Morphological findings in lungs of the horses with chronic obstructive pulmonary disease (COPD)

Abstract

The frequency and characteristics of chronic obstructive pulmonary disease (COPD) based on morphological and cytological changes in equine lungs were studied in this paper. Lungs obtained from 51 horses of different age and sex were examined grossly and tissue samples were collected for pathohistological examination. Cytological examination was done on impression smears from the tracheal bifurcation. Pathohistological preparations were stained with hematoxylin eosin (HE), toluidine blue (TB), Giemsa staining, PAS staining and Pearls reaction for iron detection. The peroxidase anti-peroxidase technique was used to demonstrate CD3+ (T lymphocytes) and CD79+ (B lymphocytes). Tracheal bifurcation cytology impression smears were stained with hematoxylin eosin (HE), Giemsa staining and PAS staining. Pulmonary emphysema and lack of pulmonary collapse were the most common gross lesions whereas alveolar emphysema was described in 70.59% of all examined horses, more frequently in the distensive form (54.90%) and less frequently in the destructive form (15.69%). Pathohistological chronic bronchitis/bronchiolitis, with characteristic changes in the lumen, mucosa, submucosa and smooth muscle layer was described in all examined horses. Increased immunoreactivity was described in the lungs. The most common lesions seen on cytology impression smears from the tracheal bifurcation were thick, viscous, PAS positive mucus which forms Curschmann's spirals. The dominant cell population consisted of desquamated airway epithelial cells, as well as eosinophils, neutrophils, mast cells, erythrocytes and alveolar macrophages. Primary pulmonary pathogens as well as potential contaminants and secundary infection agens were isolated bacteriologically from lung samples. All the above-mentioned findings correlate pointing to the fact that chronic bronchitis/bronchiolitis represents the basic substrate of chronic obstructive pulmonary disease (COPD) which has a combined inflammatory and immunological etiology. Emphysema being secondary to airway obstruction.

U ovom radu su izneti rezultati ispitivanja zastupljenosti i karakteristika hroničnog opstruktivnog oboljenja pluća (COPD) na osnovu morfoloških i citološ kih promena na plućima konja. Makroskopski su pregledana pluća od 51 konja različite starosti i pola i uzorkovano je tkivo pluća za patohistološka ispitivanja. Citološ ka ispitivanja su sprovedena na otisak preparatima sa bifurkacije dušnika. Patohistooški preparati su bojeni hematoksilinom i eozinom (HE), toluidin plavim (TB), Gimzom (Giemsa), PAS-om i Pearls-ovom reakcijom za detekciju gvožđa. Peroksidaza anti-peroksidaza metod (PAP) korišćen je za obležavanje CD3+ (T limfociti) i CD79+ (B limfociti). Citološki otisak preparati bifurkacije dušnika su bojeni hematoksilinom i eozinom (HE), Gimzom (Giemsa) i PAS-om. Emfizem i izostanak kolapsa pluća čine najčešći makroskopski nalaz kod ispitivanih konja, dok je alveolarni emfizem, češće u formi distenzivnog emfizema (54,90%), a ređe u formi destruktivnog emfizema (15,69%) ustanovljen kod 70,59% ispitivanih konja. Patohistološki je kod svih ispitivanih konja uočen hronič ni bronhitis/bronhiolitis, sa karakterističnim promenama u lumenu, na sluznici, krznu i glatko-mišićnom sloju. Imunohistohemijski je u plućima uočeno povećanje imunoreaktivnosti. Najčešće uočena promena na citološkim otisak preparatima dušnika bila je gusta, viskozna, PAS pozitivna sluz koja formira Kuršmanove spirale. Dominantnu ćelijsku populaciju čine deskvamisane ćelije epitela vazdušnih puteva, kao i eozinofilni i neutrofilni granulociti, mastociti, eritrociti i alveolarne makrofage. Iz uzoraka pluća bakteriološki su izolovani kako primarni patogeni pluća, tako i potencijalni kontaminenti i uzročnici sekundarnih infekcija. Svi navedeni nalazi su međusobno povezani i ukazuju na činjenicu da hronični bronhitis/bronhiolitis čini osnovni supstrat hroničnog opstruktivnog oboljenja pluća konja i da ima kombinovanu inflamatornu i imunološku etiologiju, a da je emfizem sekundarnog karaktera i javlja se kao posledica opstrukcije vazdušnih puteva.