Leukemia‐associated changes identified by quantitative flow cytometry: I. CD10 expression

Abstract

We have compared CDlO antigen expression in normal fetal bone marrow with that of B-lineage acute lymphoblastic leukemia (ALL). Both quantitative indirect immunofluoresence (QIFI) and direct immunofluorescence (IF) tests with Quantum beads were used to convert median fluorescence intensity (MFI) values into numbers of antigen molecules expressed per cell (AgE). Lymphoid precursors in the fetal marrow and liver expressed 3-12.5 x lo3 CD10 molecules/cell with an upper limit of 5 x 104/cell (MaxAgE). The median CDlO AgE in the different cases of acute B-lineage ALL were variable and ranged from undetectable to very high values (> 1.8 x lo5). In 24 of the 72 cases (33%) tested with QlFl the median CDlO AgE was above the highest values seen in normal samples (> 5 x 104/cell). An additional 23.6% of cases had higher median values than the normal median C D l O AgE. Next, CDlO antigen was quantitated in 78 cases during the routine multiparameter analysis of 8-lineage leukemia using CD1 O/class ll/CD34 3-color IF test or CDlO/TdT 2-color IF test. The aberrant overexpression was confirmed in 43.6% of ALL cases. The CDIObright display suggested ALL diagnosis even when few cells were available for study, e.g., in early relapse and in ALL masquerading as aplastic anemia. The levels of CDlO expression were maintained in relapse. In addition, different C D l O levels were associated with the various chromosomal alterations: high C D l O levels (> 3 x 104/cell) with hyperdiploidy, low CDlO levels ( 1 . 8 4 x 103/cell) with the t(1;191, and undetectable levels (< 1.2 x 103/cell) with the t(4;11) translocations. These findings show that while all these diseases are part of the precursor B-cell spectrum, the CDlO changes are linked to disease-associated alterations instead of truly reflecting the features of subtypes of normal B-cell precursors. The quantitative CDlO assessment should therefore be part of the routine flow cytometric assessment in ALL, and further careful studies are warranted during the regeneration phase following chemotherapy. High CDlO expression alone during strong bone marrow regeneration may not be leukemia specific and both the multiparameter analysis described above and parallel studies for gene rearrangements will be necessary to establish the relative values of these assays in detecting minimal disease amidst regenerating marrow. 0 1994 Wiley-Liss, Inc.Key terms: CD10, acute lymphoblastic leukemia, minimal residual disease, immunodiagnosis, flow cytometry, quantimetrySince the discovery of B precursor cell-associated molecules such as common acute lymphoblastic leukemia (ALL) antigen (referred to as CDlO and neutral endopeptidase) (1,2), CD34 antigen (3-5), and nuclear terminal transferase ( TdT) ( 1,6) it has been emphasized that these differentiation antigens are expressed on normal immature cells and retained on the corresponding malignancies. At the same time, the strikingly high expression of CDlO antigen on occasional cases of ALL has been recorded on the microscope (6) or by flow cytometry (7) bu...

Correlation between karyotype and quantitative immunophenotype in acute myelogenous leukemia with t(8;21)

“…13,15 Furthermore, the determination of aberrant phenotypic patterns can also allow for minimal residual disease (MRD) monitoring. 17,19 AML with t(8;21) is characterized by a unique molecular abnormality, the AML1-ETO fusion gene. It has been shown that AML1-ETO protein can regulate the transcription of many genes important for hematopoiesis including the M-CSF receptor, the G-CSF receptor and BCL2 (all upregulated) as well as GM-CSF, TCR subunits (a, b and d), NP3 and MDR1 (all downregulated).…”

“…14 Despite support for the existence of a unique immunophenotype in AML with t(8;21), quantitative immunophenotyping in this form of AML has rarely been reported. 13 Recent reports have suggested that quantitative immunophenotyping may enhance the diagnosis of leukemias with specific cytogenetic abnormalities [15][16][17] and help define aberrant immunophenotyping patterns that could be useful for monitoring minimal residual disease. [17][18][19] It has also been suggested that quantitative immunophenotyping can contribute to our understanding of the pathogenesis of acute leukemia.…”

“…13 Recent reports have suggested that quantitative immunophenotyping may enhance the diagnosis of leukemias with specific cytogenetic abnormalities [15][16][17] and help define aberrant immunophenotyping patterns that could be useful for monitoring minimal residual disease. [17][18][19] It has also been suggested that quantitative immunophenotyping can contribute to our understanding of the pathogenesis of acute leukemia. 13,15,20 We undertook this prospective study of quantitative immunophenotyping to define whether there is a distinctive pattern in patients with AML and t(8;21).…”

Performance of calibration standards for antigen quantitation with flow cytometry in chronic lymphocytic leukemia

“…Numerous publications support the relevance of FI determination in diagnostic, differential diagnosis, prognostic evaluation, and therapy monitoring of leukemias and lymphomas (5)(6)(7)(8)(9)(10)(11)(12).…”

Clinical flow cytometry, a hypothesis‐driven discipline of modern cytomics

“…7d), the cells are CD8 ϩ T cells with extra low-level (20 ϫ 10 3 ) CD4 display (monoclonal chronic T chronic lymphoid leukemia?). These simple quantitative methods, based on normal blood standards and on stabilized blood preparations, have a wide application in precisely characterizing the aberrant display of various antigens in leukemia and lymphoma (45).…”