Quantitation of cytomegalovirus DNA load in dried blood spots correlates well with plasma viral load

J Clin Microbiol. 2013 Jul;51(7):2360-4. doi: 10.1128/JCM.00316-13. Epub 2013 May 15.

Abstract

An assay to accurately quantitate cytomegalovirus (CMV) load in finger-stick-collected dried blood spots (DBS) could potentially be useful for field studies or for analyzing patient self-collected specimens. We therefore assessed CMV DNA load in paired venipuncture-collected plasma samples and finger-stick DBS, using a previously validated quantitative PCR assay. Assay variability, sensitivity, and changes in viral load during antiviral therapy in finger-stick DBS were compared to the reference plasma quantitative PCR assay, using 106 prospectively collected pairs of finger-stick DBS and plasma samples from 35 solid-organ transplant (SOT) patients. The DBS assay showed good agreement with the reference plasma viral load assay on the log10 scale (Pearson correlation coefficient, 0.92; P < 0.001). The 95% limit of detection of the DBS assay was estimated at 2,700 plasma copies/ml (675 plasma IU/ml). In 94% (76/81) of paired DBS and plasma samples above the limit of detection, the difference in CMV load was <1 log10. CMV viral load changes during antiviral treatment were comparable in plasma and DBS. We conclude that finger-stick DBS provides a convenient sample type for quantitation of CMV load that correlates well with plasma levels. Future studies to optimize and evaluate this methodology for patient self-collected samples are warranted.

Publication types

  • Comparative Study
  • Evaluation Study
  • Research Support, N.I.H., Extramural

MeSH terms

  • Adult
  • Aged
  • Blood / virology*
  • Cytomegalovirus / isolation & purification*
  • Cytomegalovirus Infections / virology
  • DNA, Viral / isolation & purification
  • Desiccation*
  • Female
  • Humans
  • Male
  • Middle Aged
  • Plasma / virology*
  • Prospective Studies
  • Reproducibility of Results
  • Sensitivity and Specificity
  • Specimen Handling / methods*
  • Transplantation
  • Viral Load / methods*

Substances

  • DNA, Viral