Is Kaposi's Sarcoma–Associated Herpesvirus Ubiquitous in Urogenital and Prostate Tissues?

Abstract

Controversy exists as to whether Kaposi's sarcoma–associated herpesvirus (KSHV) is more widespread than originally reported. Recently, Monini et al reported that KSHV is ubiquitous in urogenital and prostate tissues and sperm of healthy Italian adults using nested polymerase chain reaction (PCR). We have examined for the presence of KSHV in 10 normal prostates from Italian men and 10 from men from the United States, as well as 32 prostatic, 30 vulvar, 24 ovarian, 20 cervical, and 30 testicular cancer specimens from patients from the United States. None of the patients had a history of human immunodeficiency virus infection. The samples were tested by nested PCR. The sensitivity of this assay was determined by a dilution study performed by diluting KSHV DNA from the KS-1 cells (a primary effusion lymphoma cell line which is estimated to have 16 copies of KSHV per cell) in DNA from a K562 myeloid cell line. The nested PCR that we used can detect 2.4 copies of KSHV sequences on a background of K562 DNA. All the samples were negative for KSHV sequences. Therefore, we cannot confirm the finding that KSHV sequences are ubiquitous in urogenital and prostate tissues. Furthermore, because our samples were from both the United States and Italy, the discrepancy between results is unlikely to be explained by either ethnic or environmental factors. False-positive results easily occur using nested primer PCR because of contamination. Our data argue that KSHV is not widely disseminated in urogenital tissues from nonimmunosuppressed individuals.

Polymerase Chain Reaction Detection of Kaposi's Sarcoma-Associated Herpesvirus-Optimized Protocols and Their Application to Myeloma

“…Most of these studies used PCR methods involving an excessive cycle number (Ͼ40) or nested primers, claiming to be able to detect as little as three copies of KSHV genome per 200,000 cells. 8,24,25 With these methods, KSHV DNA sequences have been reported in a significant proportion of various diseases and even normal controls by some investigators. 8 It is possible that the enhanced sensitivity of the PCR analysis in these studies might have allowed detection of rare passenger KSHV genomes or minute amounts of randomly contaminated KSHV sequences in the samples examined.…”

Dendritic cells derived from bone marrow and CD34+ selected blood progenitor cells of myeloma patients, cultured in serum‐free media, do not contain the Kaposi sarcoma herpesvirus genome

“…The KSHV PCR was performed according to the method described by Tasaka et al (1997 ). The positive control was genomic DNA from the KSHV‐positive lymphoma cell line BCP‐1 ( Gao et al , 1996 ).…”

Macaque homologs of Kaposi's sarcoma-associated herpesvirus (KSHV) infect germinal center lymphoid cells, epithelial cells in skin and gastrointestinal tract and gonadal germ cells in naturally infected macaques

“…KSHV is not believed to be widely disseminated in urogenital tissues (Tasaka et al, 1997), and KSHV DNA is infrequently detected in semen of HIV infected men (Howard et al, 1997; Koelle et al, 1997; Monini et al, 1996). In positive samples, viral DNA was not detected in the sperm heads but was present in urothelial and other cell types in the ejaculate (Monini et al, 1996).…”