A group from the Rambam Health Care Campus in Israel has reported that the use of Bortezomib, known commercially as Velcade, may increase the risk of HHV-6 reactivation in myeloma patients undergoing stem cell transplantation. Bortezomib is a compound with FDA approval for the treatment of multiple myeloma and mantle cell lymphoma (NCI 2013). However, because Bortezomib can reportedly induce T-cell inactivation, use of this compound has led to the increased incidence of herpes zoster as well (Kim 2008). One earlier report describes a case of drug-induced hypersensitivity syndrome (DIHS) and HHV-6 reactivation as a result of a reaction to Bortezomib therapy in a patient with myeloma (Hattori 2009).
Interestingly, this is not the first time that an agent used in a transplant conditioning regimen has been correlated with increased HHV-6 reactivation. Researchers have previously suggested a similar correlation with regimens such as myeloblative conditioning (Chevallier 2010), alemtuzumab conditioning (Vu 2007), and ATG conditioning (Wang 2006). However, ATG conditioning has also been found to have no significant impact on HHV-6 reactivation in a recent study (Hill 2012).
In addition, the group found that at least 1/3 of all episodes of post-engraftment unexplained fever (PEUF) are a result of HHV-6 reactivation. Exposure to steroids was also found to be correlated with HHV-6 reactivation in this study, which has been previously described.