Nucleic Acid, Antibody, and Virus Culture Methods to Detect Xenotropic MLV-Related Virus (XMRV) in Macaque and Human Blood Samples
Mary Kearney, Kyeongeun Lee, Rachel Bagni, Ann Wiegand, Jonathan Spindler, F. Maldarelli, Peter A. Pinto, W. Marston Linehan, Cathy D. Vocke, Krista Delvis-Frankenberry, Robert deVere White, Greg Del Prete, J. W. Mellors, Jeffrey D. Lifson, Vineet KewalRamani, Vinay Pathak, John Coffin, and S. F J Le Grice
Received 21 June 2011; Revised 8 August 2011; Accepted 27 August 2011
The MLV-related retrovirus, XMRV, was recently identified and reported to be associated with both prostate cancer and chronic fatigue syndrome. At the National Cancer Institute-Frederick, MD (NCI-Frederick), we developed highly sensitive methods to detect XMRV nucleic acids, antibodies, and replication competent virus. Analysis of XMRV spiked samples and/or specimens from two pigtail macaques experimentally inoculated with 22Rv1 cell derived XMRV confirmed the ability of the assays used to detect XMRV RNA and DNA, and culture isolatable virus when present, along with XMRV reactive antibody responses. Using these assays, we did not detect evidence of XMRV in blood samples (N=134) or prostate specimens (N=19) from two independent cohorts of patients with prostate cancer. Previous studies detected XMRV in prostate tissues. In the present study, we primarily investigated the levels of XMRV in blood plasma samples collected from patients with prostate cancer. These results demonstrate that while XMRV-related assays developed at the NCI-Frederick can readily measure XMRV nucleic acids, antibodies, and replication competent virus, no evidence of XMRV was found in the blood of patients with prostate cancer.