Session Time: 5:30pm-7:30pm
Presentation Time: 5:30pm-7:30pm
Location: Exhibit Hall E
Introduction: Increased monocytic infiltration of heart transplant tissue is documented during acute rejection. It is still unclear how changes in circulating monocyte pool relate to counterpart alterations of monocyte-macrophage infiltrates on tissue level. We aimed to establish blood and tissue monocyte/macrophage profiles using serial blood samples and endomyocardial biopsies in 10 heart transplant recipients experiencing rejection in comparison to time points prior to rejection intra-individually. Blood profiles of heart transplant recipients were compared with 33 healthy individuals using a cross-sectional approach.
Method: Flow cytometric expression of co-stimulatory and migration-related molecules; HLA-DR, CD40, CD80, and CD54 were studied on different monocyte subsets. TNF-α, IFN-γ, IL-1β, IL-6, IL-10, IL-12 production capacity of monocytes were measured after LPS stimulation. Using immunohistochemistry we studied expression of CD14, CD16, CD56, CD68, CD80, CD163 in endomyocardial biopsies.
Results: Increased classical CD14++CD16- monocytes and simultaneously decreased fractions of intermediate CD14++CD16+ and non-classical CD14+CD16++ monocytes signify the subset composition of circulating monocytes in heart transplant recipients compared to healthy individuals. However, rejection was reflected by significantly increased expression of CD54 and HLA-DR within the CD16+ monocyte pool indicative of a higher antigen presentation potential and migration capacity. Cytokine production potential was consistently high and independent of rejection. Significantly more CD16+ monocytes were found in rejecting endomyocardial biopsies compared to non-rejection. Significantly more CD68+CD163+ M2 macrophages were documented during rejection parallel to this increase in intra-graft CD16+ monocyte infiltration.
Conclusions: Our data show inverse monocytic subset profile in blood and tissue during human heart transplant rejection with a simultaneous predominance of M2 anti-inflammatory macrophages.
To cite this abstract in AMA style:van T, Kraaij M, Caliskan K, Constantinescu A, Manintveld O, Leenen P, Baan C, van M, Rowshani A. Inverse Monocytic Subset Profile in Blood and Tissue During Heart Transplant Rejection [abstract]. Am J Transplant. 2015; 15 (suppl 3). https://atcmeetingabstracts.com/abstract/inverse-monocytic-subset-profile-in-blood-and-tissue-during-heart-transplant-rejection/. Accessed February 23, 2019.
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