title: Measurement of human cytomegalovirus loads by quantitative real-time PCR for monitoring clinical intervention in transplant recipients.
abstract: Quantitative monitoring of human cytomegalovirus (HCMV) infection is helpful in determining appropriate antiviral management of transplant recipients. Quantitative PCR technologies have demonstrated accuracy in measuring systemic HCMV loads. A total of 298 consecutive whole-blood specimens submitted to the Clinical Virology Laboratory at Vanderbilt University Medical Center from 15 February to 31 October 1999 were included in the study. In addition to a qualitative colorimetric microtiter plate PCR assay (MTP-PCR) and a semiquantitative pp65 antigenemia assay, each specimen was measured for HCMV loads by a quantitative PCR assay performed on an ABI PRISM 7700 Sequence Detection System (TaqMan). Compared to results of the MTP-PCR, the sensitivity, specificity, positive predictive value, and negative predictive value were 70.5, 97.5, 87.8, and 92.8% for the antigenemia assay and were 96.7, 92.0, 75.6, and 99.1% for the TaqMan assay, respectively. There was a high correlation between antigenemia values and HCMV loads as determined by the TaqMan (r = 0.989; P < 0.001). Antigenemia values of 0, 1 to 10, 11 to 100, 101 to 1,000, and over 1,000 positive cells per 2 x 10(5) leukocytes corresponded to median HCMV loads measured by TaqMan of 125, 1,593, 5,713, 16,825, and 5,425,000 copies/ml, respectively. Corresponding to antigenemia values of 1 to 2, 10, and 50 positive cells per 2 x 10(5) leukocytes, HCMV viral loads of 1,000, 4,000, and 10,000 copies/ml are proposed as cutoff points for initiating antiviral therapy in patient groups with high, intermediate, and low risk of CMV diseases.
authors.affiliation: Department of Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee 37232, USA.
authors.forename: Haijing
authors.initials: H
authors.lastname: Li
authors.forename: J Stephen
authors.initials: JS
authors.lastname: Dummer
authors.forename: Wray R
authors.initials: WR
authors.lastname: Estes
authors.forename: Shufang
authors.initials: S
authors.lastname: Meng
authors.forename: Peter F
authors.initials: PF
authors.lastname: Wright
authors.forename: Yi-Wei
authors.initials: YW
authors.lastname: Tang
mesh_terms: D003587:Cytomegalovirus / Q000502:physiology*; D003586:Cytomegalovirus Infections / Q000821:virology; D006801:Humans; D016133:Polymerase Chain Reaction / Q000379:methods*; D014180:Transplantation; D019737:Transplants / Q000009:adverse effects; D019562:Viral Load