title: The immunophenotype of bone marrow lymphocytes in children with immune thrombocytopenic purpura.
abstract: OBJECTIVE
  Primary immune thrombocytopenic purpura (ITP), caused by immune system dysfunction, is recognized as the leading cause of thrombocytopenia in pediatric population. Nonetheless, inadequate studies have been performed on bone marrow immunophenotyping of children with ITP. In this study, we aimed to investigate the immunophenotype of bone marrow lymphocytes in these children.
  
  
  METHODS
  Between 2008 and 2012, 35 children with ITP and 26 age and sex matched healthy controls were recruited. All participants underwent bone marrow aspiration. Appropriate B-cell, T-cell, and myeloid lineage monoclonal antibodies were employed to determine the immunophenotype of these patients.
  
  
  RESULTS
  CD10, CD19, and CD20, all indicative of premature B-cell markers, were significantly greater in children with ITP. CD22, mainly expressed on mature B cells was slightly, but not significantly reduced in the patients' group (P = .42). On the other hand, T cell markers including CD2, CD3, CD5, and CD7 were underexpressed. CD33, a specific marker for myeloid lineage, was underexpressed in the patients' group (5.6 ± 4.7 vs. 12.9 ± 7.3, P < .001). Noteworthy, the immunophenotype did not significantly differ between acute and persistent cases.
  
  
  CONCLUSIONS
  Overall, a phenotype characterized by increased pre-B-cell markers along with decreased T cell immunophenotypic markers was observed in bone marrow lymphocytes of children with ITP in the present study. Further larger scale studies are recommended to confirm our findings, as precise mapping of the immunophenotype of lymphocytes in these patients would pave the road to improved diagnosis and treatment.
authors.affiliation: Pediatric Congenital Hematologic Disorders Research Center, Mofid Children's Hospital, Shahid Beheshti University of Medical Sciences , Tehran , Iran.
authors.forename: Samin
authors.initials: S
authors.lastname: Alavi
authors.forename: Zahra
authors.initials: Z
authors.lastname: Aryan
authors.forename: Farid
authors.initials: F
authors.lastname: Ghazizadeh
authors.forename: Nahid
authors.initials: N
authors.lastname: Arabi
authors.forename: Mahin
authors.initials: M
authors.lastname: Nikougoftar
authors.forename: Maryam
authors.initials: M
authors.lastname: Ebadi
mesh_terms: D000293:Adolescent; D001402:B-Lymphocytes / Q000276:immunology* / Q000473:pathology; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D016130:Immunophenotyping; D007223:Infant; D016131:Lymphocyte Subsets / Q000276:immunology / Q000473:pathology; D008297:Male; D022423:Myeloid Cells / Q000276:immunology* / Q000473:pathology; D016553:Purpura, Thrombocytopenic, Idiopathic / Q000276:immunology* / Q000473:pathology*; D013601:T-Lymphocytes / Q000276:immunology* / Q000473:pathology
keywords: bone marrow lymphocytes; cellular immunology; childhood; immune thrombocytopenic purpura; immunophenotype