Immunophenotyping is an independent factor for risk stratification in AML

Clinicopathological Significance of Common Genetic Alterations in Patients With Acute Promyelocytic Leukemia

OBJECTIVE/BACKGROUND

Acute myeloid leukemia (AML) is one of the common forms of hematological malignancy and acute promyelocytic leukemia (APL) is a unique subtype of AML conferring favorable prognosis. We aimed to determine the prevalence and prognostic impact of Fms-like tyrosine kinase 3 (FLT3), nucleophosmin 1 (NPM1) mutation, epidermal growth factor receptor (EGFR), and flow marker's expression in patients with APL.

METHODS

In the present study, 165 de novo APL patients were molecularly characterized for promyelocytic leukemia (PML) breakpoint and additional genetic alterations. Reverse transcriptase polymerase chain reaction (PCR) and real-time PCR assays were used to detect genetic alterations.

RESULTS

PML/RARα was detected in 29/165 (17.5%) samples with breakpoint cluster region 1 (bcr1) in 17/29 (58.5%) and bcr3 in 12/29 (41.5%) samples. The prevalence of FLT3-ITD, NPM1, and EGFR were detected in 5/29 (17.5%), 11/29 (38%), and 5/29 (17.5%) patients, respectively. Patients expressing bcr-3 hybrid transcript had lower overall survival compared with bcr1 ( p = .254). White blood cell (WBC) count was significantly higher in bcr3 in comparison with bcr1 patients ( p = .002). Patients with positive EGFR expression ( p = .042) and higher WBC ( p = .002) were significantly associated with poor survival ( p < .05).

CONCLUSIONS

We documented the higher prevalence of bcr1 and confirmed that the association of FLT3-ITD significantly reduced the chances of survival in APL. The mortality rate of bcr3 was comparatively higher than that of bcr1. Higher WBC count and EGFR expression were significantly associated with poor survival.

The Prognostic Significance of C-Reactive Protein to Albumin Ratio in Newly Diagnosed Acute Myeloid Leukaemia Patients

Background

The ratio of C-reactive protein to albumin (CAR) is an inflammatory marker that has been demonstrated to be a simple and reliable prognostic factor in several solid tumours and chronic lymphocytic leukaemia (CLL). However, no studies have investigated the prognostic value of the CAR in patients with acute myeloid leukaemia (AML).

Objectives and Methods

We retrospectively analysed 212 newly diagnosed non-M3 AML patients. Using the receiver operating characteristic curve (ROC) method, the optimal cut-off value for CAR was determined. We investigated the correlations of the pretreatment CAR levels with clinical characteristics, treatment response of induction chemotherapy, overall survival (OS) and event-free survival (EFS). We also assessed the prognostic value of the CAR compared with other inflammation-based prognostic parameters by the area under the curve (AUC).

Results

According to the ROC curve, the optimal cut-off value of CAR was 1.015. CAR was associated with age, C-reactive protein (CRP) levels, albumin levels, ferritin levels, bone marrow blast percentage, French-American-British (FAB) classification, immunophenotype and 2017 European Leukemia Net (2017 ELN) risk stratification. Importantly, we found that high CAR was a powerful indicator of a lower complete remission (CR) rate (p<0.001), worse OS (p<0.001) and worse EFS (p<0.001). Subgroup analysis showed that a high CAR was associated with shorter OS and EFS in patients with intermediate risk stratification or those aged ≤65 years or those without haematopoietic stem cell transplantation (HSCT). In the multivariate analysis, the CAR was an independent prognostic factor for OS and EFS. Furthermore, the predictive value of CAR for OS is superior to that of CRP, albumin and GPS in de novo AML patients aged ≤65 years old.

Conclusion

CAR is a simple and effective prognostic marker in patients with AML. It could be an additional prognostic factor that help further precise the current risk stratification of non-M3 AML, particularly for patients in intermediate risk stratification and those aged ≤65 years and those who did not undergo HSCT.

DNAM-1/CD226 is functionally expressed on acute myeloid leukemia (AML) cells and is associated with favorable prognosis

DNAM-1 is reportedly expressed on cytotoxic T and NK cells and, upon interaction with its ligands CD112 and CD155, plays an important role in tumor immunosurveillance. It has also been reported to be functionally expressed by myeloid cells, but expression and function on malignant cells of the myeloid lineage have not been studied so far. Here we analyzed expression of DNAM-1 in leukemic cells of acute myeloid leukemia (AML) patients. We found substantial levels of DNAM-1 to be expressed on leukemic blasts in 48 of 62 (> 75%) patients. Interaction of DNAM-1 with its ligands CD112 and CD155 induced release of the immunomodulatory cytokines IL-6, IL-8 IL-10 and TNF-α by AML cells and DNAM-1 expression correlated with a more differentiated phenotype. Multivariate analysis did not show any association of DNAM-1 positivity with established risk factors, but expression was significantly associated with clinical disease course: patients with high DNAM-1 surface levels had significantly longer progression-free and overall survival compared to DNAM-1^low patients, independently whether patients had undergone allogenic stem cell transplantation or not. Together, our findings unravel a functional role of DNAM-1 in AML pathophysiology and identify DNAM-1 as a potential novel prognostic maker in AML.

CRISPR screen identifies genes that sensitize AML cells to double-negative T-cell therapy

Acute myeloid leukemia (AML) remains a devastating disease in need of new therapies to improve patient survival. Targeted adoptive T-cell therapies have achieved impressive clinical outcomes in some B-cell leukemias and lymphomas but not in AML. Double-negative T cells (DNTs) effectively kill blast cells from the majority of AML patients and are now being tested in clinical trials. However, AML blasts obtained from ∼30% of patients show resistance to DNT-mediated cytotoxicity; the markers or mechanisms underlying this resistance have not been elucidated. Here, we used a targeted clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein 9 (Cas9) screen to identify genes that cause susceptibility of AML cells to DNT therapy. Inactivation of the Spt-Ada-Gcn5-acetyltransferase (SAGA) deubiquitinating complex components sensitized AML cells to DNT-mediated cytotoxicity. In contrast, CD64 inactivation resulted in resistance to DNT-mediated cytotoxicity. Importantly, the level of CD64 expression correlated strongly with the sensitivity of AML cells to DNT treatment. Furthermore, the ectopic expression of CD64 overcame AML resistance to DNTs in vitro and in vivo. Altogether, our data demonstrate the utility of CRISPR/Cas9 screens to uncover mechanisms underlying the sensitivity to DNT therapy and suggest CD64 as a predictive marker for response in AML patients.

Fc gamma receptor expression serves as prognostic and diagnostic factor in AML

Risk assessment in acute myeloid leukemia (AML) mainly relies on (cyto-)genetic and morphologic features. Nonetheless, further markers are needed to allow for accurate risk stratification. Type I Fc gamma receptors (FcγRs) such as CD16, CD32, and CD64 play an important role in mediating immunomodulatory functions in different myeloid cell types as well as NK and B cells. We here evaluated expression of the three FcγR on peripheral blood AML blasts. Using flow cytometry, we found heterogeneous expression of the FcγR throughout the patient cohort. Correlation of expression levels with disease outcome revealed significantly shorter OS in patients with CD16⁺ blasts at first diagnosis. CD32 and CD64 expression showed no association with survival but correlated with a mature phenotype and FAB M6. Our data provide clear evidence for the value of immunophenotyping FcγR expression on leukemic cells using peripheral blood, which is rapidly available and improves risk stratification in AML.

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.

Activity of everolimus (RAD001) in relapsed and/or refractory multiple myeloma: a phase I study

The mammalian target of rapamycin plays an important role in multiple myeloma. The allosteric mammalian target of rapamycin inhibitor everolimus has long been approved for immunosuppression and has shown activity in certain cancers. This investigator-initiated phase I trial explored the use of everolimus in relapsed and/or refractory multiple myeloma patients who had received two or more lines of prior treatment. Following a dose-escalation design, it called for a fixed dose of oral everolimus. Blood drug levels were monitored and the biological activity of everolimus was evaluated in bone marrow. Seventeen patients were enrolled (age range, 52 to 76 years). All had been previously treated with stem cell transplantation and proteasome inhibitors and almost all with immunomodulatory drugs. No dose-limiting toxicity was observed and the intended final daily dose of 10 mg was reached. Only one severe adverse event was assessed as possibly related to the study drug, namely atypical pneumonia. Remarkably few infections were observed. Although the trial was mainly designed to evaluate feasibility, anti-myeloma activity, defined as clinical benefit, was documented in ten of 15 evaluable patients at every dose level including eight patients with stable disease, one patient with minor remission and one with partial remission. However, the median time to progression was 90 days (range, 13 to 278 days). The biomarker study documented on-target activity of everolimus in malignant plasma cells as well as the microenvironment. The observed responses are promising and allow further studies to be considered, including those testing combination strategies addressing escape pathways. This trial is registered with EudraCT number 2006-002675-41.

Curcumin reduces expression of Bcl-2, leading to apoptosis in daunorubicin-insensitive CD34+ acute myeloid leukemia cell lines and primary sorted CD34+ acute myeloid leukemia cells

Background

Acute myeloid leukemia (AML) is an immunophenotypically heterogenous malignant disease, in which CD34 positivity is associated with poor prognosis. CD34⁺ AML cells are 10-15-fold more resistant to daunorubicin (DNR) than CD34^- AML cells. Curcumin is a major component of turmeric that has shown cytotoxic activity in multiple cancers; however, its anti-cancer activity has not been well studied in DNR-insensitive CD34⁺ AML cells. The aim of this study was to therefore to explore curcumin-induced cytotoxicity in DNR-insensitive CD34⁺ AML cell lines (KG1a, Kasumi-1), DNR-sensitive U937 AML cells, and primary CD34⁺ AML bone-marrow-derived cells.

Methods

Primary human CD34⁺ cells were isolated from peripheral blood mononuclear cells or bone marrow mononuclear cells using a CD34 MicroBead kit. The growth inhibitory effects of curcumin were evaluated by MTT and colony-formation assays. Cell cycle distribution was examined by propidium iodide (PI) assay. Apoptosis was analyzed by Wright-Giemsa, Hoechst 33342 and Annexin-V/PI staining assays. The change in mitochondrial membrane potential (MMP) was examined by JC-1 staining and flow cytometry. Expression of apoptosis-related proteins was determined by reverse transcription-polymerase chain reaction and Western blotting. Short interfering RNA (siRNA) against Bcl-2 was used in CD34⁺ KG1a and Kasumi-1 cells incubated with/without DNR.

Results

Curcumin inhibited proliferation and induced apoptosis and G1/S arrest in both DNR-insensitive KG1a, Kasumi-1 and DNR-sensitive U937 cells. Curcumin-induced apoptosis was associated with reduced expression of both Bcl-2 mRNA and protein, subsequent loss of MMP, and activation of caspase-3 followed by PARP degradation. Curcumin synergistically enhanced the cytotoxic effect of DNR in DNR-insensitive KG1a and Kasumi-1 cells, consistent with decreased Bcl-2 expression. Accordingly, siRNA against Bcl-2 increased the susceptibility of KG1a and Kasumi-1 cells to DNR-induced apoptosis. More importantly, curcumin suppressed Bcl-2 expression, selectively inhibited proliferation and synergistically enhanced the cytotoxicity of DNR in primary CD34⁺ AML cells, while showing limited lethality in normal CD34⁺ hematopoietic progenitors.

Conclusion

Curcumin down-regulates Bcl-2 and induces apoptosis in DNR-insensitive CD34⁺ AML cell lines and primary CD34⁺ AML cells.

Leukemia-initiating cells from some acute myeloid leukemia patients with mutated nucleophosmin reside in the CD34(-) fraction

Leukemia-initiating cells (LICs) in acute myeloid leukemia (AML) are believed to be restricted to the CD34(+) fraction. However, one of the most frequently mutated genes in AML is nucleophosmin (NPM), and this is associated with low CD34 expression. We, therefore, investigated whether NPM-mutated AMLs have LICs restricted to the CD34(+) fraction. We transplanted sorted fractions of primary NPM-mutated AML into immunodeficient mice to establish which fractions initiate leukemia. Approximately one-half of cases had LICs exclusively within the CD34(-) fraction, whereas the CD34(+) fraction contained normal multilineage hematopoietic repopulating cells. Most of the remaining cases had LICs in both CD34(+) and CD34(-) fractions. When samples were sorted based on CD34 and CD38 expression, multiple fractions initiated leukemia in primary and secondary recipients. The data indicate that the phenotype of LICs is more heterogeneous than previously realized and can vary even within a single sample. This feature of LICs may make them particularly difficult to eradicate using therapies targeted against surface antigens.

Expression patterns of CD33 and CD15 predict outcome in patients with acute myeloid leukemia

Expression patterns of CD33 and CD15 in normal/reactive bone marrow (n = 13) and in leukemic blasts from patients with acute myeloid leukemia (n = 129) were determined using multiparameter flow cytometry and a standard panel of triple antibody combinations. Five patterns, corresponding to the consecutive stages of myeloid differentiation, were identified [I: CD33-/CD15- (n = 18), II: CD33+/CD15- (n = 43), III: CD33+/CD15 heterogeneous (n = 10), IV: CD33+/CD15+ (n = 50), V: CD33-/CD15+ (n = 8)]. Patients with pattern II had the highest relapse rate and shortest median overall survival (OS, 8 months), but they were also the oldest (median age 72 years) and had the highest frequency of unfavorable cytogenetic aberrations. Pattern V patients had a short OS (median 14 months) even though they were the youngest (median age 50 years), had high remission rate and did not have unfavorable cytogenetics. In multivariate analysis, age, cytogenetics, CD15 expression and the presented immunophenotypic classification were significant for OS (age p = 0.004, cytogenetics p = 0.011, immunophenotype pattern p = 0.024, CD15 p = 0.031). Age (p = 0.001) and immunophenotypic classifications (p = 0.015) were significant for disease-free survival in patients who achieved complete remission.

Negative effect of DNA hypermethylation on the outcome of intensive chemotherapy in older patients with high-risk myelodysplastic syndromes and acute myeloid leukemia following myelodysplastic syndrome

PURPOSE

Promoter hypermethylation of, for example, tumor-suppressor genes, is considered to be an important step in cancerogenesis and a negative risk factor for survival in patients with myelodysplastic syndromes (MDS); however, its role for response to therapy has not been determined. This study was designed to assess the effect of methylation status on the outcome of conventional induction chemotherapy.

EXPERIMENTAL DESIGN

Sixty patients with high-risk MDS or acute myeloid leukemia following MDS were treated with standard doses of daunorubicin and 1-beta-d-arabinofuranosylcytosine. Standard prognostic variables and methylation status of the P15(ink4b) (P15), E-cadherin (CDH), and hypermethylated in cancer 1 (HIC) genes were analyzed before treatment.

RESULTS

Forty percent of the patients achieved complete remission (CR). CR rate was lower in patients with high WBC counts (P = 0.03) and high CD34 expression on bone marrow cells (P = 0.02). Whereas P15 status alone was not significantly associated with CR rate (P = 0.25), no patient with hypermethylation of all three genes achieved CR (P = 0.03). Moreover, patients with CDH methylation showed a significantly lower CR rate (P = 0.008), and CDH methylation retained its prognostic value also in the multivariate analysis. Hypermethylation was associated with increased CD34 expression, but not with other known predictive factors for response, such as cytogenetic profile.

CONCLUSIONS

We show for the first time a significant effect of methylation status on the outcome of conventional chemotherapy in high-risk MDS and acute myelogenous leukemia following MDS. Provided confirmed in an independent study, our results should be used as a basis for therapeutic decision-making in this patient group.

The role of cytotoxic therapy with hematopoietic stem cell transplantation in the therapy of acute myelogenous leukemia in adults: an evidence-based review

Clinical research examining the role of hematopoietic stem cell transplantation (HSCT) in the therapy of acute myelogenous leukemia (AML) in adults is presented and critically evaluated in this systematic evidence-based review. Specific criteria were used for searching the published literature and for grading the quality and strength of the evidence and the strength of the treatment recommendations. Treatment recommendations based on the evidence are presented in Table 3, entitled Summary of Treatment Recommendations Made by the Expert Panel for Adult Acute Myelogenous Leukemia, and were reached unanimously by a panel of AML experts. The identified priority areas of needed future research in adult AML include: (1) What is the role of HSCT in treating patients with specific molecular markers (eg, FLT3, NPM1, CEBPA, BAALC, MLL, NRAS, etc.) especially in patients with normal cytogenetics? (2) What is the benefit of using HSCT to treat different cytogenetic subgroups? (3) What is the impact on survival outcomes of reduced intensity or nonmyeloablative versus conventional conditioning in older (>60 years) and intermediate (40-60 years) aged adults? (4) What is the impact on survival outcomes of unrelated donor HSCT vesus chemotherapy in younger (<40 years) adults with high risk disease?

Specific inhibition of basal mitogen-activated protein kinases and phosphatidylinositol 3 kinase activities in leukemia cells: a possible therapeutic role for the kinase inhibitors

OBJECTIVE

The roles of phosphatidylinositol 3 (PI3K) and mitogen-activated protein kinases (MAPK) have been widely studied in terms of the differentiation process induced by several drugs (phorbol ester, vitamin D-3, retinoic acid, etc.), but their exact functions in leukemic cells' phenotype and their potential therapeutic role remain incompletely clarified.

MATERIALS AND METHODS

In order to investigate this query, leukemia cells were cultured in presence of kinase inhibitors (KIs). Proliferation, apoptosis, and differentiation were analyzed at the cellular and molecular levels, using flow cytometry and reverse transcriptase quantitative polymerase chain reaction.

RESULTS

SB203580, a P38 MAPK inhibitor, had no effect on cell proliferation, whereas LY294002, a PI3K inhibitor, and PD098059, a selective inhibitor of mitogen-activated extracellular regulated kinase (MEK) phosphorylation, arrested cells in G(0)/G(1). However, LY294002 and PD098059 acted using different mechanisms: LY294002 decreased the expression of phosphorylated S6RP, whereas PD098059 increased P21/waf1 antigen expression. SP600125, an inhibitor of N-terminal c-jun kinases, arrested cells in G(2) and induced an endoreplicative process. SP600125 increased p21 at both the mRNA and protein levels. G(2) blockage is dependent on the PI3K pathway and the endoreplicative process is dependent on the PI3K and extracellular regulated kinase (ERK) pathways and mRNA synthesis. On the other hand, PD098059 potentiated the apoptotic process induced by either SP600125 or LY294002. Modulation of the expression of CD11, CD15, CD18, and CD54 was cell-dependent.

CONCLUSION

Our results suggest that KIs modulate proliferation of leukemia cells and that the MEK/ERK inhibitor, PD098059, in combination with either SP600125 or LY294002, could have clinical value.

Cytomics as a new potential for drug discovery

At the single-cell level in conjunction with data-pattern analysis, high-content screening by image analysis or flow cytometry of clinical cell- or tissue-section samples provides differential molecular profiles for the personalized prediction of therapy-dependent disease progression in patients. The molecular reverse-engineering of these molecular profiles, which is the exploration of molecular pathways, backwards, to the origin of the observed molecular differentials, by systems biology has the potential to detect new drug targets in knowledge spaces, typically inaccessible to traditional hypotheses. Furthermore, predictive medicine, by cytomics in stratified patient groups, opens a new way for personalized (or individualized) medicine, as well as for the early detection of adverse drug reactions in patients.

Early prediction of therapy response in patients with acute myeloid leukemia by nucleosomal DNA fragments

BACKGROUND

Elevated levels of nucleosomal DNA fragments can be detected in plasma and sera of patients with malignant diseases.

METHODS

We investigated the course of nucleosomal DNA, thymidine kinase, lactate dehydrogenase and leukocytes in sera of 25 patients with acute myeloid leukemia during the first cycle of induction chemotherapy and tested their power to distinguish between patients with complete remission and those with no remission.

RESULTS

Almost all patients showed strongly decreasing levels of nucleosomal DNA during the first week, in some cases after initial peaks. In overall analysis of variance, DNA levels could clearly distinguish between patients with complete remission, who had higher DNA values, and those with insufficient response (p = 0.017). The area under the curve of DNA values of days 2-4 after start of therapy (AUC 2-4) discriminated between both groups with a sensitivity of 56% at a specificity of 100%. Further, pretherapeutic levels and AUC 2-4 of nucleosomal DNA correlated significantly with blast reduction after 16 days. A tendency to higher levels in patients with complete response was also found for thymidine kinase, lactate dehydrogenase and leukocytes, however the difference did not reach the level of significance (p = 0.542, p = 0.260, and p = 0.144, respectively).

CONCLUSION

Our results indicate that nucleosomal DNA fragments are valuable markers for the early prediction of therapeutic efficacy in patients with acute myeloid leukemia.

Systems biology and clinical cytomics: The 10th Leipziger Workshop and the 3rd International Workshop on Slide-Based Cytometry, Leipzig, Germany, April 2005

Despite very significant technical and software improvements in flow cytometry (FCM) since the 1980's, the demand for a cytometric technology combining both quantitative cell analysis and morphological documentation in Cytomics became evident. Improvements in microtechnology and computing permit nowadays similar quantitative and stoichiometric single cell-based high-throughput analyses by microscopic instruments, like Slide-Based Cytometry (SBC). SBC and related techniques offer unique tools to perform complex immunophenotyping, thereby enabling diagnostic procedures during early disease stages. Multicolor or polychromatic analysis of cells by SBC is of special importance not only as a cytomics technology platform but also because of low quantities of required reagents and biological material. The exact knowledge of the location of each cell on the slide permits repetitive restaining and reanalysis of specimens. Various separate measurements of the same specimen can be ultimately fused to one database increasing the information obtained per cell. Relocation and optical evaluation of cells as typical SBC feature, can be of integral importance for cytometric analysis, since artifacts can be excluded and morphology of measured cells can be documented. Progress in cell analytic: In the SBC, new horizons can be opened by the new techniques of structural and functional analysis with the high resolution from intracellular and membrane (confocal microscopy, nanoscopy, total internal fluorescence microscopy (TIRFM), and tissue level (tissomics), to organ and organism level (in vivo cytometry, optical whole body imaging). Predictive medicine aims at the detection of changes in patient's state prior to the manifestation of the disease or the complication. Such instances concern immune consequences of surgeries or noninfectious posttraumatic shock in intensive care patients or the pretherapeutic identification of high risk patients in cancer cytostatic therapy. Preventive anti-infectious or anti-shock therapy as well as curative chemotherapy in combination with stem cell transplantation may provide better survival chances for patient at concomitant cost containment. Predictive medicine-guided optimization of therapy could lead to individualized medicine that gives significant therapeutic effect and may lower or abrogate potential therapeutic side effects. The 10th Leipziger Workshop combined with the 3rd International Workshop on SBC aimed to offer new methods in Image- and Slide-Based Cytometry for solutions in clinical research. It moved towards practical applications in the clinics and the clinical laboratory. This development will be continued in 2006 at the upcoming Leipziger Workshop and the International Workshop on Slide-Based Cytometry.

Adverse prognostic impact of CD36 and CD2 expression in adult de novo acute myeloid leukemia patients

BACKGROUND AND OBJECTIVES

A consecutive series of acute myeloid leukemias (AML) patients was analyzed in conditions which reduce the inter-assay variations (the same flow cytometer, the same observers and the same panel of monoclonal antibodies) in order to investigate the prognostic information provided by flow cytometry.

DESIGN AND METHODS

Two hundred and sixty-six bone marrow (BM) samples from 326 patients enrolled in the LMA-99 protocol from the CETLAM group were studied by multiparametric flow cytometry. Immunophenotyping studies were performed on erythrocyte-lysed BM samples. Antigen expression of leukemic cells was analyzed using triple stainings with fluorochrome-conjugated combinations of monoclonal antibodies.

RESULTS

CD2 was positive in 21 cases (8%); an associated inv(16) was detected in eight CD2+ cases (38%). Two-year overall survival (OS) rate for CD2+/inv(16)+ patients was 75%, whereas it was 0% for CD2+/inv(16)- patients and 47% for CD2- patients (p=0.0001). CD36 was expressed in 37% of patients (n=98). Two-year leukemia-free survival (LFS) rate was 34% for CD36+ patients and 55% for CD36- patients (p=0.001). In the multivariate analysis, CD2+ (RR=8.4; p=0.0001) and adverse karyotype (RR=10.2; p=0.0001) were associated with a lower CR rate, CD36+ (RR=1.5; p=0.03), CD2+ (RR=2; p=0.04) and adverse karyotype (RR=4; p=0.0001) were associated with a lower OS and CD36+ (RR=2; p=0.002) and adverse karyotype (RR=3.5; p=0.005) predicted a lower LFS.

CONCLUSIONS

CD2+ patients had a very poor OS when CD2/inv(16)+ cases were excluded. CD36 and CD2 expression at diagnosis can provide prognostically important information in adult de novo AML.

Immunophenotypic features of acute myeloid leukemias overexpressing the interleukin 3 receptor alpha chain

In a previous study we have shown that the interleukin-3 receptor alpha chain (IL-3Ralpha) is over expressed in about 45% of acute myeloid leukemias (AMLs) and this phenomenon was associated with high blast cell counts at diagnosis, high rate of cycling of leukemic blasts and with a worse prognosis. Here we have investigated the immunophenotypic features of 125 AML patients subdivided into three groups (IL-3R(high), IL-3R(middle) and IL-3R(low)) according to the level of IL-3Ralpha expression. AMLs over expressing the IL-3Ralpha represent a subgroup of AMLs with a peculiar immunophenotype mainly consisting in the elevated expression of CD34 and several receptor membrane tyrosine kinases, such as c-kit and flt3, and in a usually low expression of myeloid-associated antigens such as CD11b, CD14 and CD15. These findings suggest that IL-3Ralpha + + + AMLs are blocked at an early stage of differentiation and express at elevated levels several growth factor receptors. It is proposed that these findings may further help to understand the mechanisms involved in the development of high-risk acute leukemias.

Data pattern analysis for the individualised pretherapeutic identification of high-risk diffuse large B-cell lymphoma (DLBCL) patients by cytomics

BACKGROUND

Clinical outcome predictions in phase III studies are mostly derived for patient groups, but not for individual patients, although individualised predictions are an ultimate goal to permit a personalised fine tuning of therapy. This may permit earlier application of target therapies, minimise general damage to the organism, and result in improved complete remission rates in malignant diseases.

METHODS

In this study, Lymphochip cDNA microarray gene expression results of DLBCL patients, from a published prospective meta-analysis study on the prediction of group prognosis, were analysed for individualised predictions using a nonstatistical data pattern classification approach. The training set was comprised of the same 160 DLBCL patients as in the prognosis study, with the validation set of 80 patients remaining unknown to the learning process. This permits the assessment of prospective classifier performance towards unknown patients.

RESULTS

Pretherapeutic predictions for the training and validation set patients were correct in 98.1% and 78.3% of the cases for nonsurvival and in 67.3% and 45.3% for survival. The discriminatory data pattern consisted of 14 known and 10 unknown gene products.

CONCLUSIONS

The better than 95% correct pretherapeutic prediction for about one-half of the ultimately nonsurviving high-risk patients of the training set is promising for clinical considerations about individualised therapy in such cases. Reliable individualised survival predictions are not possible with the information content of the present dataset. It seems necessary to investigate additional gene products, since survival may significantly depend on non-lymphocyte-associated genes that escape to the lymphocyte-oriented Lymphochip gene activation analysis.

Pretherapeutic identification of high-risk acute myeloid leukemia (AML) patients from immunophenotypic, cytogenetic, and clinical parameters

BACKGROUND

The goal of this study concerned the pretherapeutic identification of high-risk acute myeloid leukemia (AML) patients by data pattern analysis from flow cytometric immunophenotype, cytogenetic, and clinical data.

METHODS

Sixty-seven parameters of AML patients at diagnosis were classified for predictive information by algorithmic data sieving using iteratively self optimizing triple matrix data pattern analysis (http://www.biochem.mpg.de/valet/classif1.html).

RESULTS

Pretherapeutic predictive values for nonsurvival within five years and two years were 100.0% and 83.2%, respectively, compared to 13.9% and 47.4% for the prediction of survival at five years and two years, respectively. At diagnosis, five-year nonsurvivors showed increased patient age and higher concentration of cells in the analyzed specimen, as well as increased levels of % CD2, CD4, CD13, CD36, and CD45 positive AML blasts. Two-year nonsurvivors were characterized by a data pattern of increased patient age and levels of % CD4, CD7, CD11b, CD24, CD45, TH126, and HLA-DR positive AML blasts and decreased levels of % CD1, CD65, CD95, and TC25 positive AML blasts. Cytogenetic abnormalities were not selected for the optimized discriminatory data patterns.

CONCLUSIONS

The comparatively accurate pretherapeutic identification of high-risk AML patients may prove useful for the development of individualized therapy protocols in stratified clinical patients groups.

Cytomics in predictive medicine

Patient-specific, disease-course predictions with >95% or >99% accuracy during therapy would be highly valuable for everyday medicine. If these predictors were available, disease aggravation or progression, frequently accompanied by irreversible tissue damage or therapeutic side effects, could then potentially be avoided by early preventive therapy. The molecular analysis of heterogeneous cellular systems (cytomics) by cytometry in conjunction with pattern-oriented bioinformatic analysis of the multiparametric cytometric and other data provides a promising approach to individualized or personalized medical treatment or disease management. As a consequence, better patient care and new forms of inductive scientific hypothesis development based on the interpretation of predictive data patterns are at reach.