Title: Progressing centrilobular lung emphysema
Stain hematoxylin-eosin, adult human. Emphysema is defined as enlargement of the airspaces (X) distal to the terminal bronchioles, with destruction of the alveolar walls. At (3) remnant of a respiratory bronchiolus. Alveolar walls are destructed and other alveolar walls are thickened (1) and shows an increased cellularity. Locally smooth muscles (2) as well as blood vessels are present. Note thickened alveolar tips (↓)
Title: Fibrillin in the alveoli of lung emphysema
Anti-fibrillin antibody immunoperoxidase staining with diaminobenzidin reaction, adult human. Fibrillin is one of the elastin-associated microfibrillar proteins, and marks therefore also the presence of elastin in lung tissue.
The immunostaining then reveals the sparsely brown stained fibrillin (1) in the thin alveolar septa and fragmented tips (↓).
(3) Indicates capillaries in the septal wall. (M) Macrophage.
At (X) brown stained fibrillins associated with elastic membranes are still found in an intact small pulmonary artery. During the severe course of emphysema the decrease and fragmentation of fibrillin is progressive. Therefore the antifibrillin antibody marks the gravity of destruction of the alveoli during emphysema.
Background: In centrilobular emphysema (e.g. in lungs of smokers) the lesions are more common and severe in the upper lobes i.e. the air spaces are dilated and chronic inflammation is found around bronchi and bronchioli. There is an imbalance between protease and antiprotease activities in the lung. Upon stimulation by among others cigarette smoke macrophages and neutrophilic granulocytes release elastase out from their lysosomes. In this way the initiation of tissue destruction starts, alveoli are broken down and the result is a permanent enlargement of the air spaces with the breakdown of elastin.
Keywords/Mesh: respiratory system, lung, pulmonary artery, emphysema, alveolus, alveolar tip, elastin, elastin-associated protein, microfibril, fibrillin, histology, pathology, POJA collection