title: Unusual expression of CD94 on CD8+ TCR-alpha beta T cells in infectious mononucleosis.
abstract: Infectious mononucleosis, caused by primary Epstein-Barr virus (EBV) infection, is usually a benign, self-limited lymphoproliferative disorder. We report a case of a 21-year-old woman who presented with fever, sore throat, severe neutropenia, and absolute lymphocytosis with atypical lymphocytes. In situ hybridization for EBV-encoded small RNA performed on the marrow aspirate clot specimen demonstrated scattered positive cells. EBV serology was compatible with primary infection. Flow cytometry immunophenotypic studies performed on aspirate material revealed a profoundly expanded population of CD8+ T-cell receptor (TCR)-alphabeta T cells with uniform expression of CD94. No evidence of a monoclonal T-cell population was found as assessed by V(beta) use with flow cytometry and by TCR gamma-chain gene rearrangement using a polymerase chain reaction method. Uniform expression of CD94 in an exuberant reactive proliferation of CD8+ TCR-alphabeta T cells in infectious mononucleosis has not been reported previously, and combined with atypical morphology might be misinterpreted as a malignant neoplasm.
authors.affiliation: Department of Hematopathology, Box 72, The University of Texas M D Anderson Cancer Center, Houston, TX 77030, USA.
authors.forename: Yongsheng
authors.initials: Y
authors.lastname: Ren
authors.forename: L Jeffrey
authors.initials: LJ
authors.lastname: Medeiros
authors.forename: Hesham M
authors.initials: HM
authors.lastname: Amin
authors.forename: Michael E
authors.initials: ME
authors.lastname: Rytting
authors.forename: Jeffrey L
authors.initials: JL
authors.lastname: Jorgensen
authors.forename: Weina
authors.initials: W
authors.lastname: Chen
mesh_terms: D000328:Adult; D018414:CD8-Positive T-Lymphocytes / Q000378:metabolism* / Q000473:pathology; D049109:Cell Proliferation; D005260:Female; D005786:Gene Expression Regulation; D006801:Humans; D016130:Immunophenotyping; D007244:Infectious Mononucleosis / Q000276:immunology* / Q000473:pathology; D051920:NK Cell Lectin-Like Receptor Subfamily D / Q000235:genetics / Q000378:metabolism*; D016693:Receptors, Antigen, T-Cell, alpha-beta / Q000235:genetics / Q000378:metabolism*
chemical_list: D051920:NK Cell Lectin-Like Receptor Subfamily D; D016693:Receptors, Antigen, T-Cell, alpha-beta