Flow Cytometric Analysis of Cell Size in B-Cell Non-Hodgkin Lymphoma: Reliability and Potential Diagnostic Significance

Context.— Nodular lymphocyte-predominant Hodgkin lymphoma (NLPHL) is characterized by neoplastic lymphocyte-predominant cells frequently rimmed by CD3+/CD57+/programmed death receptor-1 (PD-1)+ T cells. Because of the rarity of lymphocyte-predominant cells in most cases, flow cytometric studies on NLPHL often fail to show evidence of malignancy. Objective.— To evaluate the diagnostic utility of PD-1 in detecting NLPHL by flow cytometry, in conjunction with the CD4:CD8 ratio and the percentage of T cells doubly positive for CD4 and CD8. Design.— Flow cytometric data obtained from cases of NLPHL (n = 10), classical Hodgkin lymphoma (n = 20), B-cell non-Hodgkin lymphoma (n = 22), T-cell non-Hodgkin lymphoma (n = 5), benign lymphoid lesions (n = 20), angioimmunoblastic T-cell lymphomas (n = 6) and T-cell/histiocyte–rich large B-cell lymphomas (n = 2) were analyzed and compared. Results.— Compared with the other groups, NLPHL showed significantly higher values in the following parameters: CD4:CD8 ratio, percentage of T cells doubly positive for CD4 and CD8, percentage of PD-1–positive T cells, and median fluorescence intensity of PD-1 expression in the doubly positive for CD4 and CD8 subset. Using a scoring system (0–4) based on arbitrary cutoffs for these 4 parameters, all 10 NLPHL cases scored 3 or higher, as compared with only 3 cases from the other groups, producing an overall sensitivity of 100% and a specificity of 96% (72 of 75). Two of the 3 outliers were non-Hodgkin lymphoma, and both showed definitive immunophenotypic abnormalities leading to the correct diagnosis. The remaining outlier was a case of T-cell/histiocyte–rich large B-cell lymphoma. Conclusions.— The inclusion of anti–PD-1 in flow cytometry is useful for detecting NLPHL in fresh tissue samples, most of which would have otherwise been labeled as nondiagnostic or reactive lymphoid processes.

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Flow Cytometric Analysis of Lymphomas: Current Status and Usefulness

Archives of Pathology & Laboratory Medicine ◽

10.5858/2006-130-1850-fcaolc ◽

2006 ◽

Vol 130 (12) ◽

pp. 1850-1858

Author(s):

Zahid Kaleem

Keyword(s):

Flow Cytometry ◽

Hodgkin Lymphoma ◽

Flow Cytometric Analysis ◽

Molecular Diagnostic ◽

Routine Practice ◽

Becton Dickinson ◽

Color Flow ◽

Non Hodgkin Lymphoma ◽

Flow Cytometric ◽

Diagnosis And Classification

Abstract Context.—Immunophenotyping has become a routine practice in the diagnosis and classification of most cases of non-Hodgkin lymphoma, and flow cytometry is often the method of choice in many laboratories. The role that flow cytometry plays, however, extends beyond just diagnosis and classification. Objective.—To review and evaluate the current roles of flow cytometry in non-Hodgkin lymphoma, to compare it with immunohistochemistry, and to discuss its potential future applications in the molecular diagnostic era. Data Sources.—The information contained herein is derived from peer-reviewed articles on the subject published in the English-language medical literature during the years 1980 to 2005 that were identified using PubMed (http://www.ncbi.nlm.nih.gov/entrez/query.fcgi, 1980–2005) search, various books and other sources on flow cytometry, and the author's personal experience of more than 10 years with flow cytometric analysis of lymphomas and leukemia using Becton-Dickinson (San Jose, Calif) and Beckman-Coulter (Miami, Fla) flow cytometers. Study Selection.—Studies were selected based on adequate material and methods, statistically significant results, and adequate clinical follow-up. Data Extraction.—The data from various sources were compared when the methods used were the same or similar and appropriate controls were included. Most of the studies employed 2-color, 3-color, or 4-color flow cytometers with antibodies from Becton-Dickinson, Beckman-Coulter, or DakoCytomation (Carpinteria, Calif). Results were evaluated from studies utilizing the same or similar techniques and flow cytometers. Only objective data analyses from relevant and useful publications were included for reporting and discussion. Data Synthesis.—Flow cytometry serves a variety of roles in the field of lymphoma/leukemia including rapid diagnosis, proper classification, staging, minimal residual disease detection, central nervous system lymphoma detection, evaluation of prognostic markers, detection of target molecules for therapies, ploidy analysis of lymphoma cell DNA, and evaluation of multidrug-resistance markers. It offers many advantages in comparison to immunohistochemistry for the same roles and provides uses that are either not possible or not preferable by immunohistochemistry such as multiparameter evaluation of single cells and detection of clonality in T cells. Conclusions.—By virtue of its ability to evaluate not only surface but also cytoplasmic and nuclear antigens, flow cytometry continues to enjoy widespread use in various capacities in lymphoma evaluation and treatment. Additional roles for flow cytometry are likely to be invented in the future and should provide distinctive uses in the molecular era.

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