Complex measurements may be required to establish the prognostic impact of immunophenotypic markers in AML

High CD34 surface expression in BCP-ALL predicts poor induction therapy response and is associated with altered expression of genes related to cell migration and adhesion

Minimal residual disease (MRD) constitutes the most important prognostic factor in B‐cell precursor acute lymphoblastic leukemia (BCP‐ALL). Flow cytometry is widely used in MRD assessment, yet little is known regarding the effect of different immunophenotypic subsets on outcome. In this study of 200 BCP‐ALL patients, we found that a CD34‐positive, CD38 dim‐positive, nTdT dim‐positive immunophenotype on the leukemic blasts was associated with poor induction therapy response and predicted an MRD level at the end of induction therapy (EOI) of ≥ 0.001. CD34 expression was strongly and positively associated with EOI MRD, whereas CD34‐negative patients had a low relapse risk. Further, CD34 expression increased from diagnosis to relapse. CD34 is a stemness‐associated cell‐surface molecule, possibly involved in cell adhesion/migration or survival. Accordingly, genes associated with stemness were overrepresented among the most upregulated genes in CD34‐positive leukemias, and protein–protein interaction networks showed an overrepresentation of genes associated with cell migration, cell adhesion, and negative regulation of apoptosis. The present work is the first to demonstrate a CD34‐negative immunophenotype as a good prognostic factor in ALL, whereas high CD34 expression is associated with poor therapy response and an altered gene expression profile reminiscent of migrating cancer stem‐like cells.

Joint profiling of DNA and proteins in single cells to dissect genotype-phenotype associations in leukemia

Studies of acute myeloid leukemia rely on DNA sequencing and immunophenotyping by flow cytometry as primary tools for disease characterization. However, leukemia tumor heterogeneity complicates integration of DNA variants and immunophenotypes from separate measurements. Here we introduce DAb-seq, a technology for simultaneous capture of DNA genotype and cell surface phenotype from single cells at high throughput, enabling direct profiling of proteogenomic states in tens of thousands of cells. To demonstrate the approach, we analyze the disease of three patients with leukemia over multiple treatment timepoints and disease recurrences. We observe complex genotype-phenotype dynamics that illustrate the subtlety of the disease process and the degree of incongruity between blast cell genotype and phenotype in different clinical scenarios. Our results highlight the importance of combined single-cell DNA and protein measurements to fully characterize the heterogeneity of leukemia.

Early T-cell precursor acute lymphoblastic leukemia and other subtypes: a retrospective case report from a single pediatric center in China

PURPOSE

Early T-cell precursor acute lymphoblastic leukemia (ETP-ALL) is rare in China and case reports are varied. We conducted an in-depth analysis of newly diagnosed children with T-ALL from January 1999 to April 2015 in our center, to show the biological differences between Chinese ETP-ALL children and other immune types of T-ALL.

METHODS

The newly diagnosed children with T-ALL were divided into four groups according to their immunophenotype: ETP-ALL, early non-ETP-ALL, cortical T-ALL and medullary T-ALL. Disease-free survival (DFS), event-free survival (EFS), and overall survival (OS) rates were estimated by the Kaplan-Meier method. The Cox regression model was used for multivariate analysis.

RESULTS

A total of 117 newly diagnosed children with T-ALL were enrolled in this study. The 10-year EFS and OS rates for all patients were 59.0 ± 4.7% and 61.0 ± 4.7%, respectively, with a median follow-up of 64 (5-167) months. Univariate analysis showed that ETP-ALL patients had the lowest 10-year DFS rate of 32.1 ± 11.7%, while cortical T-ALL had the highest DFS rate of 81.3 ± 8.5% compared with early non-ETP-ALL (61.6 ± 7.0%) and medullary T-ALL (59.1 ± 10.6%). Multivariate analysis demonstrated that only ETP-ALL and involvement of the central nervous system were independent prognostic factors.

CONCLUSION

Compared with other subtypes, pediatric ETP-ALL had a poor treatment response and high recurrence rate while cortical T-ALL appeared to have much better outcome. Our observations highlight the need for an individualized treatment regime for ETP-ALL.

Quantitative flow cytometric evaluation of CD200, CD123, CD43 and CD52 as a tool for the differential diagnosis of mature B-cell neoplasms

BACKGROUND

Distinction between mature B-cell neoplasms can be difficult due to overlapping of immunologic features and clinical manifestations. This study investigated whether quantifying mean fluorescence intensity of four monoclonal antibodies in a flow cytometry panel is useful for the differential diagnosis and characterization of these disorders.

METHODS

The expressions of CD52, CD200, CD123 and CD43 were analyzed in samples from 124 patients with mature B-cell neoplasms. The quantitative estimation of these antigens was assessed by mean fluorescence intensity.

RESULTS

The cases included were 78 chronic lymphocytic leukemias, three atypical chronic lymphocytic leukemias, six marginal zone lymphomas, 11 splenic marginal zone lymphomas, nine lymphoplasmacytic lymphomas, six mantle cell lymphomas, two hairy cell leukemias, two hairy cell leukemias variant, five follicular lymphomas, one Burkitt lymphoma and one diffuse large B-cell lymphoma. The mean fluorescence intensity of CD200 was higher in atypical chronic lymphocytic leukemia, chronic lymphocytic leukemia and hairy cell leukemia cases. CD123 showed higher mean fluorescence intensities in hairy cell leukemia cells. Chronic lymphocytic leukemia, atypical chronic lymphocytic leukemia and mantle cell lymphoma had higher expression of CD43 and all follicular lymphoma cases had very low mean fluorescence intensity values. CD52 expression was consistently positive among all cases.

CONCLUSION

Quantitative evaluation of these markers can be a useful additional tool to better identify some types of mature B-cell neoplasms.

Role of new Immunophenotypic Markers on Prognostic and Overall Survival of Acute Myeloid Leukemia: a Systematic Review and Meta-Analysis

Despite technological advances, the prognosis and survival of acute myeloid leukemia (AML) adult patients remain low, compared with other hematologic malignancies. Some antigens detected by immunophenotyping may soon play a significant role in the pathophysiologic, prognostic, and overall survival (OS) rate of AML patients. Therefore, we conducted a systematic review and meta-analysis of PubMed, Scopus, Science Direct, Web of Science, and the Cochrane Library (using PRISMA guidelines). We analyzed 11 studies and 13 antigens, detected through the immunophenotyping of 639 patients. From them, twelve exhibited a negative impact with AML prognosis. The meta-analysis demonstrated a high expression of AML markers, which have been associated with a decrease in survival over 10 months (RR 2.55; IC 95%; 1.49-4.37) and over 20 months (RR 2.46; IC 95%; 1.75-3.45). Knowing that the expression of immunophenotypic markers, which are not used on a routine basis, might be able to influence disease behavior, looks promising. However, they have been associated with a poor prognosis as well as a decrease in survival. This may allow for different chemotherapeutical protocols, including future studies for new therapeutic targets.

CD34 expression and the outcome of nucleophosmin 1-mutated acute myeloid leukemia

CD34 positivity has been considered as an adverse prognostic factor in acute myeloid leukemia (AML). Although nucleophosmin 1-mutated (NPM1m) AML is usually CD34 negative, this marker may be expressed at diagnosis or acquired at relapse in a variable number of cases. Our objective was to ascertain if CD34 expression has any influence on the general outcome of this form of acute leukemia. Analysis of clinical outcome (complete remissions, relapses, disease-free survival, and overall survival) was performed depending on the degree of expression of CD34 determined by flow cytometry, in 67 adult patients with NPM1m AML. CD34 expression did not have any influence on the variables analyzed whatever the percentage of blasts expressing this marker. In contrast to other forms of AML, CD34 expression is not an unfavorable prognostic factor in NPM1m AML, neither at diagnosis nor at relapse.

[Clinical and biological prognostic factors in relapsed acute myeloid leukemia patients]

BACKGROUND AND OBJECTIVE

Acute myeloid leukemia (AML) is the most frequent type of acute leukemia in adults. Despite recent advances in the characterization of pathogenesis of AML, the cure rates are under 40%, being leukemia relapse the most common cause of treatment failure. Leukaemia relapse occurs due to clonal evolution or clonal escape. In this study, we aimed to analyze the clinical and biological factors influencing outcomes in patients with AML relapse.

PATIENTS AND METHODS

We included a total of 75 AML patients who experienced leukaemia relapse after achieving complete remission. We performed complete immunophenotyping and conventional karyotyping in bone marrow aspirates obtained at diagnosis and at leukemia relapse.

RESULTS

Overall survival (OS) of the series was 3.7%±2.3, leukaemia progression being the most common cause of death. Patients relapsing before 12 months and those with adverse cytogenetic-molecular risk had statistically significant worse outcomes. A percentage of 52.5 of patients showed phenotypic changes and 50% cytogenetic changes at relapse. We did not find significant clinical factors predicting clonal evolution. The presence of clonal evolution at relapse did not have a significant impact on outcome.

CONCLUSIONS

Patients with relapsed AML have a dismal prognosis, especially those with early relapse and adverse cytogenetic-molecular risk. Clonal evolution with phenotypic and cytogenetic changes occurred in half of the patients without predictive clinical factors or impact on outcome.

Independent prognostic impact of CD15 on complete remission achievement in patients with acute myeloid leukemia

The prognostic role of CD15 in acute myeloid leukemia (AML) has been tested in different studies with conflicting results. To address this issue, we retrospectively evaluated a cohort of 460 AML patients of all ages with the exclusion of acute promyelocytic leukemia (M/F 243/217, median age 50.6 years [range 0.9-81.2]) intensively treated at our institute between January 1999 and December 2010. CD15 positivity was found in 171 of 406 evaluable patients (42.1%). Complete remission (CR) was achieved by 334 patients (72.6%), while 82 (17.8%) were resistant and 44 (9.6%) died during induction: the median CR duration was 15.5 months (range 0.6-176.0), with 2-year disease-free survival rate of 45.1% (95% confidence interval 39.6-50.6). The median overall survival was 14.4 months (range 0.3-177.0), with 2-year overall survival rate of 42.2% (95% confidence interval 37.5-46.9). At univariate analysis for CR achievement, age < 60 years (P < .001), World Health Organization classification (P = .045), low-risk karyotype (P < .001), no high-risk karyotype (P = .006), positivity for AML-ETO (P = .004)/CBFβ-MYH11 (P = .003)/CD15 (P = .006)/CD11b (P = .013), negativity for FLT3-ITD (P = .001), Hb > 8 g/dL (P = .020), and white blood cell < 50 × 10⁹ /L (P = .034) had a favorable impact. At a multivariate logistic regression model, CD15 positivity (P = .002), age < 60 years (P = .008), white blood cell < 50 × 10⁹ /L (P = .017), and low-risk/no high-risk karyotype (P = .026/P = .025) retained an independent prognostic role on CR achievement. The baseline assessment of CD15 positivity appears to have a role in the risk evaluation for CR achievement in AML patients undergoing intensive chemotherapy and should be assessed in prospective studies together with other clinical and biologic features already reported.

Assessment of myeloid and monocytic dysplasia by flow cytometry in de novo AML helps define an AML with myelodysplasia-related changes category

AIMS

In recent years, multiparameter flow cytometry has been increasingly recognised as an important tool in diagnosis of myelodysplastic syndrome and acute myeloid leukaemia (AML). Assessment of myeloid and monocytic 'immunophenotypic' dysplasia by flow cytometry in de novo AML has not been evaluated.

METHODS

97 cases of de novo AML cases were identified and reviewed by three hematopathologists. 'Immunophenotypic' dysplasia was assessed on blasts, monocytes and granulocytes by mean fluorescence intensity.

RESULTS

Using the 2008 WHO classification criteria, there were 53 AML-not otherwise specified (NOS) (55%) and 28 AML with myelodysplasia-related changes (AML-MRC) (29%), while 16 cases were ambiguous as to AML-MRC status due to limited maturing cells for morphologic but adequate events number for immunophenotypic evaluation (AML-not evaluable, 16%). Compared with AML-NOS, granulocytic cells in AML-MRC had higher CD33 expression but lower CD45, CD11b and CD15. Monocytes in AML-MRC had lower expression of CD14, CD56 and CD45. Morphologic dysplasia was associated with significantly lower granulocytic forward scatter, side scatter and CD10 but higher CD33 expression.

CONCLUSIONS

Our results suggest that the workup of AML cases should include flow cytometric assessment of granulocytes and monocytes. This analysis can aid a morphologic impression of multilineage dysplasia in distinguishing AML-MRC from AML-NOS, especially in cases with limited maturing myeloid cells.