Multivariate Analysis of the Effectiveness of Using Antibody Induction Therapy According to the Degree of HLA Mismatches

The impact of induction therapy in low-immunological risk kidney transplant recipients regardless of HLA matching

BACKGROUND

Induction agents have proved to reduce the rate of acute rejection (AR) in kidney transplant recipients (KTRs) without improving long-term graft and patient survival (PS).

OBJECTIVE

This study evaluates the utility of induction therapy in low immunological risk KTRs regardless of donor-to-recipient HLA matching.

METHODS

We retrospectively reviewed the records of 218 patients undergoing kidney transplantation (KT). These patients were divided into two groups according to the usage of induction therapy: 82 did not receive any induction therapy (Group I), and 136 patients received either Anti-IL2 receptor antibodies or anti-thymocyte globulin (Group II). All patients had panel reactive antibody (PRA) < 20% and absence of donor-specific antibodies (DSA). The difference in outcomes were assessed at different intervals following KT.

RESULTS

The rate of bacterial infections at one year (p-value = 0.032) and the frequency of CMV disease (p-value = 0.044) were significantly higher in Group II (with induction therapy). The duration of hospital stay, the rate and severity of acute rejection, the occurrence of delayed graft function, the rate and type of surgical complications at one year, and the graft function and survival at one and three years were similar between the two groups (p-value = NS). In addition, the financial burden is much less in Group I (without induction therapy), reducing the total cost of the transplant procedure.

CONCLUSION

We conclude that induction therapy in low-immunological risk kidney transplant patients is not a must regardless of donor-to-recipient HLA matching. Therefore, induction therapy did not yield significant health results, but had negative financial consequences.

Effects of antibody induction on transplant outcomes in human leukocyte antigen zero-mismatch deceased donor kidney recipients

BACKGROUND

We aimed to investigate the impact of antibody induction on outcomes in human leukocyte antigen (HLA) 0-mismatched deceased donor kidney recipients.

METHODS

Using the Organ Procurement and Transplant Network/United Network of Organ Sharing database as of November 2009, we identified 44,008 adult deceased donor kidney recipients who received primary kidney transplants alone between 2003 and 2008 (HLA 0 mismatch, n = 6274; ≥ 1 mismatch, n=37,734; median follow-up: 834 days). The impact of induction (thymoglobulin, interleukin-2 receptor antagonists [IL-2RA], or alemtuzumab; vs. no induction) on rejection (initial hospitalization, 6 months, first year), death-censored graft failure, and mortality were analyzed using multivariate logistic and Cox regression in the two groups. The impact of individual agents on outcomes was further analyzed in 0-mismatch recipients.

RESULTS

There was a decreased risk of rejection over the first 6 months for HLA 0-mismatch recipients of antibody induction (adjusted odds ratio=0.71, P=0.003), but this effect was not observed at 1 year; in comparison, induction was associated with a reduced risk of rejection over the first year for HLA-mismatched recipients (0.87, P<0.001). The use of thymoglobulin (0.72, P=0.02) and IL-2RA (0.67, P=0.004) was associated with a decreased risk of rejection compared with no-induction at 6 months but was not different at 1 year (thymoglobulin: 0.77, P=0.05; IL-2RA:0.81, P=0.11) in HLA 0-mismatched recipients. Induction was not associated with improved graft or patient survival in HLA 0-mismatch recipients.

CONCLUSION

In HLA 0-mismatch deceased donor recipients, antibody induction was associated with a decreased risk of rejection at 6 months posttransplant. Its use did not improve graft and patient survival over the follow-up period.

Multivariate analysis of antibody induction therapy and their associated outcomes in live donor kidney transplantation in the recent era

The majority of kidney transplant recipients in the United States receive antibody induction, but its impact on outcomes in living donor transplant is not well-described. We used Organ Procurement and Transplant Network/United Network for Organ Sharing (OPTN/UNOS) data as of November 2009 to compare acute rejection (AR) and graft survival among all primary adult living donor kidney recipients of no antibody induction, antithymocyte globulin (ATG) and interleukin-2 receptor antagonists (IL-2RA) in an earlier era (1998-2002; n=21,919) and a later era (2003-2008, n=26,837). The incidence of AR in the overall cohort decreased from 18.5% in 1998 to 8% in 2008. From 1998 to 2002, antibody induction was associated with a decreased risk of acute rejection at six months (RR 0.67, 95% CI 0.62-0.72) and one yr (RR 0.71, 0.65-0.76), while in the recent era, induction was not associated with acute rejection at six months (RR 0.97, 0.88-1.07) or one yr (RR 1.01, 0.91-1.10). There was no difference in graft survival over five yr with antibody induction in either era. Although antibody induction was associated with a decreased risk of AR from 1998 to 2002, it was not associated with a decreased risk of acute rejection from 2003 to 2008, nor was it associated with a difference in graft survival in either era.

Impact of human leukocyte antigen-DR mismatch status on kidney graft survival in a predominantly African-American population under the newer immunosuppressive era

BACKGROUND

Human leukocyte antigen (HLA)-DR has been shown to be immunogenic and associated with poor long-term graft function. However, under potent induction immunosuppression with antithymocyte globulin, the impact of the HLA-DR remains unclear.

METHOD

We reviewed 672 renal transplant recipients who received their transplants between 1998 and 2007. All patients received antithymocyte globulin as induction therapy followed by tacrolimus + prednisone + mycophenolate mofetil for maintenance immunosuppression. We divided the patients into three groups according to HLA-DR mismatch status (zero, one, or two mismatches).

RESULTS

The three groups were different in total number of mismatches, deceased donor transplant, and delayed graft function, respectively. By Kaplan-Meier survival analysis, actuarial graft survival was significantly lower in the HLA-DR two mismatches group (72%) compared to HLA-DR zero mismatches group (78.5%) or HLA-DR one mismatch group (78.5%; P = .05, by log-rank test). Using Cox regression analysis, the risk of graft failure with two HLA-DR mismatches as compared with zero HLA-DR mismatches was 1.6 (95% confidence interval = 1.0-2.44, P = .049). When adjusted for age, wait time, race, type of transplant, retransplant status, T-cell flow crossmatch, delayed graft function, acute rejection, HLA-A and HLA-B, the effect of HLA-DR on survival was not significant (P = .55).

CONCLUSION

The independent effect of HLA-DR mismatches on adverse graft survival is diminished under potent antibody induction and maintenance immunosuppression in our predominantly African-American population.

Induction therapy: why, when, and which agent?

The long-term outcome of paediatric transplantation has improved over the last decade with an increase in the armamentarium of immunosuppressive agents. However, the battle against the hostile immune response at the time of and after transplantation continues. Induction therapy can reduce early injury, to optimize the long-term allograft survival. The goal of induction immunosuppression in paediatric transplantation is to permit the use of lower doses of maintenance immunosuppressive agents without increased rates of acute allograft rejection and chronic allograft damage. The aim of this review is to summarize the current literature relating to the use of antibody agents for induction in paediatric solid organ transplantation.