Hart, Allyson

Abstract Background Antibody‐mediated rejection (AMR) is a leading cause of kidney allograft failure, but its incidence, risk factors, and outcomes are not well understood. Methods We searched Ovid MEDLINE, Cochrane, EMBASE, and Scopus from January 2000 to January 2020 to identify published cohorts of ≥500 incident adult or 75 pediatric kidney transplant recipients followed for ≥1 year post‐transplant. Results At least two reviewers screened 5061 articles and abstracts; 28 met inclusion criteria. Incidence of acute AMR was 1.1%‐21.5%; most studies reported 3%‐12% incidence, usually within the first year post‐transplant. Few studies reported chronic AMR incidence, from 7.5%‐20.1% up to 10 years. Almost all patients with acute or chronic AMR received corticosteroids and intravenous immunoglobulin; most received plasmapheresis, and approximately half with rituximab. Most studies examining death‐censored graft failure identified AMR as an independent risk factor. Few reported refractory AMR rates or outcomes, and none examined costs. Most studies were single‐center and varied greatly in design. Conclusions Cohort studies of kidney transplant recipients demonstrate that AMR is common and associated with increased risk of death‐censored graft failure, but studies vary widely regarding populations, definitions, and reported incidence. Gaps remain in our understanding of refractory AMR, its costs, and resulting quality of life.

Background and objectives Dialysis is a preference-sensitive decision where prognosis may play an important role. Although patients desire risk prediction, nephrologists are wary of sharing this information. We reviewed the performance of prognostic indices for patients starting dialysis to facilitate bedside translation. Design, setting, participants, & measurements Systematic review and meta-analysis following the PRISMA guidelines. We searched Ovid MEDLINE, Ovid Embase, Ovid Central Register of Controlled Trials, Ovid Cochrane Database of Systematic Reviews, and Scopus for eligible studies of patients starting dialysis published from inception to December 31, 2018. Selection Criteria: Articles describing validated prognostic indices predicting mortality at the start of dialysis. We excluded studies limited to prevalent dialysis patients, AKI and studies excluding mortality in the first 1–3 months. Two reviewers independently screened abstracts, performed full text assessment of inclusion criteria and extracted: study design, setting, population demographics, index performance and risk of bias. Pre-planned random effects meta-analysis was performed stratified by index and predictive window to reduce heterogeneity. Results Of 12,132 articles screened and 214 reviewed in full text, 36 studies were included describing 32 prognostic indices. Predictive windows ranged from 3 months to 10 years, cohort sizes from 46 to 52,796. Meta-analysis showed discrimination area under the curve (AUC) of 0.71 (95% confidence interval, 0.69 to 073) with high heterogeneity ( I 2 =99.12). Meta-analysis by index showed highest AUC for The Obi, Ivory, and Charlson comorbidity index (CCI)=0.74, also CCI was the most commonly used (ten studies). Other commonly used indices were Kahn-Wright index (eight studies, AUC 0.68), Hemmelgarn modification of the CCI (six studies, AUC 0.66) and REIN index (five studies, AUC 0.69). Of the indices, ten have been validated externally, 16 internally and nine were pre-existing validated indices. Limitations include heterogeneity and exclusion of large cohort studies in prevalent patients. Conclusions Several well validated indices with good discrimination are available for predicting survival at dialysis start.