Organ transplant has become one of the strategies for treatment of malignant disease. The transplant-related complications restricted the further development of organ transplantation; graft rejection is most prominent among these complications, which remains a major cause of morbidity and mortality after organ transplant. Toll like receptors 4 (TLR-4) has been shown as a key molecule in innate immunity and immune tolerance. The role of TLR4 in graft rejection after organ transplant is still unknown. This article will review the role and the mechanism of TLR4 to control APC mature, activate T cells, trigger immune attack to organ graft; therefore bring new insights into the pathophysiology of graft rejection and foster the development of new therapies to control graft rejection after organ transplant.
Graft Rejection ; immunology ; Humans ; Toll-Like Receptor 4 ; immunology

BACKGROUNDThe status of sensitization in kidney transplant recipients in the last 10 years and the trend of induction and maintenance therapy in patients of different panel-reactive antibody (PRA) levels have not been analyzed. The aim of this study was to investigate the current status of pre-transplant sensitization and its association with graft outcome.

METHODSA total of 155 570 kidney transplants reported to United Network for Organ Sharing (UNOS) during 2000 - 2009 were included in this study. We investigated the current status of pre-transplant sensitization and its association with graft outcome, and also compared the usage trend of 16 induction agents and 7 maintenance immunosuppressants in patients at different PRA levels. The difference of distributions of categorical variables between groups was investigated using the chi-square test. Unpaired t test or one-way analysis of variance (ANOVA) were used for numerical variables. The survival rates of transplant recipients were estimated using Kaplan-Meier methods and significance was determined by Log-rank test. Two-side P value < 0.05 was considered statistically significant. All statistical analyses were performed using STATA 10 with all available updates as of March 2010 (StataCorp LP, College Station, Texas 77845, USA).

RESULTSDespite the fact of the decreased percentages of kidney transplant recipients with presensitization history, the mean PRA levels of all kidney recipients has been increasing in the last 7 years, which was possibly due to the introduction of more sensitive antibody testing techniques. The percentage of patients with treated rejection episodes within one year post-transplant were significantly higher in sensitized patients (PRA = 50% - 100%:14.3% and PRA = 1% - 49%:13.9%) than in non-sensitized patients (12.4%). Both 1- and 5-year graft survival rates improved in the last 10 years; this was more significant in high PRA patients. Thymoglobulin was the most commonly used induction agent in last 10 years. Its users increased from 10% to 46% in non-sensitized patients, from 12% to 57% in PRA 1% - 49% patients, and from 19% to 63% in PRA 50% - 100% patients. The users of Campath, intravenous immunoglobulin (IVIG), and Rituximab have been increasing and reached 16%, 20%, and 11% in highly sensitized patients. In the last 5 years, steroid-free patients were 33% - 36%, 30% - 37%, and 10% - 25% for PRA 0, 1% - 49%, and 50% - 100% respectively. Almost 90% of patients were on Prograf at discharge. It seems that Myfortic users have been increasing since 2005 and it may soon replace mycophenolate mofetil (MMF) if long-term follow-up study conforms its safety and efficacy.

CONCLUSIONSApplication of sensitive antibody testing techniques increased the mean PRA levels of transplant recipients in spite of a decreased percentage of sensitized recipients. Induction and maintenance therapy differed in patients at different PRA levels.

Graft Rejection ; immunology ; Graft Survival ; immunology ; Humans ; Immunosuppression ; methods ; Immunosuppressive Agents ; therapeutic use ; Kidney Transplantation ; immunology

Antibodies ; immunology ; Graft Rejection ; drug therapy ; immunology ; prevention & control ; Graft Survival ; immunology ; Humans

Graft Rejection ; immunology ; Humans ; Immune Tolerance ; Liver ; immunology ; Liver Regeneration ; immunology ; Liver Transplantation ; immunology ; Transplantation, Homologous

OBJECTIVETo review the role of polymorphism of major histocompatibility complex class I-related chain A (MICA) gene and antibodies against MICA antigens in transplant immunology.

DATA SOURCESThe data used in this review were mainly from our own results and from the relevant English language literatures published from 1999 to 2010. Some data presented in this review are in press.

STUDY SELECTIONArticles regarding MICA gene discovery and pioneering finding of antibodies against MICA antigen and allograft rejection were selected. This review chronicles the development of our understanding of the role that MICA antigens and antibodies may play in organ transplantation.

RESULTSPolymorphic glycoprotein MICA antigens were detected on freshly isolated human umbilical cord endothelial cells, but not on peripheral lymphocytes. Antibodies were found and typing of recipients and donors by sequencing the MICA alleles has established that de novo antibodies produced in kidney transplant recipients are directed at mismatched MICA epitopes and are associated with acute rejection and chronic transplant failure. The specificity of antibodies against the epitopes of MICA antigens were well characterized by donor MICA typing, single antigen array testing with antibody absorption and elution. Acute graft-versus-host disease was observed in stem-cell recipients who were mismatched for MICA.

CONCLUSIONSImmunization against mismatched MICA epitopes encountered in donor organs after transplantation may result in antibodies against MICA alleles. Testing for MICA donor-specific antibodies (DSA) which are associated with early failure of kidney transplants may be helpful for identifying some of the targets of antibodies against antigens other than the human leukocyte antigen (HLA) and for improving transplantation outcome.

Antibodies ; immunology ; Graft Rejection ; immunology ; Histocompatibility Antigens Class I ; immunology ; Humans ; Organ Transplantation

Hepatocyte growth factor (HGF) is a pleiotropic cytokine, its roles in the physiology and pathology of immune system, have been investigated thoroughly, great deal of data have been documented on its immunoregulatory activity. In this review, according to advance of study on HGF in recent years, the role of HGF in the immune regulation, such as immunoregulatory effects of HGF on T lymphocytes, B lymphocytes and dendritic cell, modulation of HGF on specific humoral and cellular immune response, control of acute GVHD and acceleration of myeloid and immunologic reconstitution in allogenetic bone marrow transplantation models, promotion of tissue repair and regeneration, and alleviation of immune rejection in allogeneic organ transplantation including the heart, liver and kidney transplantation, prevention of grafts from injury as well as applicably useful of HGF in the therapy of autoimmune disorders were summarized.
Animals ; Graft Rejection ; immunology ; prevention & control ; Graft vs Host Disease ; immunology ; prevention & control ; Graft vs Leukemia Effect ; immunology ; Hepatocyte Growth Factor ; physiology ; Humans ; Immunity, Cellular ; immunology

OBJECTIVETo review the current status and progress on pig islet xenotransplantation.

DATA SOURCESData used in this review were mainly from English literature of Pubmed database. The search terms were "pig islet" and "xenotransplantation".

STUDY SELECTIONThe original articles and critical reviews selected were relevant to this review's theme.

RESULTSPigs are suggested to be an ideal candidate for obtaining available islet cells for transplantation. However, the potential clinical application of pig islet is still facing challenges including inadequate yield of high-quality functional islets and xenorejection of the transplants. The former can be overcome mainly by selection of a suitable pathogen-free source herd and the development of isolation and purification technology. While the feasibility of successful preclinical pig islet xenotranplantation provides insights in the possible mechanisms of xenogeneic immune recognition and rejection to overwhelm the latter. In addition, the achievement of long-term insulin independence in diabetic models by means of distinct islet products and novel immunotherapeutic strategies is promising.

CONCLUSIONSPig islet xenotransplantation is one of the prospective treatments to bridge the gap between the needs of transplantation in patients with diabetes and available islet cells. Nonetheless, further studies and efforts are needed to translate obtained findings into tangible applications.

Animals ; Graft Rejection ; immunology ; prevention & control ; Islets of Langerhans Transplantation ; immunology ; methods ; Swine ; Transplantation, Heterologous ; methods

OBJECTIVETo establish a calculated panel reactive antibody (CPRA) method to analyze the donor-recipient incompatibility rate in PRA-positive kidney recipients and estimate the probability of these recipients to receive kidney transplantation.

METHODSBased on the database of HLA-A, -B, -DR genes and A-B, A-DR, B-DR, A-B-DR haplotype frequencies collected from 2004 donors from Jan 2000 to Dec 2012, we analyzed CPRA in 202 PRA-positive recipients and evaluated the consistency between PRA and CPRA assessments using a CPRA-Java calculator software, which returned a percentage of CPRA (representing the probability of unacceptable HLA in the donor group) after input of HLA-specific antibodies of a PRA-positive recipient.

RESULTSThe mean PRA intensity of the 202 PRA-positive recipients was (23.12∓17.83)% with a mean CPRA% of (46.07∓23.30)%. A significant difference was found between the mean PRA% and CPRA% in low sensitized recipients (PRA 0-10%) [(6.87∓2.41)% vs (21.63∓11.75)%, P<0.05) and in moderately sensitized recipients (PRA 10%-30%) [(20.15∓5.70)% vs (50.56∓16.86)%, P<0.05), but not in highly sensitized recipients (PRA>30%); The concordance rates between PRA% and CPRA% in the 3 groups were 19.35% (P<0.05), 10.99% (P<0.05), and 100% (P>0.05), respectively.

CONCLUSIONSLowly sensitized kidney recipients might have a lower probability of actually receiving a transplant than PRA% shows. A PRA%>30% is a risk factor for kidney transplantation. PRA reflects the sensitized level of a renal recipient, and reliable detection of HLA antibody specificity is of critical importance. CPRA accurately reflects the probability of a recipient to receive a transplant to assist clinicians in predicting the waiting time and selecting the transplant approach.

Antibodies ; Antibody Specificity ; Graft Rejection ; immunology ; Graft Survival ; immunology ; HLA Antigens ; genetics ; Haploidy ; Histocompatibility Testing ; methods ; Humans ; Kidney Transplantation

OBJECTIVETo evaluate the influence of major histocompatibility complex class I chain-related gene A (MICA) antibodies on acute rejection (AR) and renal function in early stage after renal transplantation.

METHODSA total of 197 renal transplant candidates admitted in Nanfang Hospital in 2009-2010 were enrolled in this study. MICA antibodies and their specificity were detected in all the patients, and 139 patients were followed up for early acute rejection (AR) and graft function after transplantation.

RESULTSMICA antibodies were positive before transplantation in 45 candidates (22.84%). Eleven specific MICA antibodies were identified, among which the frequency of MICA019 antibody (65.7%) was significantly higher than that of MICA015 (8.6%) and MICA017 (8.6%) (P<0.01). Eighteen patients with positive MICA antibodies were single-specific and 17 were polyspecific (51.4% vs 48.6% ). Of the 139 patients undergoing renal transplantation, 39 developed early AR (28.1%). Of the 45 candidates positive for MICA antibodies, 38 received renal transplantation and early AR occurred in 14 of them (36.8%); 101 of 152 candidates negative for MICA antibodies underwent renal transplantation, and 25 experienced early AR (24.8%).

CONCLUSIONMICA019 antibody is a frequent MICA antibody possibly due to the high frequency MICA019 gene in Chinese population.

Adult ; Antibodies ; immunology ; Antibody Specificity ; Female ; Graft Rejection ; immunology ; Graft Survival ; immunology ; Histocompatibility Antigens Class I ; genetics ; immunology ; Humans ; Kidney Transplantation ; Male ; Middle Aged

BACKGROUNDAdvances in transplantation immunology show that the balance between dendritic cells (DCs) and their subsets can maintain stable immune status in the induction of tolerance after transplantation. The aim of this study was to investigate if DCs and DC subpopulations in recipient peripheral blood are effective diagnostic indicators of acute rejection following kidney transplantation.

METHODSImmunofluorescent flow cytometry was used to classify white blood cells (WBCs), the levels of mononuclear cells and DCs (including the dominant subpopulations, plasmacytoid DC (pDC) and myeloid DC (mDC)) in peripheral blood at 0, 1, 7, and 28 days and 1 year after kidney transplantation in 33 patients. In addition, the blood levels of interleukin-10 (IL-10) and IL-12 were monitored before and after surgery. Fifteen healthy volunteers served as normal controls. Patients were undertaking hemodialysis owing to uremia before surgery.

RESULTSThe total number of DCs, pDC, and mDC in peripheral blood and the pDC/mDC ratio were significantly lower in patients than controls (P < 0.05). Peripheral DCs suddenly decreased at the end of day 1, then gradually increased through day 28 but remained below normal levels. After 1 year, levels were higher than before surgery but lower than normal. The mDC levels were higher in patients with acute rejection before and 1 day after surgery (P < 0.005). There was no significant difference in IL-10 and IL-12 levels between patients with and without acute rejection.

CONCLUSIONThe changes in DCs and DC subpopulations during the acute rejection period may serve as effective markers and referral indices for monitoring the immune state, and predicting rejection and reasonably adjusting immunosuppressants.

Adolescent ; Adult ; Dendritic Cells ; immunology ; Graft Rejection ; immunology ; Humans ; Kidney Transplantation ; adverse effects ; Middle Aged ; Myeloid Cells ; immunology ; Young Adult