title: CD4+ T-lymphocytopenia in long-term survivors following intensive chemotherapy in childhood cancers.
abstract: BACKGROUND
  It is generally believed the effects of short intensive courses of therapy are rapidly reversible in childhood cancers, and immunologic function following years of maintenance treatment with chemotherapy usually returns to normal by 6 months or less when treatment is terminated. However, we previously demonstrated that dysregulation of immunoglobulins, especially IgD, was observed in long-term survivors following intensive chemotherapy in cancer patients. With regard to cellular immunity, investigators reported that antineoplastic chemotherapy significantly reduces the number of CD4+ T-lymphocytes, and production of newly developing CD4+ T-lymphocytes was inversely related to the patients' age. However, the incidence of CD4+ lymphocytopenia in long-term survivors of childhood cancers is not known.
  
  
  METHODS
  Here, we report the flow cytometric analysis of peripheral blood from long-term survivors who continue complete remission off chemotherapy for more than 5 years.
  
  
  RESULTS
  Six out of 74 long-term survivors (8.1%), showed low CD4+ T-lymphocyte count (<300/mm3). Three of six patients showed continued CD4+ T-lymphocytopenia over a year. In spite of the persistent low levels of CD4+ T cells, these three patients were not susceptible to severe infections.
  
  
  CONCLUSIONS
  Intriguingly, in patients with CD4+ T-lymphocytopenia there has been a tendency toward increased numbers of natural killer cells or gamma delta T cells that may be operating as a thymus-independent compensatory mechanism to defend the hosts.
authors.affiliation: Department of Pediatrics and Clinical Immunology, Mie University School of Medicine, Tsu, Japan.
authors.forename: E
authors.initials: E
authors.lastname: Azuma
authors.forename: M
authors.initials: M
authors.lastname: Nagai
authors.forename: J
authors.initials: J
authors.lastname: Qi
authors.forename: M
authors.initials: M
authors.lastname: Umemoto
authors.forename: M
authors.initials: M
authors.lastname: Hirayama
authors.forename: T
authors.initials: T
authors.lastname: Kumamoto
authors.forename: S
authors.initials: S
authors.lastname: Hiratake
authors.forename: Y
authors.initials: Y
authors.lastname: Komada
authors.forename: M
authors.initials: M
authors.lastname: Sakurai
mesh_terms: D000293:Adolescent; D000328:Adult; D000970:Antineoplastic Agents / Q000009:adverse effects*; D018791:CD4 Lymphocyte Count; D015496:CD4-Positive T-Lymphocytes / Q000187:drug effects*; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D008231:Lymphopenia / Q000139:chemically induced* / Q000276:immunology; D008297:Male; D009369:Neoplasms / Q000188:drug therapy*
chemical_list: D000970:Antineoplastic Agents