CD43 and CD5 antibodies define four normal and neoplastic B-cell subsets: a three-color flow cytometric study
E F Lynch1, P A Jones, S H Swerdlow
1Department of Pathology, University of Pittsburgh School of Medicine, Pennsylvania, USA.
Insights
CD43 expression on B cells, including neoplastic B cells, is common and not aberrant. This study characterized CD43 and CD5 expression in normal and malignant B cells using flow cytometry.
Area of Science:
- Immunology
- Hematology
- Cell Biology
Background:
- CD43 antibodies are utilized to identify T cells and certain B-cell neoplasms in tissue sections.
- The presence of CD43 on normal and neoplastic B cells requires further investigation.
Purpose of the Study:
- To investigate the frequency and significance of CD43 expression in normal and neoplastic B cells.
- To analyze the relationship between CD43 and CD5 expression in different B-cell subsets and malignancies.
Main Methods:
- Three-color flow cytometry was employed to analyze 138 specimens.
- B-cell subsets were defined based on CD43 and CD5 expression.
Main Results:
- Four normal B-cell subsets were identified using CD43 and CD5.
- Increased CD43+ B cells were observed in cord blood and HIV+ samples.
- Common B-cell neoplasms originated from CD43+/CD5+ and CD43-/CD5- subsets.
- CD43 expression on B cells was weaker than on T cells, potentially leading to underestimation in paraffin sections.
Conclusions:
- CD43 expression in neoplastic B cells is not an aberrant phenomenon.
- CD43 and CD5 expression on B cells are independent, despite frequent co-expression.
- CD43's weaker expression on B cells compared to T cells may impact diagnostic interpretation in tissue samples.
Abstract:
CD43 antibodies are best known for identifying normal and neoplastic T cells and a subset of neoplastic B cells in paraffin sections. The frequency of nonneoplastic CD43 + B cells in different reactive settings, the proportion of B-cell neoplasms with small CD43+ populations, and the relationship of CD43+ B cells was therefore studied in 138 specimens using three-color cytometric analysis. CD43 and CD5 defined four normal B-cell subsets (CD43 + CD5 +, CD43 + CD5-, CD43 - CD5+, and CD43-CD5-). A significantly greater proportion of CD43+ B cells was found in cord blood and putative HIV+ blood samples than in normal control bloods. B-cell neoplasms derived from each of these four B-cell subsets were identified, with CD43+ /CD5+ and CD43-/CD5- neoplasms being most common. The predominant B-cell population coexpressed CD43 alone in 2/39 neoplasms and CD5 alone in four. A minority of cases showed heterogeneous CD43 expression. The B cells in two of three posttransplant lymphoproliferative disorders coexpressed CD43. B cells showed weaker CD43 staining than did T-cells (relative fluorescence 0.38 +/- 0.29). These findings support the concept that CD43 expression by neoplastic B cells is not an aberrant finding. CD43 expression on normal and neoplastic B cells is independent of CD5 expression even though CD43 and CD5 are frequently coexpressed. CD43 expression by B cells sometimes might be underestimated in paraffin sections because it is much weaker than on T cells.(ABSTRACT TRUNCATED AT 250 WORDS)
