Ir al contenido principal

How can aberrant B lymphoblasts in B lymphoblastic leukemia (B-ALL) be distinguished from hematogones?

Hematogones are immature B-cell precursors that are found primarily in the bone marrow from which they arise. They are found in greatest abundance in infants and young children and decline with age. They are frequently increased in regenerating bone marrow after chemotherapy or bone marrow transplant, but also can be increased in other inflammatory, hematologic, oncologic, and inflammatory disorders. They are rarely detected in peripheral blood.
It is particularly important to be able to differentiate hematogones from neoplastic B-cell precursors in the diagnosis and monitoring of B-ALL. B-lineage lymphoblasts and hematogones often share immunophenotypic characteristics. Thus, hematogone hyperplasia can be mistaken for B-ALL at diagnosis and regenerating hematogones can be mistaken for minimal residual disease after therapy.
Figure 1A shows normal B-lineage maturation. All hematogones are positive for CD19 (not shown) and show variable expression of CD58. The earliest hematogones are bright for CD9, CD10, and CD38, positive for CD34, dim for CD45, and negative for CD20. As they mature, they gain CD20 and then lose CD10. They lose CD34 and then lose CD9 expression. The intensity of CD45 increases and then the intensity of CD38 decreases.
B lymphoblasts in ALL can be differentiated from hematogones by aberrant expression of at least one, but frequently more than one of these markers. An example is shown in Figure 1B. These aberrancies can include over-expression of an antigen, such as CD10, CD34, or CD58, or under-expression of an antigen, such as CD38 or CD45. There can be aberrant co-expression of markers not typically expressed together, such as CD20 and CD34. Sometimes there is aberrant expression of a non-B-cell marker, such as CD13 or CD33. Often aberrancies are most apparent when viewed in combination on 2-dimensional histograms (see Figure 3). The most helpful of these have been shown to be CD58xCD38 and CD10xCD20.
�
Understanding the normal immunophenotype of hematogones and how these can be altered aberrantly in B lymphoblasts can help to distinguish hematogone hyperplasia from B-ALL, which is critically important both at diagnosis and during post-therapy monitoring for minimal residual disease
Further Reading:
�1. McKenna RW, Asplund SL, Kroft SH (2004) Immunophenotypic analysis of hematogones (B-lymphocytes precursors) and neoplastic lymphoblasts by 4-color flow cytometry. Leuk Lymphoma. 45:277-285.
�2. Seegmiller AC, Kroft SH, Karandikar NJ, McKenna RW (2009) Characterization of immunophenotypic aberrancies in 200 cases of B acute lymphoblastic leukemia. Am J Clin Pathol. 132:940-949.
3. Shaver AC, Greig BW, Mosse CA, Seegmiller AC (2015) B-ALL Minimal Residual Disease Flow Cytometry: An Application of a Novel Method for Optimization of a Single-Tube Model. AmJ Clin Pathol. 143:716-724.

Etiquetas:

Comentarios

Publicar un comentario

Entradas Populared

ONKODIN Image Bank - Image database for hematological cytology and case reports

Editor: H. Link, Kaiserslautern ONKODIN Image Bank is an online informational resource for experts, physicians and students, that has been in existence since July of 2004. Its focus is on supporting education and research in hematological neoplasia occurring in blood, bone marrow, lymph node and body fluid specimens such as cerebral spinal fluid, ascites and pleural effusions. ONKODIN Image Bank contains normal and pathological findings, hematological diseases, and other diseases containing hematological findings, as well as classifications, an expert panel and general information. The images are mostly presented in a case-based format that allows both the images and text to be searched. Images can be zoomed to get a detailed presentation of the image. This project is an ongoing development due to the multitude of hematological cases and images, as well as the constant influx of new information appearing in the field. Active decision support tools that quiz the website-users wil...
Publicar un comentario
Leer más

An atlas of cells with consensual nomenclature by the WP10 Morphology Faculty

This section provides a collection of a consensus-based cell library of meaningful hematopoietic images provided, identified and named by members of the European Morphology Faculty, including 28 experts from 17 different European countries. In this cell collection of 228 pictures there are 604 labelled hematopoietic cells and an excel file where each cell is identified by its code on the images, by the type of stain used, the lineage and the consensual name agreed upon by the ELN Diagnosis Morphology Faculty. From May 2007 on, each Faculty member first submitted a set of images. After several rounds of electronic circulation of digitalized pictures, the Faculty reached full agreement for 348 cells, while the agreement on the remaining 256 cells (highlighted with a red circle on the web site) was pending. The latter was reached after a 2-full-day meeting in October 2008. This cell library is the first ELN European tool to train and test European morphologists, aiming to provide a harmo...
Publicar un comentario
Leer más

Atlas Of Hematology by Nivaldo Medeiros, MD

This Atlas has the goal of supplying hematologists, laboratory technicians, medical school students, biologists as well as professionals working in the field of morphology of blood cells. The majority of the smears come from blood and bone marrow samples, however note that also are shown here cavitary fluid materials, scraped, etc. The panchromic stain used is always "Leishman", and are added in addition rare cytochemistry reactions. The pictures taken were scaled up of magnifications such:  x200 ; x400 ;  x630 ; and specially  x1,000  with photomicroscopes  Zeiss  and  Nikon . These pictures show normal cells from blood and bone marrow and continuing to a substantial variety of hematologic diseases, being some of these rather  Fotografias de Maduracion en Medula Osea, alteraciones eritrocitarias, Anemias, Leucemias, etc. Para acceder haga  Click Aqui.
Publicar un comentario
Leer más