النمط الظاهري المناعي لحالات سرطان الدم الليمفاوي الحاد لدى الأطفال الفلسطينيين من خلال تجربة مركز سرطان واحد في جنوب الضفة الغربية باستخدام جهاز التدفق الخلوي
اسامة نبيل غطاس سلامة
Ussama Nabeel Ghattas Salameh
Background: Acute Lymphoblastic Leukemia (ALL) is the most common cancer in children, represents approximately 75–80% of acute leukemia. Global incidence is about 3-4 cases per 100,000 population under 15 years old. Researches about pediatric ALL in Palestine are limited. This study provides the immunophenotyping of pediatric ALL patients at a single cancer center experience in southern west bank area in Palestine. Objectives: The main objectives of this study are to characterize the immunophenotypic pattern of pediatric ALL subtypes among Palestinians, highlight the importance of some clinical features according to age and immunophenotypic pattern in patients prognosis and response to treatment, and to determine the response to therapy after induction phase using the minimal residual disease (MRD) in time point 1 (day 33). Materials and Methods: This study is an incident study, was conducted from January 2015 to December 2015 at Huda Al-Masri pediatric cancer department at Beit-Jala hospital, which is located in the southern area of west bank in Palestine. A total of 15 consecutive children (7 females, 8 males) < than 14 years with newly diagnosed ALL were selected by pediatric oncologists at Huda Al-Masri pediatric cancer department at Beit-Jala hospital, this hospital is one of the largest pediatric centers for leukemia patients in Palestine. Archived data of pediatric ALL patients in their medical files were reviewed with ethical consideration of patient privacy to obtain some clinical features of the given patient. All cases either retrospective or incident were tested by College of American Pathologists (CAP)accreditation pathology department at King Hussein Cancer Center (KHCC) in Amman-Jordan on bone marrow aspirate samples collected in Ethylenediaminetetraacetic acid (EDTA) tubes according to a two step strategy using panels of monoclonal antibodies based on European Group for Immunological Characterization of Leukemia (EGIL). For the study purpose, the immunophenotyping of the incident target cases at 2015 was performed at Huda Al-Masri pediatric cancer department at Beit-Jala hospital in Bethlehem on bone marrow aspirate samples collected in EDTA tubes according to a two step strategy using Flow Cytometer, and for validation purpose, the achieved results were compared with the KHCC results of the same cases and no significant difference was notedMinimal Residual Disease results were evaluated by examining the most common antigens or CD markers through reactivity of fluorescent conjugated monoclonal antibodies directed against lymphoid associated antigens for each ALL type on the surface of bone marrow cells after the induction point 1 at day 33 of treatment by flow cytometry technique. Results: Statistical analysis of the results was performed, and the study group comprised 15 newly diagnosed acute lymphoblastic leukemia cases (<14 years). There were 7 females and 8 males with a male/female ratio of 1.14:1. The age distribution of the precursor B-cell ALL subtype showed that precursor B-cell ALL patients were younger with peak incidence between 2 and 5 years. Geographical distribution of Palestinian pediatric ALL showed that about half of the cases (46.7%) from Hebron governorate, but with the same percentage of cases diagnosed in Bethlehem governorate depending on the number of inhabitants. Immunophenotyping analysis showed that the precursor B-cell phenotype was encountered in 14 (93.3%) cases, mature B-cell in Zero (0%) cases, and T-cell in 1 (6.7%) case. Lineage Heterogeneity was found only in precursor B-cell ALL cases having one or two myeloid associated antigens (CD13,CD33) expressed on their blast cells. Lineage Heterogeneity for both antigens was found in 7.1% of precursor B-cell ALL cases. By the examining of MRD, we found that 13 of pediatric ALL cases (86.7%) were subjected to complete remission after the end of induction point 1 at day 33 with the only case of T-cell ALLand 85.7% of precursor B-cell ALL cases, but not statistically significant. Conclusion: This study is a unique study providing a clear idea about the munophenotyping of pediatric ALL cases at a single cancer center experience in southern west bank area in Palestine, and this immunophenotypic distribution was similar to the general immunophenotypic distribution pattern in developed countries. The age distribution showed a peak incidence between 2 and 5 years among the precursor B-cell ALL subtype as in developed countries. Geographical distribution of Palestinian pediatric ALL showed that about half of the cases (46.7%) from Hebron governorate, but with the same percentage of cases diagnosed in Bethlehem governorate depending on the number of inhabitants. The response to treatment for ALL patients was very good as in developed countries, due to the negative MRD at the end of induction point 1 at day 33 was 86.7% of ALL patients.
الكيمياء الحيوية والاحياء الجزيئية , Biochemistry & Molecular Biology