Human herpesvirus 7 detection by quantitative real time polymerase chain reaction in primary cutaneous T-cell lymphomas and healthy subjects: lack of a pathogenic role.

BACKGROUND: Primary cutaneous T-cell lymphomas (CTCLs) are a heterogeneous group of lymphomas where the tumour population emerges within a multiple subclone pattern. Mycosis fungoides (MF) and Sézary syndrome (SS) are characterized by the expansion of clonal CD4+/CD45RO+ memory T cells. Lymphomatoid papulosis (LyP) is a chronic, lymphoproliferative disorder included in the CD30+ primary CTCL spectrum. Several studies have suggested a role of viral infection for super-antigenic activation of T lymphocytes; however, evidence of their association with CTCLs is still lacking. Human herpesvirus (HHV) 7 is a CD4+ T-lymphotropic herpesvirus; its restricted cellular tropism and the ability to induce cytokine production in infected cells could make it an important pathogenic cofactor in lymphoproliferative disorders.
OBJECTIVES: To investigate the presence of HHV7 DNA on CTCL and healthy skin donors (HD).
METHODS: We used quantitative real time polymerase chain reaction to evaluate the potential pathogenic role of HHV7.
RESULTS: Twenty-seven of 84 (32.1%) HD were positive for HHV7 DNA. Twenty-one of 148 (14.2%) patients with CTCLs were positive for HHV7 DNA: nine of 39 (23.1%) SS, six of 14 (42.9%) CD30+ CTCLs and six of 24 (25.0%) LyP, and HHV7 DNA was negative in all 71 patients with MF.
CONCLUSIONS: These results seem to exclude a pathogenic role of HHV7 in CTCLs, suggesting the possibility of skin as a latency site.