PURPOSE: 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. PATIENTS AND 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. CONCLUSION: 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.
PURPOSE: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. PATIENTS AND 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. CONCLUSION: 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.