Nakov Radislav, Sarafov Stayko, Nakov Ventsislav, Gospodinova Mariana, Ianiro Gianluca, Todorov Tihomir, Todorova Albena, Tournev Ivailo
Clinic of Gastroenterology, Tsaritsa Yoanna University Hospital.
Clinic of Nervous Diseases, Alexandrovska University Hospital, Medical University, Sofia, Bulgaria.
Medicine (Baltimore). 2020 Mar;99(11):e19509. doi: 10.1097/MD.0000000000019509.
Transthyretin amyloid (ATTR) amyloidosis is a rare systemic disorder characterized by amyloid deposits formed by misfolded monomers of the transthyretin. Gastrointestinal (GI) manifestations are common in ATTR amyloidosis; however, their pathogenesis is not fully elucidated. In the present study, we aim to evaluate the diagnostic role of fecal calprotectin (FC) in ATTR amyloidosis patients with GI manifestations.We recruited 21 consecutive ATTR amyloidosis patients and 42 sex and age-matched healthy controls. The presentation of GI symptoms and the severity of peripheral neuropathy were evaluated. Colonoscopy and FC assessment were performed in all subjects.Mean levels of FC in ATTR amyloidosis patients (184 μg/g [30-430]) were significantly higher thаn those of controls (40 μg/g [30-70]), P < .001. Receiver operating characteristic curve analysis indicated a FC cut-off level of 71 μg/g, which differentiates ATTR amyloidosis with GI manifestations from healthy subjects with 91% sensitivity, 100% specificity, 100% positive predictive value, 95% negative predictive value and 97% overall accuracy. FC values were significantly associated with the presence of neutrophilic granulocytic infiltration in the colonic mucosa (P = .002), with the presence of amyloid deposits in rectal mucosa (P = .007) and the presence of diarrhea (P = .046).FC levels are elevated in patients with ATTR amyloidosis with GI manifestations, which suggests an inflammatory component in the pathogenesis of the disease. The presence of elevated FC concentrations could help gastroenterologists to include ATTR amyloidosis in their diagnostic work-up.
转甲状腺素蛋白淀粉样变性（ATTR）淀粉样变是一种罕见的全身性疾病，其特征是由转甲状腺素蛋白错误折叠的单体形成淀粉样沉积物。胃肠道（GI）表现在ATTR淀粉样变中很常见；然而，其发病机制尚未完全阐明。在本研究中，我们旨在评估粪便钙卫蛋白（FC）在有GI表现的ATTR淀粉样变患者中的诊断作用。我们连续招募了21例ATTR淀粉样变患者和42例年龄和性别匹配的健康对照。评估了GI症状的表现和周围神经病变的严重程度。对所有受试者进行了结肠镜检查和FC评估。ATTR淀粉样变患者的FC平均水平（184μg/g[30 - 430]）显著高于对照组（40μg/g[30 - 70]），P<0.001。受试者工作特征曲线分析表明，FC临界值为71μg/g，可将有GI表现的ATTR淀粉样变与健康受试者区分开来，敏感性为91%，特异性为100%，阳性预测值为100%，阴性预测值为95%，总体准确率为97%。FC值与结肠黏膜中性粒细胞浸润的存在（P = 0.002）、直肠黏膜淀粉样沉积物的存在（P = 0.007）以及腹泻的存在（P = 0.046）显著相关。有GI表现的ATTR淀粉样变患者的FC水平升高，这表明该疾病的发病机制中存在炎症成分。FC浓度升高有助于胃肠病学家在诊断工作中考虑ATTR淀粉样变。
