Minimal Residual Disease (MRD) is the most important independent prognostic factor in acute lymphoblastic leukemia (ALL) and refers to the deep level of measurable disease in cases with complete remission by conventional pathologic analysis, especially by cytomorphology. MRD can be detected by multiparametric flow cytometry, molecular approaches such as quantitative polymerase chain reaction for immunoglobulin and T‐cell receptor (IG/TR) gene rearrangements or fusion genes transcript, and high‐throughput sequencing for IG/TR. Despite the proven clinical usefulness in detecting MRD, these methods have differences in sensitivity, specificity, applicability, turnaround time and cost. Knowing and understanding these differences, as well as the principles and limitations of each technology, is essential to laboratory standardization and correct interpretation of MRD results in line with treatment time points, therapeutic settings, and clinical trials. Here, we review the methodological approaches to measure MRD in ALL and discuss the advantages and limitations of the most commonly used techniques.
Objective: To validate multilineage score system correlating results of flow cytometry, cytogenetics, cytomorphology and histology from samples of patients with suspected myelodysplastic syndrome or cytopenia of unknown origin. Methods: A retrospective study analyzing laboratory data of 49 patients with suspected myelodysplastic syndrome or cytopenia of unknown origin, carried out between May and September 2017. The inclusion criteria were availability of flow cytometry results, and at least one more method, such as morphology, histology or cytogenetics. Thirtyeight patients were classified as diagnosis of myelodysplastic syndromes, whereas 11 were classified as normal. Patients were evaluated based on score systems, Ogata score and flow cytometry multilineage score. Results: Comparing the scores obtained in the Ogata score and the multilineage score, it was observed that in four cases the Ogata score was zero or 1 point, while the multilineage score was higher than 3 points. In addition, in 12 cases with Ogata score of 2, the multilineage score was greater than 3. Conclusion: The flow cytometry multilineage score system demonstrated to be more effective in dysplasia analysis, by assessing the erythroid, monocytic, granulocytic and precursor cell lineages, apart from the parameters evaluated by the Ogata score.
Multiparameter flow cytometry (MFC) has been used for diagnosis and monitoring of hematological malignancies and enables detection of immunophenotype different from normal (DfN) and leukemia-associated immunophenotypes (LAIP). MFC is useful for measurement of minimal residual disease (MRD), especially in B-cell acute lymphoblastic leukemia (B-ALL). [1][2][3] Conventional flow cytometry (FC) testing can achieve a sensitivity of 10 À3 to 10 À5 , depending on technical standardization, device configuration, and number of events analyzed. Some research groups
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.