胰岛素瘤及正常胰腺组织中胰岛素原、胰岛素的表达

Expression of proinsulin and insulin in insulinoma and normal pancreas

目的 检测胰岛素瘤及瘤旁正常胰腺组织中胰岛素、胰岛素原、C肽的表达水平,探讨它们的作用.方法 选取2006年9月至2009年12月确诊的38例胰岛素瘤及20例相应瘤旁正常胰腺组织标本,采用免疫组化染色的方法检测组织中胰岛素原、胰岛素、C肽的表达.结果 胰岛细胞瘤和瘤旁正常胰腺组织均表达胰岛素、C肽、胰岛素原.100%的胰岛素瘤组织胰岛素原和C肽强表达,而55%～60%正常胰腺组织为弱表达;79%的胰岛素瘤组织胰岛素表达为＋＋＋,而85%的正常胰腺组织胰岛素的表达为＋＋＋＋.38例胰岛素瘤的胰岛素原、C肽阳性表达细胞数占80%～100%,胰岛素阳性表达细胞数占50%～70%,胰岛素原/胰岛素＞1占78.9%,正常胰腺组织分别为20%～80%、60%～90%、10.0%,两者差异均非常显著（P值均＜0.05）.结论 胰岛素瘤组织的胰岛素原/胰岛素＞1者占78.9%,测定血浆胰岛素原可能有助于其诊断.

Objective To investigate the expression of proinsulin, insulin, C-peptide in insulinoma and normal pancreas and their roles. Methods Thirty-eight cases of insulinoma and 20 cases of normal pancreas from Sep. 2006 to Dec. 2009 in our hospital were selected. Immunohistochemistry was used to determine the expression of proinsulin, insulin, C-peptide. Results Proinsulin, insulin, C-peptide was expressed in insulinoma and normal pancreas. Proinsulin, C-peptide were strongly expressed in 100%insulinoma, while they were weekly expressed in 55% ～60% normal pancreas; insulin was expressed as ＋ ＋ ＋in 79% insulinoma, while it was expressed as ＋ ＋ ＋ ＋ in 85% normal pancreas. Proinsulin, C-peptide positive cell accounted for 80% ～ 100% of 38 insulinoma, and insulin positive cell accounted for 50% ～ 70%,the proinsulin/insulin ratio ＞ 1 accounted for 78.9%; while the corresponding values were 20% ～ 80%, 60% ～90%, 10.0% in normal pancreas, and the difference was statistically significant （ P ＜ 0.05 ）. Conclusions The proinsulin/insulin ratio ＞ 1 is 78.9% in insulinoma, and detection of proinsulin may help to diagnose insulinoma.