Evaluation and Treatment of Acute Rejection in Kidney Allografts

A Medication Adherence Promotion System to Reduce Late Kidney Allograft Rejection: A Quality Improvement Study

RATIONALE AND OBJECTIVE

Adolescent and young adult kidney transplant recipients have high risk of rejection related to suboptimal adherence. Multi-component interventions improve adherence in controlled trials, but clinical implementation is lacking. We describe an initiative to reduce allograft rejection using evidence-based adherence promotion clinical strategies.

STUDY DESIGN

Interrupted time series.

SETTING AND PARTICIPANTS

Kidney transplant recipients cared for at Cincinnati Children's Hospital ≥1 year post-transplant and taking ≥1 immunosuppressive medication from 2014 through 2017.

QUALITY IMPROVEMENT ACTIVITIES

The following interventions were implemented over 14 months: 1) adherence promotion training for clinical staff, 2) EHR-supported adherence risk screening, 3) systematic assessment of medication adherence barriers, 4) designation of specific staff to address adherence barriers, 5) shared decision-making with the patients to overcome adherence barriers, 6) follow-up to assess progress, 7) optional electronic medication monitoring.

OUTCOMES

Primary Outcome: Late acute rejection. Process measures: barriers assessments performed, barriers identified, number of interventions performed. Secondary outcomes/balancing measures: de novo DSA, biopsy rate, rejections per biopsy.

ANALYTICAL APPROACH

Time series analysis using statistical process control, evaluated patient-days between acute rejections as well as monthly rejections per 100 patient-months before and after implementation. To control for known rejection risk factors including changes in treatment and case mix, multivariable analyses were performed.

RESULTS

The monthly rejection rate fell from 1.61 rejections/100 patient-months in the 26-months pre-implementation to 0.88 rejections/100 patient-months in the 22-months post-implementation. In multivariable analysis, MAPS was associated with a 50% reduction in rejection incidence (IRR 0.50, 95% CI: 0.27-0.91, p=0.02). DSA and time since transplant were also associated with rejection incidence (IRR 2.27, p=0.02 and IRR 0.87, p=0.02, respectively) LIMITATIONS: A single center study. Potential confounding by unmeasured variables.

CONCLUSIONS

Clinical implementation of evidence-based adherence-promotion strategies was associated with a 50% reduction in acute rejection incidence over two years.

Intravenous immunoglobulins do not prove beneficial to reduce alloimmunity among kidney transplant recipients with BKV-associated nephropathy

Reduced immunosuppression during BKV-DNAemia has been associated with T-cell mediated rejection (TCMR), de novo donor-specific antibodies (DSA) and antibody-mediated rejection (ABMR). Intravenous immunoglobulins (IVIG) may reduce alloimmunity. We studied 860 kidney transplant recipients (KTRs) for the development of BKV-DNAuria and BKV-DNAemia (low-level <10 000 IE/ml, high-level >10 000 IE/ml). 52/131 KTRs with high-level BKV-DNAemia received IVIG. The HLA-related immunological risk was stratified by the Predicted Indirectly Recognizable HLA Epitopes (PIRCHE) algorithm. BKV-DNAuria only was observed in 86 KTRs (10.0%), low-level BKV-DNAemia in 180 KTRs (20.9%) and high-level BKV-DNAemia in 131 KTRs (15.2%). KTRs with low-level BKV-DNAemia showed significantly less TCMR compared to KTRs with high-level BKV-DNAemia (5.2% vs. 25.5%; P < 0.001) and no BKV-replication (13.2%; P = 0.014), lowest rates of de novo DSA (21.3%), ABMR (9.2%) and flattest glomerular filtration rate (GFR) slope (-0.8 ml/min). KTRs with low-level BKV-DNAemia showed significantly higher median (interquartile range) total PIRCHE if they developed TCMR [100.22 (72.6) vs. 69.52 (49.97); P = 0.020] or ABMR [128.86 (52.99) vs. 69.52 (49.96); P = 0.005]. Administration of IVIG did not shorten duration of BKV-DNAemia (P = 0.798) or reduce TCMR, de novo DSA and ABMR (P > 0.05). KTRs with low-level BKV-DNAemia showed best protection against alloimmunity, with a high number of PIRCHE co-determining the remaining risk. The administration of IVIG, however, was not beneficial in reducing alloimmunity.

Kidney Transplantation and Diagnostic Imaging: The Early Days and Future Advancements of Transplant Surgery

The first steps for modern organ transplantation were taken by Emerich Ullmann (Vienne, Austria) in 1902, with a dog-to-dog kidney transplant, and ultimate success was achieved by Joseph Murray in 1954, with the Boston twin brothers. In the same time period, the ground-breaking work of Wilhelm C. Röntgen (1895) and Maria Sklodowska-Curie (1903), on X-rays and radioactivity, enabled the introduction of diagnostic imaging. In the years thereafter, kidney transplantation and diagnostic imaging followed a synergistic path for their development, with key discoveries in transplant rejection pathways, immunosuppressive therapies, and the integration of diagnostic imaging in transplant programs. The first image of a transplanted kidney, a urogram with intravenous contrast, was shown to the public in 1956, and the first recommendations for transplantation diagnostic imaging were published in 1958. Transplant surgeons were eager to use innovative diagnostic modalities, with renal scintigraphy in the 1960s, as well as ultrasound and computed tomography in the 1970s. The use of innovative diagnostic modalities has had a great impact on the reduction of post-operative complications in kidney transplantation, making it one of the key factors for successful transplantation. For the new generation of transplant surgeons, the historical alignment between transplant surgery and diagnostic imaging can be a motivator for future innovations.

Treatment of Antibody-Mediated Rejection After Kidney Transplantation: Immunological Effects, Clinical Response, and Histological Findings

Background

Antibody-mediated rejection (AMR) presents with diverse clinical manifestations and can have a potential negative impact on graft function and survival. If not treated successfully, AMR can lead to 20–30% graft loss after 1 year. Little is known about the efficacy of AMR treatment, and the most appropriate therapeutic strategy has not yet been determined. This study evaluated the effects of AMR treatment with plasmapheresis (PP) and intravenous immunoglobulin (IVIG) on renal function, intensity of anti-HLA antibodies, and graft biopsy morphology.

Material/Methods

This single-center retrospective cohort study included renal transplant recipients with biopsy-proven AMR who were treated with PP and/or IVIG. Clinical findings, mean fluorescence intensity of donor-specific anti-HLA antibodies (DSA), and graft histology findings, classified according to Banff score at the time of AMR and 6 and 12 months later, were evaluated.

Results

Of the 42 patients who met the inclusion criteria, 38 (90.5%) received IVIG and 26 (61.9%) underwent PP. At AMR diagnosis, 36 (85.7%) patients had proteinuria, with their estimated glomerular filtration rate remaining stable during follow-up. During the first year, 8 (19.0%) patients experienced graft failure, but none died with a functioning graft. Reductions in the class I panel of reactive antibodies were observed 6 and 12 months after AMR treatment, with significant reductions in DSA-A and -B fluorescence intensity, but no changes in DSA-DQ. Graft biopsy showed reductions in inflammation and C4d scores, without improvements in microvascular inflammation.

Conclusions

AMR treatment reduced biopsy-associated and serological markers of AMR, but did not affect DSA-DQ.

Urinary Biomarkers for Diagnosis and Prediction of Acute Kidney Allograft Rejection: A Systematic Review

Noninvasive tools for diagnosis or prediction of acute kidney allograft rejection have been extensively investigated in recent years. Biochemical and molecular analyses of blood and urine provide a liquid biopsy that could offer new possibilities for rejection prevention, monitoring, and therefore, treatment. Nevertheless, these tools are not yet available for routine use in clinical practice. In this systematic review, MEDLINE was searched for articles assessing urinary biomarkers for diagnosis or prediction of kidney allograft acute rejection published in the last five years (from 1 January 2015 to 31 May 2020). This review follows the Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) guidelines. Articles providing targeted or unbiased urine sample analysis for the diagnosis or prediction of both acute cellular and antibody-mediated kidney allograft rejection were included, analyzed, and graded for methodological quality with a particular focus on study design and diagnostic test accuracy measures. Urinary C-X-C motif chemokine ligands were the most promising and frequently studied biomarkers. The combination of precise diagnostic reference in training sets with accurate validation in real-life cohorts provided the most relevant results and exciting groundwork for future studies.