الفهرس | Only 14 pages are availabe for public view |
Abstract B-acute lymphoblastic leukemia (B-ALL) is the most common acute leukemia in children and also can occur in adults. It is an aggressive but potentially curable disease in which monitoring the immediate and early response to therapy is of critical importance for optimal management. Current management protocols require assessment of residual leukemic cells at defined intervals after initiation of chemotherapy. CD123 molecule is encoded by IL-3R as one family member of hematopoietic growth factor receptors, which expressed in undifferentiated leukemia cells. The present study selected pediatric patients with B-ALL at diagnosis and at day 28 to characterize the expression of CD34/CD123 on leukemic blasts to distinguish residual leukemic blasts and compare it with discordant expression pattern on normal B-cell precursors (hematogones)This study involved 50 children grouped as follows: ● Control group (group A): included 20 children as a control. ● Patient group (group B): included 30 pediatric B-ALL cases. All groups were subjected to complete medical history, physical examination and laboratory investigations including complete blood count, bone marrow examination and immunophenotypic classification. Summary & conclusion In addition, patient group were subjected to flowcytometric analysis of CD34/CD123 expression on leukemic blasts in newly diagnosed B- ALL and after induction therapy, and also control group to characterize the normal pattern of expression in hematogones. ● There were significant decrease in TLC, blast percentage and significant increase in hemoglobin concentration and platelet count at day 28 when compared to same parameters at diagnosis. ● There was a significant increase in CD34 expression on ALL blasts when compared to hematogones with moderate CD45 expression in control. Also there were significant differences in CD34 positivity on ALL blasts when compared to hematogones with either dim or moderate CD45 expression, but there was no significant difference between CD34 expressions ALL blasts when compared to hematogones with dim CD45 expression. ● There was significant increase in CD123 expression on ALL blasts when compared to hematogones with either dim or moderate CD45 expression in control. Also there was significant difference in CD123 positivity in ALL blasts when compared to hematogones with dim CD45 expression, but there was no significant difference between CD123 positivity in ALL blasts when compared to hematogones with moderate CD45 expression. There were significant differences between CD34/ CD123 patterns of expression in ALL blasts when compared to hematogones with either dim or moderate CD45. 154expressions and positivity were decreased significantly in day 28 when compared to those measured at diagnosis. Although CD34+/CD123+ (double positive) population expressions were decreased significantly in day 28 when compared to those measured at diagnosis; positivity did not reach significant level. There were no statistical significant difference in each of the age, gender and laboratory data in different CD34/CD123 patterns of expression; at diagnosis and at day 28 of studied ALL cases. There were no significant differences between common B and pre- B immunophenotypes in different CD34/CD123 patterns of expression; at diagnosis and at day 28. There were no significant differences in clinical outcome in different CD34/CD123 patterns of expression; at diagnosis and at day 28 and in both positive and negative MRD at day 28. There were no significant differences between patients having normal and those having abnormal cytogenetics in different CD34/CD123 patterns of expression; at diagnosis and at day 28. There were no significant differences in CD33 positivity in different CD34/CD123 patterns of expression; at diagnosis and at day 28 and in both positive and negative MRD. Also there were no significant differences in clinical outcome in both positive and negative CD33. There were no significant differences in survival times in different CD34/CD123 patterns of expression. Also there were no significant differences between survival times in both positive and negative MRD. The present study reported that there was a discordant pattern of CD34/CD123 expression on hematogones and a concordant pattern of CD34/CD123 expression on B-ALL blasts. This distinction is useful in correctly differentiating small populations of residual blasts from hematogones |