Evaluation of an automated method for viability testing of lymphocytes for crossmatching before kidney transplantation and a retrospective evaluation of transplantation outcome
Translated title
Evaluering af en automatiseret metode til at teste lymfocytviablilitet til crossmatching før nyrertransplantation samt en retrospektiv evaluering af transplantationsoutcome
Authors
Petersen, Marie Weinreich ; Svendsen, Anette Sand
Term
4. term
Publication year
2015
Submitted on
2015-05-29
Pages
60
Abstract
Formål: For at forbedre resultaterne efter nyretransplantation er det vigtigt at vurdere donor-modtager-kompatibilitet (crossmatch) og at måle immunceller pålideligt i laboratoriet. Denne undersøgelse havde tre mål: 1) at se, om resultater af tests før transplantation kunne forudsige forløbet efter transplantationen; 2) at afprøve magnetic activated cell sorting (MACS), en metode til at adskille T- og B-celler fra perifere blodmononukleære celler (PBMC) og optøet miltvæv; og 3) at evaluere Vi-CELL XR Cell Viability Analyzer (Vi-CELL) til at måle koncentration og levedygtighed (andel levende celler) af lymfocytter. Metode: Kliniske data fra 147 modtagere af nyrer fra afdøde donorer transplanteret 2011-2013 på Aarhus Universitetshospital, Skejby, blev gennemgået. MACS blev brugt til at adskille T- og B-celler, og koncentration og levedygtighed før og efter adskillelse blev målt med flowcytometri (en standard laboratoriemetode). Prøver med lymfocytter fra optøet milt og PBMC blev analyseret med både Vi-CELL og flowcytometri og sammenlignet. Resultater: Der blev ikke fundet statistisk signifikante sammenhænge mellem prætransplantationstests og udfald efter transplantation (P > 0,05). Data tydede dog på, at tilstedeværelse af human leukocyte antigen (HLA)-antistoffer og donorspecifikke antistoffer hos modtageren kan hænge sammen med lavere estimeret glomerulær filtrationsrate (eGFR) og øget risiko for afstødning. Med MACS var ændringen i lymfocytlevedygtighed før/efter adskillelse acceptabel (≤ 5 procentpoint) i to ud af tre tilfælde, men det lykkedes ikke at opnå både høj renhed (> 90 %) og lavt celletab (< 10 %). For Vi-CELL var det ikke muligt at indstille instrumentet til at måle lymfocytkoncentration inden for ≤ 15 % af flowcytometri, men målingen af levedygtighed var for størstedelen af prøverne i god overensstemmelse (≤ 5 procentpoint). Konklusion: I dette materiale kunne udfald efter nyretransplantation ikke forudsiges af prætransplantationstests. MACS gav acceptable niveauer for ekstra celledød, men ikke for renhed og tab af celler. Vi-CELL målte levedygtighed pålideligt, men ikke lymfocytkoncentration sammenlignet med flowcytometri.
Aim: To improve kidney transplant outcomes, it is important to better assess donor-recipient compatibility (crossmatch) and to measure immune cells reliably in the lab. This study had three aims: (1) to examine whether results from tests done before transplantation could predict outcomes after surgery; (2) to test magnetic activated cell sorting (MACS), a method for separating T and B cells from peripheral blood mononuclear cells (PBMC) and thawed spleen tissue; and (3) to evaluate the Vi-CELL XR Cell Viability Analyzer (Vi-CELL) for measuring lymphocyte concentration and viability (the share of living cells). Methods: We reviewed clinical data from 147 recipients of deceased-donor kidneys transplanted in 2011-2013 at Aarhus University Hospital, Skejby. MACS was used to separate T and B cells, and cell concentration and viability before and after separation were measured by flow cytometry (a standard laboratory method). Lymphocytes from thawed spleen and PBMC were analyzed with both the Vi-CELL and flow cytometry and the results compared. Results: There were no statistically significant associations between pre-transplant tests and transplant outcomes (P > 0.05). However, the data suggested that the presence of human leukocyte antigen (HLA) antibodies and donor-specific antibodies in recipients may be linked to lower estimated glomerular filtration rate (eGFR) and a higher risk of rejection. With MACS, the change in lymphocyte viability before versus after separation was acceptable (≤ 5 percentage points) in two out of three cases, but acceptable purity (> 90%) and low cell loss (< 10%) were not achieved. For the Vi-CELL, it was not possible to set parameters to measure lymphocyte concentration within ≤ 15% of flow cytometry, but viability measurements agreed for most samples (≤ 5 percentage points). Conclusion: In this cohort, pre-transplant tests did not predict kidney transplant outcomes. MACS limited additional cell death but fell short on purity and cell loss. The Vi-CELL measured viability reliably, but not lymphocyte concentration, compared with flow cytometry.
[This abstract was generated with the help of AI]
Documents