Siminovitch K A, Greer W L, Novogrodsky A, Axelsson B, Somani A K, Peacocke M
Department of Medicine, University of Toronto, ON, Canada.
J Investig Med. 1995 Apr;43(2):159-69.
The Wiskott-Aldrich syndrome (WAS) is an X-linked recessive disease characterized by severe thrombocytopenia, eczema, and impaired immunity. While the diagnosis is usually straightforward, the syndrome may be expressed in an attenuated form, a phenotype which is difficult to distinguish from other types of congenital thrombocytopenia. Although a molecular-based assay for diagnosis of the spectrum of WAS patients has not been available, recent data indicate that WAS is associated with a specific profile of impaired mitogen responsiveness and suggest that detection of this abnormality may provide a diagnostic marker for all forms of the disease. To address this issue, we have studied patients with classical and atypical WAS for their lymphocyte proliferative responses to four T cell mitogenic stimuli and compared their response patterns to those detected in unaffected children.
Clinical histories and informed consent were obtained from 23 patients with either classical or putative (ie, atypical) WAS, 16 subjects with other disorders, and 12 healthy children. Peripheral blood mononuclear cells (PBMCs) collected from patients and controls were resuspended in culture medium, stimulated with the T cell mitogens phytohemagglutinin (PHA), concanavalin A (Con A), neuraminidase/galactose oxidase (NAGO), or periodate, and cultured for 60 h in 0.2 mL aliquots. Following a 20 h pulse with 3H-thymidine, cultures were harvested and the 3H-thymidine uptake was evaluated by liquid scintillation counting.
The most striking observation involved response to periodate. While lymphocytes from all healthy control children proliferated in response to periodate treatment, cells from both classical as well as atypical WAS patients consistently failed to proliferate in response to this mitogen. By contrast, lymphocyte proliferative responses to PHA, Con A, and NAGO were detected in all patients and controls, although responses generally were lower in cells from classical WAS patients compared to other children. In two WAS patients, bone marrow transplantation and clinical improvement were associated with a change from no periodate response (pre-transplant) to periodate responsiveness (post-transplant). In contrast to the WAS patients, cells from patients with other hematologic and primary immune deficiency diseases responded uniformly to all four mitogens, including periodate.
The data presented here indicate that T cells from patients with either classical or attenuated WAS fail to undergo proliferation in response to periodate, an agent that induced extensive T cell mitogenesis of cells from all healthy controls as well as patients with diseases other than WAS. As the WAS patients' cells did proliferate in response to treatment with other T cell mitogens, it appears that periodate induced T cell proliferation is selectively impaired in WAS and that detection of this defect may be of value in the distinction of both classical and attenuated WAS from other thrombocytopenic conditions.
威斯科特-奥尔德里奇综合征（WAS）是一种X连锁隐性疾病，其特征为严重血小板减少、湿疹和免疫功能受损。虽然通常诊断较为直接，但该综合征可能以一种症状较轻的形式表现出来，这种表型很难与其他类型的先天性血小板减少症区分开来。尽管目前尚无基于分子检测的方法来诊断所有类型的WAS患者，但最近的数据表明，WAS与丝裂原反应受损的特定特征相关，并且检测这种异常可能为该疾病的所有形式提供一个诊断标志物。为了解决这个问题，我们研究了经典型和非典型型WAS患者对四种T细胞丝裂原刺激的淋巴细胞增殖反应，并将他们的反应模式与未受影响儿童的反应模式进行了比较。
获取了23例经典型或疑似（即非典型）WAS患者、16例患有其他疾病的受试者以及12名健康儿童的临床病史并获得了知情同意。从患者和对照者采集的外周血单个核细胞（PBMC）重悬于培养基中，用T细胞丝裂原植物血凝素（PHA）、刀豆蛋白A（Con A）、神经氨酸酶/半乳糖氧化酶（NAGO）或高碘酸盐刺激，并在0.2 mL分装液中培养60小时。在用3H-胸腺嘧啶脉冲处理20小时后，收获培养物并通过液体闪烁计数评估3H-胸腺嘧啶摄取。
最显著的观察结果涉及对高碘酸盐的反应。虽然所有健康对照儿童的淋巴细胞在高碘酸盐处理后均发生增殖，但经典型和非典型型WAS患者的细胞对这种丝裂原始终无增殖反应。相比之下，在所有患者和对照中均检测到对PHA、Con A和NAGO的淋巴细胞增殖反应，尽管经典型WAS患者细胞的反应通常低于其他儿童。在两名WAS患者中，骨髓移植和临床改善与从无高碘酸盐反应（移植前）转变为高碘酸盐反应性（移植后）相关。与WAS患者不同，患有其他血液学和原发性免疫缺陷疾病的患者的细胞对所有四种丝裂原，包括高碘酸盐，均有一致反应。
此处呈现的数据表明，经典型或症状较轻型WAS患者的T细胞在高碘酸盐刺激下无法增殖，而高碘酸盐能诱导所有健康对照以及非WAS疾病患者的细胞发生广泛的T细胞有丝分裂。由于WAS患者的细胞在其他T细胞丝裂原处理后确实发生了增殖，看来高碘酸盐诱导的T细胞增殖在WAS中被选择性损害，并且检测这种缺陷可能有助于将经典型和症状较轻型WAS与其他血小板减少症区分开来。
