IMMUNOGISTOCHEMICAL STUDIES OF THE LUNGS IN FIRE PENETRATION INJURIES

Abstract

Summary. The aim of the study was to analyze the data of immunohistochemical studies of the lungs after a gunshot wound penetrating at different times. Materials and methods. Lung tissue removed from the wounded with an encapsulated foreign body or without a foreign body of fire origin in the period from 1 day to 10 months after injury was studied. Results and discussion. At 1 day after injury, pathological type IV collagen and transforming growth factor begin to accumulate in the damaged areas. On day 2 of the wound, there is a slight increase in the expression of TGF-β1 and Collagen IV, VEGF is practically not produced, the number of CD68 + macrophages increases. Day 10 was characterized by a progressive increase in the content of transforming growth factor in leukocytes, lymphocytes, fibroblasts, macrophages and collagen type IV in the surrounding wounds. Ten months after injury and surgery, the wound canal was a large area of dense connective tissue with single venous vessels, often without a muscular layer. Transforming growth factor showed pronounced expression in macrophages and vascular endothelium, while VEGF was manifested as a weak positive response in vascular endothelial cells and single macrophages. Type IV collagen remained between the fibers of dense fibrous tissue, which replaced the wound canal, and was also found in the walls of blood vessels, interalveolar membranes, fibroblasts of the adjacent lung parenchyma. Conclusions. 1. Traumatic disorders in the lung parenchyma in FPI in the first hours after injury are accompanied by the accumulation of CD68 + macrophages, which persist for 10 months after FPI and become the main producers of TGF-β1 and VEGF. 2. Transforming growth factor TGF-β1 and vascular-endothelial growth factor VEGF are found in large quantities in macrophages, leukocytes, lymphocytes, fibroblasts and vascular endothelium from the first day of trauma to the lung parenchyma; up to 10 days the expression of TGF-β1 becomes significant, while VEGF weakly marks capillary endotheliocytes, arterioles, single macrophages. This immunohistochemical picture explains the long healing period of FPI. 3. The content of pathological collagen type IV Collagen IV on the first day of gunshot wound is minimal, increases up to 10 days and is detected in the fields of fibrosis and dystelectasis of the lung parenchyma after 10 months. 4. Determination of IHC expression of CD68, TGF-β1, VEGF and Collagen IV in the first 10 days after FPI and in the subsequent stages of treatment of the wounded will help to predict the course of combat trauma and adjust the methods of treatment.