title: Dried blood spot HIV-1 RNA quantification: a useful tool for viral load monitoring among HIV-infected individuals in India.
abstract: OBJECTIVE
  Monitoring of HIV-infected individuals on antiretroviral treatment (ART) ideally requires periodic viral load measurements to ascertain adequate response to treatment. While plasma viral load monitoring is widely available in high-income settings, it is rarely used in resource-limited regions because of high cost and need for sophisticated sample transport. Dried blood spot (DBS) as source specimens for viral load measurement has shown promise as an alternative to plasma specimens and is likely to be a useful tool for Indian settings. The present study was undertaken to investigate the performance of DBS in HIV-1 RNA quantification against the standard plasma viral load assay.
  
  
  METHODS
  Between April-June 2011, 130 samples were collected from HIV-1-infected (n=125) and non-infected (n=5) individuals in two district clinics in southern India. HIV-1 RNA quantification was performed from DBS and plasma using Abbott m2000rt system after manual RNA extraction. Statistical analysis included correlation, regression and Bland-Altman analysis.
  
  
  RESULTS
  The sensitivity of DBS viral load was 97 per cent with viral loads >3.0 log 10 copies/ml. Measurable viral load (>3.0 log 10 copies/ml) results obtained for the 74 paired plasma-DBS samples showed positive correlation between both the assays (r=0.96). For clinically acceptable viral load threshold values of >5,000 copies/ml, Bland-Altman plots showed acceptable limits of agreement (-0.21 to +0.8 log 10 copies/ml). The mean difference was 0.29 log 10 copies/ml. The cost of DBS was $2.67 lower compared to conventional plasma viral load measurement in the setting.
  
  
  CONCLUSIONS
  The significant positive correlation with standard plasma-based assay and lower cost of DBS viral load monitoring suggest that DBS sampling can be a feasible and economical means of viral load monitoring in HIV-infected individual in India and in other resource-limited settings globally.
authors: St. John's National Academy of Health Sciences, Bangalore, India.
authors: Ujjwal
authors: U
authors: Neogi
authors: Soham
authors: S
authors: Gupta
authors: Rashmi
authors: R
authors: Rodridges
authors: Pravat Nalini
authors: PN
authors: Sahoo
authors: Shwetha D
authors: SD
authors: Rao
authors: Bharat B
authors: BB
authors: Rewari
authors: Suresh
authors: S
authors: Shastri
authors: Ayesha De
authors: AD
authors: Costa
authors: Anita
authors: A
authors: Shet
mesh_terms: D000328:Adult; D059788:Dried Blood Spot Testing / Q000191:economics / Q000379:methods*; D015658:HIV Infections / Q000175:diagnosis* / Q000235:genetics; D015497:HIV-1 / Q000235:genetics*; D006801:Humans; D007194:India; D008875:Middle Aged; D012367:RNA, Viral / Q000097:blood / Q000302:isolation & purification*; D060888:Real-Time Polymerase Chain Reaction / Q000379:methods; D019562:Viral Load / Q000379:methods*
chemical_list: D012367:RNA, Viral
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