title: Retracted: outcome and immune reconstitution of HBV-specific immunity in patients with reactivation of occult HBV infection after alemtuzumab-containing chemotherapy regimen.
abstract: Whether preemptive anti- hepatitis B virus (HBV) therapy should be considered in all hepatitis B surface antigen (HBsAg)-negative patients with occult HBV infection receiving alemtuzumab containing chemotherapy is uncertain. We determined the outcome and effect on HBV-specific immunity of an alemtuzumab-containing chemotherapy regimen in occult HBV-infected patients. Twenty-one consecutive occult HBV-infected patients treated with an alemtuzumab containing chemotherapy regimen were studied. T cell reactivity to HBV antigens and -peptides were quantified by ELISpot and the T cell subset by flow cytometry. Six of the 21 patients (28.6%) developed HBsAg seroreversion. The median (range) time to development of HBsAg seroreversion after the end of chemotherapy was 1.8 months (0.2-2.3 months). Direct sequencing showed that the occult HBV infection of all six patients (100%) was reactivated. These six patients developed severe HBV-related hepatitis. At the end of follow-up, four of these six patients (66.7%) had become negative for HBsAg again. Recovery of CD4+ T cell count and CD4+T cell reactivity against hepatitis B core antigen (HBcAg) occurred 9 months after the end of chemotherapy. Loss of HBsAg occurred after recovery of the CD4+T cell count and increased CD4+T cell reactivity against HBcAg 9 months after the end of chemotherapy.
  
  
  CONCLUSIONS
  An alemtuzumab-containing chemotherapy regimen is associated with a high risk of reactivation of occult HBV infection. Suppression of HBV immunity by an alemtuzumab-containing chemotherapy regimen would persist until 9 months after the end of chemotherapy. In occult HBV-infected patients receiving an alemtuzumab-containing chemotherapy regimen, preemptive anti-HBV therapy should be continued until 9 months after the end of chemotherapy, when recovery of HBV immunity has occurred.
authors.affiliation: Department of Microbiology, University of Hong Kong, Queen Mary Hospital, Hong Kong, Special Administrative Region, China. ckh23@hku.hk
authors.forename: Chee-Kin
authors.initials: CK
authors.lastname: Hui
authors.forename: Winnie W
authors.initials: WW
authors.lastname: Cheung
authors.forename: Kar-Wai
authors.initials: KW
authors.lastname: Leung
authors.forename: Vincent C C
authors.initials: VC
authors.lastname: Cheng
authors.forename: Bone S F
authors.initials: BS
authors.lastname: Tang
authors.forename: Iris W S
authors.initials: IW
authors.lastname: Li
authors.forename: John M
authors.initials: JM
authors.lastname: Luk
authors.forename: Nikki P
authors.initials: NP
authors.lastname: Lee
authors.forename: Yok-Lam
authors.initials: YL
authors.lastname: Kwong
authors.forename: Wing-Yan
authors.initials: WY
authors.lastname: Au
authors.forename: Kwok-Yung
authors.initials: KY
authors.lastname: Yuen
authors.forename: George K
authors.initials: GK
authors.lastname: Lau
authors.forename: Raymond
authors.initials: R
authors.lastname: Liang