Department of Pathology and Oregon National Primate Center, Oregon Health and Science University, Portland, OR, USA.
Islets. 2011 Nov-Dec;3(6):344-51. doi: 10.4161/isl.3.6.17866. Epub 2011 Nov 1.
AIMS/HYPOTHESIS: Islet amyloid polypeptide is originally identified as the chief constituent of amyloid in insulinomas and type 2 diabetic islets. This study aimed to identify islet amyloid polypeptide by immunocytochemical staining in pancreatic endocrine tumors including 30 cases of insulinomas and non-β-cell pancreatic endocrine tumors.
In normal islets, 62% of islet cells and 52% of insulin cells were granularly positive for insulin and IAPP, respectively, with more insulin positive cells than IAPP positive cells and some densely positive staining for insulin and IAPP in irregularly shaped a nuclear, degenerating islet β-cells. In pancreatic endocrine tumors, all 10 insulinomas were positive for islet amyloid polypeptide but 2 glucogonomas, 1 somatostatinoma, 6 of 7 pancreatic polypeptidomas, all 7 gastrinomas and all 3 non-functioning pancreatic endocrine tumors were negative for islet amyloid polypeptide whereas one pancreatic polypeptidoma was positive for islet amyloid polypeptide.
Using commercially available rabbit anti-islet amyloid polypeptide antibody, immunocytochemical staining was performed on 30 cases of pancreatic endocrine tumors, consisting of 10 insulinomas, 2 glucagonomas, 1 somatostatinoma, 7 pancreatic polypeptidomas, 7 gastrinomas and 3 non-functioning pancreatic endocrine tumors. Pancreatic tissues containing pancreatic endocrine tumors were systematically immunostained for insulin, glucagon, somatostatin, pancreatic polypeptide, gastrin and chromogranin A, in addition to islet amyloid polypeptide. When normal pancreatic tissues adjacent to pancreatic endocrine tumors were present, insulin, glucagon, somatostatin and islet amyloid polypeptide positive cells were counted for a total of 20 islets, which were divided into large islets and medium islets for each case.
CONCLUSIONS/INTERPRETATIONS: All 10 insulinomas and 1 pancreatic polypeptidoma were granularly positive for islet amyloid polypeptide, suggesting all 10 insulinomas contained enough insulin granules for IAPP whereas only one non-β-cell pancreatic endocrine tumor was co-localized with islet amyloid polypeptide in their secretary granules.
目的/假设：胰岛淀粉样多肽最初被鉴定为胰岛素瘤和 2 型糖尿病胰岛中淀粉样物质的主要成分。本研究旨在通过免疫细胞化学染色鉴定包括 30 例胰岛素瘤和非β细胞胰腺内分泌肿瘤在内的胰腺内分泌肿瘤中的胰岛淀粉样多肽。
在正常胰岛中，62%的胰岛细胞和 52%的胰岛素细胞分别呈胰岛素和 IAPP 颗粒状阳性，胰岛素阳性细胞多于 IAPP 阳性细胞，并且一些不规则形状的胰岛β细胞的核呈退行性变，呈密集阳性染色。在胰腺内分泌肿瘤中，所有 10 例胰岛素瘤均为胰岛淀粉样多肽阳性，但 2 例胰高血糖素瘤、1 例生长抑素瘤、7 例胰多肽瘤、7 例胃泌素瘤和 3 例无功能胰腺内分泌肿瘤均为胰岛淀粉样多肽阴性，而 1 例胰多肽瘤为胰岛淀粉样多肽阳性。
使用商业上可获得的兔抗胰岛淀粉样多肽抗体，对 30 例胰腺内分泌肿瘤（包括 10 例胰岛素瘤、2 例胰高血糖素瘤、1 例生长抑素瘤、7 例胰多肽瘤、7 例胃泌素瘤和 3 例无功能胰腺内分泌肿瘤）进行免疫细胞化学染色。除胰岛淀粉样多肽外，还对含有胰腺内分泌肿瘤的胰腺组织进行胰岛素、胰高血糖素、生长抑素、胰多肽、胃泌素和嗜铬粒蛋白 A 的系统免疫染色。当存在与胰腺内分泌肿瘤相邻的正常胰腺组织时，对总共 20 个胰岛进行计数，每个病例分为大胰岛和中胰岛。
结论/解释：所有 10 例胰岛素瘤和 1 例胰多肽瘤均呈胰岛淀粉样多肽颗粒状阳性，提示所有 10 例胰岛素瘤均含有足够的胰岛素颗粒用于 IAPP，而仅有 1 例非β细胞胰腺内分泌肿瘤在其分泌颗粒中与胰岛淀粉样多肽共定位。
