Mappouras D G, Philippou G, Haralambous S, Tzartos S J, Balafas A, Souvatzoglou A, Lymberi P
Department of Immunology, Hellenic Pasteur Institute, Athens, Greece.
Clin Exp Immunol. 1995 May;100(2):336-43. doi: 10.1111/j.1365-2249.1995.tb03674.x.
In the present study we analysed by ELISA the ability of sera from 50 patients with myasthenia gravis (MG), 20 with Hashimoto's thyroiditis (HT), 53 with Graves' disease (GD) and 36 healthy controls (CR) to react with acetylcholinesterase (AChE) from Electrophorus electricus and human thyroglobulin (Tg). Significantly increased anti-AChE activity was exhibited by a high proportion of MG (IgG 36%) and GD (IgG 21%) sera, while increased anti-Tg activity was detected in all three patient groups (MG, IgG 26% and IgA 26%; HT, IgG 85% and IgA 40%; and GD, IgG 51%). Interestingly, a significant proportion of MG and GD sera exhibited both IgG anti-AChE and anti-Tg activities (MG, 18%; P < 0.001; and GD, 15%; P < 0.001, versus CR, 0%). This bi-reactivity was exhibited by anti-AChE antibodies cross-reacting with Tg (anti-AChE/Tg activity); (i) serum anti-AChE activity was effectively inhibited by soluble Tg, and (ii) affinity-purified anti-Tg antibodies cross-reacted with AChE. Cross-reactivity seems to be a property of pathological (auto)antibodies; induced (rabbit) antibodies to AChE or Tg were highly monospecific. Analysis of clinical data showed that increased IgG anti-AChE/Tg activity was well associated with: (i) overlapping GD in MG (P < 0.02), and (ii) ophthalmopathy in GD (P < 0.01). In contrast, no correlation was noted in MG between anti-AChE activity units and anti-Tg activity units or acetylcholine receptor antibody titres. The clinical significance of anti-AChE/Tg antibodies remains to be elucidated.
在本研究中，我们通过酶联免疫吸附测定（ELISA）分析了50例重症肌无力（MG）患者、20例桥本甲状腺炎（HT）患者、53例格雷夫斯病（GD）患者以及36名健康对照者（CR）的血清与电鳗乙酰胆碱酯酶（AChE）和人甲状腺球蛋白（Tg）发生反应的能力。高比例的MG（IgG 36%）和GD（IgG 21%）血清显示出抗AChE活性显著增加，而在所有三个患者组中均检测到抗Tg活性增加（MG，IgG 26%和IgA 26%；HT，IgG 85%和IgA 40%；GD，IgG 51%）。有趣的是，相当比例的MG和GD血清同时表现出IgG抗AChE和抗Tg活性（MG为18%；P<0.001；GD为15%；P<0.001，而CR为0%）。这种双反应性由与Tg发生交叉反应的抗AChE抗体（抗AChE/Tg活性）表现出来；（i）可溶性Tg可有效抑制血清抗AChE活性，（ii）亲和纯化的抗Tg抗体与AChE发生交叉反应。交叉反应似乎是病理性（自身）抗体的一种特性；诱导产生的（兔）抗AChE或抗Tg抗体具有高度单一特异性。临床数据分析表明，IgG抗AChE/Tg活性增加与以下情况密切相关：（i）MG中的重叠性GD（P<0.02），以及（ii）GD中的眼病（P<0.01）。相比之下，MG患者的抗AChE活性单位与抗Tg活性单位或乙酰胆碱受体抗体滴度之间未发现相关性。抗AChE/Tg抗体的临床意义仍有待阐明。
