Pleurisy as a novel clinical manifestation associated with human herpesvirus 6 after unrelated cord blood transplantation

Abstract

We report the case of a 45-year-old male patient who developed human herpesvirus 6 (HHV6)-associated pleurisy after an unrelated cord blood transplantation (CBT) for acute lymphoblastic leukemia. A large amount of pleural effusion accompanied by interstitial pneumonitis was noted on the right side on day 37 posttransplantation. A real-time quantitative PCR (RQ-PCR) assay revealed that the HHV6 viral load was substantially higher in the pleural effusion than in the peripheral blood plasma at the onset of pleurisy, with 2.2 × 102 and 7.9 × 103 copies of HHV6 DNA/mL in the peripheral blood plasma and the supernatant of the pleural effusion, respectively. Moreover, HHV6 DNA was still detected in the pleural effusion after antiviral therapy. Therefore, the pleural cavity may have been the primary site of HHV6 replication in the present case. To our knowledge, the present study is the first detailed report of adult HHV6-associated pleurisy after CBT. HHV6-associated pleurisy should be considered a potential complication when pleural effusion of unknown cause is encountered after CBT, even in the absence of HHV6 DNA in the peripheral blood.