Concordance among hematopathologists in classifying blasts plus promonocytes: A bone marrow pathology group study.

Enumeration of blasts and promonocytes is essential for World Health Organization (WHO) classification of myelomonocytic neoplasms. The accuracy of distinguishing blasts, promonocytes and monocytes, including normal vs abnormal monocytes, remains controversial. The objective of this analysis is to assess concordances between experienced hematopathologists in classifying cells as blasts, promonocytes, and monocytes according to WHO criteria. Each of 11 hematopathologists assessed glass slides from 20 patients [12 with chronic myelomonocytic leukemia (CMML) and 8 with acute myeloid leukemia (AML)] including blood and BM aspirate smears, and limited nonspecific esterase (NSE) stains. All cases were blindly reviewed. Fleiss' extension of Cohen's kappa for multiple raters was used on these variables, separately for peripheral blood (PB) and bone marrow (BM). Spearman's rank correlation was used to assess correlations between each pair of hematopathologists for each measurement. For the classification based on the sum of blasts and promonocytes in the BM, Fleiss' kappa was estimated as 0.744. For PB, categorizing patients according to the sum of blasts and promonocytes, Fleiss' kappa was estimated as 0.949. Distinction of abnormal monocytes from normal monocytes in PB did not achieve a good concordance and showed strong evidence of differences between hematopathologists (P < .0001). The hematopathologists achieved a good concordance rate of 74% in CMML vs AML classification and a high k rate, confirming that criteria for defining the blasts equivalents (blasts plus promonocytes) could be applied consistently. Identification of monocyte subtypes (abnormal vs normal) was not concordant. Our results support the practice of combining blasts/promonocytes into a single category.

Comparison of blast percentage calculated based on bone marrow all nucleated cells and non-erythroid cells in myelodysplastic syndromes with erythroid hyperplasia.

It is controversial whether blast percentage based on all nucleated cells (ANC) or non-erythroid cells (NEC) more accurately reflects the prognosis of patients with myelodysplastic syndromes (MDS). We considered that the impact of blast percentage on survival should be similar in MDS with erythroid hyperplasia (MDS-E) and MDS with no erythroid hyperplasia (MDS-NE), and from this perspective, we retrospectively analyzed 322 patients, including 44 with MDS-E and 278 with MDS-NE. Overall survival was similar between the MDS-E and MDS-NE groups (P = 0.94). In a subgroup of patients with bone marrow (BM) blasts of < 5%, no difference in survival was found between MDS-E and MDS-NE by either calculation method. However, in patients with a blast percentage between 5 and 10%, a significant difference in survival was observed only when the blast percentage in MDS-E was calculated from ANC (P < 0.001 by ANC and P = 0.66 by NEC). A similar result was observed when we analyzed the remaining patients with higher blasts together with those with blasts between 5 and 10%. These results suggest that the calculation of the BM blast percentage based on NEC in MDS-E provides a blast percentage value with a clinical impact consistent with that in MDS-NE.

Validation of the 2017 revision of the WHO chronic myelomonocytic leukemia categories.

The 2017 revision of the World Health Organization (WHO) classification includes substantial changes to the subclassification of chronic myelomonocytic leukemia (CMML): (1) a 3-tiered blast-based scheme including a novel "CMML-0" category replacing a 2-tiered system in place since 2001 and (2) 2 CMML subtypes, myelodysplastic (MDS-CMML) and myeloproliferative (MP-CMML), based on a white blood cell count cutoff of 13 × 109/L. The clinical utility of this subclassification scheme, particularly the expansion of blast-based subgroups, has not been validated. In this study, a large single-institution CMML patient cohort (n = 629) was used to assess the prognostic impact of the newly proposed categories. Patients were risk stratified according to the CMML-specific Prognostic Scoring System (CPSS) and the MD Anderson Prognostic Scoring System. MP-CMML patients had significantly shorter overall survival (OS; P < .0001; hazard ratio: 0.53, 95% confidence interval: 0.42-0.65) and median duration to acute myeloid leukemia (AML) transformation (P < .0001; 15.2 vs 22.0 months) compared with MDS-CMML patients. The CMML-0 group included 36.4% patients with higher risk CPSS categories and 11.2% of patients with high-risk cytogenetics. Among treatment-naïve patients (n = 499), there was a marginal difference in OS between the CMML-0 and CMML-12017 subgroups (P = .0552). The WHO 2017 blast-based categories were not associated with AML-free survival. Incorporation of the WHO 2017 blast-based subgroups in a modified CPSS scheme had a neutral effect and did not improve its prognostic strength. Our data support the inclusion of MP-CMML and MDS-CMML subtypes in the WHO 2017 revision. Although of some utility in MP-CMML, the 3-tiered blast-based system is not well supported in this study.

Refined medullary blast and white blood cell count based classification of chronic myelomonocytic leukemias.

Since 2001, chronic myelomonocytic leukemia (CMML) is classified by the WHO as myeloproliferative/myelodysplastic neoplasm. Herein we tried to better describe CMML patients with regard to hematological characteristics and prognosis using data of the Duesseldorf registry. We created 6 CMML subgroups, by dividing dysplastic and proliferative CMML at the cut-off of white blood cell count of 13,000/µL and splitting these two groups into 3 subgroups: CMML 0 with <5% blasts (n=101), CMML I with 5-9% blasts (n=204) and CMML II with 10-19% blasts (n=81). For comparison we included patients with RCMD, RAEB I and II. The newly created CMML 0 group had better prognosis than CMML I and II, median survival times were 31 months (ms), 19ms and 13ms, respectively (p<0.001). Median survival times between the corresponding dysplastic and proliferative subgroups 0 and 1 differed significantly: CMML 0 dysplastic 48ms and CMML 0 proliferative 17ms (p=0.03), CMML I dysplastic 29ms and CMML I proliferative 15ms (p=0.008), CMML II dysplastic 17ms and CMML II proliferative 10ms (p=0.09). Outcome of CMML patients worsens with increasing medullary blasts and when presenting as proliferative type. Therefore it is justified to separate CMML with <5% medullary blasts.

Chronic myelomonocytic leukemia: myelodysplastic or myeloproliferative?

Chronic myelomonocytic leukemia (CMML) is a clonal disease of the hematopoietic stem cell that provokes a stable increase in peripheral blood monocyte count. The World Health Organisation classification appropriately underlines that the disease combines dysplastic and proliferative features. The percentage of blast cells in the blood and bone marrow distinguishes CMML-1 from CMML-2. The disease is usually diagnosed after the age of 50, with a strong male predominance. Inconstant and non-specific cytogenetic aberrations have a negative prognostic impact. Recurrent gene mutations affect mainly the TET2, SRSF2, and ASXL1 genes. Median survival is 3 years, with patients dying from progression to AML (20-30%) or from cytopenias. ASXL1 is the only gene whose mutation predicts outcome and can be included within a prognostic score. Allogeneic stem cell transplantation is possibly curative but rarely feasible. Hydroxyurea, which is the conventional cytoreductive agent, is used in myeloproliferative forms, and demethylating agents could be efficient in the most aggressive forms of the disease.

5-LOX, 12-LOX and 15-LOX in immature forms of human leukemic blasts.

Several reports have demonstrated an important role of leukotriene B(4) (LTB(4)) in the immune system. We investigated whether leukemic blasts from acute myeloid leukemic (AML) and acute lymphoid leukemic (ALL) patients produced LTB(4), 12- and 15-hydroxyeicosatetraenoic acids (12-HETE and 15-HETE) and whether these compounds affected blast proliferation and apoptosis. Leukemic blasts from AML M(0-2) and ALL patients expressed 5-LOX, 12-LOX and 15-LOX transcripts. Quantitative polymerase chain reaction indicated that 5-LOX transcripts were far more abundant than 12-LOX and 15-LOX ones. Leukemic blasts expressed 5-LOX activating protein (FLAP) transcripts and produced LTB(4) in response to calcium ionophore. In contrast no 15-HETE production was found. Calcium ionophore-stimulated leukemic blasts produced 12-HETE but also released thromboxane A(2) suggesting that contaminating platelets accounted for the release of these compounds. No significant effect of LTB(4), 12-HETE or 15-HETE could be documented on leukemic blast growth and on their apoptose rate. Results of the present study indicate that immature form of leukemic blasts produce LTB(4). However, the three major lipoxygenase metabolites of arachidonic acid; i.e., LTB(4), 12-HETE or 15-HETE, had no evident effect on their growth and apoptosis. We may speculate that LTB(4)-derived blast cells might initiate, augment or prolong tissue inflammation and damages by affecting the marrow and blood cytokine network.

Identification of genomic classifiers that distinguish induction failure in T-lineage acute lymphoblastic leukemia: a report from the Children's Oncology Group.

The clinical and cytogenetic features associated with T-cell acute lymphoblastic leukemia (T-ALL) are not predictive of early treatment failure. Based on the hypothesis that microarrays might identify patients who fail therapy, we used the Affymetrix U133 Plus 2.0 chip and prediction analysis of microarrays (PAM) to profile 50 newly diagnosed patients who were treated in the Children's Oncology Group (COG) T-ALL Study 9404. We identified a 116-member genomic classifier that could accurately distinguish all 6 induction failure (IF) cases from 44 patients who achieved remission; network analyses suggest a prominent role for genes mediating cellular quiescence. Seven genes were similarly upregulated in both the genomic classifier for IF patients and T-ALL cell lines having acquired resistance to neoplastic agents, identifying potential target genes for further study in drug resistance. We tested whether our classifier could predict IF within 42 patient samples obtained from COG 8704 and, using PAM to define a smaller classifier for the U133A chip, correctly identified the single IF case and patients with persistently circulating blasts. Genetic profiling may identify T-ALL patients who are likely to fail induction and for whom alternate treatment strategies might be beneficial.

Primary myelofibrosis (PMF), post polycythemia vera myelofibrosis (post-PV MF), post essential thrombocythemia myelofibrosis (post-ET MF), blast phase PMF (PMF-BP): Consensus on terminology by the international working group for myelofibrosis research and treatment (IWG-MRT).

The International Working Group for Myelofibrosis Research and Treatment (IWG-MRT) is comprised of hematologists, hematopathologists, and laboratory scientists and its main goal is to provide a forum for scientific exchange and collaboration. During its first general meeting in April 2006, the IWG-MRT established uniform treatment response criteria for chronic idiopathic myelofibrosis (CIMF); also known as agnogenic myeloid metaplasia (AMM), myelofibrosis with myeloid metaplasia (MMM), and many other names in the hematologic literature. This document summarizes the proceedings from the second meeting of the IWG-MRT, in November 2006, where the group discussed and agreed to standardize the nomenclature referring to CIMF: (i) the term primary myelofibrosis (PMF) was chosen over several other designations including CIMF, AMM, and MMM, (ii) myelofibrosis that develops in the setting of either polycythemia vera (PV) or essential thrombocythemia (ET) will be referred to as post-PV MF and post-ET MF, respectively, and (iii) "leukemic" transformation will be recognized as blast phase disease (PMF-BP, post-PV/ET MF in blast phase).

[The immunophenotypic and cytogenetic characteristics of the blast cells in subvariants of acute myeloid leukemia]. / Immunofenotipicheskaia i tsitogeneticheskaia kharakteristika blastnykh kletok pri nekotorykh podvariantakh ostroi mieloidnoi leikemii.

The results of study of morpho-cytochemical peculiarities, antigenic profile and peripheric blood and/or bone marrow blast cell karyotype of 21 patients with acute myeloid leukemia are presented. Hemopoietic cell immunophenotyping was carried out with the use of cytofluorometer FACScan and chromosome cytogenetic analysis with the use of analyzer "Metascan". It has been shown that in the AML M1 blast cell plasmatic membrane carries pan-myeloid CD33 and CD13 antigens, the last having high density of expression, and the CD38 antigen, which is a myeloid cell-precursor marker. In these patients tetraploidy, being the testimony of karyotype change, has been ascertained. It has been found out that the AML M2 blasts, except pan-myeloid antigens, express the cell proliferation CD71 marker. Blast cell karyotype peculiarities typical for this leukemia sub-variant have been revealed. In patients with the AML M4 in 3 of 6 cases an anomalous karyotype has been found. It has been also shown that the CD14 antigen, and rather its percentage in blast total population, is the differential-diagnostic criterion for the AML M4 and M5.

The relationship between the location of the breakpoint within the M-bcr and clinical parameters.

The Philadelphia chromosome (t9;22)(q34;q11) is a characteristic abnormality in chronic myeloid leukemia. In greater than 95% of the cases, the breakpoint occurs with the M-bcr region of the BCR gene on chromosome 22. Several studies have attempted to correlate the location of the breakpoint within the M-bcr with a clinical parameter. The majority of studies have examined the relationship between the site of breakpoint and the median chronic phase duration (CPD). Some studies have reported a correlation, with 5' breakpoint patients who have a longer median CPD than patients with a 3' breakpoint. However, other groups have reported that no correlation exists. Furthermore, data from some of the latter groups have suggested that a correlation may exist with the lineage of blast crisis which developed and 3' breakpoint patients had a higher than expected number of lymphoid blast crisis. A correlation between high platelet counts at diagnosis and patients with a 3' breakpoint or those who expressed a b3-a2 BCR-ABL mRNA has also been described. No consistent conclusion from any of these studies can be drawn. This may due, in part, to some degree of patient and sample selection, although environmental, genetic or life-style factors may also contribute.

[Differential diagnostic criteria of blast cells in the peripheral blood in acute myeloid leukemias]. / Differentsial'no-diagnosticheskie kriterii blastnykh kletok perifericheskoi krovi pri ostrykh mieloidnykh leikozakh.

The authors present their data on results of an investigation of blast cells including morphocytochemical examination, determination of the presence of receptors to Fc-fragments of Ig, to C3 component of the complement. Criteria were obtained permitting to differentiate myeloid forms of acute leukosis.