Case Control Study
Copyright ©The Author(s) 2015. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Feb 14, 2015; 21(6): 1827-1837
Published online Feb 14, 2015. doi: 10.3748/wjg.v21.i6.1827
Digitally reinforced hematoxylin-eosin polarization technique in diagnosis of rectal amyloidosis
Basak Doganavsargil, Gulruh Emiroglu Buberal, Huseyin Toz, Banu Sarsik, Burcin Pehlivanoglu, Murat Sezak, Sait Sen
Basak Doganavsargil, Gulruh Emiroglu Buberal, Banu Sarsik, Burcin Pehlivanoglu, Murat Sezak, Sait Sen, Department of Pathology, Ege University Faculty of Medicine, Izmir 35100, Turkey
Huseyin Toz, Department of Nephrology, Ege University Faculty of Medicine, Izmir 35100, Turkey
Author contributions: Doganavsargil B and Sen S contributed equally to the conception and design of this work; Doganavsargil B and Buberal GE conducted the research and analyzed the data; Toz H collected the clinical data; Doganavsargil B, Buberal GE, and Sen S interpreted the data; Sarsik B and Sen S designed and optimized the technique used in the study; Sezak M and Sen S arranged the study and control groups; Pehlivanoglu B and Doganavsargil B drafted the manuscript; and Doganavsargil B approved the final version of the paper.
Ethics approval: Our study has been conducted according to the general approval of our hospital’s ethics committee for education and investigation using the tissue slides of cases that were diagnosed in our department before August 2011. Upon the code of Turkish Ministry of Health on 19.08.2011 with the number 28030, it is confirmed that the blood, urine, tissue samples, radiology images and materials etc. that had been obtained with an informed consent before August 2011 are considered anonymous.
Institutional animal care and use committee: No animal-derived material was used in the study.
Conflict-of-interest: All authors have no conflict of interest related to the manuscript.
Data sharing: Technical appendix, statistical code, and dataset available from the corresponding author at bdoganavsargil@yahoo.com. Informed consent was not obtained but the presented data are anonymized and risk of identification is low, because our study simply focuses on histopathologic findings.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Correspondence to: Basak Doganavsargil, MD, Department of Pathology, Ege University Faculty of Medicine, Bornova, Izmir 35100, Turkey. bdoganavsargil@yahoo.com
Telephone: +90-232-3881025 Fax: +90-232-3736143
Received: October 5, 2014
Peer-review started: October 6, 2014
First decision: November 14, 2014
Revised: November 28, 2014
Accepted: December 19, 2014
Article in press: December 22, 2014
Published online: February 14, 2015
Processing time: 128 Days and 23.7 Hours
Abstract

AIM: To investigate the efficacy of the digitally reinforced hematoxylin-eosin polarization (DRHEP) technique for detection of amyloidosis in rectal biopsies.

METHODS: One hundred hematoxylin-eosin (HE) stained rectal biopsies with Congo-red (CR)-positive amyloid depositions and 50 control cases with CR-negative amyloid-mimicking areas were scanned blinded to the CR results for amyloid depositions under both bright and polarized light, and digitally photographed using the DRHEP technique, to accentuate the faint birefringence observed in HE slides under polarization. The results of DRHEP and HE evaluation were statistically correlated with CR polarization results with respect to presence and localization of amyloid deposits as well as amyloid types.

RESULTS: Amyloid deposits showed yellowish-green birefringence by DRHEP, which allowed identification of amyloidosis in 41 HE-unsuspected cases (P = 0.016), 31 of which only had vascular deposits. True positivity was higher, and false negativity and positivity were lower by DRHEP, compared to evaluation by HE (69%, 31%, and 0.8% vs 33%, 67%, and 33%, respectively; P < 0.0001). The sensitivity, specificity, accuracy, and positive and negative predictive values for DRHEP were 69%, 98%, 78.6%, 98.5%, and 61.25%, respectively. Reasons for DRHEP false negativity were presence of extensive background birefringence in 12 cases, absence of CR birefringent vessel in 3 cases, and missing of the tiny deposits in 9 cases, which could be improved by experience, especially in the latter case. No correlation was found between age, gender, sites of deposits, or amyloid types.

CONCLUSION: The DRHEP technique improves diagnostic accuracy when used as an adjunct or a prior step to CR staining, especially for cases with limited tissues for further analysis.

Keywords: Amyloidosis; Congo red; Hematoxylin-eosin; Microscopy; Polarization; Rectum

Core tip: Amyloid fibrils show a faint birefringence with polarization microscopy even when they are stained with hematoxylin-eosin (HE), and this effect can be reinforced when digital images are captured. We researched the efficacy of this technique in rectal biopsies and observed that it allowed identification of unsuspected cases with HE. True positivity was higher, and false negativity and positivity were lower compared to evaluation by HE. Therefore it can be used as an adjunct or a prior step to Congo-red staining, especially for cases with limited tissues for further analysis as it is a fast and safe method.