Sfikakis P P, Tesar J, Theocharis S, Klipple G L, Tsokos G C
Department of Medicine, Uniformed University of the Health Sciences, Bethesda, MD.
Ann Rheum Dis. 1994 Feb;53(2):122-7. doi: 10.1136/ard.53.2.122.
Activated T lymphocytes are involved in the pathogenesis of scleroderma (systemic sclerosis, SSc); such cells rapidly divide in vivo and are thus theoretically subject to random mutation more frequently than resting cells. To study whether SSc is associated with rapidly expanding T cell clones the frequency was determined of in vivo mutated T cells (MF) at the hypoxanthine guanine phosphoribosyl transferase (hprt) gene in the peripheral blood from patients with SSc. Specific clinical or serological associations were also investigated.
Peripheral blood lymphocytes from 16 healthy individuals and 20 patients with SSc were cultured using an hprt clonal assay; mutated and wild T cell clones were established to assess individual values of T cell MF. T cell clones were further expanded in vitro and their phenotype was determined by standard immunofluorescence technique. Enzyme-linked immunosorbent assays were used for simultaneous measurements of plasma levels of soluble Interleukin-2 receptors (s-IL-2R) and Intercellular adhesion molecule-1 (s-ICAM-1).
Mean (SD) value of T cell MF in patients with SSc was 2.5-fold higher than the normal mean (SD) value [10.6 (6.6) x 10(-6) v [4.4 (2.8) x 10(-6), p = 0.0007]. Eleven of 20 patients with SSc (55%) had T cell MF values greater than two SD above the normal mean value. The majority (84%) of mutated T cells had a helper/inducer, memory phenotype while 12% were cytotoxic/suppressor T cells. There was no association between T cell MF and the extent of skin involvement or the duration of Raynaud's phenomenon. High individual T cell MF values were not related to a possible concurrent immune overactivity as assessed by plasma levels of s-IL-2R and s-ICAM-1. Patients with long standing skin disease, however, had almost double T cell MF values than patients with early skin disease [(13.6 (7.4)) x 10(-6) v (7.5 (4.3)) x 10(-6), p = 0.03], suggesting that increased T cell MF in SSc may reflect an ongoing process of chronic in vivo T cell proliferation and/or prolonged survival.
Increased in vivo T cell mutation in patients with SSc suggests that excessive division and/or survival of T cell clones contribute to the pathology in SSc; this approach can be used in further investigations to identify the stimulus that is triggering T cell activation in this disease.
活化的T淋巴细胞参与硬皮病（系统性硬化症，SSc）的发病机制；此类细胞在体内迅速分裂，因此理论上比静止细胞更频繁地发生随机突变。为研究SSc是否与快速扩增的T细胞克隆相关，测定了SSc患者外周血中次黄嘌呤鸟嘌呤磷酸核糖转移酶（hprt）基因的体内突变T细胞（MF）频率。还研究了特定的临床或血清学关联。
使用hprt克隆分析法培养16名健康个体和20名SSc患者的外周血淋巴细胞；建立突变和野生T细胞克隆以评估T细胞MF的个体值。T细胞克隆在体外进一步扩增，并通过标准免疫荧光技术确定其表型。采用酶联免疫吸附测定法同时测量血浆中可溶性白细胞介素-2受体（s-IL-2R）和细胞间黏附分子-1（s-ICAM-1）的水平。
SSc患者T细胞MF的平均（标准差）值比正常平均值（标准差）高2.5倍[10.6（6.6）×10⁻⁶ 对 [4.4（2.8）×10⁻⁶，p = 0.0007]。20名SSc患者中有11名（55%）的T细胞MF值高于正常平均值两个标准差以上。大多数（84%）突变T细胞具有辅助/诱导、记忆表型，而12%为细胞毒性/抑制性T细胞。T细胞MF与皮肤受累程度或雷诺现象持续时间之间无关联。通过s-IL-2R和s-ICAM-1的血浆水平评估，高个体T细胞MF值与可能同时存在的免疫过度活跃无关。然而，患有长期皮肤病的患者的T细胞MF值几乎是早期皮肤病患者的两倍[（13.6（7.4））×10⁻⁶ 对 （7.5（4.3））×10⁻⁶，p = 0.03]，这表明SSc中T细胞MF增加可能反映了体内T细胞慢性增殖和/或存活延长的持续过程。
SSc患者体内T细胞突变增加表明T细胞克隆的过度分裂和/或存活导致了SSc的病理改变；这种方法可用于进一步研究以确定引发该疾病中T细胞活化的刺激因素。
