Objectives: The new human herpesvirus type 8 (HHV-8) has been detected in all types of Kaposi's sarcomas, as well as in body-cavity lymphomas and Castleman's disease. Recently, HHV-8 has also been associated with encephalitis in HIV-positive and HIV-negative patients. Interstitial pneumonitis, combined with detection of HHV-8 in non HIV-infected patients, indicates a pathogenetic role of HHV-8 in unexplained lung diseases. We have studied two HIV-infected patients, with otherwise unexplained interstitial pneumonitis for the presence of HHV-8.
Methods: Lung biopsies of both patients were investigated for HHV-8 sequences. A nested PCR method was used for amplification of HHV-8 DNA fragments, and the nature of the amplification products was confirmed by Southern blot hybridization. In addition, we used an in situ hybridization technique and immunohistochemical staining for detection of HHV-8 infected cells.
Results: Amplification of HHV-8 DNA fragments was seen with template DNA from lung biopsies of both cases and the appropriate positive controls, but not with negative controls. In situ hybridization and immunohistochemical staining demonstrated HHV-8 infected lymphoid cells and alveolar macrophages in both patients as well.
Conclusions: HHV-8 was found in HIV-infected patients with otherwise unexplained interstitial pneumonitis, but the pathogenic role of HHV-8 in patients with interstitial pneumonia remains unclear.