HHV-6 reactivation tied to increased mortality and acute GVHD in HSCT

Investigators from the University of Washington, Seattle Children’s Research Institute and Fred Hutchinson Cancer Research Center found high HHV-6 levels (>1,000 DNA copies/mL) associated with both increased mortality and acute graft-versus-host disease (GVHD) grades II-IV (p<0.001). High-level HHV-6 with acute GVHD grades II-IV activation and stages 3-4 skin acute GVHD (p=0.04) were associated with HHV-6 reactivation, and an even stronger association was reported with high-level HHV-6 reactivation (p=0.03). All HHV-6 infections were type B.

The authors also report an association between HHV-6 reactivation and subsequent cytomegalovirus (CMV) reactivation; high-level HHV-6 reactivation was found to be associated with an increased risk of subsequent high-level CMV reactivation (p=0.002).

Finally, the authors also found that high-level HHV-6 reactivation was significantly associated with non-relapse mortality (p=0.02). Of the 40 patients who died from non-relapse mortality 17 (43%) had a fatal infection.

Of 315 post-HSCT patients prospectively studied, 111 (35%) were found to have HHV-6 plasma viremia.

For more information on the dangers of HHV-6 reactivation in transplantation, visit our webpage on HHV-6 & Transplant Complications.