Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN 55905, United States of America.
Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN 55905, United States of America.
J Immunol Methods. 2022 Oct;509:113327. doi: 10.1016/j.jim.2022.113327. Epub 2022 Aug 5.
B cells are one of the fundamental components of the adaptive immune system and are best known for their ability to produce antibodies. Among the various types of inborn errors of immunity, antibody deficiencies represent the largest group in terms of the number of affected individuals. Not all antibody deficiencies are due to B cell intrinsic defects but investigating B cell number and function are a critical part of the diagnostic process. B cells studies in clinical practice almost always rely on flow cytometry as the main tool of investigation. The advantage of flow cytometry is that it allows absolute and relative counting of B cells, and their phenotypic and functional evaluation at a single-cell level, while allowing the analysis of a large number of cells. Although versatile and broad in its utility, clinical flow cytometry has both theoretical and practical limitations. These include lack of consensus about definitions and classifications, and the use of non-standardized methods. Patients in all age groups, from newborns to the elderly, may require testing, yet B cells show significant changes in both numbers and subset distribution over the lifespan, requiring distinct reference ranges for narrowly defined age brackets for accurate interpretation. Sampling for testing is usually restricted to peripheral blood samples, and the number of markers routinely used are limited. This paper will provide a brief overview of flow cytometry and B cell biology, describe the human peripheral B cell subsets most commonly identified in clinical flow cytometry and discuss their clinical relevance in different settings.
B 细胞是适应性免疫系统的基本组成部分之一，以产生抗体的能力而闻名。在各种先天性免疫缺陷中，抗体缺陷在受影响个体的数量方面代表了最大的群体。并非所有抗体缺陷都是由于 B 细胞内在缺陷引起的，但调查 B 细胞数量和功能是诊断过程的关键部分。临床实践中的 B 细胞研究几乎总是依赖流式细胞术作为主要的研究工具。流式细胞术的优点在于它允许对 B 细胞进行绝对和相对计数，以及在单细胞水平上对其表型和功能进行评估，同时允许对大量细胞进行分析。尽管具有多功能性和广泛的用途，但临床流式细胞术在理论和实际应用方面都存在局限性。这些局限性包括缺乏定义和分类的共识，以及使用非标准化方法。所有年龄段的患者，从新生儿到老年人，都可能需要进行检测，但 B 细胞在整个生命周期中数量和亚群分布都有显著变化，因此需要为准确解释提供针对特定年龄范围的明确参考范围。检测采样通常仅限于外周血样本，并且常规使用的标记物数量有限。本文将简要概述流式细胞术和 B 细胞生物学，描述临床流式细胞术中最常识别的人类外周 B 细胞亚群，并讨论它们在不同情况下的临床相关性。
