Subclassification Of Acute Leukemia Research Articles

Spectrum of acute leukemias diagnosed on flow cytometry: Analysis from tertiary care centre from North India

BACKGROUND: Acute leukemias (ALs) are a heterogeneous group of malignancies with varying clinical, morphologic, immunologic, and molecular characteristics. WHO 2008 classification of ALs require a multi-parametric approach to the diagnosis. This study aims to evaluate the role of flow cytometry in diagnosis and sub-classification of acute leukemias. METHODS: Consecutive patients of adult and paediatric ALs during June 2012 to May 2013 were retrospectively analyzed and studied using BD FACS Canto-II flow cytometer. The results of immunophenotyping were reviewed and analyzed for cross-lineage antigen expression. RESULT: Over a period of year, 422 individuals were diagnosed as AL. There were 287 males and 135 females with M:F = 2.1:1. There were 237 adults & 185 children. 36.3% were AML and 60.4% were ALL, while 3.3% of cases were mixed phenotypic acute leukemia (MPAL). The commonest WHO subtype in AML group was AML with maturation being 31%. In case of ALL there were 83.9% B-ALLs and 16.1% T-ALLs. In MPAL B-Myeloid was 71.4%, whereas T-Myeloid was 28.6% of cases. Both AML and MPAL were more frequently seen in adults accounting to 83% and 92.9% respectively of all ALs cases. In contrast, 62% of ALLs were children and only 38% were adults. Out of all ALs, 37.6% of showed cross lineage antigen expression. In AML, B-ALL and T-ALL cross lineage antigen expression were 26.14%, 39.71% and 82.9% respectively. CONCLUSION: Flow cytometry is useful in diagnosis and sub classification of AL. It is essential in cytochemical myeloperoxidase (MPO) negative cases. Cross- lineage antigen expression is frequent in ALs, and hence, lineage specific intra-cytoplasmic antibodies including anti-MPO and cytoplasmic-CD3 are essential for correct categorization of ALs. DOI: http://dx.doi.org/10.3126/acclm.v1i1.12308 Ann. Clin. Chem. & Lab. Med. 1(1) 2015: 12-15

Leukemia blast cell identification

Acute leukemia is a heterogeneous group of disorders, characterized by different laboratory and prognostic features. An adequate diagnosis of acute leukemia, based on the identification of a leukemic cell population and the hematopoietic lineage assessment, is the first goal toward defining correct risk stratification of patients and tailoring specific therapies to patients. Diagnosis of acute leukemia underwent an important change since the 1970s when the only available diagnostic tools were cytomorphology and cytochemistry. Nowadays, the development of modern techniques and their combined use in a multimodal approach lead to a better identification and sub-classification of acute leukemia. Thus, blast identification in acute leukemia required a comprehensive global approach, by combining cytomorphology, cytochemistry, multiparameter flow cytometry MFC, cytogenetic, fluorescence in situ hybridization FISH and molecular genetic methods. At least, new sequencing technologies, such as gene expression profiling GEP and whole-genome sequencing, DNA methylation arrays, and comparative genomic hybridization array, could represent the new frontiers in the characterization of genetic heterogeneity in acute leukemia. WIREs Data Mining Knowl Discov 2015, 5:74-85. doi: 10.1002/widm.1146

Laboratory diagnosis of acute leukemia in Iraq, the available options.

Diagnosis of acute leukemia in Iraq is mainly dependent on the personal experience of the laboratory physician. Local guidelines in this field were never proposed and the international guidelines are very difficult to apply as the only available techniques include morphology of peripheral blood and bone marrow specimens plus very limited immunohistochemistry CD markers and PCR testing for BCR-ABL oncogene only, therefore the aim for diagnosis, classification and subclassification of acute leukemia in this country should be that of diagnosis and lineage assignment that serves a clear therapeutic goal. Having been working in the field of laboratory hematology since 2003 in the major teaching hospitals in Baghdad, I found that the following scheme is the available useful option: Acute leukemia should be classified on the basis of FAB group, but using a cut-off point of 20% blast cells, as proposed in the WHO classification [1].

Expression of lineage markers using real-time quantitative polymerase chain reaction (RT-qPCR) in normal and in leukemia bone marrow

The study of lineage markers by real-time quantitative polymerase chain reaction (RT-qPCR) at diagnosis enables differentiation between acute myeloblastic leukemia, B- or T-lineage acute lymphoblastic leukemia, without cell sorting. Our objective was to assess the relationship between protein expression and the amount of lineage marker mRNA in acute leukemia samples and to determine whether four lineage markers could be used to differentiate between normal and acute leukemia bone marrow (BM) without cell sorting. Quantification of the mRNA of CD19, CD79a, CD3e, and myeloperoxidase was performed by RT-qPCR on 130 acute leukemia BM samples at diagnosis and on 20 BM samples from healthy donors, without cell sorting. Immunophenotyping of leukemia samples was performed after manual gating around the blastic population. Reference values for the four lineage markers were established by RT-qPCR for normal BM. The mRNA expression levels of these four lineage markers allowed the distinction between normal samples and 100% of acute leukemia samples. With 92% congruence for protein expression and amount of mRNA in acute leukemias, these four lineage markers, essential for diagnosis and subclassification of acute leukemias by flow cytometry, also represent excellent candidate genes when using RT-qPCR technology as a diagnostic tool for molecular cancer class prediction.

Immunohistochemistry in bone marrow pathology: a useful adjunct for morphologic diagnosis

Pathomorphological examination of trephine biopsies of the bone marrow (BM) represents a standard method for the diagnosis and staging of hematologic neoplasms and other disorders involving the BM. The increasing knowledge about the genetic basis and biology of hematologic neoplasms, as well as the recently proposed WHO classification system, provide the framework for an accurate diagnosis. Although conventional morphology remains the gold standard for paraffin-embedded BM trephines, immunohistochemical stainings have become an integral part of the diagnostic workup. Antibodies suitable for paraffin sections are generally applicable to BM trephines, but modifications of staining protocols may be necessary due to the alternative fixatives and decalcification procedures used for BM biopsies. The indications for immunostainings range from confirmation and classification of lymphoma involvement, subclassification of acute leukemias, and estimating blast counts in myelodysplastic and myeloproliferative syndromes to characterization of BM involvement in nonhematologic neoplasms. Although subtyping of NHL in the BM is more difficult from the point of morphology, classification of the entities that frequently involve the BM, especially the small B-cell lymphomas, can easily be achieved with the help of immunohistochemistry. In this review, we try to summarize the current state of the art in BM immunohistochemistry for the diagnosis of hematologic disorders. Moreover, diagnostic algorithms and useful antibody panels are proposed for a rational and cost-effective approach.

Immunological Classification of Childhood Acute Lymphoblastic Leukemia

Seven hundred and forty-four newly diagnosed patients with acute leukemias between 1978 and 1990 were classified on the basis of immunological phenotypes. The majority of the patients were enrolled in the Tokyo Children's Cancer Study Group (TCCSG) studies. The incidence of subclassification of acute leukemias in this study was as follows: 522 patients with ALL (70%), 139 patients with ANLL (18%), 29 patients with biphenotypic leukemia, 8 patients with Ph1-positive acute leukemia (Ph1-AL), and 45 patients with infant leukemia. ALLs were classified into common ALL (cALL, 77%), T-ALL (15%), B-ALL (4%), and unclassified ALL (3%). The incidence of ALL subtypes in this study reflected those of TCCSG. Biphenotypic leukemias were categorized into 4 groups as follows; 1) cALL with positive myelomonocytic antigen(s) (N = 11), 2) unclassified ALL with positive myelomonocytic antigen(s) (N = 5), 3) ANLL with positive B-lymphoid antigen(s) (N = 4), and 4) acute leukemia with positive T-lymphoid and myeloid antigen(s). Infant leukemias were classified into ALL type (N = 27) and ANLL type (N = 18). In this present study, clinical features and immunological phenotypes of the acute leukemias with a poor prognosis, i.e. biphenotypic leukemia, Ph1-AL, and infant leukemia are analyzed and discussed.