Medical College of Wisconsin, Milwaukee, WI, USA.
Am J Clin Pathol. 2022 Oct 6;158(4):456-471. doi: 10.1093/ajcp/aqac079.
Mature T-cell neoplasms are a challenging area of diagnostic hematopathology. Flow cytometry has emerged as a useful technique for T-cell assessment.
We discuss the application of flow cytometry to the evaluation of mature T-cell proliferations, to include illustrative cases, theoretical framework, detailed review of normal and reactive T-cell subsets, and examination of diagnostic pitfalls.
Immunophenotypic aberrancy can be construed as a direct expression of the neoplastic phenotype, in contrast to clonal expansion, which is seen in reactive and neoplastic T-cell proliferations. Major and minor T-cell subsets show characteristic patterns of antigen expression. Reactive states can manifest expansions of normal minor subsets and also show alterations of antigen expression on certain populations. However, some patterns of antigen expression are either never or very rarely encountered in reactive T cells. Flow cytometric tools are now available to directly assess clonality in specific T-cell populations. Technical and biological pitfalls may complicate the interpretation of T-cell flow cytometry.
Flow cytometry is a very useful tool in the diagnostic armamentarium for the assessment of mature T-cell proliferations, but it must be interpreted based on a thorough knowledge of the T-cell immune response, as well as an awareness of clinical context.
成熟 T 细胞肿瘤是诊断血液病理学的一个具有挑战性的领域。流式细胞术已成为评估 T 细胞的有用技术。
我们讨论了流式细胞术在评估成熟 T 细胞增殖中的应用，包括说明性病例、理论框架、详细回顾正常和反应性 T 细胞亚群以及检查诊断陷阱。
免疫表型异常可以被理解为肿瘤表型的直接表达，与克隆性扩张不同，克隆性扩张见于反应性和肿瘤性 T 细胞增殖中。主要和次要 T 细胞亚群表现出特征性的抗原表达模式。反应性状态可以表现为正常小亚群的扩张，也可以表现为某些群体的抗原表达改变。然而，某些抗原表达模式在反应性 T 细胞中从未或很少遇到。现在有流式细胞术工具可用于直接评估特定 T 细胞群体的克隆性。技术和生物学陷阱可能会使 T 细胞流式细胞术的解释复杂化。
流式细胞术是评估成熟 T 细胞增殖的诊断工具中非常有用的工具，但必须基于对 T 细胞免疫反应的深入了解以及对临床背景的认识来进行解释。
