Profile of Kidney Histopathology in Cases of Burns - Particular Emphasis on Acridine Orange Fluorescence Study and to Explore its Forensic Utility

Abstract

Introduction: The major cause of death in the burn patients includes multiple organ failure and infection but, sometimes the exact cause of death in many fatally burned patients is difficult to detect. Many times in medico-legal post-mortem examinations in cases of burns, histopathological examination of organs is requested.

Aim: The aim was to study various histopathological changes in kidneys in the post-mortem cases of burns, by using routine Haematoxylin and Eosin stain (H&E stain), special Periodic and Schiff's Stain (PAS) stain, to study the role of acridine orange fluorescence study, to explore the forensic utility of this microscopic study and to find out the relationship between duration of survival and histopathological changes observed.

Materials and methods: An experimental longitudinal prospective study from October 2010 to September 2012. Total 32 cases of death due to burns were autopsied at mortuary, the Department of Forensic Medicine and Toxicology in our hospital. Bilateral kidneys were removed and preserved in 10% formalin solution. These were forwarded to Department of Pathology for histopathological examination. Routine microscopic examination by H&E stain as well as PAS stain and fluorescence study by acridine orange stain were done in all cases.

Results: It was observed that in 21 (65.63%) cases gross findings in kidneys were normal, in 06 (18.75%) were grossly pale and in 05 (15.62%) heavy & congested. Sections taken from kidneys and studied by H&E stain showed overlapping histopathological changes in all cases. In 26 (81.25%) cases, changes of Acute Tubular Necrosis (ATN) while in remaining 06 (18.75%), changes of cloudy swelling were observed. The sections stained by acridine orange and observed under fluorescent microscope were lightly positive in 15 (46.88%), brightly positive in 08 (25.00%) whereas, negative in 09 (28.12%).

Conclusion: Microscopy by various methods helps in getting specific lesions in kidney due to burns. However, it does not add any new tool to resolve any forensic issues of burns. Therefore, microscopy (including florescent), if done would be redundant.

Keywords: Burn injury; Florescent microscopy; Forensic aspect.

[Table/Fig-1]:

a) PAS positive mucosal glands of appendix (Control slide- PAS stain, 40X, 54% zoomed image in Microsoft picture manager; (b) lightly positive in early myocardial infarct (control slide- Acridine Orange, 400X); (c) brightly positive in old myocardial infarct (control slide- Acridine Orange, 400X); (d) Fluorescent artefact (Acridine Orange, 400X).

[Table/Fig-4]:

a) Gross appearance of kidney showing no remarkable changes; (b) Gross appearance of enlarged kidneys showing marked congestion; (c) Microscopic changes of cloudy swelling in kidneys (H&E stain, 400X, 34% zoomed image in Microsoft picture manager); (d) Microscopic changes of ATN-initiation phase showing early changes of necrosis in epithelial cells (H&E stain, 400X, 34% zoomed image in Microsoft picture manager).

[Table/Fig-6]:

a) Microscopic changes of ATN-maintenance phase showing necrotic areas and cast formation (arrows) within the renal tubules (H&E stain, 400X, 35% zoomed image in Microsoft picture manager);(b)Microscopic changes of ATN-recovery phase showing regeneration of epithelial cells (arrows) (H&E stain, 400X, 34% zoomed image in Microsoft picture manager);(c) PAS positive hyaline material (arrow) within renal tubules (PAS stain, 400X, 34% zoomed image in Microsoft picture manager);(d)lightly positive in kidneys (Acridine Orange, 400X); (e)brightly positive necrotic tubules in kidneys (Acridine Orange, 400X).