 years follow-up to explore how sHLA-G evolved and the factors associated. During pregnancy, plasma levels of sHLA-G remained stable and increased significantly at delivery (p<0.001). Multigravid women seemed to have the highest levels (p = 0.039). In infants, the level was highest in cord blood and decreased before stabilizing after 18 months (p<0.001). For children, a high level of sHLA-G was associated with malaria infection during the follow-up (p = 0.02) and low birth weight (p = 0.06). The mean level of sHLA-G during infancy was strongly correlated with the mother’s level during pregnancy (<0.001), and not only at delivery. Moreover, mothers with placental malaria infection had a higher probability of giving birth to a child with a high level of sHLA-g (p = 0.006). High sHLA-G levels during pregnancy might be associated with immune tolerance related to placental malaria. Further studies are needed but this study provides a first insight concerning the potential role of sHLA-G as a biomarker of weakness for newborns and infants.

Soluble HLA-G and HLA-E Levels in Bone Marrow Plasma Samples Are Related to Disease Stage in Neuroblastoma Patients

The role of nonclassical HLA-class Ib molecules HLA-G and HLA-E in the progression of Neuroblastoma (NB), the most common pediatric extracranial solid tumor, has been characterized in the last years. Since BM infiltration by NB cells is an adverse prognostic factor, we have here analyzed for the first time the concentration of soluble (s)HLA-G and HLA-E in bone marrow (BM) plasma samples from NB patients at diagnosis and healthy donors. sHLA-G and sHLA-E are present in BM plasma samples, and their levels were similar between NB patients and controls, thus suggesting that these molecules are physiologically released by resident or stromal BM cell populations. This hypothesis was supported by the finding that sHLA-G and sHLA-E levels did not correlate with BM infiltration and other adverse prognostic factors (MYCN amplification and age at diagnosis). In contrast, BM plasma levels of both molecules were higher in patients with metastatic disease than in patients with localized NB, thus suggesting that concentration of these molecules might be correlated with disease progression. The prognostic role of sHLA-G and sHLA-E concentration in the BM plasma for NB patients will be evaluated in future studies, by analyzing the clinical outcome of the same NB patients at follow-up.

Human Leukocyte Antigen G Polymorphism and Expression Are Associated with an Increased Risk of Non-Small-Cell Lung Cancer and Advanced Disease Stage

Human leukocyte antigen (HLA)-G acts as negative regulator of the immune responses and its expression may enable tumor cells to escape immunosurveillance. The purpose of this study was to investigate the influence of HLA-G allelic variants and serum soluble HLA-G (sHLA-G) levels on risk of non-small-cell lung cancer (NSCLC). We analyzed 191 Caucasian adults with NSCLC and 191 healthy subjects recruited between January 2009 and March 2014 in Ariana (Tunisia). Serum sHLA-G levels were measured by immunoassay and HLA-G alleles were determined using a direct DNA sequencing procedures. The heterozygous genotypes of HLA-G 010101 and -G 010401 were associated with increased risks of both NSCLC and advanced disease stages. In contrast, the heterozygous genotypes of HLA-G 0105N and -G 0106 were associated with decreased risks of NSCC and clinical disease stage IV, respectively. Serum sHLA-G levels were significantly higher in patients with NSCLC and particularly in those with advanced disease stages compared to healthy subjects. The area under the receiver-operating characteristic (ROC) curves was 0.82 for controls vs patients. Given 100% specificity, the highest sensitivity achieved to detect NSCLC was 52.8% at a cutoff value of 24.9 U/ml. Patients with the sHLA-G above median level (≥ 50 U/ml) had a significantly shorter survival time. This study demonstrates that HLA-G allelic variants are independent risk factors for NSCLC. Serum sHLA-G levels in NSCLC patients could be useful biomarkers for the diagnostic and prognosis of NSCLC.

Association between decreased plasma levels of soluble human leukocyte antigen-G and severe pre-eclampsia

OBJECTIVE

The aim of this study was to investigate the levels of different isoforms of soluble human leukocyte antigen-G (sHLA-G) in maternal plasma during early and late pregnancy, and to investigate the expression of sHLA-G isoforms in women with early or late-onset severe preeclampsia.

METHODS

This prospective, nested, case-control study was performed in 24 early-onset severe preeclamptic, 34 late-onset severe preeclamptic, and 74 uncomplicated pregnant women. Plasma levels of sHLA-G1/5 were measured using ELISA.

RESULTS

Plasma sHLA-G1 levels in women with late-onset severe preeclampsia were markedly lower compared with normal controls (median: 0 vs. 1.22 ng/mL) at the first trimester, and plasma sHLA-G1 levels in women with early-onset severe preeclampsia were markedly lower compared with normal controls at the second (median: 0 vs. 1.24 ng/mL) and third (median: 0 vs. 1.34 ng/mL) trimesters. There was no difference between the late-onset and early-onset groups at three trimesters. As for sHLA-G5, there was no difference in concentrations among the three groups at any time point. However, compared with controls, more women with early- or late-onset severe preeclampsia had undetectable sHLA-G5 levels in the first (71.4% and 76.2% vs. 14.1%), second (75.0% and 73.3% vs. 19.0%), and third (100.0% and 70.4% vs. 14.8%, respectively) trimester (all P<0.05). sHLA-G1 levels in the first (odds ratio [OR]=0.254, 95% confidence interval [CI]=0.109-0.591, P=0.010), second (OR=0.315, 95% CI=0.158-0.627, P=0.001), and third (OR=0.170, 95% CI=0.054-0.533, P=0.002) trimester was a risk factor for severe preeclampsia.

CONCLUSION

Severe preeclampsia was associated with low/undetectable maternal plasma levels of sHLA-G. Low sHLA-G1 levels might be a risk marker for severe preeclampsia.

Behavior of soluble HLA-A, -B, -C and HLA-G molecules in patients with chronic hepatitis C virus infection undergoing pegylated interferon-α and ribavirin treatment: potential role as markers of response to antiviral therapy

The serum levels of soluble HLA class I antigens (sHLA-A, -B, -C and sHLA-G) were determined in 40 HCV genotype 1-infected patients before (T ₀), after 3, 6, and 12 months (T ₃, T ₆, and T ₁₂) of pegylated-IFN-α plus ribavirin therapy and 6 months (T ₁₈) after the end of treatment. Twenty patients were sustained virological responders (SVR), and 20 were non-responders (NR). sHLA-A, -B, -C levels at T ₀ were significantly higher in both SVR (mean 10.48 μg/ml) and NR (mean 11.87 μg/ml) patients as compared to healthy controls (mean 0.34 μg/ml, p < 0.0001) and HIV-infected subjects (mean 1.22 μg/ml, p < 0.0001). sHLA-G levels at T ₀ were significantly higher in SVR (mean 24.78 ng/ml) and NR (mean 24.93 ng/ml) patients as compared to healthy controls (mean 10.34 ng/ml, p = 0.015 and p = 0.014, respectively) but were lower as compared to HIV-infected subjects (mean 48.00 ng/ml, p < 0.0001). The levels of sHLA-A, -B, -C and sHLA-G significantly decreased in SVR from T ₀ to T ₁₈ (mean 1.64 and 1.43 ng/ml, respectively, p < 0.0001) and correlated with HCV-RNA, AST, ALT, γGT, and ALP levels. The determination of soluble HLA class I levels could be proposed as a surrogate marker to discriminate SVR and NR HCV-infected patients during PEG-IFN-α plus ribavirin therapy.

Long non-coding RNA HOTAIR promotes HLA-G expression via inhibiting miR-152 in gastric cancer cells

Recent studies have shown that the long non-coding RNA HOTAIR plays critical roles in tumor biology, including cancer progression and metastasis. However, the potential biological role HOTAIR in tumor escape remains undefined. Here, HOTAIR expression was measured in sixty paired gastric cancer (GC) tissue samples by real-time PCR, and then subjected to correlation analysis with human leukocyte antigen (HLA)-G levels which show close links with tumor escape mechanisms. Significant HOTAIR overexpression was observed in GC tissues, as well as strong positive correlations with HLA-G levels in both tissue and peripheral blood samples, detected by real-time PCR and ELISA assays respectively. Further gain- and loss-of-function studies indicated that HLA-G could be upregulated HOTAIR at both mRNA and secretion levels in vitro. On the other hand, bioinformatics analysis indicated the interaction between HOTAIR and miR-152, which shows potential regulation on HLA-G. And, altered miR-152 expression in GC tissues was also identified, and showed negative correlation with HOTAIR expression. Moreover, the negative regulation of miR-152 on HLA-G was verified in GC cells, while miR-152 induced decrease of HLA-G 3'UTR activity could be attenuated by HOTAIR co-overexpression with the assistant of mutation studies. Therefore, it was concluded that HOTAIR overexpression might also get involved in tumor escape mechanisms, involving HLA-G upregulation via inhibiting miR-152. Furthermore, this study recommended the potential application of HOTAIR in GC immunotherapy for better prognosis and improved survival.

The paradox of high availability and low recognition of soluble HLA-G by LILRB1 receptor in rheumatoid arthritis patients

HLA-G is a regulatory molecule involved in immunologic tolerance. Growing evidence indicates that HLA-G plays a role in the regulation of inflammatory processes and autoimmune diseases. This study aimed at a systematic evaluation of soluble HLA-G (sHLA-G) in plasma of rheumatoid arthritis (RA) patients with long-lasting chronic inflammation. RA patients (n=68) and healthy controls (n=26) had their plasmatic sHLA-G measured by ELISA whereas the binding capability of sHLA-G to its cognate LILRB1 receptor was measured by a Luminex-based assay. All subjects were PCR-genotyped for HLA-G 14bp polymorphism (rs66554220). Significantly higher sHLA-G levels were observed in patients (p<0.001), however no significant differences were observed in LILRB1 binding capacity between RA patients and controls. Remarkably, the proportion of patients presenting specific binding of sHLA-G to LILRB1 was significantly decreased as compared to controls (56% vs. 81%, p=0.027). Patients without rheumatoid factor (RF-) were significantly overrepresented in the group of patients positive for LILRB1 binding as compared to patients without LILRB1 binding (31% vs 10%, p=0.033). Furthermore, methotrexate treated patients (n=58) revealed significantly lower LILRB1 binding to sHLA-G molecules than non-treated patients (medians: 12.2 vs. 67.7 units/ml, p=0.031). Unlike in controls, no significant differences in sHLA-G levels were observed among patients grouped by 14pb genotype. Thus, in a substantial number of late RA patients, the circulating sHLA-G molecules are impaired regarding LILRB1 recognition, meaning that although increased levels are observed; these molecules are not qualified to exert their protective functions against inflammation. Our findings offer new insights into the immunopathology of RA patients with long-lasting anti-RA-treatment and highlight the importance to also measure the binding capability of sHLA-G to LILRB1.

HLA-G5 and G7 Isoforms in Pregnant Women

Human leukocyte antigen-G which is an immune tolerance effecter molecule has an important role in the maintenance of fetus during pregnancy. Abortion is one of the complications of pregnancy period.  In this research, we have studied levels of HLA-G 5, HLA-G7 isoforms in the abortion-threatened pregnant women in comparison with controls. In a case-control study, 101 abortion-threatened women and 101 healthy pregnant women (healthy controls) with age range 21-32 years were studied. Gene expression of HLA-5 and HLA-7 isoforms was analyzed by real-time polymerase chain reaction after mRNA extraction and cDNA synthesis. The results indicated that HLA-G5 was significantly lower in abortion-threatened women in comparison with the control group whereas HLA-G7 was not significantly differentbetween the 2 groups. HLA-G is a vital molecule during pregnancy that can be a key factor in prevention of abortion. It is concluded that determination of HLA-G5 can be of value in pregnancy.

Human leukocyte antigen G and renal allograft transplant

OBJECTIVES

Studying immune tolerance induced by HLA-G in kidney allograft acceptance may help understanding of its mechanisms, hoping in the future to boaster it and decrease the immunosuppressive drugs given that are well known to have serious adverse effects.

MATERIALS AND METHODS

The current study sought to evaluate soluble HLA-G in 3 groups: kidney transplanted patients with no rejection episodes, transplanted patients with biopsy-proven renal rejection, and healthy age-matched non transplanted individuals. Three groups were studied: kidney transplanted patients with no rejection episodes (n = 43); transplanted patients with biopsy-proven renal rejection (n = 27); healthy, age-matched, nontransplanted individuals as controls (n = 42). Soluble HLA-G level was measured in the serum by a quantitative sandwich enzyme linked immunosorbent assay.

RESULTS

sHLAG level was significantly higher in the transplanted patients compared with the control. Prograf and not cyclosporine or Rapamune had positive effects on sHLAG levels. Patients with chronic rejection had a significant lower level of sHLAG compared with a graft stable group. No effect of donor type, infection or duration posttransplant, on sHLAG levels was found.

CONCLUSIONS

The results of the current study are consistent with previous studies addressing the role of sHLAG in inducing immunotolerance postkidney transplant. The findings from the current study on the chronic rejection group, supports the on-going research of having a treatment with HLA-G/or derivate, which may constitute in the future a novel efficient antigraft rejection therapy.

Serum HLA-G levels in women with polycystic ovary syndrome

This study was designed to determine serum human leukocyte antigen-G (HLA-G) levels and establish whether serum HLA-G level is related with insulin resistance, oxidative stress, dyslipidemia and ovarian hyperandrogenism in women with polycystic ovary syndrome (PCOS). Twenty-five patients with PCOS and 23 healthy control women were evaluated in this study. Serum HLA-G, lipid fractions, glucose, insulin, malondialdehyde (MDA), glutathione (GSH), white blood cell (WBC), sex hormone-binding globulin (SHBG) and other hormone (gonadotropins and androgens) levels were measured. The estimate of insulin resistance was calculated by homeostasis model assessment (HOMA-IR). Serum luteinizing hormone (LH), total testosterone, fasting insulin, WBC levels and LH/follicle-stimulating hormone (FSH) ratio, free androgen index (FAI) and HOMA-IR values were significantly higher in patients with PCOS compared with healthy women. However, the women with PCOS had considerably lower serum FSH, SHBG, MDA, GSH and HLA-G levels than healthy subjects. HLA-G was inversely related with HOMA-IR, FAI, LH/FSH ratio and WBC, but positively with high-density lipoprotein cholesterol. Decreased serum HLA-G level may be related with insulin resistance, ovarian hyperandrogenism and oxidative stress in women with PCOS. Nevertheless, the exact role of HLA-G in the pathogenesis of the disease remains to be elucidated.

Association of soluble HLA-G with acute rejection episodes and early development of bronchiolitis obliterans in lung transplantation

Lung transplantation has evolved into a life-saving therapy for select patients with end-stage lung diseases. However, long-term survival remains limited because of bronchiolitis obliterans syndrome (BOS). Soluble HLA-G, a mediator of adaptive immunity that modulates regulatory T cells and certain classes of effector T cells, may be a useful marker of survival free of BOS. We conducted a retrospective, single-center, pilot review of 38 lung transplant recipients who underwent collection of serum and bronchoalveolar lavage fluid 3, 6 and 12 months after transplantation, and compared soluble HLA-G concentrations in each to the presence of type A rejection and lymphocytic bronchiolitis in the first 12 months and to the presence of BOS at 24 months after transplantation. Lung soluble HLA-G concentrations were directly related to the presence of type A rejection but not to lymphocytic bronchiolitis. Our data demonstrate that soluble HLA-G concentrations in bronchoalveolar lavage but not in serum correlates with the number of acute rejection episodes in the first 12 months after lung transplantation, and thus may be a reactive marker of rejection.

HLA-G expression as a prognostic indicator in B-cell chronic lymphocytic leukemia

BACKGROUND

The expression of human leukocyte antigen (HLA)-G was studied in certain malignancies and its role in escaping from immunosurveillance in cancers was proposed since HLA-G is a non-conventional HLA class I molecule that protects the fetus from immunorecognition during pregnancy. Some particles involved in the regulation of an immune system might represent prognostic value for B-cell chronic lymphocytic leukemia (B-CLL). The identification of novel prognostic factors in B-CLL may help define patient subgroups that may benefit from early therapeutic intervention.

OBJECTIVE

To evaluate the prognostic significance of HLA-G expression in B-CLL patients and its relationship with other well-established prognostic markers.

METHODOLOGY

Thirty B-CLL patients diagnosed by clinical, morphological and immunophenotyping criteria were studied for HLA-G expression by flow cytometry. The relationship between HLA-G expression and some known prognostic markers was evaluated.

RESULTS

HLA-G was expressed in 36.7% of CLL patients at diagnosis, with a mean expression level of 35.31 ± 12.35%. A significant association between HLA-G expression and common prognostic markers of progressive disease was detected. The group of patients with positive HLA-G expression showed significantly higher absolute lymphocyte counts and serum levels of LDH and β2-microglobulin, lower platelet counts, positive CD38 expression and advanced stages of Binet clinical staging.

CONCLUSION

The present study demonstrated that HLA-G expression correlates with prognostic markers of a poor B-CLL outcome, mainly Binet clinical staging and CD38 expression by B-CLL cells, which indicates that this parameter may play a role as an important prognosticator of disease progression and consequently targeted therapy in B-CLL.

Intrathecal soluble HLA-E correlates with disease activity in patients with multiple sclerosis and may cooperate with soluble HLA-G in the resolution of neuroinflammation

Expression and function of the immunoregulatory molecule HLA-E was investigated in patients with relapsing-remitting (RR) multiple sclerosis (MS). Serum and cerebrospinal fluid (CSF) soluble (s)HLA-E and -G levels were measured by ELISA in 80 RRMS patients. Controls were patients with other inflammatory neurological disorders (OIND, n = 81) and noninflammatory neurological disorders (NIND, n = 86). Serum sHLA-E concentrations were higher in RRMS than in NIND patients only. CSF sHLA-E concentrations were higher in RRMS than controls. Increased CSF sHLA-E levels were detected in MRI inactive and clinically stable RRMS patients. sHLA-E intrathecal synthesis (ITS) was higher in RRMS than controls, and the number of patients with sHLA-E ITS above cut-off was higher i) in MS than controls, and ii) in clinically stable than clinically active MS patients. sHLA-E CSF levels and ITS correlated with i) the same sHLA-G parameters, and ii) disease duration. HLA-E expression and co-expression with CD markers were investigated in MS plaques from three different cases by immunohistochemistry and confocal microscopy, respectively. Infiltrating T lymphocytes and macrophages, as well as resident microglial cells and astrocytes expressed HLA-E. CSF samples from MS patients were finally tested for inhibitory activity of in vitro CTL and NK cell mediated cytotoxicity. sHLA-E⁺ were more effective than sHLA-E⁻ CSF samples in such inhibition. Maximum inhibition was achieved with sHLA-E⁺/sHLA-G⁺ CSF samples In conclusion, increased sHLA-E CSF levels may play an immunomodulatory role in MS, contributing to the inhibition of intrathecal inflammatory response. The potential of sHLA-E as biomarker of MS activity warrants further investigation.

Total expression of HLA-G and TLR-9 in chronic lymphocytic leukemia patients

Suppressed immune status facilitates immune escape mechanisms that allow chronic lymphocytic leukemia cells to proliferate and expand. The expression of HLA-G could effectively inhibit the immune response. In immune response inhibitory signals follow activation of immune system which might be occur during bacterial or viral infection in CLL patients. In the current study we characterized two components of immune system, inhibitory molecule HLA-G with its receptor - CD85j and Toll-like receptor 9. The material was obtained from 41 CLL patients and 41 HV with similar median age. In CLL patients expression of intracellular and surface HLA-G and soluble HLA-G levels were significantly higher than in HV. We found higher expression of CD85j compared to HV and the positive correlation between expression of HLA-G and CD85j. All the CLL cells expressed TLR-9, and the level of expression positively correlated with expression of HLA-G and CD85j. Patients with higher expression of intracellular expression of TLR-9 have significantly longer treatment-free survival than patients with low expression of TLR-9 (57 months vs. 8 months, respectively). Summarizing in CLL we characterized activatory and inhibitory components of immune system that might be connected functionally. Analysis of TLR-9 expression might have additional prognostic value for CLL patients.

HLA-G expression in the peripheral blood of live kidney transplant recipients

BACKGROUND

The human leukocyte antigen-G (HLA-G) has been considered to be an important tolerogeneic molecule playing an essential role in maternal-fetal tolerance, upregulated in the context of transplantation, malignancy, and inflammation, and has been correlated with various clinical outcomes. The aim of this study was to investigate the clinical relevance of the expression of membrane HLA-G (mHLA-G), intracellular HLA-G (iHLA-G), and soluble HLA-G (sHLA-G) in the peripheral blood of live kidney transplant recipients.

METHODS

We compared the expression of the three HLA-G isoforms in three groups, healthy donors (n=20), recipients with acute rejection (n=19), and functioning transplants (n=30). Flow cytometry was used to detect the expression of mHLA-G and iHLA-G in the T lymphocytes of peripheral blood from subjects in the three groups. Enzyme-linked immunosorbent assays were used to detect sHLA-G in the plasma from the three groups.

RESULTS

There were no significant differences in mHLA-G and intracellular HLA-G among the three groups, but the sHLA-G plasma level was higher in the functioning group than in the acute rejection or healthy group. We found a subset of CD4(+)HLA-G(+) and CD8(+)HLA-G(+) T lymphocytes with low rates of mHLA-G expression in the peripheral blood of kidney transplantation recipients. Intracellular expression of HLA-G was detected in T lymphocytes. However, there was no correlation between acute rejection and the mHLA-G or intracellular HLA-G expression.

CONCLUSION

sHLA-G was the major isoform in the peripheral blood of live kidney transplant recipients and high sHLA-G levels were associated with allograft acceptance.

Soluble human leukocyte antigen G molecule expression in allogeneic hematopoietic stem cell transplantation: good predictor of acute graft-versus-host disease

BACKGROUND

Graft-versus-host disease (GVHD) remains a main complication of allogeneic hematopoietic stem cell transplantation (allo-HSCT). Human leukocyte antigen G (HLA-G) is a non-classical class I molecule exerting multiple immunoregulatory functions. The aim of this study was to explore the relationship between soluble HLA-G (sHLA-G) and GVHD after allo-HSCT.

METHODS

The sHLA-G levels were examined using enzyme-linked immunosorbent assay in patients with hematological malignancies (n = 106) before transplantation, on days +15 and +30 after transplantation, as well as healthy volunteers (n = 10).

RESULTS

The levels of sHLA-G5, sHLA-G6 and sHLA-G7 in patients on days +15 and +30 after transplantation were all significantly higher than those before transplantation (all p ≤ 0.001). The increased levels of sHLA-G5 on days +15 and +30 after transplantation were both significantly higher in patients with grade 0-I acute GVHD (aGVHD) compared to those with grade II-IV aGVHD (both p < 0.001). The increased levels of sHLA-G5 on days +15 and +30 after transplantation were both negatively correlated with the severity of aGVHD (both p < 0.001).

CONCLUSION

sHLA-G5 might be a predictor of the occurrence and severity of aGVHD, which may help to establish individual prophylaxis against aGVHD and improve the survival for patients after allo-HSCT.

The expression of human leukocyte antigen G (HLA-G) is associated with sacroiliitis stages of ankylosing spondylitis

Recent studies have demonstrated that human leukocyte antigen G (HLA-G) may play an important role in autoimmune diseases. The present study is to investigate whether or not HLA-G is associated with sacroiliitis stages of ankylosing spondylitis (AS), a systemic autoimmune disease. Plasma levels of soluble HLA-G (sHLA-G) and HLA-G expression on the surface of peripheral blood mononuclear cells (PBMCs) were measured in 55 AS patients and 49 healthy controls by using a specific HLA-G ELISA and flow cytometric (FCM) analysis, respectively. Association of HLA-G expression with sacroiliitis stages of the patients was statistically analyzed. The plasma sHLA-G concentrations were noticeably lower in the AS patients when compared to the healthy controls while the mean fluorescence intensity (MFI) of the HLA-G expression on the surface of PBMCs was significantly higher in the AS patients than in the healthy controls (both P<0.0001). The HLA-G expression on the surface of PBMCs, plasma sHLA-G levels and HLA-B27 expression were significantly correlated to each other. Moreover, the plasma sHLA-G was inversely associated with the sacroiliitis stages (P=0.008), while the HLA-G expression on the surface of PBMCs increased from stage 0 to II but decreased in stage III (P=0.001). The significant association of HLA-G expressions with AS sacroiliitis stages suggests that HLA-G is possibly involved in the pathology of the disease. The detection of HLA-G expression may therefore be a useful laboratory test to reveal disease process in AS patients.

Cytokine production by non-stimulated peripheral blood NK cells and lymphocytes in early-onset severe pre-eclampsia without HELLP

Preeclampsia involves an exacerbated maternal inflammatory response that suggests a possible role of innate immunity. NK cells can promote this kind of response through cytokine production and the expression of activating or inhibitory receptors. The aims of the present study were to explore cytokine production by peripheral blood mononuclear cells, as well as cytotoxic ability and receptor expression for HLA-E and HLA-G molecules in peripheral natural killer (NK) cells of women with early-onset severe preeclampsia without HELLP (hemolysis, elevated liver enzyme levels and a low platelet count) syndrome. The expression of the ILT2, KIRDL4, NKG2A, and NKG2C receptors and of cytotoxic activity was measured in non-stimulated NK cells, whereas the intracellular expression of IL-4, IL-10, IL-13, IL-12, IFNγ, TNF and VEGF, was assessed in non-stimulated peripheral blood mononuclear cells subsets using flow cytometry. Circulating soluble HLA-G was also determined by ELISA. The intracellular cytokines tested were significantly higher in NK cell subsets from severely preeclamptic women compared with the control group. On the other hand, the percentage of NK cells expressing NKG2A or NKG2C and the cytotoxic activity of NK cells were significantly higher in severely preeclamptic women. Furthermore, there was a significant correlation between urine protein concentration and soluble human leukocyte antigen G (soluble HLA-G) in serum. We conclude that patients with early-onset severe preeclampsia without HELLP syndrome have increased NK cell function related to cytokine production, cytotoxicity and expression of lectin-like receptors such as NKG2.

The maternal HLA-G 1597ΔC null mutation is associated with increased risk of pre-eclampsia and reduced HLA-G expression during pregnancy in African-American women

The non-classical major histocompatibility complex molecule, human leukocyte antigen (HLA)-G, is thought to contribute to maternal immune tolerance and successful placentation during pregnancy. Genetic polymorphisms in HLA-G are known to influence expression levels as well as the relative expression of individual protein isoforms. As diminished or aberrant HLA-G expression patterns may contribute to the development of certain pregnancy complications, we sought to investigate the association between functional HLA-G polymorphisms and the risk of pre-eclampsia (PE) in African-American women. The association between maternal and fetal genotype at six HLA-G polymorphisms and risk of PE was assessed in 372 pregnancies (314 normotensive; 58 pre-eclamptic). We observed an elevated risk of PE (P = 0.00027) in pregnancies where the mother carried the 1597ΔC allele, a null allele that abolishes expression of full-length HLA-G isoforms. Furthermore, the frequency of the maternal 1597ΔC allele was highest in the subset of pre-eclamptic pregnancies that were delivered preterm, suggesting an association between the null allele and the severity of PE. We then replicated the association between higher maternal 1597ΔC allele frequency and increased severity of PE (P = 0.038) in an independent sample of 533 African-American women. Finally, to investigate the mechanistic basis of this association, we measured circulating soluble HLA-G (sHLA-G) concentrations in maternal serum collected during pregnancy in 51 healthy, normotensive African-American control women and found significantly lower levels in women carrying the 1597ΔC allele (P = 0.012). These results demonstrate that maternal HLA-G genotype is significantly associated with risk of PE in African-American women and is predictive of circulating sHLA-G levels during pregnancy.

Maternal serum soluble HLA-G levels in missed abortions

BACKGROUND AND OBJECTIVE. It is unclear how immune tolerance develops to a semiallograft fetus in pregnancy. Human leukocyte antigen G (HLA-G) expressed by extravascular trophoblasts plays an important role in the recognition of the gestational tissues as self and the development of immune tolerance against the gestational tissues by the maternal immune system. The soluble form of the HLA-G (sHLA-G) molecule in the maternal serum is also reported to contribute to the prevention of rejection during pregnancy. The aim of the study was to compare the maternal serum sHLA-G levels of the women with missed abortions and control subjects with uncomplicated pregnancies. MATERIAL AND METHODS. The prospective cross-sectional study involving 40 with missed abortions and 40 control women, matched by age, gestational age, and body mass index, was carried out. The study group consisted of the women with singleton pregnancies, who were diagnosed with a missed abortion. Only the patients who were confirmed to have an uncomplicated term delivery during follow-up were included in the control group. The serum sHLA-G level was compared between the groups. RESULTS. There was no significant difference in the mean serum sHLA-G levels in terms of gravidity (P=0.761) and a history of abortion (P=0.379) in the control group. The median serum sHLA-G level in the missed abortion group was significantly lower compared with the control group (16.8 [8.5-35.8] vs. 26 [11-135] U/mL, P<0.001). All the women in the control group had uncomplicated term deliveries. CONCLUSION. Our results showed that the women with missed abortions had significantly lower serum sHLA-G levels compared with the healthy pregnant controls, which may have potentially played a role in the impairment of physiological immunological tolerance during pregnancy. However, the determination of the exact role and the potential clinical utility of maternal serum sHLA-G for the detection/prediction of a missed abortion risk requires further detailed studies.

HLA-G may predict the disease course in patients with early rheumatoid arthritis

The current management of early rheumatoid arthritis (ERA) is to start an intensive treatment as soon as possible. To avoid under/overtreatment, it is important to identify reliable ERA evolution biomarkers. HLA-G molecules has been associated with rheumatoid arthritis, suggesting a role in disease regulation. HLA-G antigens are expressed as membrane bound and soluble isoforms (mHLA-G, sHLA-G) that act as ligand for immune-inhibitory receptors (ILT2, ILT4, KIR2DL4). Expression of HLA-G is influenced by a 14 bp insertion/deletion polymorphism in exon 8 of the gene, where the deletion is associated with mRNA stability. We analyzed 23 ERA patients during a 12 months follow-up disease treatment for sHLA-G, IL-1beta, IL-6, IL-10 and TNF-alpha levels in plasma samples by ELISA, mHLA-G and ILT2 expression on peripheral blood CD14 positive cells by flow cytometry and typed HLA-G 14 bp deletion/insertion polymorphism by Real-Time PCR. Disease status (DAS28), ultrasonography with power Doppler and laboratory data were checked. Cytokine levels confirmed the anti-inflammatory effect of the treatment. sHLA-G, mHLA-G and ILT2 expression inversely correlated with DAS28 disease scores. The frequency of 14 bp deletion allele increased in patients with disease remission. Based on these results, HLA-G may be a candidate biomarker to evaluate early prognosis and disease activity in ERA patients.

[Association of HLA-G 14bp gene polymorphisms and plasma sHLA-G level with susceptibility to EV71 infection in children]

OBJECTIVE

Explore the relationship between the HLA-G 14bp insertion/deletion polymorphism and the infection of Enterovirus 71 (EV71) for children.

METHODS

We genotyped HLA-G 14bp insertion/deletion polymorphism of 125 severe HFMD children infected with EV71 and 133 normal controls by PCR-PAGE;detected the plasma sHLA-G level of 66 heavy type and 15 critical type and 133 normal controls by ELISA.

RESULTS

Frequencies of the genotype 14 bp - / - ,14 bp + / - and 14 bp + / + were 49.6% , 42.4% and 8.0% for the severe HFMD children infected with EV71, and 34.6%, 48.9% and 16.5% for the normal controls, respectively. A significant difference was observed for the frequencies of the HLA-G 14bp genotype between the two groups(chi2 = 7.850, P = 0.020). And for the allele frequencies. The plasma sHLA-G levels in heavy type were dramatically higher than that in normal controls (Z = -9.692, P = 0.000). The plasma sHLA-G levels in children with critical HFMD were dramatically higher than that with heavy type (Z = -2.420, P = 0.016).

CONCLUSION

There was a relationship between the HLA-G 14 bp insertion/deletion polymorphism and the susceptibility to the severe HFMD children infected with EV71 and the plasma sHLA-G might be considered as a index for auxiliary diagnosis the severe HFMD infected with EV71.

Soluble human leukocyte antigen-g and its insertion/deletion polymorphism in papillary thyroid carcinoma: novel potential biomarkers of disease?

INTRODUCTION

Human leukocyte antigen-G (HLA-G), a nonclassical major histocompatibility complex class I antigen, plays a pivotal role in immune tolerance and a paradoxical role in cancers.

AIMS

Our aims were to evaluate plasma soluble HLA-G (sHLA-G) concentrations and the 14-bp insertion/deletion polymorphism of the HLA-G gene in patients with papillary thyroid carcinoma (PTC) or Hashimoto's thyroiditis (HT) and to assess the possible association of these parameters with PTC aggressiveness.

METHODS

Samples for the analysis of sHLA-G and +14/-14-bp HLA-G polymorphism were obtained from 121 patients with HT and 183 with PTC; 245 gender- and age-matched healthy subjects served as controls. PTC histopathological aggressiveness was defined according to the last American Thyroid Association guidelines.

RESULTS

Positive serum antithyroid antibody titers were observed in 22% of PTC patients and lymphocyte infiltration of thyroid parenchyma at histological examination in 21%, whereas both circulating and histological autoimmunity was detectable in 12% of PTC patients. No differences in the +14/-14-bp polymorphism frequencies were observed between the study groups. The prevalence of detectable sHLA-G was lower in healthy controls (52%) as compared with both HT (57%) and PTC (62%) patients. By stratifying the study groups according to sHLA-G level of positive subjects, significantly higher plasma sHLA-G values in PTC (42.9 ± 3.3 ng/ml; P = 0.002) and HT patients (49.1 ± 2.6 ng/ml; P < 0.002) as compared with healthy controls (8.5 ± 1.8 ng/ml) were obtained. Moreover, PTC patients with detectable plasma sHLA-G levels showed a higher aggressive behavior (P < 0.04) than those without.

CONCLUSIONS

Although confirming the frequent association between PTC and chronic autoimmune thyroiditis, these data suggest that elevated circulating sHLA-G levels, besides an important signal of alterations of immune homeostasis, may be considered a potential, novel marker of PTC histopathological aggressiveness at diagnosis. Additional studies are needed to confirm the actual role and clinical relevance of the HLA-G complex in PTC development and progression.

Assessment of different biomarkers provides valuable diagnostic standards in the evaluation of the risk of acute rejection

Acute rejection (AR) is a strong risk factor for chronic rejection in renal transplant recipients. Accurate and timely diagnosis of AR episodes is very important for disease control and prognosis. Therefore, objectively evaluated the immune status of patients is essential in the field of post-transplantation treatment. This longitudinal study investigated the usefulness of five biomarkers, human leukocyte antigen (HLA)-G5 and sCD30 level in sera, intracellular adenosine triphosphate (iATP) release level of CD4(+) T cells, and granzyme B/perforin expression in peripheral blood mononuclear cells (PBMCs) and biopsies, to detect AR and the resolution of biomarkers in a total of 84 cases of renal transplantation. The data demonstrated that recipients with clinical or biopsy proven rejection significantly increased iATP release level of CD4(+) T cells, and elevated sCD30 but lowered HLA-G5 level in sera compared with individuals with stable graft function. Expression levels of granzyme B and perforin were also elevated in PBMCs and graft biopsies of AR patients. Taken together, we identified that upregulation of sCD30, iATP, granzyme B, perforin, and downregulation of HLA-G5 could provide valuable diagnostic standards to identify those recipients in the risk of AR. And iATP may be a better biomarker than others for predicting the graft rejection episode.

Soluble human leukocyte antigen-G expression in patients with ductal and lobular breast malignancy

BACKGROUND

Human leukocyte antigen-G (HLA-G) has been closely associated with diagnosis and prognosis in many types of human cancer. The current study aims to investigate soluble (s) HLA-G expression in patients with breast malignancy.

PATIENTS AND METHODS

sHLA-G plasma expression was determined in 120 patients with breast cancer and 40 healthy controls using enzyme-linked immunosorbent assay.

RESULTS

Plasma sHLA-G levels were significantly higher in breast cancer patients compared to healthy controls (p<0.001), with an area under the receiver operating characteristic (ROC) curve of 0.735 (95% Confidence interval=0.630-0.841, p<0.001). Significantly increased sHLA-G expression was detected in patients with mixed type of coexisting ductal and lobular breast lesions, compared to patients with pure ductal carcinoma or pure lobular neoplasia (p<0.05).

CONCLUSION

sHLA-G expression is closely associated with the histological type of breast cancer. Our findings support the application of sHLA-G as a potential biomarker in body fluids for preoperative breast cancer detection and diagnosis.

[Effects of electroacupuncture on embryo implanted potential for patients with infertility of different symptom complex]

OBJECTIVE

To explore the impacts of electroacupuncture on embryo implanted potential and its molecular mechanism in the patients with infertility of different symptom complex.

METHODS

Among the patients with infertility treated with electroacupuncture and in vitro fertilization and embryo transplantation (IVF-ET), 82 cases of kidney deficiency (group A), 74 cases of liver qi stagnation (group B) and 54 cases of phlegm dampness (group C) were selected. All of the patients in three groups received long-program ovarian hyper-stimulation. Additionally, electroacupuncturecan was applied before controlled ovarian hyper-stimulation (COH) and in the process of ovarian hyper-stimulation. The levels of human leukocyte antigen-G (HLA-G) in the serum were determined on the 2nd day of the menstruation (M2), on the day of human Chorionic Gonadotropin (hCG) injection and on the day of embryo transplantation in the culture solution in three groups separately. The fertilization rate, implantation rate and clinical pregnancy rate were observed for the patients in three groups.

RESULTS

The levels of HLA-G in the serum on hCG injection day and in the culture solution on embryo transplantation day in group A and B were significantly higher than those in group C (all P < 0.05). But, there was no significant difference in serum HLA-G levels on M2 day among three groups. The high-quality embryo rate in either group A (73.6%, 352/478) or group B (70.6%, 379/537) was higher significantly than that in group C (54.2%, 208/384) separately, presenting statistical significant difference (all P < 0.01). But there were no significant differences in clinical pregnancy rate, fertilization rate and cleavage rate among three groups.

CONCLUSION

Electroacupuncture can increase the contents of HLA-G in the body and the level of HLA-G secreted in embryos for the patients in the process of IVF-ET. Eventually, the pregnancy outcome and the pregnancy rate are improved. The clinical effects of electroacupuncture for the patients of kidney deficiency and liver qi stagnation are better than those for the patients of phlegm dampness.

[Relationship between the expression of human leukocyte antigen G and preeclampsia]

OBJECTIVES

To detect the expression of human leukocyte antigen-G (HLA-G) in tissues from pregnant women with preeclampsia and discuss the relationship between HLA-G and preeclampsia.

METHODS

Pregnant women with preeclampsia in Maternal and Child Health Hospital of Shaanxi Province from March 2009 to December 2009 were included. Eight were included into mild preeclampsia groups and 22 were included into severe preeclampsia group. And 30 age-matched normal pregnancies were referred as the control group. All women in the three groups received cesarean section. The soluble HLA-G (sHLA-G) levels in peripheral blood, umbilical blood and amniotic fluid were examined by ELISA; the expressions of HLA-G protein in placenta, fetal membrane and umbilical cord were examined by western blot.

RESULTS

(1) The sHLA-G levels in peripheral blood, umbilical blood and amniotic fluid in each group. The sHLA-G levels in peripheral blood in mild and severe preeclampsia group were (50 ± 14) and (30 ± 6) µg/L respectively, and the sHLA-G levels in umbilical blood were (34 ± 10) and (26 ± 8) µg/L respectively. All were significantly lower than those in the control group (P < 0.01), which were (100 ± 16) and (70 ± 9) µg/L respectively. There was also statistical difference between mild and severe preeclampsia group (P < 0.01). Although the sHLA-G level in umbilical blood of severe preeclampsia group was lower than that in mild preeclampsia group, there was no statistical difference (P > 0.05). The sHLA-G levels in amniotic fluid in mild and severe preeclampsia groups were (26 ± 7) and (25 ± 5) µg/L respectively, which were lower than that in the control group (27 ± 6) µg/L, but the differences were not significant (P > 0.05). There was no statistical difference between mild and severe preeclampsia groups (P > 0.05). (2) The expression levels of HLA-G protein in placenta, fetal membrane and umbilical cord in each group. The expression levels of HLA-G in placenta and fetal membrane in the control group were 1.59 ± 0.36 and 0.42 ± 0.09 respectively. The expression of HLA-G in placenta was significantly higher than that in fetal membrane (P < 0.05). The expression level of HLA-G in umbilical cord in the control group was 0.24 ± 0.17, statistically different from those in placenta and fetal membrane, respectively (P < 0.01). The expression levels of HLA-G in placenta in mild and severe preeclampsia groups were 0.78 ± 0.21 and 0.29 ± 0.17 respectively, significantly different from the control group (P < 0.01). There was no expression of HLA-G in fetal membrane and umbilical cord in mild and severe preeclampsia groups.

CONCLUSIONS

The expressions of HLA-G in the peripheral blood, umbilical blood and placenta in women with preeclampsia are significantly lower than those in normal pregnant women. The abnormal expression of HLA-G might be associated with the pathogenesis of preeclampsia.

Soluble human leukocyte antigen-G serum levels in patients with acquired immune deficiency syndrome affected by different disease-defining conditions before and after antiretroviral treatment

We have previously reported that the serum levels of soluble human leukocyte antigen (HLA)-A, -B, -C, and -G antigens are elevated in human immunodeficiency virus (HIV)-infected subjects and decrease after antiretroviral therapy. In this study, we measured soluble HLA-G serum levels in patients with acquired immune deficiency syndrome (AIDS) affected by different AIDS-defining conditions before and during antiretroviral therapy and correlated them with virologic and immunologic parameters of response to treatment. Soluble HLA-G levels were significantly higher in AIDS patients before treatment as compared with healthy controls and significantly decreased after 36 months of therapy. The decrease of soluble HLA-G correlated with the decrease of plasma HIV-RNA level and CD8(+) T-lymphocytes number and with the increase of CD4(+) T-lymphocytes number. Soluble HLA-G levels were significantly higher in patients with opportunistic infections and Kaposi's sarcoma compared with patients with the wasting syndrome. These data suggest that infections and neoplasms may trigger the shedding of soluble HLA-G molecules, and confirm that the level of soluble HLA-G in serum might represent a surrogate marker to monitor virologic response and immune reconstitution in HIV-positive individuals.

[Expression of serum sHLA-G in patients with hemophagocytic syndrome and its clinical significance]

In order to investigate the expression of serum sHLA-G in hemophagocytic syndrome (HPS) patients and to evaluate its clinical significance, the clinical data of HPS patients in Capital Medical University Beijing Friendship Hospital during the period from September 2008 to July 2010 were collected. They were divided into infection-associated HPS, tumor-associated HPS and rheumatological disease-associated HPS according to cause of diseases. The serum concentration of sHLA-G in HPS patients and 25 healthy controls was measured by enzyme-linked immunosorbent assay (ELISA), the correlations between sHLA-G level and laboratory indicators were analyzed. The results showed that the level of serum sHLA-G in HPS patients was significantly higher than that in healthy controls (p = 0.003), but the difference was not statistically significant between HPS groups of different causes (p = 0.233). The positive correlation of sHLA-G level in HPS patients with platelet count was found, but there was no positive correlation of their sHLA-G levels with WBC, Hb, Plt, ALT, AST, LDH, Alb, TBil, DBil, IBil, Cr, BUN, TG, fibrinogen and ferritin levels detected on same day. It is concluded that the the increase of serum sHLA-G levels in HPS patients may be caused by different factors such as infection, tumor, T cell activation and over-stimulation of several cytokines. sHLA-G can inhibit NK cell activity, resulting in formation of abnormal immune storm, and may be play a role in the pathogenesis of HPS.

Soluble human leukocyte antigen-G (SHLA-G) in Tunisian kidney transplantation

To investigate the relationship between the soluble HLA-G (sHLA-G) and the appearance of acute renal rejection (AR) episodes we have quantify in this study the level of sHLA-G by enzyme-linked immunosotrbent assay in 42 kidney transplant patients classified in two groups: G1: 17patients with acute rejection (AR+) and G2: 25 patients without AR (AR-). To establish our normal sHLA-G ranges, serum samples from 18 healthy controls were tested. Pre-transplantation sHLA-G levels were significantly increased in patients (mean +/- standard error of the mean, 60.48 +/- 12.18 units/ml) than healthy subjects (19.11 +/- 4.9 units/ml) (p = 0.001). Although the difference was not statistically significant, G1 patients (AR+) revealed lower levels of sHLA-G (mean +/- standard error of the mean, 31.25 +/- 6.71 units/ml) compared to G2 patients (AR-) (53.43 +/- 1721 units/ml). Nevertheless, the course of total sHLA-G levels was nearly identical in patients with and without rejection. Nonparametric analysis revealed that pre-transplantation levels of sHLA-G < 18.00 units/ ml (sensitivity: 87.8% and specificity of 72.2%) were not related to rejection. Also, multivariate analysis regarding anti-HLA antibody status, recipient age and gender showed that sHLA-G could not be an independent risk factor for renal graft rejection. However, a higher sera levels of sHLA-G seemed to contribute to better kidney allograft survival rate after 10 years of follow-up (significance tendency: p = 0.091) as shown by the survival analysis. Because of the small number of subjects studied, these results must be treated with caution. A much larger cohort of kidney transplant patients according to acute rejection would seem necessary to confirm these findings.

[Clinical implications of HLA-G protein expression in acute leukemia]

OBJECTIVE

To detect the expression of membrane-bound HLA-G (mHLA-G) and serum HLA-G (sHLA-G) in acute leukemia patients and investigate the correlation between HLA-G expression and the occurrence and development of acute leukemia.

METHODS

Enzyme-linked immunosorbent assay and flow cytometry were used to detect the expression levels of sHLA-G and mHLA-G in 40 newly diagnosed leukemia cases, 10 refractory and relapsed leukemia cases, and 30 leukemia cases receiving chemotherapy. Ten normal individuals served as the normal control group.

RESULTS

The mean serum level of sHLA-G in normal individuals was 5.87±2.07 ng/ml, as compared to 10.05±6.58 ng/ml in newly diagnosed leukemia patients and 12.32±5.85 ng/ml in refractory and relapsed cases. The mean level of mHLA-G in normal individuals, newly diagnosed cases, and refractory and relapsed cases were (0.29±0.20)%, (0.60±0.44)%, and (0.77±0.41)%, respectively. The mean levels of sHLA-G and mHLA-G were significantly higher in the newly diagnosed cases than that in the normal controls (P<0.05), and significantly higher in patients before chemotherapy than in those with complete remission after chemotherapy (P<0.05).

CONCLUSION

HLA-G expression levels might influence the treatment outcomes and can serve as a prognostic factor for acute leukemia.