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

BACKGROUNDRenal transplantation in sensitized candidates remains a highly significant challenge worldwide. The production of panel reactive antibody (PRA) against human leukocyte antigen (HLA) is a major risk factor in presensitized recipients. The aim of this study was to evaluate the impact of HLA matching and recipients' PRA on two-year outcome in presensitized renal allograft recipients.

METHODSWe determined the percentage of panel reactivity and specificity of anti-HLA immunoglobulin (Ig) G antibodies in 73 presensitized renal allograft recipients compared with 81 unsensitized recipients (control group). HLA genotyping of both recipients and corresponding donors was performed by PCR with sequence-specific primers (PCR-SSP). We analyzed the factors influencing the early graft outcome (two-year rejection rates and survival rates of the grafts), including HLA mismatching, class and degree of panel reactivity, and target antigen of donors.

RESULTSPresensitized recipients had a worse two-year outcome than unsensitized recipients (P = 0.019 for rejection rate, P = 0.01 for survival rate). The difference in number of HLA-mismatched alleles with either 6-antigen matching (Ag M) standard or amino acid residue matching (Res M) standard was not significant between the rejection and non-rejection groups of presensitized recipients or between the graft survival group and graft loss group. Compared with the control group, recipients with both PRA-I and PRA-II antibodies had a significantly worse two-year outcome (P = 0.001 for rejection rate, P = 0.002 for survival rate). The two-year outcomes of the peak PRA >/= 50% group and its subgroup, at-transplant PRA > or = 50% group, were significantly worse compared with the control group (P = 0.025 and P = 0.001 for rejection rate, P = 0.043 and P = 0.024 for survival rate). The rejection rates of the at-transplant target antigen positive group and its subgroup, HLA-I target antigen positive group, were significantly higher than the control group (P = 0.001 and P = 0.001), target antigen negative group (P = 0.003 and P = 0.001), and peak target antigen positive with negative at-transplant target antigen group (P = 0.024 and P = 0.002). Two-year graft survival rates of the target antigen positive group and HLA-I target antigen positive group were significantly lower than the control group (P = 0.012 and P = 0.001). The two-year outcome of target antigen unknown group was similar to that of the target antigen positive group. Presensitized recipients with pre-transplant plasmapheresis or immunoadsorption (PRA prepared group) had a better but non-significant two-year outcome than the control group. However, the PRA unprepared presensitized recipients were different to the control group (P = 0.004 for rejection rate and P = 0.005 for survival rate). Hyperacute rejection (HR) occurred in three recipients with positive HLA-I target antigen and without mismatch according to Res M and in one case with positive PRA-II (for an unknown target antigen). No HR occurred in eight cases with positive HLA-II target antigens.

CONCLUSIONSPre-transplant PRA preparations might improve the access of presensitized patients to renal donors. Avoiding antigen-positive donors remains a fundamental measure in preventing HR and early rejections.

Adult ; Enzyme-Linked Immunosorbent Assay ; Female ; Graft Rejection ; immunology ; Graft Survival ; immunology ; HLA Antigens ; immunology ; Histocompatibility Testing ; Humans ; Isoantibodies ; blood ; Kidney Transplantation ; adverse effects ; immunology ; mortality ; Male ; Middle Aged ; Transplantation, Homologous ; immunology ; Treatment Outcome

No abstract available.
Animals ; Antigen-Presenting Cells/immunology ; Graft Rejection/immunology/*prevention & control ; Graft Survival ; *Histocompatibility ; Humans ; Immunosuppression/*methods ; Intercellular Adhesion Molecule-1/immunology ; Isoantigens/*immunology ; Organ Transplantation/*adverse effects ; *Transplantation Tolerance

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

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

OBJECTIVETo investigate the correlation between major histocompatibility complex (MHC) class I chain-related gene A (MICA) gene alleles matching rates and graft rejection in small intestine, liver and kidney transplantation.

METHODSGenome DNA were extracted from blood samples or pathological sections collected from donors and recipients of living-related transplantation, included 4 cases of small bowel transplantation, 5 cases of liver transplantation and 6 cases of kidney transplantation. The correlation between MICA alleles matching rates and acute graft rejection was analyzed following 13 MICA alleles determination by polymerase chain reaction based on sequence-specific primers (PCR-SSP).

RESULTSHLA zygosity of all donors and recipients was confirmed to be half-matching. The recipients displaying higher matching rates of MICA alleles with donors showed lighter clinical and pathological rejection and longer survival time. On the contrary, recipients with lower matching rates of MICA alleles with donors showed severer clinical and pathological rejection and shorter survival time relatively.

CONCLUSIONMatching rates of MICA alleles has negative relevance to acute rejection, and positive relevance to survival time of recipients in small bowel, liver, and kidney transplantation.

Alleles ; Graft Rejection ; genetics ; immunology ; Histocompatibility Antigens Class I ; genetics ; Humans ; Intestine, Small ; transplantation ; Kidney Transplantation ; immunology ; Liver Transplantation ; immunology ; Living Donors ; Organ Transplantation

Human tissue typing methods were employed in developing a porcine allotransplantation model. 23 Chinese Sichuan White Pigs(2-3 months old, 17.5+/-4.6kg, with clear family background) were selected for tissue typing, ABO blood type cross reaction, complement-dependent cytotoxicity (CDC) cross reaction and one way mixed lymphocyte reaction (MLR). 6 pairs of swine that showed better matching results were selected as donors and recipients. Single-kidney orthotopic transplantation was conducted after removing both kidneys of the recipient. Five recipients showed low matching results (MLR ranging from 2175 to 3560, CDC from 1 to 4); of them, 2 died of operation, 2 died of acute renal tubular necrosis and accelerating rejection 4 days after operation respectively, and 1 died of acute renal tubular necrosis 4 days after operation. 6 recipients showed high matching results (MLR ranging from 982 to 1916, CDC from 2 to 4); of them, 1 died of anaesthesia during operation, 3 died of accelerating rejection and acute rejection 2 weeks after operation respectively, 1 had good kidney function, and 1 presented weak rejection 1 week after operation but the kidney function came back to normal afterwards. Human tissue typing methods could be adopted in developing the porcine model. Hyperacute rejection could be avoided by screening ABO blood type, CDC and MLR tests. However, based on these primary data, it was hard to evaluate the predictive values of CDC and one-way MLR for accelerating rejection, acute rejection and graft chronic dysfunction. Further research by expanding experiments in these aspects is still going on.
ABO Blood-Group System ; immunology ; Animals ; Cytotoxicity Tests, Immunologic ; Graft Rejection ; prevention & control ; Histocompatibility Testing ; Kidney Transplantation ; immunology ; Swine ; T-Lymphocytes ; immunology ; Transplantation, Homologous ; immunology

BACKGROUND: The success of allogeneic bone marrow transplantation(allo-BMT) is affected by underlying disease relapse. Although mixed chimerism(MC) is not necessarily a poor prognostic factor, several groups have suggested that MC is associated with an increased risk of disease relapse. There is evidence that patients with MC benefit from additional immunotherapy if the treatment is started in minimal residual disease status(mixed chimerism status), not in frank hematological relapse. The purposes of this study are to evaluate 1) the risk for relapse or graft rejection in correlation to persistent MC status after allo-BMT, and 2) the possibility of preventing relapse by immune modulation treatments (withdrawal or rapid taper-off of post-transplant immuno-suppression, additional interferon treatment, or the administration of donor lymphocytes) in hematologic malignancies. PATIENTS AND METHODS: Of 337 allogeneic donor-recipient pairs between March 1996 and August 1998, 12 patients who showed persistent or progressive MC and who received immune modulation treatments were evaluated. Twelve patients, median age 31 years(range 9 to 39 years), received an allo-BMT for: acute myelogenous leukemia(AML, n = 5), chronic myelogenous leukemia(CML, n = 4), acute lymphocytic leukemia(ALL, n = 3). Serial polymerase chain reaction(PCR) analysis of YNZ 22-, 33.6-minisatellites or Y chromosome-specific PCR analysis at short term intervals(pre- and post-transplant 1, 3, 6, 9, ... months) was performed. Once MC was detected, immune modulation treatments on the basis of increasing MC in an early phase of recurrence of underlying disease were started. RESULTS: Nine of 12 patients converted to complete chimerism(CC) (AML 5/5, CML 3/4, ALL 1/3). Four of 9 CC patients developed graft-versus-host disease(GVHD) grade < or = 2 during immune modulation. All were treated successfully with steroids. Three patients who were not converted to CC showed relapse of underlying diseases or graft failure. CONCLUSION: The results demonstrate that, in patients with hematologic malignancies after allo-BMT, persistent MC is associated with relapse of underlying diseases or graft failure. Furthermore, when patients receive early immune modulation treatment, MC can be changed to complete donor pattern chimerism and ultimately prevent relapse.
Adolescence ; Adult ; Bone Marrow Transplantation/immunology* ; Child ; Chimera ; Female ; Graft vs Host Disease/etiology* ; Histocompatibility Testing ; Human ; Leukemia/therapy* ; Leukemia/mortality ; Male ; Polymerase Chain Reaction ; Polymorphism, Restriction Fragment Length ; Recurrence ; Transplantation, Homologous

We examined the effect of class II transactivator (CIITA) down-modulation on allograft rejection. To inhibit the function of CIITA, we constructed a series of CIITA mutants and found one exhibiting the dominant-negative effect on the regulation of major histocompatibility complex (MHC) class II expression. To test whether the CIITA dominant-negative mutant reduces immunogenecity, CIITA-transfected melanoma cells were injected into allogeneic host and assessed for immune evading activity against host immune cells. We demonstrated that the CIITA dominant-negative mutant allowed tumor nodules to develop earlier in the lung than control by this tumor challenge study. Furthermore, skin grafts deficient for CIITA also survived longer than wild-type in allogeneic hosts. Both the tumor challenge and skin graft studies suggest the inhibition of CIITA molecules in donor tissue would be beneficial to the control of allo-response.
Transplantation, Homologous ; Transfection ; Trans-Activators/genetics/*immunology/metabolism ; Trans-Activation (Genetics)/genetics/immunology ; Skin Transplantation ; Nuclear Proteins/genetics/*immunology/metabolism ; Mutation ; Mice, Transgenic ; Mice, Knockout ; Mice, Inbred C57BL ; Mice, Inbred BALB C ; Mice ; Melanoma, Experimental/genetics/immunology/pathology ; Male ; Interferon Type II/pharmacology ; Humans ; Histocompatibility Antigens Class II/genetics/*immunology/metabolism ; Graft Survival/genetics/immunology ; Graft Rejection/genetics/*immunology ; Genes, MHC Class II/genetics/immunology ; Flow Cytometry ; DNA, Complementary/genetics ; Cell Proliferation/drug effects ; Cell Line, Tumor ; Animals