Xenotropic Murine Leukemia Virus-Related Virus Proviral DNA Not Detected in Blood Samples Donated in Japan

Abstract

SUMMARY:The xenotropic murine leukemia virus-related virus (XMRV) was first described as a novel human gammaretrovirus in prostate tumor tissues and was reported to be found in blood, suggesting the possibility of XMRV transmission via blood transfusion. The gag and env regions of the XMRV proviral DNA that were detected in 1,030 blood samples collected from the greater Tokyo area were examined by real-time PCR analysis. However, XMRV infection was not found in the samples; this suggested that the risk of XMRV transmission via transfusion is very low in Japan.Xenotropic murine leukemia virus (MLV)-related virus (XMRV) was first described as a novel human gammaretrovirus in prostate tumor tissues in 2006 (1). In 2009, XMRV genomes were detected in 67z (68/101) of chronic fatigue syndrome (CFS) patients (2). However, this finding remains controversial as several research groups failed to confirm the presence of the gammaretrovirus in patients with CFS or prostate cancer (3-5). Moreover, genomic sequences of XMRV were found in 0-3.7z of blood samples obtained from healthy populations (2,3). XMRV can be transmitted via activated lymphocytes and cell-free plasma of individuals who are diagnosed as virus positive by PCR analysis, and XMRV can replicate in prostate carcinoma cell lines (2,6). These findings indicate the possibility of viral transmission via blood transfusion, which poses a great threat. Therefore, we examined the presence of XMRV proviral DNA in samples of donated blood to evaluate the risk of XMRV infection via blood transfusion in Japan. This study was approved by the ethics committee of the Japanese Red Cross Society.Samples of donated blood (1,030 whole blood samples) from the greater Tokyo area were collected randomly and anonymously from May 2011 to July 2011. The donors comprised of 712 men and 318 women aged 16-66 years. Cellular DNA was purified from the blood samples using a QIAsymphony DNA Midi kit (QIAGEN, Tokyo, Japan). The number of DNA molecules having the human CD81 gene, which is present as a single-copy gene per haploid genome, was estimated by real-time PCR analysis to examine the quality and concentration of human DNA in the purified DNA molecules. The primers and minor groove binder (MGB)-bound and VIC-labeled probes that were used are shown in Table 1. A DNA sample containing 300,000 copies of the DNA sequences containing the CD81 gene weights approximately 1 mg. The gag and env regions of XMRV proviral DNA were amplified by real-time PCR consisting of 45 amplification cycles. The primers for the gag region were 419F (forward) (2) and 518R (reverse), and the FAM-labeled MGB probe was 446MGB. The env region was detected according to the method described by Groom et al. (5) using the following: forward primer, 6173envF; reverse primer, 6173envR; and the FAM-labeled MGB probe, 6173envMGB. Two real-time PCRs were performed in duplicates for detecting XMRV genome, and approximately 1 mg DNA from a blood sample was used for each reaction. The real-time PCRs were performed using TaqMan F...

Cytomegalovirus (CMV) seroprevalence in Japanese blood donors and high detection frequency of CMV DNA in elderly donors

“…To adjust the amount of CMV DNA for the number of WBCs in the sample, we estimated the number of Exon 5 sequences of CD81 in specimens using real‐time PCR . CD81 was chosen as a marker of WBCs as it is present with two haploids in a cell.…”