2017, Number 2
CD19 and CD22 expression in patients with acute lymphoblastic leukemia: relationship with age and morphological variants
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ABSTRACTBackground: Flow cytometry is a diagnostic tool applied in cases of acute lymphoblastic leukemia (ALL) to identify markers in neoplastic clones and to classify the lineage and maturation degree.
Objetive: To establish the frequency of CD19 and CD22 expression and to identify if there is variation of expression between the different age groups
Material and Method: A retrospective, cross-sectional, observational study based on the records of patients attended from July 2009 to June 2015 with diagnosis of de novoALL. The samples for immunophenotype by flow cytometry were bone marrow or peripheral blood in patients with hyperleukocytosis or difficult to obtain bone marrow. Samples should contain ›20% blasts.
Results: A total of 208 cases were studied with a mean age of 32 (2-88) years old. The 68% (n=141) were samples of bone marrow and the rest of peripheral blood (32%, n=67). It was identified that 193 cases (93%) showed B-type immunophenotype, 12 of T-lineage (5.5%) and 3 were non-classifiable (1.5%). The common B variant was the most frequent phenotype in all age groups. The 90% (n=176) was CD22 +, with a mean expression of 63%. The 91% (n=179) was CD19+, with a mean expression of 76%. Age did not influence expression of these markers (p›0.05).
Conclusions: The analyzed cell markers were frequently expressed, unaffected by the patient’s age. The immunophenotype in ALL patients is indispensable to offer them highly specific treatments.
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Topp MS, Gokbuget N, Zugmaier G, Klappers P, Stelljes M, Neumann S, et al. Phase II trial of the anti-CD19 bispecific T Cell-Engager blinatumomab shows hematologic and molecular remissions in patients with relapsed or refractory B-precursor acute lymphoblastic leukemia. J Clin Oncol 2014;32:4134-40.