HHV-6 Reactivation linked to complications in Allogenic Stem Cell Transplantation

HSCT specialists from France studied 235 allo-SCT patients and found that HHV-6 reactivation was significantly associated with interstitial pneumonia, pleurisy, encephalitis, epileptic seizures, and acute & high-grade acute Graft-versus-host-disease (GVHD).

112 (48%) experienced early reactivation of HHV-6. Myeloablative conditioning and the use of cord blood as a stem cell source were identified as significant risk factors for HHV-6 reactivation.

Furthermore, antiviral therapy had a beneficial effect and was recommended by the authors. A total of 44 symptomatic patients received antiviral therapy, and a treatment response was observed in 34 of 38 evaluable patients (89%). Of these, 14 patients achieved a negative HHV-6 result and 20 experienced significantly decreased HHV-6 load in response to antiviral therapy. The duration of HHV-6 reactivation was shorter in patients who received antiviral treatment compared with those who were not treated.

The group concludes that “careful monitoring of HHV-6 viral load is important” in patients undergoing allo-SCT, as early detection of HHV-6 and related clinical symptoms can be suggestive of acute GVHD. Furthermore, they suggest that proper antiviral treatment for this complication should become a focus of future hematological research. They recommend that all patients undergoing allo-SCT be monitored for HHV-6, particularly patients who are receiving cord blood as a stem cell source and who are experiencing symptoms related to HHV-6 reactivation post-transplantation, and antiviral treatment with foscarnet and/or ganciclovir be strongly considered for patients suspected of early HHV-6 reactivation.

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