title: Clinical comparison of branched DNA and reverse transcriptase-PCR and nucleic acid sequence-based amplification assay for the quantitation of circulating recombinant form_BC HIV-1 RNA in plasma.
abstract: OBJECTIVE
  To investigate the correlation between three viral load assays for circulating recombinant form (CRF)_BC.
  
  
  METHODS
  Recent studies in HIV-1 molecular epidemiology, reveals that CRF_BC is the dominant subtype of HIV-1 virus in mainland China, representing over 45% of the HIV-1 infected population. The performances of nucleic acid sequence-based amplification (NASBA), branched DNA (bDNA) and reverse transcriptase polymerase chain reaction (RT-PCR) were compared for the HIV-1 viral load detection and quantitation of CRF_BC in China.
  
  
  METHODS
  Sixteen HIV-1 positive and three HIV-1 negative samples were collected. Sequencing of the positive samples in the gp41 region was conducted. The HIV-1 viral load values were determined using bDNA, RT-PCR and NASBA assays. Deming regression analysis with SPSS 12.0 (SPS Inc., Chicago, Illinois, USA) was performed for data analysis.
  
  
  RESULTS
  Sequencing and phylogenetic analysis of env gene (gp41) region of the 16 HIV-1 positive clinical specimens from Guizhou Province in southwest China revealed the dominance of the subtype CRF_BC in that region. A good correlation of their viral load values was observed among three assays. Pearson's correlation between RT-PCR and bDNA is 0.969, Lg(VL)RT-PCR = 0.969 * Lg(VL)bDNA + 0.55; Pearson's correlation between RT-PCR and NASBA is 0.968, Lg(VL)RT-PCR = 0.968 * Lg(VL)NASBA + 0.937; Pearson's correlation between NASBA and bDNA is 0.980, Lg(VL)NASBA = 0.980 * Lg(VL)bDNA - 0.318.
  
  
  CONCLUSIONS
  When testing with 3 different assays, RT-PCR, bDNA and NASBA, the group of 16 HIV-1 positive samples showed the viral load value was highest for RT-PCR, followed by bDNA then NASBA, which is consistent with the former results in subtype B. The three viral load assays are highly correlative for CRF_BC in China.
authors.affiliation: National Center for AIDS/STD Control and Prevention, Beijing, China.
authors.forename: Pinliang
authors.initials: P
authors.lastname: Pan
authors.forename: Xiaoxia
authors.initials: X
authors.lastname: Tao
authors.forename: Qi
authors.initials: Q
authors.lastname: Zhang
authors.forename: Wenge
authors.initials: W
authors.lastname: Xing
authors.forename: Xianguang
authors.initials: X
authors.lastname: Sun
authors.forename: Lijian
authors.initials: L
authors.lastname: Pei
authors.forename: Yan
authors.initials: Y
authors.lastname: Jiang
mesh_terms: D021121:Branched DNA Signal Amplification Assay; D002681:China; D015752:Genes, env; D005838:Genotype; D015700:HIV Envelope Protein gp41 / Q000235:genetics; D015658:HIV Infections / Q000097:blood / Q000821:virology*; D015497:HIV-1 / Q000145:classification / Q000235:genetics / Q000302:isolation & purification*; D006801:Humans; D021141:Nucleic Acid Amplification Techniques; D010802:Phylogeny; D012367:RNA, Viral / Q000097:blood*; D015203:Reproducibility of Results; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods*; D012680:Sensitivity and Specificity; D019562:Viral Load / Q000379:methods*; D014766:Viremia / Q000821:virology*
chemical_list: D015700:HIV Envelope Protein gp41; D012367:RNA, Viral