Department of Pathology, Loyola University Medical Center, Maywood, Illinois, USA,
Acta Haematol. 2020;143(4):322-334. doi: 10.1159/000506696. Epub 2020 May 11.
The amyloidoses are a rare and heterogeneous group of disorders that are characterized by the deposition of abnormally folded proteins in tissues ultimately leading to organ damage. The deposits are mainly extracellular and are recognizable by their affinity for Congo red and their yellow-green birefringence under polarized light. Current classification of amyloid in medical practice is based on the amyloid protein type. To date, 36 proteins have been identified as being amyloidogenic in humans.
in clinical practice, it is critical to distinguish between treatable versus non-treatable amyloidoses. Moreover, amyloidoses with a genetic component must be distinguished from the sporadic types and systemic amyloidoses must be distinguished from the localized forms. Among the systemic amyloidoses, AL continues to be the most common amyloid diagnosis in the developed world; other clinically significant types include AA, ALECT2, and ATTR. The latter is emerging as an underdiagnosed type in both the hereditary and wild-type setting. Other hereditary amyloidoses include AFib, several amyloidoses derived from apolipoproteins, AGel, ALys, etc. In a dialysis setting, systemic amyloid derived from β2 microglobulin (Aβ2M) should be considered, although a very rare hereditary variant has also been reported; several amyloidoses may be typically associated with aging and several iatrogenic types have also emerged. Determination of the amyloid protein type is imperative before specific therapy can be implemented and the current methods are briefly summarized. A brief overview of the target organ involvement by amyloid type is also included. Key Messages: (1) Early diagnosis of amyloidosis continues to pose a significant challenge and requires the participation of many clinical and laboratory specialties. (2) Determination of the protein type is imperative before specific therapy can be implemented. (3) While mass spectrometry has emerged as the preferred method of amyloid typing, careful application of immune methods is still clinically useful but caution and experience, as well as awareness of the limitations of each method, are necessary in their interpretation. (4) While the spectrum of amyloidoses continues to expand, it is critical to distinguish between those that are currently treatable versus those that are untreatable and avoid causing harm by inappropriate treatment.
淀粉样变是一组罕见且异质性的疾病，其特征是异常折叠的蛋白质在组织中沉积，最终导致器官损伤。沉积物主要是细胞外的，并且可以通过它们对刚果红的亲和力以及在偏振光下的黄色-绿色双折射来识别。目前，在医学实践中，淀粉样变的分类基于淀粉样蛋白的类型。迄今为止，已有 36 种蛋白质被确定为人类中的淀粉样变原。
在临床实践中，区分可治疗与不可治疗的淀粉样变至关重要。此外，必须区分具有遗传成分的淀粉样变与散发性类型，必须区分系统性淀粉样变与局限性形式。在系统性淀粉样变中，AL 仍然是发达国家最常见的淀粉样变诊断；其他临床上重要的类型包括 AA、ALECT2 和 ATTR。在后一种情况下，遗传性和野生型均存在诊断不足的情况。其他遗传性淀粉样变包括 AFib、几种源自载脂蛋白的淀粉样变、AGel、ALys 等。在透析环境中，应考虑源自β2 微球蛋白（Aβ2M）的系统性淀粉样变，尽管也有报道非常罕见的遗传性变体；几种淀粉样变可能与衰老有关，并且也出现了几种医源性类型。在实施特定治疗之前，必须确定淀粉样蛋白的类型，并且简要总结了当前的方法。还包括对淀粉样蛋白类型的靶器官受累的简要概述。关键信息：（1）淀粉样变的早期诊断仍然是一个重大挑战，需要许多临床和实验室专业人员的参与。（2）在实施特定治疗之前，必须确定蛋白类型。（3）尽管质谱分析已成为淀粉样蛋白分型的首选方法，但免疫方法的谨慎应用在临床上仍然有用，但在解释时需要谨慎和经验，以及对每种方法的局限性的认识。（4）尽管淀粉样变的范围不断扩大，但区分目前可治疗与不可治疗的淀粉样变至关重要，并避免因不适当的治疗而造成伤害。
