Tehran University Medical Journal (May 2007)
Comparison of HCMV DNA load and antigenemia results in hematopoietic transplant recipients based on GVHD grade
Abstract
Background: Human Cytomegalovirus (HCMV) infections are a significant challenge in patients with Hematopoietic Cell Transplant (HCT). Acute Graft vs. Host (GVHD) is recognized as a predisposing factor for increased incidence of HCMV reactivation. Availability of rapid and accurate tests for HCMV detection in HCT recipients is of foremost importance in developing countries, such as Iran. Methods: A total of 201 peripheral blood leukocyte (PBL) and plasma specimens from 26 allogeneic HCT recipients were examined for HCMV DNA by polymerase chain reaction (PCR) assay. Densitometric analysis of 257bp PCR products from clinical samples and 101-106 "cloned plasmid" per µg DNA containing a HCMV specific fragment were analyzed using LabWorks software (v3.0.02). Optical density of amplicons was plotted, and calculated HCMV viral loads were compared with the patients' antigenemia results. Results: HCMV viral loads ranged between <102 to 1.35×102 copies per µg DNA among 7 HCT patients. In addition, 14 episodes of positive antigenemia assay in 7 patients in which peak HCMV load were compared with GVHD grade II-IV patients. Significant correlation was also detected between HCMV DNA load in PBL and plasma samples, as well as HCMV DNA load in PBL samples and antigenemia results. Receiver–Operating Characteristic analysis determined that 2,200 HCMV copies in PBL samples as the threshold value for initiation of Ganciclovir therapy. Conclusion: This report shows that rapid and sensitive assays, like quantitative PCR, are extremely valuable for detection of active HCMV infection, and life-threatening HCMV disease in HCT recipients during the post transplant period. Furthermore, high HCMV DNA load among GVHD grade II-IV patients confirms the high risk of HCMV reactivation among these HCT recipients. Tests such as quantitative PCR also helps physicians initiate timely preemptive therapy and for a shorter period, which may lead to better clinical outcome in HCMV-infected transplant patients.
