Expression of COX-2, HMGB-1 and CD68 in lung tissue in sheep fibrinous bronchopneumonia

Abstract

This study aimed to determine the expression of some cytokines, such as cyclooxygenase-2 (COX-2), High Mobility Group Box-1 (HMGB-1) and CD68, in the lung tissue of sheep with fibrinous bronchopneumonia by immunohistochemical methods. Forty sheep which had suffered from respiratory problems were brought for necropsy to the Faculty of Veterinary Medicine, Department of Pathology, Aksaray University, between November 2014 and December 2017. After necropsy, lung tissues grossly diagnosed with fibrinous bronchopneumonia were processed histologically, and stained histopathologically and immunohistochemically. Bacteriological culture was also applied to the lung tissues to isolate the agents. In histopathological examinations, congestion, red consolidation and grey consolidation stages were detected in the lung tissues. In such cases, we observed fibrin masses accumulated in some alveolar lumens, as well as inflammatory cell infiltrations of various extent in alveolar and bronchiolar lumens. In the interalveolar septum, a thickening was observed due to a fibrin mass and thrombotic vessels. Immunohistochemically, it was determined that COX-2 and HMGB-1 cytokines showed positive reactions, especially in bronchial, bronchiolar and alveolar epithelia, as well as goblet cells and macrophages. CD68 was found to be expressed in alveolar macrophages. COX-2 and HMGB-1, which have been implicated in the inflammatory response, were also shown to be expressed in fibrinous bronchopneumonia in sheep for the first time. Thus, these cytokines are thought to play a role in the pathogenesis of the disease. Moreover, their increased expression suggests that it may be helpful in the diagnosis of the disease.