Blood regulatory T cells in inflammatory bowel disease, a systematic review, and meta-analysis.

INTRODUCTION: Inflammatory bowel disease (IBD) is an autoimmune disease involving various parts of the gastrointestinal (GI) tract, which includes Crohn's disease (CD) and ulcerative colitis (UC). Due to the contradictory results regarding the percentage of peripheral blood (PB) regulatory T cells (Tregs) in IBD patients, this meta-analysis aimed to determine the Tregs frequency in IBD patients. METHOD: We searched PubMed, Web of Science, SCOPUS, and Google Scholar databases for relevant observational articles that analyzed and reported the frequency of PB Tregs in IBD patients and healthy control groups. After choosing the related articles by two reviewers, the data regarding the definition of Tregs and their frequencies in different groups were recorded. RESULT: In 22 studies, the results showed a nonsignificant difference in the frequency of PB Tregs between IBD cases and control subjects (SMD: -0.27, 95 % CI: -0.78, 0.23). However, the frequency of CD4+CD25+CD127- (SMD: -0.89, 95 % CI: -1.52, -0.26) and CD4+CD25+FoxP3+ (SMD: -1.32, 95 % CI: -2.37, -0.26) Tregs were significantly lower in IBD cases, compared to healthy subjects. Also, UC cases and active IBD cases showed a significantly lower frequency of Treg cells, compared to controls and remission IBD cases, respectively (SMD: -0.68, 95 % CI: -1.24, -0.11 and SMD: -0.60, 95 % CI: -0.93, -0.27). CONCLUSION: Our study highlighted a probable decrease of Tregs in IBD patients, especially the patients with active states of the disease. The decrease of Treg cells might cause an imbalance in the immune system and the over-activation of auto-immune responses against the digestive tract.

The impact of killer cell immunoglobulin-like receptor (KIR) genes and human leukocyte antigen (HLA) class I ligands on predisposition or protection against prostate cancer.

Natural killer (NK) cell development largely depends on killer cell immunoglobulin-like receptors (KIRs) and human leukocyte antigen (HLA) class I ligands. In the current study, we investigated the role of KIR genes, HLA ligands, and KIR-HLA combinations in vulnerability or protection against prostate cancer (PC). To analyze the frequency of 16 KIR genes and 5 HLA ligands, polymerase chain reaction with sequence-specific primers (PCR-SSP) was conducted in 150 PC patients and 200 healthy controls (CNs). KIR2DL5 (p = 0.0346, OR = 0.606, CI = 0.3916-0.9336), KIR2DS5 (p = 0.0227, OR = 0.587, CI = 0.3793-0.9139), HLA-B Bw4Thr80 (p = 0.0401, OR = 0.3552, CI = 0.1466-0.9059), HLA Bw4 (p = 0.0190, OR = 0.4744, CI = 0.2656-0.8521), and T4 gene cluster (including KIR2DS5-2DL5-3DS1-2DS1 genes) (p = 0.0194, OR = 0.5575, CI = 0.3449-0.8938) had a lower frequency in the PC patients compared to the control group. Moreover, a lower frequency of the genotypes contacting activating KIR (aKIR) > inhibitory KIR (iKIR) (p = 0.0298, OR = 0.5291, CI = 0.3056-0.9174) and iKIR + HLA < aKIR + HLA (p = 0.0183, OR = 0.2197, CI = 0.0672-0.7001) in PC patients compared to the CNs implies a protective role for aKIR genes. In the case of KIR-HLA interactions, we detected a significant association between KIR3DS1+ + HLA-A Bw4+ (p = 0.0113, OR = 0.5093, CI = 0.3124-0.8416) and KIR3DL1- + HLA-A Bw4+ (p = 0.0306, OR = 0.1153, CI = 0.0106-0.6537) combinations and resistance to prostate cancer. In contrast, the presence of KIR3DL1 in the absence of HLA-A Bw4 (p = 0.0040, OR = 2.00, CI = 1.264-3.111), HLA Bw4 (p = 0.0296, OR = 2.066, CI = 1.094-3.906), and HLA-Bw4Thr80 (p = 0.0071, OR = 2.505, CI = 1.319-4.703) genes probably predisposes to prostate cancer. Carrying the CxT4 genotype in PC patients was positively associated with lower tumor grades (Gleason score ≤ 6) (p = 0.0331, OR = 3.290, and CI = 1.181-8.395). Altogether, our data suggest a protective role for aKIRs, HLA-B Bw4Thr80, and HLA Bw4 ligands as well as a predisposing role for certain KIR-HLA combinations in prostate cancer. The findings of this study offer new insight into the population's risk assessment for prostate cancer in men. Additionally, predicting immunotherapy response based on KIR-HLA combinations aids in implementing the most effective therapeutic approach in the early stages of the disease.

Isolation and in vitro Expansion of Regulatory T Cells from ß-Thalassemia Major Kids and in vitro Evaluation of Their Plasticity and Inhibitory Effects in the Presence of Pro-Inflammatory Cytokines.

INTRODUCTION: Graft-versus-host disease (GvHD) is a life-threatening syndrome commonly associated with hematopoietic stem cell transplantation (HSCT). Preventing the incidence of GVHD after HSCT along with minimizing long-term immunosuppression is currently under investigation with regulatory T cells (Tregs). As Tregs are a low-frequency population and the yield of all memory Tregs is not sufficient for clinical application, an initial Treg expansion is essential. METHODS: Thirty milliliters of peripheral blood from the ß-thalassemia major (beta-TM) patients and healthy controls were obtained and Tregs were isolated using MACS. Isolated cells were cultured in the presence of rapamycin and rIL-2 followed by activated with anti-CD3/CD28-coated beads. To evaluate Treg plasticity, expanded Tregs were cultured in a medium containing IL1ß, IL6, TGFß, and IL2, with or without 500 nM rapamycin for 72 h. To assess the functional properties of Tregs, CFSE dilution assays were performed to evaluate the ability of in vivo expanded Tregs from beta-TM patients. Statistical analysis was performed using paired t-test and independent t-test, with the aid of SPSS version 12.0. p-value ≤0.05 was considered significant. RESULTS: The percentage of Tregs isolated from the control group was significantly higher than the Tregs isolated from patients (p-value = 0.01), which is probably due to the iron overload in beta-TM patients as a result of continuous blood transfusion. Also, the percentage of Tregs after 5 days of expansion had a significant increase in both groups compared to before expansion (p-value = 0.03). Our results also showed that the expansion of Tregs after 72 h in the presence of inflammatory cytokines and in the absence of rapamycin led to the increase in the intracellular expression of IL-17 (p-value = 0.01), while intracellular expression of IL-17 remained low following the addition of 100 nM rapamycin to the culture medium (pvalue = 0.073). The results of the functional evaluation of expanded Tregs showed relatively differences in both patient and control groups. Thus, expanded Tregs inhibited the proliferation of responder T cells in a dose-dependent manner in the control group (p-value = 0.028), while in the patient group this inhibitory effect was not significant (p-value = 0.055). CONCLUSION: Tregs isolated from beta-TM patients have poorer inhibitory performance than Tregs isolated from healthy individuals. Also, we concluded that rapamycin stabilizes the Treg population by inhibiting the production of IL-17, all necessitating the administration of appropriate immunosuppressive drugs in patients receiving Treg therapy.

Natural killer cells and killer cell immunoglobulin-like receptors in solid organ transplantation: Protectors or opponents?

Among all the cells of innate immunity, natural killer (NK) cells are well-known for the fight against tumors and virally-infected cells. NK cells have been implicated in the pathogenesis of immune-mediated allograft damage, but mounting evidence suggests they can potentially promote allograft tolerance as well. In addition, NK cells express a wide variety of activating and inhibiting receptors, and the signals sent by these molecules, particularly killer cell immunoglobulin-like receptors (KIRs), determine their ultimate function. The role of KIRs and their human leukocyte antigen (HLA) class I ligands have been extensively investigated in hematopoietic stem cell transplantation (HSCT). Previous studies have suggested that, in the setting of solid organ transplantation, having certain KIR genes or KIR/HLA combinations probably affects allograft survival. Therefore, it may be helpful to analyze KIR/HLA combinations in donors and recipients to choose the optimal donor, anticipate harmful effects post-transplantation, and develop NK cell-based immunotherapies to enhance the success of solid organ transplantation. In this review, we will discuss the dual function of NK cells in solid organ transplantation, followed by a brief introduction to KIRs and the association of KIR and HLA genes with kidney, liver, and lung transplant outcomes.

Association of IL-15 and IP-10 Serum Levels with Cytomegalovirus Infection, CMV Viral Load and Cyclosporine Level after Kidney Transplantation.

BACKGROUND: Cytomegalovirus (CMV) infection is the most common complications following kidney transplantation. Natural killer (NK) cells demonstrated critical anti-viral role in controlling and elimination of CMV after transplantation. Interleukin-15 (IL-15) is a pleiotropic cytokine that promotes the activity of NK cells and strengthens the acquired immune system. Also, IP10 (CXCL10) is a chemotactic factor which regulates NK cell recruitment and antiviral immune response. We aimed to determine the correlation between the serum levels of IL-15 and IP-10 cytokines with CMV infection, CMV viral load, and cyclosporine as a major immunosuppressive treatment after transplantation. METHODS: Fifty-eight kidney transplant recipient patients without evidence of CMV virus disease before transplantation surgery were included in the study. From the day of transplant surgery, the patients were evaluated based on the presence of CMV Ag pp65, CMV viral load, serum levels of IL-15 & IP-10, Cyclosporine levels (C0 & C2), Glomerular Filtration Rate (GFR), and hematological & biochemical Index, up to 75 days. RESULTS: Comparison analysis of serum levels of IL-15 and IP-10 showed no significant association with CMV infection in kidney transplant recipients. In addition, CMV viral load and cyclosporine levels at C0 and C2 did not affect patients' IL-15 and IP-10 levels. CONCLUSION: The levels of IP-10 and IL-15 cytokines are not affected with CMV infection, even if a viral infection occurs in the early days after transplantation or long afterwards. In addition, taking the different levels of cyclosporine did not affect the cytokines levels. Other mechanisms may play a role in maintaining the levels of these cytokines.

Association of HLA Class II Alleles with Disease Severity and Treatment Response in Iranian Patients with Myasthenia Gravis.

Myasthenia gravis is an autoimmune neuromuscular disease with a multifactorial etiology. A major part of the genetic susceptibility belongs to the HLA encoding genes. In this study, we investigated the role of HLA class II polymorphism in disease severity, and treatment response. In our 146 patients, 15 DRB1, 7 DQA1, and 9 DQB1 alleles, and 19 haplotypes were found. Adjusted p-values did not show any significant associations between these loci, disease severity and treatment outcome. Further studies in different populations with a larger number of patients are needed to determine the exact contribution of HLA class II alleles to MG prognosis.

Cell therapy in transplantation: A comprehensive review of the current applications of cell therapy in transplant patients with the focus on Tregs, CAR Tregs, and Mesenchymal stem cells.

Organ transplantation is a practical treatment for patients with end-stage organ failure. Despite the advances in short-term graft survival, long-term graft survival remains the main challenge considering the increased mortality and morbidity associated with chronic rejection and the toxicity of immunosuppressive drugs. Since a novel therapeutic strategy to induce allograft tolerance seems urgent, focusing on developing novel and safe approaches to prolong graft survival is one of the main goals of transplant investigators. Researchers in the field of organ transplantation are interested in suppressing or optimizing the immune responses by focusing on immune cells including mesenchymal stem cells (MSCs), polyclonal regulatory Tcells (Tregs), and antigen-specific Tregs engineered with chimeric antigen receptors (CAR Tregs). We review the mechanistic pathways, phenotypic and functional characteristics of these cells, and their promising application in organ transplantation.

Investigating the Role of BAFF and Its Receptors in Renal Transplant Recipients with Chronic Antibody-Mediated Rejection.

BACKGROUND: Kidney transplantation is the best treatment option for end stage renal disease (ESRD), but graft rejection is still a big obstacle that occurs in spite of immunosuppressive therapy. B cells are considered as the major reason for renal graft rejection because of antibody production. Due to their roles in B cell function, we intended to evaluate the B cell activating factor (BAFF) and its receptors including BAFF receptor (BAFF-R), B cell maturation antigen (BCMA), and transmembrane activator and cyclophilin ligand interactor (TACI) in renal transplant patients. METHOD: The study included 40 kidney allograft patients with cAMR, 40 stable kidney allograft patients, and 8 healthy volunteers with normal kidney function. The percentage and absolute number of CD19+ B cells were analyzed by flow cytometry, the serum level of BAFF was analyzed by ELISA, and mRNA expressions of BAFF and BAFF receptors (BAFF-R, BCMA, and TACI) were measured using quantitative real-time PCR. RESULTS: The percentage and the absolute number of B cells decreased significantly in stable and cAMR patients compared to healthy individuals. The serum level and gene expression of BAFF, as well as the mRNA level of BCMA, were increased significantly in both cAMR and stable patients compared to healthy volunteers. There was an overexpression of TACI mRNA in cAMR patients compared to stable patients. CONCLUSIONS: Both soluble protein and mRNA transcript of BAFF increased in transplant recipients. However, BAFF neither at the serum level nor at the mRNA transcript level cannot be a good biomarker for the prediction of cAMR. In addition, expression of TACI, compared to other receptors of BAFF, confers a potential to be used in distinguishing cAMR and stable kidney transplant patients.

B cell modulation strategies in the improvement of transplantation outcomes.

Successful transplantation outcome is the final goal in most end stage and nonfunctional organs; however, despite using different therapeutic strategies, antibody-mediated rejection is still a big obstacle. B cells have a key role in transplant rejection by several functions, such as antibody production, antigen presenting, contribution in T cell activation, forming the germinal center, and tertiary lymphoid organs. Therefore, B cells modulation seems to be very crucial in transplant outcome. A double-edged sword function is considered for B cells during transplantation; On the one hand, antibody production against the transplanted organ induces antibody-mediated rejection. On the other hand, IL10 production by regulatory B (Breg) cells induces graft tolerance. Nowadays, several monoclonal antibodies (mAb) are available for B cell modulation that are routinely used in transplant recipients, among which rituximab (anti-CD20 mAb) act in eliminating B cells. However, there are some other monoclonal antibodies, such as epratuzumab and Inotuzumab ozogamicin (IO), which exert anti-CD22 activity, resulting in disruption of B cell functions and induction of tolerance in autoimmune disease or B cell malignancies; that notwithstanding, these mAbs have not yet been tried in transplantation. In this review, we focus on different methods for modulating the activity of B cells as well as induction of Breg cells, aiming to prevent the allograft rejection.

TLR-2, TLR-4 and MyD88 genes expression in renal transplant acute and chronic rejections.

BACKGROUND: Graft rejection due to alloreactivity is still the main obstacle to successful renal transplantation. Toll-like receptors (TLRs), which are significantly involved in initiating inflammation, triggering innate immunity, occurrence of ischaemia reperfusion injury (IRI) and subsequent deterioration of allograft function, are of interest in molecular diagnosis of graft rejection. METHODS: In present research, we have evaluated the mRNA expressions of TLR-4, TLR-2 and myeloid differentiation primary response gene 88 (MyD88) in peripheral blood mononuclear cells (PBMCs) and biopsy samples of 26 stable graft function (SGF), 14 acute T-cell-mediated rejection (ACMR), six acute antibody-mediated rejection (AAMR), 10 chronic T-cell-mediated rejection (CCMR) and four chronic antibody-mediated rejection (CAMR) cases of renal transplant recipients, using TaqMan detector real-time polymerase chain reaction (RT-PCR). RESULTS: It was found that TLR4 mRNA level was significantly elevated in PBMCs of both ACMR (P.v: 0.025) and CCMR (P.v: 0.007) cases, while TLR2 gene was upregulated only in PBMCs of ACMR (P.v: 0.024). Moreover, MyD88 expression was increased in biopsy samples of all rejection groups AAMR (P.v: 0.032), ACMR (P.v: 0.002), CAMR (P.v: 0.038) and CCMR (P.v: 0.013) and could distinguish them from stable grafts with AUC (area under curve) of 0.81, 0.80, 0.83 and 0.77, respectively. CONCLUSION: These data showed that MyD88 gene upregulation in renal tissue could have diagnostic value and increased level of TLR4 mRNA in PBMCs could be suggestive of cell-mediated rejections. Therefore, monitoring the expression level of inflammatory signalling genes might be useful in predicting allograft rejection.

Antiapoptotic Molecule Survivin in Transplantation: Helpful or Harmful?

Survivin, an antiapoptotic molecule from inhibitor of apoptosis protein (IAP) family, is most known for its implication in cancer as there are some efforts to apply it for diagnostic as well as therapeutic purposes in oncology. On the other hand, it could be a useful molecule to be positively targeted when trying to save tissue and promote cells viability. Since protecting the allograft from ischemia reperfusion injury and inflammation-induced damage is a considerable objective in transplantation, it is reasonable to take advantage from antiapoptotic agents like survivin in order to achieve this goal. However, survivin's potential ability to induce malignancies makes some concerns about its use in clinic. The other barrier is this molecule's involvement in lymphocytes development and proliferation which might increase the risk of graft rejection due to adaptive immune system overactivation. In this review we summarize the few studies carried out about survivin's effect on graft survival and probable advantages and disadvantages of its overexpression in transplantation.

High Expression of FOXP3 mRNA in Blood and Urine as a Predictive Marker in Kidney Transplantation.

BACKGROUND: Diagnosis of allograft dysfunction by noninvasive biomarker tests is preferable to invasive allograft biopsies and has been extensively considered in recent years. This study aims to evaluate blood and urinary forkhead box P3 (FOXP3) messenger RNA (mRNA) expression in renal transplant recipients in an attempt to determine whether differential diagnosis of graft dysfunction is feasible using mRNA profiles. METHODS: We analyzed FOXP3 mRNA expression in paired urinary and peripheral blood mononuclear cell (PBMC) samples. A total of 91 kidney transplant recipients enrolled in this study that were classified into 3 groups: biopsy-proven acute rejection (AR; n = 27), chronic allograft nephropathy (n = 19), and well-functioning graft (n = 45). The FOXP3 mRNA expression was quantified by TaqMan probe real-time polymerase chain reaction. RESULTS: Acute rejection patients had a higher expression level of transcription factor FOXP3 compared to the chronic nephropathy and control groups. Analysis of receiver operating characteristic curves showed that rejection could be diagnosed with 100% sensitivity and 96% specificity in urine, and 92% sensitivity and 86% specificity in PBMC samples using the optimal FOXP3 mRNA cutoff value. We subdivided the AR group into progressive and nonprogressive patients, which showed a significant difference in FOXP3 mRNA expression. This result confirmed the role of FOXP3 as a diagnostic marker in predicting transplantation outcomes. CONCLUSION: Our results suggested that elevated expression of FOXP3 in blood and urine samples from kidney transplant recipients could be a useful noninvasive biomarker to diagnose graft dysfunction.

Expression patterns of Toll like receptor (TLR)-2, TLR-4 and myeloid differentiation primary response gene 88 (MYD88) in renal transplant patients developing allograft dysfunction; a cohort study.

This cohort intends to determine the sequential dynamic changes in Toll-like receptor (TLR)-4, TLR-2, and myeloid differentiation primary response gene 88 (MYD88) mRNA expressions in PBMCs and biopsy samples from kidney allograft recipients in relation to graft function. This study enrolled 52 renal transplant patients, 27 with well functioning graft (WFG) and 25 graft dysfunction (GD). Peripheral blood samples pre- and post-transplantation (days 2, 90 and 180) were collected to analyze mRNA expression levels of TLR-2, TLR-4, and MYD88 genes in relation to allograft function during one-year follow up. The mean dynamic changes of post-transplant TLR-2, TLR-4, and MYD88 mRNA expressions were significantly higher in GD compared to WFG patients (P = .001). ROC curve analysis based on glomerular filtration rate (GFR) index showed the area under curve (AUC) values for the genes: TLR-2(0.89;P < .001), TLR-4(0.86;P < .001), and MYD88(0.75;P = .003) in the third month post-transplantation for GD diagnosis. The calculated AUCs for the expressions of genes in allograft biopsies were 0.94(TLR-2), 0.95(TLR-4), and 0.98(MYD88) in the sixth month post-transplant based on pathology report (P < .001). Our results indicate that sequential monitoring of the expression patterns of TLR-2, TLR-4, and MYD88 in PBMCs and biopsy samples could be considered as predictive biomarkers for early and late kidney allograft function.

Effect of TNF-α Blockade in Gingival Crevicular Fluid on Periodontal Condition of Patients with Rheumatoid Arthritis.

BACKGROUND: Periodontitis and rheumatoid arthritis (RA) share a number of clinical and pathologic features, one of which is the presence of the tumor necrosis factor alpha (TNF-α)-induced bone resorption that is involved in the pathogenesis of both. OBJECTIVES: To investigate the effect of TNF-α blockade on periodontal conditions in patients with active RA. METHOD: The periodontal statuses of 36 patients (26 females, 10 males) diagnosed with active RA were evaluated both before and after anti-TNF-α therapy. Gingival index, bleeding on probing (BOP), probing pocket depth (PPD), oral hygiene index (OHI), and levels of TNF-α in gingival crevicular fluid (GCF) were measured at the baseline and 6 weeks after the treatment. Wilcoxon signed ranked test was used for statistical analyses. RESULTS: Based on OHI (p=0.860), the level of plaque control did not change during the study period, but there was a significant reduction in gingival inflammation based on the mean BOP (p=0.049) and GI (p=0.036) before and after 6 weeks of anti-TNF-α therapy. The mean PPD index did not significantly differ at the baseline and 6 weeks after treatment (p=0.126). CONCLUSION: Anti-TNF-α therapy might have a desirable effect on periodontal conditions and might reduce TNF-α level in GCF of patients with RA.

Increased levels of CD4(+) and CD8(+) T cells expressing CCR1 in patients developing allograft dysfunction; a cohort study.

BACKGROUND: Leukocyte infiltration into the graft has pivotal effects on kidney transplantation outcome. The present study sought to determine whether the expression of sequential chemokine receptors on CD4(+) and CD8(+) T cells in human renal allograft can predict clinical episodes. METHODS: Blood samples from 52 consecutive renal transplant patients were evaluated at the time of transplantation and at three times (2, 90 and 180days) after transplantation to analyze the expression of CCR1 and CXCR3 on CD4(+) and CD8(+) T cells by flowcytometry. A total of 30 biopsies, including protocol biopsy (n=24) and cause biopsy (n=6), were investigated according to the Banff criteria. RESULTS: The mean percentage of CD4(+) and CD8(+) T cells expressing CCR1 was significantly increased in patients with allograft dysfunction (n=25) (p=0.006, p=0.004). The mean fluorescence intensity of CXCR3 on CD4(+) and CD8(+) T cells were found to be significantly higher in graft dysfunction than that in well-functioning grafts. (p<0.001, p=0.007). Receiver Operating Characteristic (ROC) Curve Analysis showed that the calculated AUC was 0.86 at the third month for CD4(+)CCR1(+) and CD8(+)CCR1(+) (p<0.001). Multiple logistic regression analysis showed that an increase in CD4(+) expressing CXCR3 leads to a lower risk of graft dysfunction (OR=0.37), while an increase in CD8(+) expressing CCR1 results in a higher risk of graft dysfunction (OR=3.66). CONCLUSION: During renal transplantation, CD4(+) and CD8(+) T cells expressing CCR1 were increased in patients who developed graft dysfunction. These findings may prospectively predict allograft dysfunction, and help elucidate the underlying pathogenic mechanisms.

Association of HLA class II (DRB1, DQA1, DQB1) alleles and haplotypes with myasthenia gravis and its subgroups in the Iranian population.

Heterogenic pattern of HLA associations with myasthenia gravis (MG) among different ethnicities and also among different MG subgroups has been the subject of debate in large series of many studies. One hundred and sixty Iranian MG patients were investigated for HLA class II (DRB1, DQA1, DQB1) associations compared to two hundred healthy controls from the same ethnic population. DRB1*11 DQA1*0501 DQB1*0301 haplotype was found to be protective for total (ocular plus generalized) MG (Pc=0.005, OR=0.49) and generalized MG (Pc=0.008, OR=0.49). DRB1*04 DQA1*0301 DQB1*0302 haplotype (Pc=0.03, OR=2.25) was predisposing for anti-acetylcholine receptor (AChR) antibody-positive MG, while DRB1*16 DQA1*0102 DQB1*05 (Pc=0.013, OR=4.28) was predisposing for anti-muscle specific tyrosine kinase (MuSK) antibody-positive MG. There was also a trend of positive association for DRB1*14 DQA1*0104 DQB1*05 haplotype with MuSK-positive MG (Pc=0.054, OR=3.97). Among other MG subgroups and with less significance, DRB1*0101 DQA1*0101 DQB1*05 haplotype (P=0.016, OR=3.68) had positive association with pure ocular MG, and DRB1*03 DQA1*0501 DQB1*0201 haplotype (P=0.024) had negative association with thymomatous MG. This study highlights the importance of appropriate MG subgrouping according to clinical and paraclinical characteristics in HLA studies among MG patients.

Differential expression of microRNAs in renal transplant patients with acute T-cell mediated rejection.

BACKGROUND: MicroRNAs (miRNAs) regulate most of encoding genes and protein. In this study, we aimed to investigate the expression levels of miR-142-5p, miR-142-3p, miR-155 and miR-223 in paired biopsy and peripheral blood mononuclear cell (PBMC) samples of renal allograft recipients with acute T-cell mediated rejection (ATCMR), compared with normal allografts (NA). METHODS: In this study, the expression levels of individual miRNAs were determined in biopsy and PBMC samples of 17 recipients with ATCMR and 18 recipients with NA. RESULTS: Our results showed that the intragraft expression levels of all studied miRNAs were significantly higher in ATCMR than NA. However, regarding the PBMC samples, miR-142-3p and miR-223 were significantly increased in ATCMR than NA. Receiver operating characteristic (ROC) analysis showed that miR-142-5p, miR-142-3p, miR-155 and miR-223 in biopsy samples and miR-142-3p and miR-223 in PBMC samples could discriminate ATCMR from NA recipients. CONCLUSION: It has been reported that high intragraft expressions of miRNAs have a profound role in the pathogenesis of ATCMR process. Our results showed that high expression of all the studied miRNAs in biopsies and miR-142-3p and miR-223 in PBMC samples could be used as suggestive diagnostic tools to discriminate ATCMR patients from NA.

Association of programmed cell death 1 and programmed cell death 1 ligand gene polymorphisms with delayed graft function and acute rejection in kidney allograft recipients.

INTRODUCTION: The genetic variations of co-stimulatory molecules can affect the extent of T cell activity during T-cell mediated immunity, especially in transplant patients. This study aimed to investigate the association of programmed cell death 1 (PDCD1) and programmed cell death 1 ligand 1 (PDCD1LG1) gene polymorphisms with clinical outcome of kidney transplantation. MATERIALS AND METHODS: A total of 122 patients with a kidney transplant were included in this retrospective study. Patients were classified into two groups of biopsy-proven acute allograft rejection (AAR) and stable graft function (SGF) during the 5-year follow-up period. Four single nucleotide polymorphisms in PDCD1 and PDCD1LG1 were determined in the groups of patients as well as in 208 healthy control individuals. RESULTS: The frequencies of PD-1.3 (+7146 G>A), PD-1.9 (+7625 C>T), PD-L1 (8923 A>C), and PD-L1 (+6777 C>G) genotypes and alleles were not significantly different between the AAR and SGF groups. In comparison with healthy controls, PD-1.9 (+7625 C>T) genotype and T allele were significantly more frequent in all of the patients and in those with SGF. Overall, 27 of 122 kidney allograft recipients experienced delayed graft function, and a higher frequency of PD-1.9 (+7625 C>T) genotype and T allele was observed in this group versus those without delayed graft function. Similarly, a significant high frequency of this genotype was found among the AAR subgroup of patients with delayed graft function. CONCLUSIONS: Our results indicate that potentially functional genetic variation in PDCD1 can influence the outcome of kidney transplantation.

Soluble major histocompatibility complex class I chain-related antigen A level in chronic allograft dysfunction.

INTRODUCTION: Soluble major histocompatibility complex class I chain-related antigen A (soluble MICA) has recently been considered as an inhibitory molecule which is shed from tumors and protects them against natural killers and some subgroups of T cells' cytolysis. In transplantation, soluble MICA is also a foreign antigenic molecule that can induce allospecific responses. This study aimed to clarify its possible role in long-term kidney allograft outcome. MATERIALS AND METHODS: Thirty patients with biopsy-proven chronic allograft dysfunction (CAD) were pair-matched with kidney allograft recipients with 30 stable graft function. Fifteen healthy individuals were enrolled as controls. Soluble MICA antigen and anti-HLA antibodies were measured in their serum. RESULTS: There was no significant difference between CAD patients, stable recipients, and healthy volunteers in frequency or titer of soluble MICA; however, soluble MICA-positive patients were more frequent in the stable group was than the CAD group (43.4% versus 33.3%). In addition, a high level of soluble MICA was accompanied by enhanced humoral responses. No significant difference was found in anti-HLA antibodies production between the CAD and stable groups. CONCLUSIONS: Our data suggest that soluble MICA, at least in a defined range, can protect the allograft against natural killers and T cell cytolysis; nonetheless, its excessive amounts might stimulate immune system to exert enhanced humoral response. In order to confirm the protective or detrimental role of soluble MICA in kidney transplantation, conducting larger studies is necessary.

Altered Expression of MicroRNAs Following Chronic Allograft Dysfunction with Interstitial Fibrosis and Tubular Atrophy.

Chronic allograft dysfunction (CAD) remains the major cause of renal transplant loss and characterized by interstitial fibrosis and tubular atrophy (IFTA). MicroRNAs (miRNAs) are implicated in many biological processes as well as innate and adaptive immune responses. We aimed to investigate whether CAD with IFTA is associated with differential expression of miR-142-5p, miR-142-3p and miR-211 within biopsy and peripheral blood mononuclear cell (PBMC) samples and whether expression of miRNAs are diagnostic for CAD with IFTA and predicts renal allograft function. In this study, biopsy and PBMC samples of 16 CAD with IFTA and 17 normal allografts (NA) were collected. Using Taqman MicroRNA Assays the expression levels of miR-142-5p, miR-142-3p and miR-211 were determined in two groups. Our results showed that miR-142-5p and miR-142-3p were significantly (p<0.0001) up-regulated and miR-211 was significantly (p<0.0001) down-regulated in renal allograft tissues of CAD with IFTA compared with NA recipients. Moreover, miR-142-3p and miR-211 were significantly (p<0.0001) up-regulated and down-regulated respectively in PBMC samples of CAD with IFTA. According to the ROC curve analysis, miR-142-5p in biopsy samples, but miR-142-3p and miR-211 both in biopsy and PBMC samples could be used as a diagnostic biomarker of CAD with IFTA and a prediction factor of allograft function. In this study, miRNAs were differentially expressed in the kidney allograft biopsy and simultaneously in PBMC samples of patients with CAD with IFTA. We suggest that the expression of miRNAs in PBMC might be used for monitoring the post transplantation and also as potential non-invasive biomarkers of kidney graft function and CAD with IFTA.