Infection of T but not B lymphocytes by cytomegalovirus in lymph node. An immunophenotypic study

A 45-year-old black man presented with fever, night sweats, weight loss, and cervical lymphadenopathy. Biopsy of an enlarged node showed partial effacement of the nodal architecture by numerous cells with typical cytomegalovirus (CMV) inclusions. These were also seen by electron microscopy. CMV titers were not elevated, and he tested negative for HIV. An immunophenotypic study done on both paraffin-embedded and frozen tissue showed that the infected cells were of T-lymphocyte phenotype. These cells were remarkable for the lack of HLA-DR and IL-2R antigens, which were expressed by numerous neighboring apparently uninfected cells. The lack of HLA-DR and IL-2R expression by CMV-infected T lymphocytes may be one of the mechanism by which CMV causes immunosuppression.