title: Additional evidence that pityriasis rosea is associated with reactivation of human herpesvirus-6 and -7.
abstract: To elucidate the role of human herpesvirus (HHV)-6 and -7 (HHV-7) in pityriasis rosea (PR), we measured their DNA load in plasma, peripheral blood mononuclear cells (PBMC), and tissues using a calibrated quantitative real-time PCR assay. We also studied HHV-6- and HHV-7-specific antigens in skin by immunohistochemistry and anti-HHV-7 neutralizing activity using a syncytia-inhibition test. Plasma and PBMC were obtained from 31 PR patients (14 children, 17 adults), 12 patients with other dermatites, and 36 blood donors. Skin biopsies were obtained from 15 adults with PR and 12 with other dermatites. HHV-6 and HHV-7 DNA were detected in 17% and in 39% of PR plasmas, respectively, but in no controls. HHV-7 viremia was associated with a higher PBMC load and, in adults, with systemic symptoms. HHV-7, but not HHV-6, levels in PBMC were higher in PR patients than in controls. HHV-6 and HHV-7 antigens were found only in PR skin (17% and 67% of patients analyzed, respectively), indicating a productive infection. Syncytia-neutralizing antibodies were found in PR patients and controls, but their titers were lower in patients with HHV-7 viremia. These data confirm the causal association between PR and active HHV-7 or, to a lesser extent, HHV-6 infection.
authors.affiliation: Unit of Human Virology, DIBIT San Raffaele Scientific Institute, Milan, Italy.
authors.forename: Francesco
authors.initials: F
authors.lastname: Broccolo
authors.forename: Francesco
authors.initials: F
authors.lastname: Drago
authors.forename: Anna M
authors.initials: AM
authors.lastname: Careddu
authors.forename: Chiara
authors.initials: C
authors.lastname: Foglieni
authors.forename: Laura
authors.initials: L
authors.lastname: Turbino
authors.forename: Clementina E
authors.initials: CE
authors.lastname: Cocuzza
authors.forename: Carlo
authors.initials: C
authors.lastname: Gelmetti
authors.forename: Paolo
authors.initials: P
authors.lastname: Lusso
authors.forename: Alfredo E
authors.initials: AE
authors.lastname: Rebora
authors.forename: Mauro S
authors.initials: MS
authors.lastname: Malnati
mesh_terms: D000328:Adult; D000914:Antibodies, Viral / Q000097:blood; D002648:Child; D004279:DNA, Viral / Q000097:blood; D015654:Herpesvirus 6, Human / Q000235:genetics / Q000276:immunology / Q000302:isolation & purification / Q000502:physiology*; D016199:Herpesvirus 7, Human / Q000235:genetics / Q000276:immunology / Q000302:isolation & purification / Q000502:physiology*; D006801:Humans; D017515:Pityriasis Rosea / Q000503:physiopathology / Q000821:virology*; D012867:Skin / Q000821:virology; D019562:Viral Load; D014766:Viremia / Q000097:blood; D014775:Virus Activation
chemical_list: D000914:Antibodies, Viral; D004279:DNA, Viral