Quantitation of human herpes virus 8 DNA in paraffin‐embedded biopsies of HIV‐associated and classical Kaposi’s sarcoma by PCR

Abstract

These data suggest that HHV8 viral load in Kaposi's sarcoma is relatively low and does not differ in HIV-positive and HIV-negative samples. The importance of viral load determination for prognosis or treatment monitoring remains to be elucidated.

Latency-associated nuclear antigen expression and human herpesvirus-8 polymerase chain reaction in the evaluation of Kaposi sarcoma and other vascular tumors in HIV-positive patients

“…The great majority of non-Kaposi sarcoma vascular tumors previously studied have, however, been negative for HHV-8 by PCR. 16,[27][28][29][30][31][32][33] Given that the positive cases in the present study all showed levels above our preset high threshold level, we believe our results do indicate the true presence of HHV-8, rather than representing 'false positives'. Regrettably, we did not have access to frozen tissue from these positive cases, and thus were unable to perform Southern blot confirmation.…”

“…During latent infection, the virus exists in the nucleus as circular, episomal DNA that expresses a small number of viral genes. 15 Although no significant difference in HHV-8 viral loads has been observed in biopsies from HIV-positive vs HIVnegative individuals with Kaposi sarcoma, 16 HIVinfected individuals have a more aggressive course with frequent dissemination to skin and visceral organs.…”

“…26 Our finding of uniform HHV-8 expression in Kaposi sarcoma, by PCR, is in agreement with numerous prior studies, all of which have found 490% of Kaposi sarcoma of all types to be HHV-8 positive, using both traditional and in situ PCR. 16,[27][28][29][30][31][32][33] The 100% detection rate we observed may in part be due to our use of a high cycles-tothreshold limit of 50. We chose to carry reactions out to 50 cycles-to-threshold for the purpose of detecting potentially very low viral loads in paraffinembedded tissue blocks that had been in storage for up to 10 years.…”

Infliximab and the risk of latent viruses reactivation in active Crohnʼs disease

“…Moreover, in immunocompromised patients HHV-8 has been reported to be a major risk factor for the development of Kaposi's sarcoma. 32,33 The aim of this study was to prospectively investigate the short-term effect of infliximab administration on reactivation of JCV, EBV, HHV-6, -7, -8, and CMV in active CD to determine any risks of life-threatening virus-related events during long-term follow-up.…”

Immunohistochemistry in the Diagnosis of Cutaneous Viral Infections—Part I. Cutaneous Viral Infections by Herpesviruses and Papillomaviruses

“…45,46 HHV-8 can be detected by PCR in paraffin-embedded tissue, although the viral load seems to be low. 47,48 It is much easier to perform IHC using the commercially available monoclonal antibody against HHV-8 that is directed against the C-terminus of the latent nuclear antigen-1 (LNA-1) encoded by the ORF-73 gene. 49 The presence of HHV-8 in the nuclei of proliferating cells in KS lesions may be demonstrated in all its epidemiologic variants and from the earliest phases of the process.…”