Session Time: 6:00pm-7:00pm
Presentation Time: 6:00pm-7:00pm
Location: Hall D1
Infection with Epstein-Barr virus (EBV) manifests as a spectrum of disease ranging from asymptomatic viremia to PTLD. Innate immune cells such as monocytes/macrophages, dendritic cells (DCs), and natural killer (NK) cells contribute to EBV clearance and priming of adaptive immunity against EBV. We performed detailed innate immune profiling of patients with controlled low-level and chronic high-level EBV viremia.
We prospectively enrolled consecutive adult organ transplant recipients with EBV viremia. Patients were classified into two phenotypes according to peak viral loads: chronic high viremia (≥104 IU/mL) and low level viremia (<104 IU/mL). PBMCs were collected during active EBV viremia and innate cell populations were identified using mass cytometry with the following cell-surface markers: CD3, CD19, CD56, CD16, CD14, CD11c, CD11b, CD141, BDCA-2, TCRVα24 and γδTCR.
We enrolled 30 patients with median age 57.5 (range 20-74). Median peak viral load among the high (n=15) and low (n=15) viremia groups was 3×105 and 4×103 IU/mL, respectively. Types of transplants included kidney (33%), heart (30%), liver (20%), lung (10%), combined kidney and pancreas (3%) and small bowel (3%). Time post-transplant to testing was median 1.7 years (range 0.1-28). Patients were EBV seronegative at transplant (n=12) or seropositive (n=17). Use of anti-thymocyte globulin, prednisone, calcineurin-inhibitors or mycophenolate, as well as recipient EBV serostatus were similar between groups. Patients with low level EBV viremia expressed significantly greater proportions of classic monocytes/macrophages (CD14+CD16–) (24% vs 12%; p=0.03). In addition, low level viremia patients also had significantly greater proportions of CD141+ DCs (1.5% vs 0.21%; p=0.04), which have been postulated to be cross-presenting antigen presenting cells. Although the proportion of CD11c+ DCs was also greater in the low viremia group (45% vs 34%), this difference was not statistically significant (p=0.15). There was a trend to greater PD-1 expression on intermediate monocytes in the high viremia group (CD14+CD16+)(p=0.056) suggestive of an exhaustion phenotype. No differences were measured with regard to γδ T-cells, invariant NKT cells, plasmacytoid DCs, non-classical monocytes/macrophages or NK cells.
These results suggest that innate immune cells play an important role in the control of EBV viremia and provide novel insight into the immunobiology of patients who develop a chronic high viral load phenotype.
CITATION INFORMATION: Ferreira V, Batist J, Kumar D, Husain S, Humar A. In Depth Characterization of the Innate Immune Response in Transplant Recipients with EBV Viremia. Am J Transplant. 2017;17 (suppl 3).
To cite this abstract in AMA style:Ferreira V, Batist J, Kumar D, Husain S, Humar A. In Depth Characterization of the Innate Immune Response in Transplant Recipients with EBV Viremia. [abstract]. Am J Transplant. 2017; 17 (suppl 3). https://atcmeetingabstracts.com/abstract/in-depth-characterization-of-the-innate-immune-response-in-transplant-recipients-with-ebv-viremia/. Accessed December 4, 2020.
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