title: Dynamics in children and adolescents who experience varicella zoster virus             infections after haematopoietic stem cell transplantation: a case-control study.
abstract: We evaluated the incidence of varicella-zoster virus (VZV) infections, including herpes zoster (HZ), and investigated the associated risk factors for HZ and compared lymphocyte subsets of these patients at 1, 3 and 6 months following haematopoietic stem cell transplantation (HSCT) in a case-control study in children and adolescents. The incidence of HZ infection at the first year after HSCT was 17/125 (13·6%). The cumulative incidence of HZ infection was 22/125 (17·6%). Sixteen (73%) cases with HZ and 11 (32%) cases in the control group had a diagnosis of malignant disorder. No significant difference was noted between the HZ group and the control group in absolute lymphocyte number and subsets (except WBC) at the pre-transplant evaluation. Pre-transplant WBC count was statistically lower in the HZ group (P<0·05). The CD4/CD8 ratios were lower in the HZ group during the first 6 months after HSCT, and the decrease was statistically significant at 6 months compared to the control group. In conclusion, patients undergoing HSCT for a malignant disorder had a significantly higher risk of VZV infection than those with non-malignant disorders and pretransplant donor characteristics were not helpful in predicting risk of post-transplant VZV infection.
authors.affiliation: Hacettepe University Ihsan Dogramaci Children's Hospital, Haematology                     Unit, Ankara, Turkey.
authors.forename: S
authors.initials: S
authors.lastname: Aytaç
authors.forename: S S
authors.initials: SS
authors.lastname: Yalçin
authors.forename: O
authors.initials: O
authors.lastname: Küçükbayrak
authors.forename: M
authors.initials: M
authors.lastname: Çetın
authors.forename: D
authors.initials: D
authors.lastname: Uçkan
mesh_terms: D000293:Adolescent; D016022:Case-Control Studies; D002644:Chickenpox / Q000453:epidemiology*; D002648:Child; D002675:Child, Preschool; D005260:Female; D018380:Hematopoietic Stem Cell Transplantation / Q000009:adverse effects / Q000706:statistics & numerical data*; D006562:Herpes Zoster / Q000453:epidemiology*; D014645:Herpesvirus 3, Human / Q000302:isolation & purification*; D006801:Humans; D015994:Incidence; D007958:Leukocyte Count; D008297:Male; D012008:Recurrence; D012189:Retrospective Studies; D018709:Statistics, Nonparametric; D014421:Turkey / Q000453:epidemiology