Low-dose ATG is effective in treatment of acute rejection episodes

Anti-thymocyte globulin for treatment of T-cell-mediated allograft rejection

Anti-thymocyte globulin (ATG) is a pivotal immunosuppressive therapy utilized in the management of T-cell-mediated rejection and steroid-resistant rejection among renal transplant recipients. Commercially available as Thymoglobulin (rabbit-derived, Sanofi, United States), ATG-Fresenius S (rabbit-derived), and ATGAM (equine-derived, Pfizer, United States), these formulations share a common mechanism of action centered on their interaction with cell surface markers of immune cells, imparting immunosuppressive effects. Although the prevailing mechanism predominantly involves T-cell depletion via the com plement-mediated pathway, alternate mechanisms have been elucidated. Optimal dosing and treatment duration of ATG have exhibited variance across ran domised trials and clinical reports, rendering the establishment of standardized guidelines a challenge. The spectrum of risks associated with ATG administration spans from transient adverse effects such as fever, chills, and skin rash in the acute phase to long-term concerns related to immunosuppression, including susceptibility to infections and malignancies. This comprehensive review aims to provide a thorough exploration of the current understanding of ATG, encom passing its mechanism of action, clinical utility in the treatment of acute renal graft rejections, specifically steroid-resistant cases, efficacy in rejection episode reversal, and a synthesis of findings from different eras of maintenance immunosuppression. Additionally, it delves into the adverse effects associated with ATG therapy and its impact on long-term graft function. Furthermore, the review underscores the existing gaps in evidence, particularly in the context of the Banff classification of rejections, and highlights the challenges faced by clinicians when navigating the available literature to strike the optimal balance between the risks and benefits of ATG utilization in renal transplantation.

One-Year Outcomes with Use of Anti-T-Lymphocyte Globulin in Patients Undergoing Kidney Transplantation: Results from a Prospective, Multicentric, Observational Study from India

INTRODUCTION

Large-scale Indian data on the use of anti-T-lymphocyte globulin (ATLG) (Grafalon^®) as induction therapy in kidney transplantation (KT) patients is lacking. The aim of this study was to determine the 1-year patient and graft survival outcomes with the use of ATLG as induction regimen in KT.

METHODS

In a prospective, multicentric, observational study, adult patients who underwent ABO-compatible KT and had received ATLG as a part of induction were included in the study. The primary outcome measure was overall survival and death-censored graft survival at 12 months. The primary safety outcome was assessed by development of infectious complications and graft rejection.

RESULTS

In total, 359 patients were included in this study. The mean age was 42.77 ± 12.30 years and 83% were male. The average ATLG dose per patient was 6.2 ± 2.2 mg/kg whereas average cumulative dose per patient was 389.6 ± 149.8 mg. The rate of graft dysfunction was 13.4% of patients and 6.7% had biopsy-proven acute rejection (BPAR). There were a total of 12 (3.3%) deaths and one graft loss. Overall survival and death-censored graft survival at 12 months were 96.65% and 99.44%, respectively. The rate of infections was 13.6% with urinary tract infections being most common.

CONCLUSION

ATLG at an average dose of 6 mg/kg is an effective and safe induction regimen immunosuppressant for ABO-compatible KT with favourable impact on survival and graft function in Indian patients.

Rabbit anti-thymocyte globulin (rATG) versus IL-2 receptor antagonist induction therapies in tacrolimus-based immunosuppression era: a meta-analysis

BACKGROUND

The aim of this meta-analysis is to explore the effect of IL-2RA vs rATG on the rate of acute rejection, post-transplant infections, and graft as well as patient's survival in standard- and high-risk renal transplant patients receiving tacrolimus-based maintenance immunotherapy.

METHODS

Random effects model was the method used for identifying risk difference. Confidence interval including the value 1 was used as evidence for statistically significant risk difference. Heterogeneity was assessed using Der Simonian analysis. Heterogeneity was evident at the level of P value < 0.1 RESULTS: The random effects model showed no significant differences in both acute rejection rates between IL-2RA and rATG induction therapies with relative risk of 1.24 graft survival with relative risk 0.90. Patient survival also did not demonstrate any significant difference with a relative risk of 1.19. Random effects for CMV infection showed a lesser tendency for CMV infection in IL-2RA group compared to ATG group the with a relative risk of 0.73.In subgroup analysis, the random effects model for acute rejection rates in high-risk transplants showed a higher risk of acute rejection in the IL-2RA group compared to rATG (relative risk equals 1.55) In standard-risk transplants, there were no significant differences between both groups with relative risk equals 1.02 CONCLUSIONS: This meta-analysis revealed no significant difference in patient and graft survival when using IL-2RA vs rATG with the tacrolimus-based maintenance immunosuppression era. However, subgroup analysis showed less incidence of rejection in high-risk renal transplant recipient's population using rATG compared to IL-2RA.

Outcome of pediatric renal transplants in a developing country

This study was conducted to evaluate the outcome of pediatric renal transplants at our center. A retrospective analysis was done on 39 pediatric transplants (age at transplant <18 years) done at our center over the last 10 years. The mean age at transplant was 15.6+/-1 years (10-17 years). They comprised 4.2% of all renal transplants done at our center (39/921) over the period. Girls comprised 17.5% of total recipients ( n=7). Two patients had a preemptive transplant. The underlying causes of end stage renal disease were chronic glomerulonephritis ( n=21), chronic interstitial nephritis ( n=17) and Alport syndrome [1]. All the 39 children were initiated on triple drug immunosuppression (cyclosporin A (CsA) azathioprine, prednisolone). All patients received grafts from living related donors. In the first month, three patients had graft loss (serum creatinine, SCr, >5 mg/dl). Of these, two patients died because of septicemia and one had acute cortical necrosis. There was evidence of infection in 16 patients (40%). Acute rejection was seen in 17 patients (45.8%). The 1-year patient and graft survival was 89% and at 3 years 70%. The actuarial graft survival at 5 years was 50%. Twelve children discontinued CsA after 1 year post-transplant and five of these had graft loss. Graft losses were significantly greater in patients who discontinued CsA as compared to those who continued CsA (5/12 vs 2/22). After a mean follow-up of 31.5+/-3.5 months, of the 37 patients, 10 had graft loss and chronic graft dysfunction was observed in another 9 patients. The rest of the 17 (48%) patients had a mean SCr of 1.2 mg/dl. The long-term outcome of pediatric renal transplants in our country remains suboptimal. CsA discontinuation due to financial constraints and/or non-compliance remain the most important reasons for this.