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

Evaluating the efficacy of basiliximab versus no induction in low-immunological-risk kidney transplant recipients: a propensity score matched analysis

BACKGROUND

The optimal use of induction therapy in low-immunological-risk kidney transplant recipients (KTRs) remains uncertain. While Basiliximab (BSX) is widely utilized, its comparative outcomes with no induction therapy require further evaluation.

METHOD

This single-center retrospective cohort study included 182 low-immunological-risk KTRs who underwent transplantation between January 2022 and March 2023. Patients were assigned to either no induction (n = 41) or BSX induction (n = 141) groups. Propensity score matching (PSM) minimized selection bias and controlled for confounding factors. Primary outcomes included the incidence of first acute rejection (AR) within 12 months, while secondary outcomes encompassed graft function, infection rates, and adverse events.

RESULT

After 12 months, the cumulative AR incidence was comparable between groups (p = 0.46). The no induction group demonstrated superior renal function, with consistently higher estimated glomerular filtration rates (eGFR) at early postoperative intervals. Additionally, this group exhibited reduced infection-related hospitalizations (respiratory infections: 7.32 vs. 29.1%, p = 0.008) and hematological complications (thrombocytopenia: 0.00% vs. 12.8%, p = 0.014). Mortality and graft loss rates were similar between groups.

CONCLUSION

In low-immunological-risk KTRs, no induction therapy achieves comparable AR prevention and renal function outcomes to BSX while reducing infection and hematological complications. These findings challenge the necessity of universal induction therapy in this population and support a personalized approach to immunosuppression protocols.

Role of Induction in a Haplomatch, Related, Low-Risk, Living-Donor Kidney Transplantation with Triple Drug Immunosuppression: A Single-Center Study

BACKGROUND

The role of induction in low-risk, living-donor kidney transplants being treated with tacrolimus, mycophenolate mofetil, and prednisolone is debatable.

MATERIALS AND METHODS

This was a retrospective study that consisted of patients undergoing living kidney transplantation between February 2010 and June 2021 with a related haplomatch donor, with maintenance immunosuppression of tacrolimus, mycophenolate mofetil, and prednisolone. High-risk transplants, such as second or more transplants, immunologically incompatible transplants, and steroid-free transplants, were excluded. Patients were divided into three groups: no induction, basiliximab induction, and thymoglobulin induction, and the outcomes of all three were compared.

RESULTS

A total of 350 transplants were performed. There was a significant difference in the recipient sex distribution (P = 0.0373) and the number of preemptive transplants (P = 0.0272) between the groups. Other parameters were comparable. Biopsy-proven acute rejection (BPAR) was significantly less frequent in the thymoglobulin group than in the no-induction (5.3% vs. 17.5%; P = 0.0051) or basiliximab (5.3% vs. 18.8%; P = 0.0054) group. This persisted even after we performed multivariate regression analysis (thymoglobulin vs. no-induction group, P = 0.0146; thymoglobulin vs. basiliximab group, P = 0.0237). There was no difference in BPAR between the basiliximab and no-induction groups. There were no differences in other outcomes between the groups.

CONCLUSION

In a low-risk haplomatch, related, living-donor kidney transplant on tacrolimus, mycophenolate mofetil, and prednisolone, BPAR was significantly lower with thymoglobulin as opposed to no induction or basiliximab induction with a similar short-term patient and death-censored graft survival and infection rates. Basiliximab did not provide any benefit over no induction.

The use of lymphocyte-depleting antibodies in specific populations of kidney transplant recipients: A systematic review and meta-analysis

BACKGROUND

Recommendations of the use of antibody induction treatments in kidney transplant recipients (KTR) are based on moderate quality and historical studies. This systematic review aims to reevaluate, based on actual studies, the effects of different antibody preparations when used in specific KTR subgroups.

METHODS

We searched MEDLINE and CENTRAL and selected randomized controlled trials (RCT) and observational studies looking at different antibody preparations used as induction in KTR. Comparisons were categorized into different KTR subgroups: standard, high risk of rejection, high risk of delayed graft function (DGF), living donor, and elderly KTR. Two authors independently assessed the risk of bias.

RESULTS

Thirty-seven RCT and 99 observational studies were finally included. Compared to anti-interleukin-2-receptor antibodies (IL2RA), anti-thymocyte globulin (ATG) reduced the risk of acute rejection at two years in standard KTR (RR 0.74, 95%CI 0.61-0.89) and high risk of rejection KTR (RR 0.55, 95%CI 0.43-0.72), but without decreasing the risk of graft loss. We did not find significant differences comparing ATG vs. alemtuzumab or different ATG dosages in any KTR group.

CONCLUSIONS

Despite many studies carried out on induction treatment in KTR, their heterogeneity and short follow-up preclude definitive conclusions to determine the optimal induction therapy. Compared with IL2RA, ATG reduced rejection in standard-risk, highly sensitized, and living donor graft recipients, but not in high DGF risk or elderly recipients. More studies are needed to demonstrate beneficial effects in other KTR subgroups and overall patient and graft survival.

ABO incompatibility in renal transplantation

ABO blood group incompatibility (ABO-I) was historically considered an absolute contraindication to kidney transplantation due to the significant risk of acute antibody-mediated rejection and early graft loss. Nevertheless, the urge to minimize the gap between the candidates' number on the waitlist for kidney transplants and the available kidney donors encourage investigation into finding ways to use organs from ABO-I kidney donors, especially in the era of using more potent immunosuppression therapies. This review aims to discuss a general overview of ABO-I kidney transplantation and the different protocols adopted by some transplant centers to meaningfully overcome this barrier.

Clinical Outcomes of Older Kidney Transplant Recipients

BACKGROUND

Older kidney transplant recipients (OKTR) are vulnerable to infections and AKI, often prompting hospitalization. This study elucidates etiology of hospitalizations, AKI, and outcomes in OKTR.

METHODS

Retrospective study of 500 patients age ≥ 60, who underwent kidney transplantation from 2005-2015. Demographic, transplant, and outcomes data were collected.

RESULTS

OKTR had mean age 66 years; 59% males and 50% African Americans. 62% had at least one hospitalization post-transplant. Predictors of hospitalization were DGF, DM, panel reactive antibodies (PRA), dialysis duration. Hospitalization was mostly due to infection and surgical complications. Average length of stay was 6.4 days. OKTR with at least one hospitalization had 84% higher risk for graft loss (p=0.001). 56% of older kidney transplant recipients had at least one AKI episode post-transplant. Predictors of AKI included DGF, older, African American donor, and tacrolimus variability. The most common etiologies for AKI were infection, dehydration, and GI complications. OKTR with at least one AKI episode had 2.6-fold higher risk for graft loss (p<0.001).

CONCLUSIONS

Post-transplant hospitalization and AKI in OKTR significantly impact graft survival. Addressing comorbidities and risks in the pre-transplant and outpatient setting may help alleviate burden of hospitalization and risk of AKI in OKTR and improve graft outcomes.

18F-FDG PET/CT for Evaluation of Post-Transplant Lymphoproliferative Disorder (PTLD)

Post-transplant lymphoproliferative disorders (PTLD) are a spectrum of heterogeneous lymphoproliferative conditions that are serious and possibly fatal complications after solid organ or allogenic hematopoietic stem cell transplantation. Most PTLD are attributed to Epstein-Barr virus reactivation in B-cells in the setting of immunosuppression after transplantation. Early diagnosis, accurate staging, and timely treatment are of vital importance to reduce morbidity and mortality. Given the often nonspecific clinical presentation and disease heterogeneity of PTLD, tissue biopsy and histopathological analysis are essential to establish diagnosis and most importantly, determine the subtype of PTLD, which guides treatment options. Advanced imaging modalities such as ¹⁸F-FDG PET/CT have played an increasingly important role and have shown high sensitivity and specificity in detection, staging, and assessing treatment response in multiple clinical studies over the last two decades. However, larger multicenter prospective validation is still needed to further establish the clinical utility of PET imaging in the management of PTLD. Significantly, new hybrid imaging modalities such as PET/MR may help reduce radiation exposure, which is especially important in pediatric transplant patients.

Relationship between rabbit anti-thymocyte globulin and development of PTLD and its aggressive form in renal transplant population

Introduction

The aim of our study is to explore the relationship of rabbit anti-thymocyte globulin (R-ATG) on development of post-transplant lymphoproliferative disease (PTLD) and its aggressive forms (monomorphic PTLD and Hodgkin lymphoma) in renal transplant recipients.

Methodology

All patients diagnosed with PTLD post-renal transplant in the United States’ Organ Procurement and Transplantation Network from 2003 till 2013 and followed up till 2017 were retrospectively reviewed. Multi-variable logistic regression analysis assessed association of R-ATG to development of PTLD and its aggressive form.

Results

Risk of developing PTLD post renal transplant is 1.35%. In comparison to interleukin-2 blocker induction therapy, R-ATG is associated with increased risk of development of PTLD (Odds Ratio = 1.48, confidence interval ranges from 1.04 to 2.11, p = .02) and is associated with higher risk of development of aggressive PTLD (Odds Ratio = 1.83, confidence interval ranges from 1.001 to 3.34, p = .04).

Conclusion

We conclude that R-ATG induction is associated with a higher risk of PTLD and its aggressive form (monomorphic PTLD and Hodgkin lymphoma). Careful monitoring for development of PTLD in renal transplant recipients receiving R-ATG induction therapy is advised.