title: Questionable role of human herpesviruses in the pathogenesis of Kikuchi disease.
abstract: BACKGROUND
  Kikuchi disease is a self-limiting febrile lymphadenopathy characterized by a patchy area of apoptosis. Kikuchi disease is thought to be caused by a virus, but this has not been clearly demonstrated. Human herpesviruses 6 and 7 (HHV-6 and HHV-7) are lymphotropic viruses that can induce apoptosis in infected lymphocytes. Recently, HHV-8 was reported to be a possible etiologic agent of Kikuchi disease.
  
  
  OBJECTIVE
  To investigate the incidence of HHV-6, HHV-7, and HHV-8 infection in patients with Kikuchi disease.
  
  
  METHODS
  Seventy archival tissue specimens (from 50 Kikuchi disease cases and 20 control cases) were tested for the presence of HHV-6 and HHV-7 using a nested polymerase chain reaction, and for the presence of HHV-8 using single-step polymerase chain reaction. Immunohistochemistry for HHV-8 expression was carried out in those cases in which HHV-8 was detected using polymerase chain reaction.
  
  
  RESULTS
  Of the 50 cases with Kikuchi disease, 21 (42%) were HHV-6 positive and 32 (64%) were HHV-7 positive. Eight (40%) of the 20 control cases were HHV-6 positive and 9 (45%) were HHV-7 positive. Both HHV-6 and HHV-7 were detected in 15 (30%) of the cases with Kikuchi disease and in 3 (15%) of the control cases. Three (6%) of the 50 cases of Kikuchi disease were HHV-8 positive but revealed no positive cells on immunohistochemical analysis for HHV-8. Human herpesvirus 8 was not expressed in any of the control cases.
  
  
  CONCLUSIONS
  There was no association between the presence of HHV-6 or HHV-7 and Kikuchi disease. Because the HHV-8 genome but not protein was detected in a small proportion of the cases of Kikuchi disease, its potential causative role in this disease should be determined by further studies.
authors.affiliation: Department of Pathology, College of Medicine, Ewha Womans University Hospital, 911-1 Mok-6-dong Yangcheon-ku, 158-710, Seoul, South Korea. mcho1124@ewha.ac.kr
authors.forename: Min-Sun
authors.initials: MS
authors.lastname: Cho
authors.forename: Hee Jung
authors.initials: HJ
authors.lastname: Choi
authors.forename: Hae Kyung
authors.initials: HK
authors.lastname: Park
authors.forename: Sung Eun
authors.initials: SE
authors.lastname: Cho
authors.forename: Woon Sup
authors.initials: WS
authors.lastname: Han
authors.forename: Woo Ick
authors.initials: WI
authors.lastname: Yang
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D005260:Female; D006566:Herpesviridae Infections / Q000150:complications* / Q000453:epidemiology*; D015654:Herpesvirus 6, Human / Q000302:isolation & purification; D016199:Herpesvirus 7, Human / Q000302:isolation & purification; D019288:Herpesvirus 8, Human / Q000302:isolation & purification; D020042:Histiocytic Necrotizing Lymphadenitis / Q000821:virology*; D006801:Humans; D007150:Immunohistochemistry; D015994:Incidence; D008297:Male; D008875:Middle Aged; D016133:Polymerase Chain Reaction