Plasma HHV-6 viral load-guided preemptive therapy against HHV-6 encephalopathy after allogeneic stem cell transplantation: a prospective evaluation

• DOI: 10.1038/sj.bmt.1705907
• Publication Date: 2007-11-26T12:43:19Z
• Authors: M Ogata; T Satou; R Kawano; K Goto; J Ikewaki; K Kohno; T Ando; Y Miyazaki; E Ohtsuka; Y Saburi; T Saikawa; J-i Kadota
• Keywords: Adult; Male; Adolescent; Herpesvirus 6, Human; Hematopoietic Stem Cell Transplantation; Roseolovirus Infections; Kaplan-Meier Estimate; Middle Aged; Viral Load; Antiviral Agents; Chemoprevention; 3. Good health; 03 medical and health sciences; Treatment Outcome; 0302 clinical medicine; DNA, Viral; Humans; Transplantation, Homologous; Female; Encephalitis, Viral; Prospective Studies; Ganciclovir

Human herpesvirus 6 (HHV-6) causes life-threatening encephalopathy in recipients of allogeneic SCT, but no consensus has been reached regarding appropriate preventive methods. This study evaluated a plasma HHV-6 viral load-guided preemptive approach against HHV-6-associated encephalopathy. Plasma real-time PCR assay was performed once a week. Among 29 patients, 19 developed positive plasma HHV-6 DNA. Median maximum plasma HHV-6 DNA was 4593.5 copies/ml plasma (range, 150.0-127 891.0 copies/ml plasma). In one of eight events with low-level HHV-6 DNA (defined as <1000 copies/ml plasma) and four of seven events with mid-level HHV-6 DNA (1000-9999.5 copies/ml plasma), HHV-6 loads in plasma subsequently continued increasing. Ganciclovir was administered against six of nine patients with high-level HHV-6 DNA (> or =10,000 copies/ml plasma). High-level HHV-6 DNA resolved similarly in both groups with or without ganciclovir therapy. Among the nine patients with high-level HHV-6 DNA two developed encephalopathy. As encephalopathy developed before the detection of high-level HHV-6 DNA in plasma, these two patients had not received preemptive ganciclovir therapy. In conclusion, our preemptive approach against HHV-6-associated encephalopathy cannot prevent all cases of HHV-6 encephalopathy in SCT recipients due to the dynamic kinetics of plasma HHV-6 viral load.