Obwaller A, Jensen-Jarolim E, Auer H, Huber A, Kraft D, Aspöck H
Department of Medical Parasitology, University of Vienna, Austria.
Parasite Immunol. 1998 Jul;20(7):311-7. doi: 10.1046/j.1365-3024.1998.00146.x.
Infestations of humans with the parasitic nematode T. canis are common in both developing and industrialized countries. Most infestations induce a clinically inapparent course of infection, however, severe clinical manifestations, i.e. visceral larva migrans (VLM) or ocular larva migrans (OLM) syndromes are observed. To find an explanation for the different courses of toxocarosis we examined several serological parameters: the expression of (i) specific IgE (Immunoblot, IB), (ii) specific IgG subclasses (IgG1-4, ELISA and the formation of (iii) IgE/anti-IgE immune complexes. Serum samples were obtained from persons with symptomatic (VLM, OLM) and asymptomatic course (AS) of the infestation. As antigen, T. canis excretory/secretory (TES) antigen from L3 larvae was used. Reactivity of IgE against SDS-PAGE separated TES antigens was marginally higher in toxocarosis patients (35%) than in asymptomatics (24%), but without statistical significance. TES-specific IgG (1-4), predominant subclass in all three groups was IgG1, followed by IgG2, IgG4 and IgG3. Subclass IgG1, 2, 4 showed significant differences between patients with VLM associated symptoms and asymptomatic persons (P < 0.001) but not between patients with OLM associated symptoms and asymptomatics. Significantly elevated levels of IgE/anti-IgE immune complexes were detected in sera of patients with symptomatic course of the disease, both VLM and OLM (P < 0.001). Whereas specific IgG may act via antibody dependent cell-mediated cytotoxicity mechanisms, IgE/anti-IgE immune complexes might possibly participate in VLM and OLM by inducing type III hypersensitivity.
在发展中国家和工业化国家，人体被寄生线虫犬弓首蛔虫感染的情况都很常见。大多数感染会引发临床上难以察觉的感染过程，然而，也会观察到严重的临床表现，即内脏幼虫移行症（VLM）或眼部幼虫移行症（OLM）综合征。为了找出弓首蛔虫病不同病程的原因，我们检测了几个血清学参数：（i）特异性IgE的表达（免疫印迹法，IB）、（ii）特异性IgG亚类（IgG1 - 4，酶联免疫吸附测定法）以及（iii）IgE/抗IgE免疫复合物的形成。血清样本取自感染后有症状（VLM、OLM）和无症状病程（AS）的人群。作为抗原，使用了来自L3幼虫的犬弓首蛔虫排泄/分泌（TES）抗原。在弓首蛔虫病患者中，IgE对SDS - PAGE分离的TES抗原的反应性略高于无症状感染者（35%对24%），但无统计学意义。TES特异性IgG（1 - 4），在所有三组中占主导地位的亚类是IgG1，其次是IgG2、IgG4和IgG3。IgG1、2、4亚类在伴有VLM相关症状的患者和无症状者之间存在显著差异（P < 0.001），但在伴有OLM相关症状的患者和无症状者之间无显著差异。在患有该疾病有症状病程的患者血清中，即VLM和OLM患者中，检测到IgE/抗IgE免疫复合物水平显著升高（P < 0.001）。特异性IgG可能通过抗体依赖性细胞介导的细胞毒性机制发挥作用，而IgE/抗IgE免疫复合物可能通过诱导III型超敏反应参与VLM和OLM的发生。
