B-099 Validation and Clinical Implementation of Organ Procurement Serology Testing: Our Analytical and Regulatory Experience in Implementing a New Donor Testing Program
Authors: Kirchhoff D , Pinero G , Patel D , Arowolo F , Mendu D R 
Published: October 2024

Abstract

Background
The Mount Sinai Hospital recently implemented a comprehensive organ donor testing program to service the clinical needs of transplant services in the New York City metro area. Conventional serology testing is not approved by the FDA for donor testing. To support this program, the MSH Chemistry Laboratory implemented and validated a comprehensive donor testing panel on the Abbott Alinity S donor testing platform. We validated donor serology testing for the following assays: HIV-1/2 (HIV), Anti-Hepatitis B Core (Anti-HBc), Hepatitis B Surface Antigen (HBsAg), Human T-lymphotropic virus I and II (HTLV-I/II), Anti-Hepatitis C (Anti-HCV), and Trypanosoma cruzi antibodies (T.Cruzi). The Alinity S System is an automated immunoassay-based analyzer FDA-approved for donor testing. The analyzer consists of two distinct sample ‘paths’ and is effectively two instruments combined in one analyzer. The analyzer is approved for use in living donor serum and plasma and in cadaveric serum. Prior to going live, we found that there was limited guidance on laboratory quality assurance programs related to donor testing. In addition to confirming assay analytical performance, we designed and implemented a comprehensive quality assurance program prior to satisfy compliance with regulatory guidelines, addressing proficiency compliance, sample TAT, and control ranges, amongst other quality indicators.

Methods
Inter and Intraday precision was assessed through replicate analysis of positive and negative controls, where 10 replicates of both controls were assayed on a single day, and one replicate of each control was assayed daily for 7 distinct days, results were represented as %CV. Result accuracy was assessed through split sample analysis of known serologically positive (n=20) and negative samples (n=40). Each sample was assayed on two distinct lots of reagents, each with its own unique calibration curve. Accuracy was confirmed in both living donor (n=30), and cadaveric samples (n=10). In addition, split sample analysis was performed between the Alinity S and FDA-approved donor testing assays in a reference laboratory (N=7). A carryover study was performed through the analysis of triplicate replicates of low, high, and then low controls. These analyses were performed for all 6 assays.

Results
Intraday precision using assay general controls afforded the following %CV: HIV: 3.1%, 6.5%; Anti-HBc: 1.3%, 2.6%; Anti-HCV: 3.3%, 11.7%; HTLV-I,II: 2.5%, 5.9%; T.Cruzi: 2.8%, 0%; HBsAg: 3.2%, 11.6%. Interday precision yielded the following in %CV: HIV: 2.9%, 10.0%; Anti-HBc: 3.0%, 5.6%; Anti-HCV: 3.3%, 3.4%; HTLV-I,II: 2.8%, 4.6%; T.Cruzi: 2.4%, 0%; HBsAg: 4.7%, 7.8%. Accuracy studies yielded 100% positive and negative correlation for all 6 assays in both living donor and cadaveric samples. In addition, there was a 100% serological correlation for samples compared to reference laboratories. Carryover studies showed no evidence of sample carryover.

Conclusions
The Abbott Alinity S shows acceptable assay precision on all 6 validated assays. The assays are serologically accurate in both cadaveric and living donor samples. As such, the assays and platform are acceptable for use in donor screening. We designed a unique quality assurance program including a comprehensive self-proficiency and instrument crosscheck program to ensure analyzer accuracy, as well as adherence to regulatory guidelines.