Session Time: 6:00pm-7:00pm
Presentation Time: 6:00pm-7:00pm
Location: Hall D1
Cellular protection against unwanted complement activation is provided by expression of membrane-bound complement regulatory proteins including CD59. This protein prevents membrane attack complex formation and is considered to be involved in the process of accommodation following transplantation. It is unknown whether its expression is affected by immunosuppression. The aim of this study was to determine quantitative CD59 expression on distinct leukocyte subsets following transplantation and to investigate whether this differs from the pretransplant situation and healthy controls.
Peripheral blood mononuclear cells (PBMCs) were obtained from 26 lung transplant patients between month 2 and 6 after lung transplantation. Additionally, we included 10 samples that were taken just prior to lung transplantation and 9 healthy controls. Frozen PBMCs where thawed and stained for flow cytometry analyses. Quantitative CD59 antigen expression was determined using the Qifikit.
Expression of CD59 on leukocytes was significantly lower posttransplantation compared to healthy controls (p=0.002) and pretransplantation (p<0.0001). Moreover, posttransplantation CD59 expression was lower on all distinct lymphocyte subsets (p<0.02). This effect appeared to be specific for CD59 since the expression of other surface markers remained stable or tended to be higher following transplantation. The highest CD59 expression posttransplantation was observed on CD4+ T cells and monocytes (p≤0.002). On CD4+ subsets, central memory cells showed a significantly higher CD59 expression compared to naïve and terminally differentiated cells (p≤0.027). For CD8+ cells, central and effector memory cells showed a significantly higher CD59 expression compared to terminally differentiated cells (p≤0.027).
These findings show that CD59 expression on leukocytes diminishes posttransplantation on all distinct subsets. If such reduction in CD59 expression also occurs on endothelial cells from the transplanted organ this may lead to decreased resistance against antibody/complement mediated damage.
CITATION INFORMATION: Michielsen L, Budding K, Drop D, van de Graaf E, Kardol-Hoefnagel T, Verhaar M, van Zuilen A, Otten H. Reduced Expression of Membrane Complement Regulatory Protein CD59 on Leukocytes Following Lung Transplantation. Am J Transplant. 2017;17 (suppl 3).
To cite this abstract in AMA style:Michielsen L, Budding K, Drop D, Graaf Evande, Kardol-Hoefnagel T, Verhaar M, Zuilen Avan, Otten H. Reduced Expression of Membrane Complement Regulatory Protein CD59 on Leukocytes Following Lung Transplantation. [abstract]. Am J Transplant. 2017; 17 (suppl 3). https://atcmeetingabstracts.com/abstract/reduced-expression-of-membrane-complement-regulatory-protein-cd59-on-leukocytes-following-lung-transplantation/. Accessed August 14, 2020.
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