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Clinical and Developmental Immunology
Volume 2012 (2012), Article ID 451059, 9 pages
http://dx.doi.org/10.1155/2012/451059
Clinical Study

Validation of Cytomegalovirus Immune Competence Assays for the Characterization of CD8+ T Cell Responses Posttransplant

Department of Pathology, ARUP Institute for Clinical and Experimental Pathology, School of Medicine, University of Utah, 500 Chipeta Way, Salt Lake City, UT 84108, USA

Received 25 June 2012; Accepted 23 November 2012

Academic Editor: Rossana Cavallo

Copyright © 2012 Eugene V. Ravkov et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Cytomegalovirus (CMV) infection is one of the most important infectious complications of transplantation. Monitoring CMV-specific CD8 T cell immunity is useful for predicting active CMV infection and for directing targeted antiviral therapy. In this study, we examined four basic parameters for validation of CMV-specific tetramer staining and peptide stimulation assays that cover five most frequent HLA class I alleles. We also examined the potential use of CMV-specific CD8+ T cell numbers and functional and cytolytic responses in two autologous HSCT recipients treated for multiple myeloma. The coefficient of variation (CV %) of the precision within assays was 3.1−24% for HLA-tetramer staining, 2.5−47% for IFN-γ, and 3.4−59.7% for CD107a/b production upon peptide stimulation. The precision between assays was 5−26% for tetramer staining, 4−24% for IFN-γ, and 5−48% for CD107a/b. The limit of detection was 0.1−0.23 cells/μL of blood for tetramer staining, 0−0.23 cell/μL for IFN-γ, and 0.11−0.98 cells/μL for CD107a/b. The assays were linear and specific. The reference interval with 95% confidence level was 0−18 cells/μL for tetramer staining, 0−2 cells/μL for IFN-γ, and 0–3 cells/μL for CD107a/b. Our results provide acceptable measures of test performance for CMV immune competence assays for the characterization of CD8+ T cell responses posttransplant measured in the absolute cell count per μL of blood.