Acute cellular rejection treatment outcomes stratified by Banff grade in pediatric kidney transplant

Follow-up biopsies identify high rates of persistent rejection in pediatric kidney transplant recipients after treatment of T cell-mediated rejection

BACKGROUND

Incomplete resolution of T cell-mediated rejection (TCMR) after treatment may not be detected with serum creatinine monitoring and is associated with donor-specific antibodies and chronic rejection. We evaluate the utility of follow-up biopsies (FUB) to identify and characterize rates of persistent TCMR after treatment in pediatric kidney transplant patients.

METHODS

Patients from two pediatric transplant centers performing standard of care FUB at 1.5-2 months after treatment for TCMR were included. FUB were evaluated for extent of rejection resolution (complete vs. incomplete) and grade. Clinical data at time of FUB and later were reported, where available.

RESULTS

Fifty-eight patients underwent FUB, at mean of 1.7 months (SD 0.7) post-index biopsy. Rejection grade on index biopsy was Banff borderline (≥i1t1 and

CONCLUSIONS

FUB were effective at detecting persistent rejection, which was common among pediatric transplant patients after standard TCMR treatment. Until more effective rejection treatments or sensitive biomarkers are available, FUB may be effectively utilized to identify patients with ongoing rejection who would benefit from further treatment.

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Key Words

• biopsy
• pediatric
• rejection

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MESH Headings

• Humans
• Child
• Kidney Transplantation/adverse effects
• T-Lymphocytes
• Follow-Up Studies
• Biopsy
• Treatment Outcome
• Transplant Recipients
• Graft Rejection
• Kidney/pathology

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Grants

• R01 DK126807 NIDDK NIH HHS

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Affiliation(s)

Adina Landsberg Department of Medicine, University of Calgary, Calgary, AB, Canada
S. Sikandar Raza Department of Pediatrics, University of Alabama Heersink School of Medicine, Birmingham, AL, United States
Michael E. Seifert Department of Pediatrics, University of Alabama Heersink School of Medicine, Birmingham, AL, United States
Tom D. Blydt-Hansen BC Children’s Hospital, Division of Nephrology, Department of Pediatrics, University of British Columbia, Vancouver, BC, Canada

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Indoleamine 2,3-Dioxygenase 1 (IDO1) in Kidney Transplantation: A Guardian against Rejection

Kidney transplantation is a crucial treatment for end-stage kidney disease, with immunosuppressive drugs helping to reduce acute rejection rates. However, kidney graft longevity remains a concern. This study explores the role of indoleamine 2,3-dioxygenase 1 (IDO1) in kidney transplant immunology. IDO1 breaks down tryptophan, affecting immune cell behavior, primarily T-cells. The research focuses on both cellular and antibody-mediated immune responses, often causing graft damage. The study assessed IDO1 expression in renal transplant biopsies from patients with graft function decline, examining its connection to clinical parameters. A total of 121 biopsy samples were evaluated for IDO1 expression using immunohistochemistry. Patients were categorized as IDO1(+) positive or IDO1(-) negative based on immunoreactivity in tubular epithelium. Results showed a significant link between IDO1 expression and rejection incidence. IDO1(+) positive patients had lower rejection rates (32.9%) compared to IDO1(-) negative ones (62.2%) [p = 0.0017], with substantial differences in antibody-mediated rejection (AMR) (5.2% vs. 20%) [p = 0.0085] and T-cell mediated rejection (TCMR) (31.6% vs. 57.8%). These associations suggest that IDO1 may play a protective role in kidney transplant rejection. IDO1 modulation could offer novel therapeutic avenues to enhance graft survival. The study underscores IDO1 as a potential marker for rejection risk assessment, with its potential applications in personalized interventions and improved patient outcomes. Further research is needed to fully comprehend the mechanisms behind IDO1's immunomodulatory functions and its potential clinical translation.

Considerations and controversies of pharmacologic management of the pediatric kidney transplant recipient

Pediatric kidney transplantation has experienced considerable growth and improvement in patient and allograft outcomes over the past 20 years, in part due to advancements in immunosuppressive regimens and management. Despite this progress, care for this unique population can be challenging due to limited pediatric transplant data and trials, intricacies related to differences in children and adolescents compared with their adult counterparts, and limitations to long-term survival facing all solid organ transplant populations. Immunosuppression and infection prevention practices vary from one pediatric transplant center to another and clinical controversies exist surrounding treatment and dosing. This review aims to summarize key aspects of pharmacologic management in this population and present pertinent data that describe the influence of practice to serve as a resource for practitioners caring for this unique specialty patient population. Additionally, this review highlights select controversies that exist within pediatric kidney transplantation.