Automated database-guided expert-supervised orientation for immunophenotypic diagnosis and classification of acute leukemia.

Precise classification of acute leukemia (AL) is crucial for adequate treatment. EuroFlow has previously designed an AL orientation tube (ALOT) to guide towards the relevant classification panel (T-cell acute lymphoblastic leukemia (T-ALL), B-cell precursor (BCP)-ALL and/or acute myeloid leukemia (AML)) and final diagnosis. Now we built a reference database with 656 typical AL samples (145 T-ALL, 377 BCP-ALL, 134 AML), processed and analyzed via standardized protocols. Using principal component analysis (PCA)-based plots and automated classification algorithms for direct comparison of single-cells from individual patients against the database, another 783 cases were subsequently evaluated. Depending on the database-guided results, patients were categorized as: (i) typical T, B or Myeloid without or; (ii) with a transitional component to another lineage; (iii) atypical; or (iv) mixed-lineage. Using this automated algorithm, in 781/783 cases (99.7%) the right panel was selected, and data comparable to the final WHO-diagnosis was already provided in >93% of cases (85% T-ALL, 97% BCP-ALL, 95% AML and 87% mixed-phenotype AL patients), even without data on the full-characterization panels. Our results show that database-guided analysis facilitates standardized interpretation of ALOT results and allows accurate selection of the relevant classification panels, hence providing a solid basis for designing future WHO AL classifications.

Increased IL6 plasma levels in indolent systemic mastocytosis patients are associated with high risk of disease progression.

Systemic mastocytosis (SM) is a heterogeneous disease with altered interleukin (IL)-6 and IL13 plasma levels. However, no study has simultaneously investigated the plasma levels of IL1ß, IL6, IL13, CCL23 and clusterin in SM at diagnosis and correlated them with disease outcome. Here we investigated IL1ß, IL6, IL13, CCL23 and clusterin plasma levels in 75 SM patients--66 indolent SM (ISM) and 9 aggressive SM--and analyzed their prognostic impact among ISM cases grouped according to the extent of hematopoietic involvement of the bone marrow cells by the KIT D816V mutation. Although increased IL1ß, IL6 and CCL23 levels were detected in SM patients versus healthy controls, only IL6 and CCL23 levels gradually increased with disease severity. Moreover, increased IL6 plasma levels were associated with ISM progression to more aggressive disease, in particular among ISM patients with multilineal KIT mutation (ISM-ML), these patients also showing a higher frequency of organomegalies, versus other ISM-ML patients. Of note, all ISM patients who progressed had increased IL6 plasma levels already at diagnosis. Our results indicate that SM patients display an altered plasma cytokine profile already at diagnosis, increased IL6 plasma levels emerging as an early marker for disease progression among ISM cases, in particular among high-risk ISM patients who carry multilineage KIT mutation.

Revisiting guidelines for integration of flow cytometry results in the WHO classification of myelodysplastic syndromes-proposal from the International/European LeukemiaNet Working Group for Flow Cytometry in MDS.

Definite progress has been made in the exploration of myelodysplastic syndromes (MDS) by flow cytometry (FCM) since the publication of the World Health Organization 2008 classification of myeloid neoplasms. An international working party initiated within the European LeukemiaNet and extended to include members from Australia, Canada, Japan, Taiwan and the United States has, through several workshops, developed and subsequently published consensus recommendations. The latter deal with preanalytical precautions, and propose small and large panels, which allow evaluating immunophenotypic anomalies and calculating myelodysplasia scores. The current paper provides guidelines that strongly recommend the integration of FCM data with other diagnostic tools in the diagnostic work-up of MDS.

Newly diagnosed adult AML and MPAL patients frequently show clonal residual hematopoiesis.

Adult acute myeloid leukemia (AML) is a highly heterogeneous stem cell malignancy characterized by the clonal expansion of immature myeloid precursors. AML may emerge de novo, following other hematopoietic malignancies or after cytotoxic therapy for other disorders. Here, we investigated the clonal vs reactive nature of residual maturing bone marrow cells in 59 newly diagnosed adult AML and mixed phenotype acute leukemia (MPAL) patients as assessed by interphase fluorescence in situ hybridization analysis of AML and myelodysplastic syndrome-associated cytogenetic alterations and/or the pattern of chromosome X inactivation, in females. In addition, we investigated the potential association between the degree of molecular/genetic involvement of hematopoiesis and coexistence of altered immunophenotypes by flow cytometry. Our results indicate that residual maturing neutrophils, monocytes and nucleated red cell precursors from the great majority of newly diagnosed AML and MPAL cases show a clonal pattern of involvement of residual maturing hematopoietic cells, in association with a greater number of altered immunophenotypes. These findings are consistent with the replacement of normal/reactive hematopoiesis by clonal myelopoiesis and/or erythropoiesis in most newly diagnosed AML and MPAL cases, supporting the notion that in most adults presenting with de novo AML, accumulation of blast cells could occur over a pre-existing clonal hematopoiesis.

Standardization of flow cytometry in myelodysplastic syndromes: a report from an international consortium and the European LeukemiaNet Working Group.

Flow cytometry (FC) is increasingly recognized as an important tool in the diagnosis and prognosis of myelodysplastic syndromes (MDS). However, validation of current assays and agreement upon the techniques are prerequisites for its widespread acceptance and application in clinical practice. Therefore, a working group was initiated (Amsterdam, 2008) to discuss and propose standards for FC in MDS. In 2009 and 2010, representatives from 23, mainly European, institutes participated in the second and third European LeukemiaNet (ELN) MDS workshops. In the present report, minimal requirements to analyze dysplasia are refined. The proposed core markers should enable a categorization of FC results in cytopenic patients as 'normal', 'suggestive of', or 'diagnostic of' MDS. An FC report should include a description of validated FC abnormalities such as aberrant marker expression on myeloid progenitors and, furthermore, dysgranulopoiesis and/or dysmonocytopoiesis, if at least two abnormalities are evidenced. The working group is dedicated to initiate further studies to establish robust diagnostic and prognostic FC panels in MDS. An ultimate goal is to refine and improve diagnosis and prognostic scoring systems. Finally, the working group stresses that FC should be part of an integrated diagnosis rather than a separate technique.

New technologies in cancer. Protein microarrays for biomarker discovery

The emergence of proteomic techniques and methodological approaches to study disease has kindled the quest for new biomarkers. Thus, the use of protein microarrays has surged as a powerful tool for large-scale testing of biological samples. In this mini-review, we will discuss the application of protein microarray technologies that offer unique opportunities to find novel biomarkers (AU)

The immunophenotype of different immature, myeloid and B-cell lineage-committed CD34+ hematopoietic cells allows discrimination between normal/reactive and myelodysplastic syndrome precursors.

Occurrence of phenotypic abnormalities in CD34(+) hematopoietic progenitor and precursor cells (HPC) and their major B-cell and nonlymphoid compartments has been frequently reported in myelodysplastic syndromes (MDS). Here, we analyze for the first time the numerical and phenotypic abnormalities of different maturation-associated subsets of bone marrow (BM) CD34(+) HPC from 50 newly diagnosed MDS patients in comparison to normal/reactive BM (n=29). Our results confirm the existence of heterogeneously altered phenotypes among CD34(+) HPC from MDS and indicate that such variability depends both on the relative distribution of the different subsets of CD34(+) HPC committed into the different myeloid and B-lymphoid compartments, and their immunophenotype (for example, higher reactivity for CD117 and CD13 and lower expression of CyMPO, CD64 and CD65 on CD34(+) immature and neutrophil precursors), a clear association existing between the accumulation of CD34(+) HPC and that of immature CD34(+) HPC. Interestingly, expansion of erythroid- and neutrophil-lineage CD34(+) cells is detected in low-grade MDS at the expense of CD34(+) plasmacytoid dendritic cell and B-cell precursors, while expansion of immature CD34(+) precursors occurs in high-grade MDS. On the basis of the number and severity of the phenotypic abnormalities detected, a scoring system is proposed that efficiently discriminates between normal/reactive and MDS CD34(+) HPC, the mean score significantly increasing from low- to high-grade MDS.