Coppo R
Department of Medical Nephrology, University of Turin, Italy.
Am J Kidney Dis. 1988 Nov;12(5):420-4. doi: 10.1016/s0272-6386(88)80038-6.
Patients with IgA nephropathy (IgAN) can be considered high responders for IgA production; data which indicate a generalized hyperreactivity of the immune system include autoantibody production, increased response to viral vaccination, and high titers of antibodies to various common respiratory and gastrointestinal microbes. From clinical and experimental observations, two types of antigen seem to be most involved in the pathogenesis of IgAN, ie, environmental respiratory or gastrointestinal infectious agents and dietary antigens. A role played by microbes has been suggested because macroscopic hematuria shortly follows a pharyngitis or a gastrointestinal disturbance. Antibodies to a wide spectrum of viral and bacterial infectious agents have been detected in sera from patients with IgAN. The possible role of dietary antigens has been demonstrated experimentally in animal models. In human IgAN, antibodies to various dietary antigens have been detected in sera; antibodies have also been found in IgA immune complexes and renal eluates. In human IgAN, a significant decrease in serum levels of IgA-containing circulating immune complexes after a gluten-free diet has been observed. The present experience accounts for 27 IgAN patients followed for 6 months to 3 years on a gluten-free diet. A decrease in serum levels of IgA-containing circulating immune complexes was observed in 64% of the patients whose initial levels were high during a period of unrestricted diet. Patients with basal high levels also had significantly high levels of IgA antibodies to dietary antigens, including bovine serum albumin, ovalbumin, and various gluten fractions. After 1 year of gluten-free diet the levels significantly decreased. A disappearance of antigliadin IgA, observed in 80% of the cases, was paralleled by a decrease in titers of the other antibodies to dietary components. These data support the hypothesis that in patients with IgAN, gluten may act as a toxic lectin, increasing the permeability of the intestinal mucosa to various dietary antigens.
IgA肾病（IgAN）患者可被视为IgA产生的高反应者；表明免疫系统普遍存在高反应性的数据包括自身抗体产生、对病毒疫苗接种反应增强以及针对各种常见呼吸道和胃肠道微生物的高滴度抗体。从临床和实验观察来看，似乎有两种抗原在IgAN的发病机制中最为重要，即环境性呼吸道或胃肠道感染因子以及饮食抗原。由于咽炎或胃肠道紊乱后不久会出现肉眼血尿，因此有人提出微生物发挥了作用。在IgAN患者的血清中已检测到针对多种病毒和细菌感染因子的抗体。饮食抗原的可能作用已在动物模型中得到实验证明。在人类IgAN中，血清中已检测到针对各种饮食抗原的抗体；在IgA免疫复合物和肾洗脱物中也发现了抗体。在人类IgAN中，观察到无麸质饮食后含IgA的循环免疫复合物血清水平显著下降。目前的经验涉及27例IgAN患者，他们接受无麸质饮食随访6个月至3年。在饮食不受限制期间初始水平较高的患者中，64%观察到含IgA的循环免疫复合物血清水平下降。基础水平较高的患者针对饮食抗原（包括牛血清白蛋白、卵清蛋白和各种麸质成分）的IgA抗体水平也显著较高。无麸质饮食1年后，这些水平显著下降。80%的病例中观察到抗麦醇溶蛋白IgA消失，同时针对饮食成分的其他抗体滴度也下降。这些数据支持这样一种假设，即在IgAN患者中，麸质可能作为一种毒性凝集素，增加肠道黏膜对各种饮食抗原的通透性。
