role of HHV-8 in the pathogenesis of HIV negative castleman's disease: imunohistochemistry analysis

ABSTRACT

Castleman's disease [CD] is a rare atypical lymphoproliferative disorder that is morphologically and clinically heterogeneous and is associated with a risk of developing malignant lymphoma. The pathogenesis of CD is still not clear. The aim of this study is to evaluate the possible involvement of human herpcsvirus-8 [HHV-8] in the pathogenesis of CD. Immunohistochemistry for HHV-8 was performed on archival formalin- fixed, paraffin wax embedded biopsy specimens from 25 cases of CD without human immunodeficiency virus [HIV] infection at The Toronto General Hospital, University Health Network [Toronto, Canada], King Abdulaziz University Hospital and King Faisal Specialist Hospital and Research Centre [Jeddah, Saudi Arabia] The clinical histories were reviewed. Pathology sections [4 micro m] were stained using mouse monoclonal antibody [NCL-HHV8-LNA], which is specific for human herpesvirus type 8 latent nuclear antigen-1 [LNA-1]. The assays were performed at the Department of Pathology, KAUH, Jeddah, KSA in 2007. The age range was 16-90 years. There were 14 males and 11 females. Twenty-one patients had the localized form of CD and 4 patients had the multicentric form. Only one of the 25 cases [4%] showed positive nuclear staining. HHV-8 is unlikely to play a significant role in the pathogenesis of the large majority of cases of HIV-negative CD. This is in contrast to the reported involvement of HHV-8 in HIV-positive CD