Failure to detect Xenotropic murine leukaemia virus-related virus in Chinese patients with chronic fatigue syndrome

Ping Hong,Yongzhe Li,Jinming Li

doi:10.1186/1743-422x-7-224

Abstract

BackgroundRecent controversy has surrounded the question of whether xenotropic murine leukaemia virus-related virus (XMRV) contributes to the pathogenesis of chronic fatigue syndrome (CFS). To investigate the question in a Chinese population, 65 CFS patients and 85 blood donor controls were enrolled and multiplex real-time PCR or reverse transcriptase PCR (RT-PCR) was developed to analyze the XMRV infection status of the study participants. The assay was standardized by constructing plasmid DNAs and armored RNAs as XMRV standards and competitive internal controls (CICs), respectively.ResultsThe sensitivities of the multiplex real-time PCR and RT-PCR assays were 20 copies/reaction and 10 IU/ml, respectively, with 100% specificity. The within-run precision coefficient of variation (CV) ranged from 1.76% to 2.80% and 1.70% to 2.59%, while the between-run CV ranged from 1.07% to 2.56% and 1.06% to 2.74%. XMRV was not detected in the 65 CFS patients and 65 normal individuals out of 85 controls.ConclusionsThis study failed to show XMRV in peripheral blood mononuclear cells (PBMCs) and plasma of Chinese patients with CFS. The absence of XMRV nucleic acids does not support an association between XMRV infection and the development of CFS in Chinese.

Highlights

Recent controversy has surrounded the question of whether xenotropic murine leukaemia virusrelated virus (XMRV) contributes to the pathogenesis of chronic fatigue syndrome (CFS)
We developed sensitive multiplex real-time PCR and reverse transcriptase PCR (RT-PCR) assays, using a competitive internal control (CIC) strategy to ensure PCR integrity and eliminate false-negative results, to detect XMRV proviral DNA and viral RNA, respectively, in the peripheral blood mononuclear cells (PBMCs) and plasma of Chinese CFS patients
Sequencing demonstrated that the exogenous chimeric sequences were successfully inserted into the pACYCMS2 vector

Summary

Introduction

Recent controversy has surrounded the question of whether xenotropic murine leukaemia virusrelated virus (XMRV) contributes to the pathogenesis of chronic fatigue syndrome (CFS). To investigate the question in a Chinese population, 65 CFS patients and 85 blood donor controls were enrolled and multiplex realtime PCR or reverse transcriptase PCR (RT-PCR) was developed to analyze the XMRV infection status of the study participants. In previous studies of XMRV detection [4,5,6,7], non-competitive ICs, such as GAPDH, were used to monitor for false-negative reactions. The non-competitive ICs may introduce different amplification efficiencies due to their natural inter-individual variation, and may produce false-negative results. This matter is of considerable importance in the extensive controversy surrounding XMRV detection in CFS patients

Methods

Results

Conclusion