Mastracci Luca, Gambella Alessandro, Bragoni Alberto, Pigozzi Simona, Pastorino Lorenza, Vanni Irene, Tosi Ilaria, Campora Michela, Fiocca Roberto, Grillo Federica
Anatomic Pathology, Department of Surgical Sciences and Integrated Diagnostics (DISC), University of Genoa, via De Toni 14, 16132, Genoa, Italy.
IRCCS Ospedale Policlinico San Martino, Largo R. Benzi 10, 16132, Genoa, Italy.
Histochem Cell Biol. 2019 Jun;151(6):501-511. doi: 10.1007/s00418-018-1765-7. Epub 2019 Jan 2.
Formalin is toxic and has recently been classified as carcinogenic leading to a proposed European formalin ban. But, the pathology use of formalin has however been completely overlooked, and this is proving to be a relevant issue, as no alternative, reliable, tissue fixative is available. Various systems have been proposed to reduce formalin use and exposure; long-term storage and disposal of formalin is also a problem. With this in mind, under vacuum sealing (UVS) systems have been proposed for transportation/storage, however, for how long tissue retains its characteristics (morphological and molecular) is unknown. This study aims to compare histology specimens stored by formalin immersion (FI) and specimens stored after fixation with UVS technique with no additional formalin, at different time periods. Twenty tissue samples (10FI; 10UVS) were stored for different time periods (15 days, 1-2-3-6-12 months) for a total of 120 samples, compared with regard to their morphology, histochemistry, immunoreactivity (24 specific antibodies) and DNA status. All samples showed well-preserved morphology and overlapping staining quality. A significant reduction in immunoreactivity was however identified in the various time periods, particularly for heat pre-treated nuclear antigens, and this commenced earlier (1 month) for FI. UVS storage showed higher DNA content than FI but slightly poorer DNA integrity. These results add important knowledge to the use of UVS in daily practice, as long-term storage of pre-fixed tissue in UVS is not detrimental to the quality of tissue while having the boon of using very little formalin with less operator exposure and lower disposal costs.
福尔马林有毒，最近已被列为致癌物，因此欧洲提议禁止使用福尔马林。但是，福尔马林在病理学中的应用却完全被忽视了，而这已成为一个相关问题，因为目前没有替代的、可靠的组织固定剂。人们已经提出了各种系统来减少福尔马林的使用和接触；福尔马林的长期储存和处理也是一个问题。考虑到这一点，有人提出了真空密封（UVS）系统用于运输/储存，然而，组织在多长时间内保持其特征（形态学和分子特征）尚不清楚。本研究旨在比较福尔马林浸泡（FI）保存的组织学标本和采用UVS技术固定且不添加额外福尔马林后在不同时间段保存的标本。将20个组织样本（10个FI样本；10个UVS样本）在不同时间段（15天、1 - 2 - 3 - 6 - 12个月）保存，共120个样本，比较它们的形态学、组织化学、免疫反应性（24种特异性抗体）和DNA状态。所有样本均显示形态保存良好且染色质量重叠。然而，在不同时间段发现免疫反应性显著降低，尤其是对于热预处理的核抗原，FI样本的这种情况在更早的时候（1个月）就开始了。UVS保存的样本显示出比FI样本更高的DNA含量，但DNA完整性略差。这些结果为UVS在日常实践中的应用增添了重要知识，因为在UVS中对预先固定的组织进行长期储存对组织质量无害，同时具有使用极少福尔马林、减少操作人员接触和降低处理成本的优点。
