Diagnosis and monitoring of cytomegalovirus infection by the quantification of viral load in dried blood spots samples

Abstract

Evaluation of: Limaye AP, Santo Hayes TK, Huang ML, et al. Quantitation of cytomegalovirus DNA load in dried blood spots correlates well with plasma viral load. J. Clin. Microbiol. 51, 2360–2364 (2013).

Cytomegalovirus (CMV) represents the major infectious cause of birth defects, as well as an important pathogen for immune-compromised individuals. Several studies described the use of dried blood spots (DBS) for the detection of CMV DNA for late diagnosis of congenital CMV infection in cases of strong clinical suspicion. In the article under evaluation, Limaye et al. perform for the first time the quantification of CMV in pairs of finger-stick DBS and plasma samples collected from transplant patients. The work concluded that finger-stick DBS could be an alternative sample type for quantification of CMV load that correlates well with plasma levels. Prospective trials to evaluate the use of DBS for monitoring CMV load in transplant recipients will be required.

Keywords::

• congenital infection
• cytomegalovirus
• dried blood spots
• transplant patient
• viral load

Acknowledgements

English text edited by Lucy Scioscia.

Financial & competing interests disclosure

The authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending or royalties.

No writing assistance was utilized in the production of this manuscript.

Key issues

• In literature, the sensitivity of detection of cytomegalovirus (CMV) DNA in dried blood spots (DBS) samples in order to identify congenital CMV infection varies considerably.

• In studies that included a high proportion of symptomatic congenitally infected newborns, the sensitivity of detection of CMV DNA in DBS samples was excellent.

• In transplant patients, the risk of CMV disease and its severity is correlated directly to viral load.

• DBS could be an alternative sample type for quantification of CMV load that correlates well with plasma levels.

• DBS cards are already used for diagnosis and therapy monitoring of HIV infection.

• Testing CMV DNA on DBS presents several technical critical points.

• Further studies are necessary for improvement of the sensitivity of the DBS assay.

• Further studies are necessary for minimizing the variability of the DBS assay.

• Further studies are necessary for standardization of operational procedures of DBS assay.