Use of a new end-stage kidney disease risk calculator in the Kidney Disease Improving Global Outcomes guideline to evaluate the impact of different living kidney donor candidate assessments

Long-term Medical Outcomes of Living Kidney Donors

Historically, to minimize risks, living kidney donors have been highly selected and healthy. Operative risks are well-defined, yet concern remains about long-term risks. In the general population, even a mild reduction in glomerular filtration rate (GFR) is associated with cardiovascular disease, chronic kidney disease, and end-stage kidney disease (ESKD). However, reduction in GFR in the general population is due to kidney or systemic disease. Retrospective studies comparing donors with matched general population controls have found no increased donor risk. Prospective studies comparing donors with controls (maximum follow-up, 9 years) have reported that donor GFR is stable or increases slightly, whereas GFR decreases in controls. However, these same studies identified metabolic and vascular donor abnormalities. There are a few retrospective studies comparing donors with controls. Each has limitations in selection of the control group, statistical analyses, and/or length of follow-up. One such study reported increased donor mortality; 2 reported a small increase in absolute risk of ESKD. Risk factors for donor ESKD are similar to those in the general population. Postdonation pregnancies are also associated with increased risk of hypertension and preeclampsia. There is a critical need for long-term follow-up studies comparing donors with controls from the same era, geographic area, and socioeconomic status who are healthy, with normal renal function on the date matching the date of donation, and are matched on demographic characteristics with the donors. These data are needed to optimize donor candidate counseling and informed consent.

Outcomes of Living Kidney Donor Candidate Evaluations in the Living Donor Collective Pilot Registry

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Background.

Gaps in our knowledge of long-term outcomes affect decision making for potential living kidney donors.

Methods.

The Scientific Registry of Transplant Recipients was asked to determine the feasibility of a candidate registry.

Results.

Ten living kidney donor programs evaluated 2107 consecutive kidney donor candidates; 2099 of 2107 (99.6%) completed evaluations, 1578 of 2099 (75.2%) had a decision, and 790 of 1578 (50.1%) were approved to donate as of March 12, 2020. By logistic regression, candidates most likely to be approved were married or had attended college or technical school; those least likely to be approved had ≥1 of the following characteristics: Black race, history of cigarette smoking, and higher blood pressure, higher triglycerides, or higher urine albumin-to-creatinine ratios. Reasons for 617 candidates not being approved included medical issues other than chronic kidney disease risk (25.3%), chronic kidney disease risk (18.5%), candidate withdrawal (15.2%), recipient reason (13.6%), anatomical risk to the recipient (10.3%), noneconomic psychosocial (10.3%), economic (0.5%), and other reasons (6.4%).

Conclusions.

These results suggest that a comprehensive living donor registry is both feasible and necessary to assess long-term outcomes that may inform decision making for future living donor candidates. There may be socioeconomic barriers to donation that require more granular identification so that active measures can address inequities. Some candidates who did not donate may be suitable controls for discerning the appropriateness of acceptance decisions and the long-term outcomes attributable to donation. We anticipate that these issues will be better identified with modifications to the data collection and expansion of the registry to all centers over the next several years.

Evaluation of RETICs Glaucoma Diagnostic Calculators in Preperimetric Glaucoma

Purpose

To evaluate two glaucoma diagnostic calculators (GDC) in a group of eyes with preperimetric glaucoma (PPG).

Methods

All eyes (n = 265) included in this study had ocular hypertension with normal visual fields (VFs) on repeated VF tests. PPG was defined as progression in the Guided Progression Analysis software from Cirrus-optical coherence tomography (GPA-OCT). Three PPG types were defined according to the GPA-OCT software as follows: (1) GPA-OCT with one or more red boxes in two or more columns; (2) GPA-OCT with two or more red boxes in two or more columns; and (3) GPA-OCT with two or more red boxes in two or more columns (definition 2), and in the last scan one or more red box in the RNFL average or quadrants. Nonparametric tests, areas under the receiver operating characteristic curve (AUC), and Bland-Altman tests were assessed.

Results

Definitions one, two, and three were met by 44 (16.6%), 29 (10.9%), and 11 (4.2%) eyes, respectively. The GDC indices (means ± standard deviations) were, respectively, 14.49 ± 21.55% and 26.06 ± 22.50% using the combined and quantitative GDC (P < 0.001) in all eyes. Both GDC showed higher glaucoma probability in the PPG group (P < 0.04; combined GDC AUCs, 0.720–0.833; quantitative GDC AUCs, 0.700–0.839). GDC values were higher (P < 0.01) with greater GPA progression.

Conclusions

The values of both GDC were higher in the PPG group than the ocular hypertension group. The GDC were higher when more columns in the GPA software indicated progression. Both GDC showed a similar ability to detect PPG.

Translational Relevance

These calculators facilitate diagnosis of PPG in ocular hypertensive eyes.