Surveillance of Active Human Herpesvirus 6 Infection in Chinese Patients after Hematopoietic Stem Cell Transplantation with 3 Different Methods

Abstract

Human herpesvirus 6 (HHV-6) reactivation was studied in 72 consecutive allogeneic hematopoietic stem cell transplant (HSCT) recipients and 53 "healthy" donors. The feasibilities of real-time quantitative polymerase chain reaction (RQ-PCR), nested-PCR, and antigenemia assays in the assessment of HHV-6 reactivation were also evaluated. HHV-6 DNA was detected in 62.5% and 48.6% of post-HSCT patients with the nested-PCR assay and RQ-PCR analysis, respectively, and HHV-6B was identified as the predominant variant. The incidence of HHV-6 infection peaked from the second to the seventh week, whereas the HHV-6B DNA loads peaked from the second to the third week. Compared with RQ-PCR analysis, the sensitivity and specificity of the nested-PCR assay were 100% and 88%, respectively, with positive and negative predictive values of 60% and 99%, respectively. For the HHV-6 antigenemia assay, the sensitivity and specificity were 89% and 97%, respectively, and the positive and negative predictive values were both 94%. Conditioning with antithymocyte globulin in HLA-mismatched or unrelated HSCT increased the possibility of HHV-6B reactivation after HSCT (hazard ratio, 5.92; 95% confidence interval, 1.99-17.59; P = .001). In conclusion, HHV-6B reactivation is commonly encountered after HSCT. Of the 3 methods we adopted for HHV-6 detection, both RQ-PCR analysis and the antigenemia assay could be seen as essential tests for predicting HHV-6 reactivation.