Mechanisms of acute cellular allograft rejection followed liver transplantation employs the activation, proliferation and differentiation of CD4+CD154+ and CD8+CD154+ T cells into effector cells ...triggered by direct allorecognition pathway, which is performed by both but is dominated by CD4+ T cells, and indirect allorecognition pathway virtually restricted to CD8+ T cells·
Summary
Decreasing graft rejection and increasing graft and patient survival are great challenges facing liver transplantation (LT). Different T cell subsets participate in the acute cellular rejection (ACR) of the allograft. Cell‐mediated immunity markers of the recipient could help to understand the mechanisms underlying acute rejection. This study aimed to analyse different surface antigens on T cells in a cohort of adult liver patients undergoing LT to determine the influence on ACR using multi‐parametric flow cytometry functional assay. Thirty patients were monitored at baseline and during 1 year post‐transplant. Two groups were established, with (ACR) and without (NACR) acute cellular rejection. Leukocyte, total lymphocyte, percentages of CD4+CD154+ and CD8+CD154+ T cells, human leukocyte antigen (HLA) mismatch between recipient–donor and their relation with ACR as well as the acute rejection frequencies were analysed. T cells were stimulated with concanavalin A (Con‐A) and surface antigens were analysed by fluorescence activated cell sorter (FACS) analysis. A high percentage of CD4+CD154+ T cells (P = 0·001) and a low percentage of CD8+CD154+ T cells (P = 0·002) at baseline were statistically significant in ACR. A receiver operating characteristic analysis determined the cut‐off values capable to stratify patients at high risk of ACR with high sensitivity and specificity for CD4+CD154+ (P = 0·001) and CD8+CD154+ T cells (P = 0·002). In logistic regression analysis, CD4+CD154+, CD8+CD154+ and HLA mismatch were confirmed as independent risk factors to ACR. Post‐transplant percentages of both T cell subsets were significantly higher in ACR, despite variations compared to pretransplant. These findings support the selection of candidates for LT based on the pretransplant percentages of CD4+CD154+ and CD8+CD154+ T cells in parallel with other transplant factors.
Most immune system polymorphisms have undergone molecular evolution largely due to natural selection driven primarily by host-pathogen interactions, showing significant human geographic expansion ...signs. Killer cell immunoglobulin-like receptors (KIRs) show great genetic and allelic variation among different populations. The aim of this study was to analyse the frequency of KIR genes in a large cohort of healthy Spanish Caucasians (SC) to be able to compare them with other world populations. A total of 609 healthy SC unrelated individuals were analysed and compared with 16 worldwide populations. KIR genotyping was analysed by PCR-SSO technique. Our results showed that all KIR genes were present in the Spanish population. iKIR2D genes of the Spanish population were similar in different European populations like Danish, Finland, Irish and Italian populations, Czech and Turkish populations but very different to Australian, Bornean, Chinese, Indian, Venezuelan, and Russian populations. KIR3DL1 gene frequency in the Australian population was significantly lower than the Spanish population. aKIR genes frequencies of the Spanish population were similar to European populations, but slight differences were found in English, Finnish, Irish and Macedonian populations. In conclusion, our results enrich the Caucasian genetic information resources of the KIR gene pool for genetic susceptibility diseases and forensic anthropological studies.
Background. Clinical and molecular mechanisms involved in the cause and time of death of alcoholic cirrhosis (AC) patients undergoing liver transplantation (LT) are not entirely understood. In sudden ...death cases, judicial autopsy practice is mandatory for determining the cause and circumstances of death. The medico-legal autopsy data are essential for helping health authorities to guide future public health activities, assess the effectiveness of health systems, and adopt the necessary preventive measures to improve and adapt the treatments in order to increase these patients’ survival. Objective. Our study aimed to determine the different clinical and sociodemographic causes that influence the different causes of death and the short- and long-term survival of AC patients undergoing liver transplantation. Methods. A total of 122 deceased AC patients undergoing LT were analyzed at different times post-transplantation. The main pre- and post-transplant complications were analyzed in relation to the cause of death and the patient’s survival, as well as the causes and time at which the patient’s death occurred. Results. A total of 53.3% of non-sudden death was observed. A large number of the deaths of AC patients undergoing transplantation were due to non-sudden death, sepsis, and graft failure (GF), the main causes of death in the sample being similar in both sexes. In non-sudden deaths, there were no significant differences between the death rates either related or not related to the liver transplant. Sepsis was the main cause, with the highest percentage (21.3%) of mortality, followed by GF (18.9%) and multiorgan failure (15.6%) at ten years. Furthermore, our results showed how pre-transplant clinical complications, such as viral infections and encephalopathy, influence the age at which multiorgan failure occurs in the transplanted patient. Conclusion. Multiorgan failure is the leading cause of sudden death, with higher mortality during the first year after transplantation, followed by sepsis and GF. Our results show the vulnerability of AC patients, both in the hospital period after the transplant and outside.
Summary
Anti‐inflammatory cytokines have an important role in disease, tumour and transplant processes. Alterations in the regulation of several cytokines have been implicated in a variety of ...inflammatory disorders, including IBD (inflammatory bowel disease) Crohn′s disease (CD) and ulcerative colitis (UC). Cytokine polymorphisms are also known to affect the level of gene expression. Thus, the aim of this study was to determine the relationship between cytokine polymorphisms and the IBD pathologies in a Spanish population. Polymorphisms analysis was performed using PCR‐SSOP using a microbeads luminex assay. The following polymorphisms were determined: TNFα −238G/A (rs361525) and −308G/A (rs1800629), IFNγ +874A/T (rs62559044), TGFβ +869C/T (rs1982073) and +915G/C (rs1800471), IL10 −1082A/A (rs1800896), −592A/C (rs1800872), −819C/T (rs1800871), IL6 −174C/G (rs1800795), IL12p40 3′UTR −1188A/C (rs3212227), IL1α −889C/T (rs1800587), IL1β −511C/T (rs1143634) and +3962C/T (rs1143633), IL1R Pst‐1 1970C/T and IL1RA Mspa‐1 11100C/T. No statistical differences in TNFα, IFNγ, TGFβ, IL10, IL6, IL1α, IL1β, IL1R and IL1Ra genotypes and allele distributions between the IBD groups and healthy controls were found. However, we observed significant differences in the 3′UTR −1188A/C polymorphism of IL12p40. So −1188A allele was increased in patients with UC and the −1188C allele (high IL12p40 production) was increased in patients with CD with respect to controls. These data are in concordance with the fact that CD has been shown to be associated with a Th1 T‐cell‐mediated inflammation model and high IL12/IFNγ production at histological affected sites. These data suggest that cytokine polymorphisms in TNFα, IFNγ, TGFβ, IL10, IL6 and IL1α, IL1β, IL1R and IL1Ra cytokine gene do not seem to be relevant in IBD susceptibility and IL12p40 3′UTR −1188A/C polymorphism seems to be associated with a differential IBD development.
Abstract Introduction Orthotopic liver transplantation (OLT) is considered one of the few curative treatments available for early stages of hepatocellular carcinoma (HCC). It has been shown that more ...than 10% of transplanted individuals suffer relapse during the first year after surgery and most of them die because of the tumor. The circulating tumor cells (CTCs) are the main source of recurrences as they disseminate from a primary or metastatic tumor lesion through peripheral blood. We aimed to determine the concentration of CTCs in peripheral blood in these patients by 2 different approaches: the CellSearch and the IsoFlux systems to assess their applicability to this disease monitoring. Patients and Methods A comparative study was conducted in 21 patients with HCC eligible for liver transplantation according to the Milan criteria, whose peripheral blood was processed by the CellSearch and the IsoFlux systems. Results CTCs were isolated in 1 of the 21 patients (4.7%) by the CellSearch system and in 19 of the 21 patients (90.5%) by the IsoFlux method. The comparison of both methods using Bland-Altman plot shows that there is not consistency in the determination of CTCs in our patients, finding a proportional bias between them. Conclusion The results obtained by both CTCs isolation systems are not interchangeable nor transferable. The CellSearch system does not seem to be the ideal approach for studying CTCs in patients with HCC. The IsoFlux system displays greater sensitivity in the identification of CTCs and might become an important tool in patient management.
Activated regulatory T cells (aTregs) are nowadays a hot topic in organ transplantation to establish their role during acute rejection (AR) episodes. The aim of this multi-center study was to monitor ...the frequency of aTregs within the first year after transplantation in a cohort of first-time liver transplant recipients enrolled from 2010 to 2012. aTregs frequency was analyzed by means of flow cytometry. Patients who had AR showed higher levels of aTregs during first year after transplantation in comparison with patients who did not have higher levels. High levels of aTregs in liver recipients might be used as a biomarker of AR; however, further studies must be done to address the potential role of aTregs as biomarkers of AR in liver transplantation.
Summary
Tumour necrosis factor alpha (TNF‐α) has an important role in inflammatory response. Alterations in the regulation of TNF‐α have been implicated in a variety of inflammatory disorders, ...including Inflammatory bowel disease (IBD). Indeed, a common treatment for IBD is the use of TNF‐α inhibitors. Polymorphisms in the TNF‐α promoter region are known to affect the level of gene expression. Our aim was to investigate the influence of these single nucleotide polymorphisms (SNPs) in TNF‐α promoter gene play in the risk of IBD in a Spanish population and their individual response to anti‐TNF‐α treatment. DNA samples from patients with IBD and controls were screened for TNF‐α −238G/A (rs361525) and −308G/A (rs1800629) SNPs by PCR‐SSOP using a microbeads luminex assay and compared with response to TNF‐α inhibitors. There were not statistical differences in −238G/A and −308G/A allele and genotype frequencies between patients. However, we found an increased frequency of −308A allele and −308GA genotype in these nonresponders patients to TNF‐α inhibitors with respect to responders patients (Pc < 0.05). This −308GA genotype has been classified as high producer of this cytokine. This fact could actually be interesting to explain the different response of patients with IBD with respect to TNF‐α inhibitors. TNF‐α promoter gene polymorphism does not seem to play a role in IBD susceptibility, but particular TNF‐α genotypes may be involved in the different responses to TNF‐α inhibitor treatment in Spanish patients with IBD.
Abstract Background Acute rejection (AR) remains a significant cause of graft loss. Better approaches to predict AR are being investigated. Surface CD28 protein is essential for T-cell proliferation ...and survival as well as cytokine production. Patients and Methods Pretransplant CD4+ CD28+ peripheral T cells were examined in 30 liver recipients (LRs) and 31 kidney recipients (KRs) by flow cytometry. Results Pretransplant CD4+ CD28+ T cells in LRs were significantly lower in rejectors than nonrejectors ( P = .002). Furthermore, the total number of CD28 molecules per cell in LRs ( P = .02) as well as KRs ( P = .047) was significantly lower in rejectors than nonrejectors. The healthy group did not display differences when compared with patients with end-stage liver disease or renal failure; however, stratification analysis displayed higher levels of CD4+ CD28+ when compared with rejected LRs ( P = .04) but not KRs. CD28 levels <41.94% were able to discriminate LRs at high risk of AR ( P = .003). Similarly, a total number of CD28 molecules ≤8359 ( P = .031) in LRs and ≤7669 ( P = .046) in KRs correlated with high risk of AR. Conclusion The preliminary results presented herein exhibit a fast and noninvasive method that assists clinicians to prevent AR by monitoring CD4+ CD28+ peripheral T cells.
Abstract Background There is no consensus about the impact of thresholds of complement-fixing antibody assays. Recently, a C1q-SAB assay has been developed to identify complement-fixing HLA ...antibodies with high sensitivity and specificity. Our aim was to determine the correlation between IgG single antigens beads (SAB) and C1q-SAB assay results among patients on the renal waiting list. Patients and Methods Serum samples from immunized renal waiting list patients as well as negative and positive controls were valided by Luminex (LMX). These sera, which were positive for 166 antibody specificities, were tested for HLA class I in parallel by LMX-IgG and LMX-C1q. Results Comparison of antibody detection revealed no correlation based on median fluorescent intensity (MFI), levels between the IgG SAB and the C1qSAB assay ( P > .05). IgG-positive sera with MFIs as low as 700 were able to fix C1q, whereas other sera with MFIs as high 14,500 did not. Furthermore, there appeared to be disparities in the profiles of class I antigens able to fix C1q-SAB. In our series, only 34% class I IgG SAB antibodies were also C1qSAB+. In several patients, we detected C1qSAB+ against IgGSAB- that was surely due to IgM antibodies. So, the C1qSAB assay detected IgM antibodies that fix complement. Conclusion These data suggested that the C1q-SAB assay could be an important method to evaluate pretransplant virtual crossmatch and to define nonpermitted specificities (C1q-fixing) in kidney transplantation.
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