Unidad Médico-Quirúrgica de Enfermedades Respiratorias, Instituto de Biomedicina de Sevilla (IBiS), Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla, Seville, Spain.
CIBER de Enfermedades Respiratorias (CIBERES), Instituto de Salud Carlos III, Madrid, Spain.
Methods Mol Biol. 2024;2750:123-133. doi: 10.1007/978-1-0716-3605-3_12.
Most clinical laboratories quantify alpha-1 antitrypsin using either nephelometry or turbidimetry techniques because they are commercially available, amenable to automation, and precise. Both methods are based on light scatter. The foundation of both techniques is based on incubation of the specimen with anti-AAT polyclonal antibody solution, a polymer matrix between endogenous AAT and the reagent antibodies forms, leading to production of light-scattering large particles. Although these two terms are sometimes used synonymously, technically speaking they are not.Nephelometry measures the amount of turbidity or cloudiness of a solution by directly quantifying the intensity of the light scattered by insoluble particles in the sample. Therefore, this technique measures the light that passes through the sample, with the detector being placed at an angle from the sample. Turbidimetry is the process of measuring the loss of intensity of the light transmitted linearly through a sample caused by the scattering effect of insoluble particles. The decrease in light transmission is measured compared to a reference, and the absorbed light is quantified.Beyond specific technical differences between both techniques, there are two major differences between the two procedures that may influence the results. First, the concentration of the sample and the resulting intensity of scattered light relative to the intensity of the light source is one major factor. Second, the size of the scattering particles is also a key differentiating factor. This chapter describes the technical requirements, the different protocols, and the clinical applicability of these two techniques in the diagnosis of alpha-1 antitrypsin deficiency.
大多数临床实验室使用散射光浊度法或免疫比浊法来定量检测α-1 抗胰蛋白酶，因为这些方法在商业上是可用的、可自动化的且精确的。这两种方法都是基于光散射的原理。这两种方法的基础都是将标本与抗 AAT 多克隆抗体溶液孵育，内源性 AAT 与试剂抗体之间形成聚合物基质，导致产生光散射的大颗粒。虽然这两个术语有时可以互换使用，但严格来说，它们并不完全相同。散射光浊度法通过直接量化样品中不溶性颗粒散射的光强度来测量溶液的浊度或混浊程度。因此，该技术测量的是光穿过样品的强度，检测器放置在与样品成一定角度的位置。比浊法是测量线性穿过样品的光强度因不溶性颗粒的散射效应而损失的过程。与参比相比，测量光的衰减量，并定量吸收的光。除了这两种技术之间的具体技术差异外，这两种方法之间还有两个主要区别，这可能会影响结果。首先，样品的浓度以及散射光相对于光源的强度与光的吸收率是一个主要因素。其次，散射颗粒的大小也是一个关键的区分因素。本章介绍了这两种技术的技术要求、不同的方案以及在α-1 抗胰蛋白酶缺乏症诊断中的临床适用性。
