Macrophage hyperfunction as a cellular trigger for fibroplastic changes in internal organs in pneumoconiosis among miners

Abstract

Introduction. The significant prevalence of anthracosilicosis and silicosis, characterized by the rapid development of pneumofibrosis in coal mine workers, is a serious socially significant problem worldwide. A key component of the pathogenesis of pneumoconiosis is the macrophage reaction to fibrogenic dust, which is a complex immunological response, with prolonged and intense exposure leading to chronic inflammation in various organs and systems, fibrosis and a progressive decrease in their functions. A deep understanding and evaluation of the macrophage reaction as a potential biomarker for the diagnosis of lung damage in miners will allow us to develop more effective strategies to combat dust damage to organs and systems. The study aims to consider macrophage hyperfunction as a trigger mechanism for fibroplastic changes in internal organs in pneumoconiosis in miners. Materials and methods. Using light microscopy, specialists conducted extended cytological, histological and immunohistochemical studies of bronchial smears and autopsy material (fragments of bronchi, lungs, heart, liver and kidneys) of 50 miners of Kuzbass coal enterprises who died simultaneously as a result of a man-made disaster. Morphometric analysis of histological structures with measurement of linear dimensions was used for a comprehensive assessment of pathomorphological changes. Results. There was a sharp increase in the number and size of actively phagocytic alveolar macrophages loaded with dust particles in the lungs of miners. Pathological changes in internal organs were characterized by pronounced fibrosis in the peribronchial and perivascular zones, stroma with deposition of dust particles and a pronounced macrophage reaction. In a group of miners with more than 15 years of experience in the central and distal parts of the lungs, in the intermuscular zones of the myocardium, the portal tracts of the liver, and the central segments of the kidneys, there was a constant increase in the expression of immunohistochemical markers CD14, CD34, actin and vimentin, which can be used as diagnostic markers for the identification of macrophage inflammation and fibrosis, will allow to assess the degree of severity of the pathological process. A characteristic feature of the miners' long experience of dust exposure was the presence of progressive pronounced perivascular sclerosis extending beyond the vascular histione. Experts found fibroblastic cells with positive expression of CD14, CD31 and CD34 in the sclerotic zones. Limitation. The absence of cytogenetic and electron microscopic examination, which is expected in the future in conjunction with the expansion of the range of immunohistochemical research methods. Conclusion. The results of extended pathomorphological and cytological studies emphasize the importance of an integrated approach to the diagnosis of occupational diseases in the coal industry. The use of a combination of these methods will allow timely detection of macrophage inflammation and fibrous process in dust pathology, specific changes at the cellular and tissue levels, as well as to assess the severity of the pathological process. Ethics. The study of autopsy material was based on a secondary examination of blocks and ready-made histological micro-preparations (glasses) of the material of the Bureau of Forensic Medical examination of Novokuznetsk, Osinniki, Prokopyevsk. The studies of pathomorphological material were carried out strictly on the basis of Federal Law No. 323-FZ dated 11/21/2011 "On the Basics of Protecting the Health of Citizens in the Russian Federation", in particular Article 67 "Conducting pathological anatomical autopsies", Federal Law No. 8-FZ dated 12.01.1996 "On Burial and Funeral Business" (Article 5, pp. 1, 2), as well as in accordance with the Order of the Ministry of Health of the Russian Federation dated 06.06.2013 No. 354n "On the procedure for conducting pathological anatomical autopsies", Order of the Ministry of Health of the Russian Federation dated 03/24/2016 No. 179n "On the Rules for conducting pathological anatomical studies".