Transferred Herpes Simplex Virus Immunity after Stem-Cell Transplantation: Clinical Implications

Herpes simplex virus (HSV) commonly reactivates after stem-cell transplantation (SCT), despite acyclovir prophylaxis. Whether HSV-seropositive recipients with HSV-seronegative or type-discordant donors had more frequent and severe HSV infections than those with HSV type–concordant donors was explored. Banked serum samples from HSV-positive SCT recipients and their donors were tested for the presence of HSV antibodies. HSV-1–positive SCT recipients from HSV-1–negative donors had more frequent and longer episodes than HSV-1–positive SCT recipients from HSV-1–positive donors; the proportion of patients receiving antiviral treatment for >10% of follow-up days was 27.4% versus 7.2% (P