Peripheral nerve involvement in immunoglobulin light chain (AL) amyloidosis is common, characterised by severe progressive mixed neuropathy with autonomic dysfunction but there is limited data on the implications and the characteristics of small nerve fibres dysfunction (SNFD). The aim of our prospective study was to evaluate SNFD and its clinical implications in newly diagnosed AL patients. Twenty-three consecutive patients (10 male, mean age 61.78 years) and 21 age- and gender-matched healthy controls (8 male, mean age 61.28 years) underwent clinical evaluation and standard nerve conduction studies (NCS), baroreflex sensitivity (BRS) test, quantitative sensory testing (QST) and skin biopsy at the lower leg for measuring the density of the nerve fibres innervating the epidermis (IENFD). Axonal degeneration of the large nerve fibres was revealed in 15 out of 23 patients while SNFD was indicated by QST and skin biopsy in 56% and 61% of the patients respectively. BRS index significantly correlated with the IENFD and the QST results while low IENFD was associated with significantly poorer survival. Our study provides new insights and also an initial evaluation of new tools for assessment of the involvement of autonomic and small nerve fibres in AL amyloidosis. These findings also appear to have prognostic implications.

周围神经参与免疫球蛋白轻链（AL）淀粉样变性很常见，其特征是严重的进行性混合神经病变伴有自主神经功能障碍，但有关小神经纤维功能障碍（SNFD）的影响和特征的数据有限。我们的前瞻性研究旨在评估SNFD及其在新诊断的AL患者中的临床意义。连续对23例患者（10例男性，平均年龄61.78岁）和21例年龄和性别相匹配的健康对照组（8例男性，平均年龄61.28岁）进行了临床评估和标准神经传导研究（NCS），压力反射敏感性（BRS）小腿测试，定量感觉测试（QST）和皮肤活检，以测量支配表皮的神经纤维的密度（IENFD）。23例患者中有15例显示大神经纤维的轴突变性，而QST和皮肤活检表明SNFD分别占56％和61％。BRS指数与IENFD和QST结果显着相关，而IENFD较低则与较差的生存率相关。我们的研究提供了新的见解，也为评估自主神经和小神经纤维参与AL淀粉样变性的新工具提供了初步评估。这些发现也似乎具有预后意义。我们的研究提供了新的见解，也为评估自主神经和小神经纤维参与AL淀粉样变性的新工具提供了初步评估。这些发现也似乎具有预后意义。我们的研究提供了新的见解，也为评估自主神经和小神经纤维参与AL淀粉样变性的新工具提供了初步评估。这些发现也似乎具有预后意义。