Yeni Tanı Pediatrik Akut Lenfoblastik Lösemide, Kemik İliği Biyopsisinde İmmünohistokimyasal Bulguların Akım Sitometrik Bulgular ile İlişkisinin Değerlendirilmesi

Abstract

Background and objectives: The development of new therapeutic options to treat leukemia (therapies targeting chimeric antigen receptor [CAR] T cells) down-regulates markers expressed on the cell surface. Therefore, conventional immunophenotyping panels no longer make these antigens unreliable for identifying a B cell immunophenotype. In our study, we methodically compared multiparametric flow cytometry (FC) in bone marrow aspiration and immunohistochemical (IHC) analysis in bone marrow biopsy in childhood acute lymphoblastic leukemia (ALL). We sought to answer whether these two methods could be alternatives to each other in the diagnosis of leukemia. Material-Method: Twenty-eight patients diagnosed with ALL were included in the study. A Kappa test was performed between the expression rates of the antibodies studied in simultaneous FC and IHC studies in bone marrow aspiration and biopsy samples performed at the initial diagnosis. Results: Twenty-three of the patients were precursor B-ALL (BCP-ALL) and 5 were T-ALL. In the immunophenotyping of patients with BCP-ALL using FC and IHC, MPO, CD79A, CD14, CD3 expressions were the same, while CD19, CD7, CD117, CD33, CD 56, CD34 expressions were very good, good concordance for CD20 expressions and moderate for CD10 expressions. In immunophenotyping of patients diagnosed with T-ALL using FC and IHC, CD20, CD19, CD14, CD79a, MPO, CD22 expressions were the same and excellent agreement was found in terms of CD2, CD10, CD34 expressions. Conclusion: In cases where there are treatments that affect immunophenotyping, costly methods such as FC are not available, or bone marrow aspiration cannot be taken adequately, immunophenotyping with IHC can be safely performed in the diagnosis of pediatric ALL in bone marrow biopsy.