Background The 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.
Methods A 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).
Results Despite 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.
Conclusions Application 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.
相似文献Background Immunosuppression for immunologically high-risk kidney transplant patients usually involves antithymocyte globulin induction with triple drug maintenance therapy. Alemtuzumab, a humanized anti-CD52 antibody, was expected to be a promising induction therapy agent for kidney transplantation. However, currently no consensus is available about its efficacy and safety. This study aimed to evaluate the efficacy and safety of alemtuzumab as immune induction therapy in highly sensitized kidney transplant recipients.
Methods In this prospective, open-label, randomized, controlled trial, we enrolled 23 highly immunological risk patients (panel reactive antibody >20%). They were divided into two groups: alemtuzumab group (trial group) and anti-thymocyte globulin (ATG) group (control group). Patients in the alemtuzumab group received intravenous alemtuzumab (15 mg) as a single dose before reperfusion. At the 24th hour post-operation, another dosage of alemtuzumab (15 mg) was given. The control group received a bolus of rabbit ATG (9 mg/kg), which was given 2 hours before kidney transplantation and lasted until the removal of vascular clamps when the anastomoses were completed. Maintenance immunosuppression in both groups comprised standard triple therapy consisting of tacrolimus, prednisone, and mycophenolate mofetil (MMF). Acute rejection (AR) and infection episodes were recorded, and kidney function was monitored during a 2-year follow-up. χ2 test, t test and Kaplan-Meier analysis were performed with SPSS17.0 software.
Results Median follow-up was 338 days. In both the alemtuzumab group and ATG group, creatinine and blood urea nitrogen values in surviving recipients were similar (P >0.05). White blood cell counts were significantly reduced in the alemtuzumab group for the most time points up to 6 months (P <0.05). One patient receiving alemtuzumab died for acute myocardial infarction at the 65th day post-operation. Two ATG patients died for severe pulmonary infection or cardiac and pulmonary failure. Cumulative 2-year graft survival rate was 90.9% in the alemtuzumab group and 81.8% in ATG group (P >0.05) respectively. There was one graft failure in the alemtuzumab group and two graft failures in ATG group, with all graft failures at tributed to rejection episodes. The alemtuzumab group had a 2-year cumulative freedom from rejection rate of 81.8%, compared with 72.7% for the ATG group (P >0.05).
Conclusion Alemtuzumab induction therapy for highly sensitized kidney transplant recipients is an effective and safe protocol yielding an acceptable acute rejection rate.
相似文献Methods We 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.
Results Presensitized 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 〉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 ,0=-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.
Conclusions Pre-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. 相似文献
Background Sensitized recipients have a high risk of immunological graft loss due to hyperacute rejection and/or accelerated acute rejection. The presence of major histocompatibility complex class I-related chain A (MICA) antibodies has also been described associated with an increased rate of kidney-allograft rejection. The aim of this study was to describe the expression of MICA antibodies in sensitized recipients of renal transplantation and evaluate its influence on the kidney transplantation recipients.
Methods A total of 29 sensitized recipients were included in this study. All patients received the MICA antibodies detection before and after protein A immunoadsorption. Panel reactive antibody (PRA), HLA-matches, acute rejection and postoperative one to four-week serum creatinine level were also collected and analyzed, respectively. No prisoners were used in this study.
Results Eight patients (27.6%) in all 29 sensitized recipients expressed the MICA antibodies but did not show higher acute rejection rate than the non-expressed patients (3/8, 37.5% vs. 8/21, 38.1%; P=1.000). Recipients with PRA >40% showed higher expression levels of MICA antibodies than the recipients with PRA <40% (7/16, 43.8% vs. 1/13, 8.3%; P=0.044). HLA mismatch did not have any effect on the expression of MICA antibodies (P=1.000). MICA antibodies positive group had higher serum creatinine level than the control in postoperative one week ((135.4±21.4) µmol/L vs. (108.6±31.6) µmol/L, P=0.036), but no significant difference in postoperative four weeks ((89.0±17.1) µmol/L vs. (77.1±15.9) µmol/L, P=0.089). MICA antibodies decreased significantly after protein A immunoadsorption.
Conclusions MICA antibodies increase in the sensitized recipients, which have significant effects on the function of allograft in early postoperative period. Protein A immunoadsorption can decrease MICA antibodies effectively in sensitized recipients.
相似文献Methods Seven highly sensitized recipients of living-related renal transplants （4 men and 3 women, mean aged 42.5 years old （range 33-51）） were pretreated with this combination. Human leukocyte antigen （HLA） mismatch number was 2-5. Panel reactive antibody （PRA） of class Ⅰwas high in 2 cases and that of class Ⅱwas high in 1 case. All patients were pretreated with immunoadsorption 2-10 times. Immunoglobulin and PRA changes were monitored before and after absorption. The operation was conducted when PRA or immunoglobulin levels were at or below normal levels. Immunosuppressive drugs were provided 3-5 days before the operation, and one dose of RTX （375 mg/m^2） was infused with polyclonal antibody on the day of operation. Postoperative creatinine （Cr）, creatinine clearance rate （Ccr）, PRA ratio, and immunoglobulin changes were monitored.
Results All 7 patients had good recovery without delayed graft function. Acute rejection occurred in 3 cases at postoperative days 8, 10, and 14, respectively. The Banff 07 biopsy grades were la in 1 case and lla C4d0 in 2 cases. Successful reversion was achieved after giving methylprednisolone or antithymocyte immunoglobulin ＋ cyclophosphamide. All patients were discharged with normal renal function, mean class Ⅰ PRA was 14% and mean class ⅡPRA was 35%. PRA was completely negative in 3 cases.
Conclusion Protein A immunoadsorption combined with RTX can safely reduce the occurrence of humoral rejection in highly sensitized renal transplant recipients. 相似文献
Methods A cohort of 45 patients following cadaveric renal allograft transplantation were randomly divided into 3 groups based on the regimen of combination of tacrolimus, steroid, and MMF： triple therapy group, steroid withdrawal group, and MMF withdrawal group. During 2 years, survival of patients and allografts, clinical acute rejection, adverse events, hepatic and renal allograft function, and blood lipids were monitored to evaluate the safety and feasibility of steroid or MMF withdrawal after renal transplantation.
Results During two-year observation, steroid or MMF was successfully withdrawn from immunosuppressant regimen based on tacrolimus without any clinical acute rejection renal allografts kept excellent function. Some adverse events among groups. Patient and graft survival rates were 100% and all the occurred and there were no significant differences
Conclusion Withdrawal of steroid or MMF in low-immunological-risk renal allografts treated with tacrolimus-based immunosuppressant regimen can be achieved with no increased risk of acute rejection. 相似文献