When accompanied by
peribronchiolar metaplasia, centrilobular fibrosis strongly suggests prior small airway injury, perhaps due to chronic HP, and a careful search for residual granulomas or giant cells should be undertaken.
As shown in Figure 4(b), asthma group mice showed prominent neutrophil infiltration of the
peribronchiolar and perivascular connective tissues, together with the hypersecretion of mucus by epithelial cells.
We observed
peribronchiolar inflammation 1 day after Cr(VI) exposure, which increased up to 8 days after intranasal treatment (Figure 1D).
Histologically, the OP pattern is characterized by a temporally uniform proliferation of intra-alveolar organizing fibroblastic tissue in a patchy
peribronchiolar distribution.
Not much is known about the role of macrophages in this part of the disease, but pigmented macrophages were found to cluster around small airways and these were associated with
peribronchiolar fibrosis [81].
Mexico City dogs exhibit focal
peribronchiolar inflammatory infiltrates that surround the adjacent blood vessels, some of which contain platelet thrombi and marginated neutrophils (CalderOin-Garciduenas et al.
(21) In addition, small airways infections usually present with
peribronchiolar inflammation.
Scores for
peribronchiolar inflammatory cell infiltrates in sections from each lung were graded; a score of 0 indicated the absence of inflammatory cell infiltrates; a score of 1, less than five layers of inflammatory cells in <50% of the bronchiolar submucosa; 2, more than five layers of inflammatory cells in <50% of the bronchiolar submucosa; 3, less than five layers of inflammatory cells in >50% of the bronchiolar submucosa; and 4, more than five layers of inflammatory cells in >50% of the bronchiolar submucosa [18].
This technique provides for a wide dissemination of particles in a
peribronchiolar pattern within the alveolar region (Rao et al.
Detailed morphometric analysis has extensively expanded our knowledge of airway alterations in both membranous and respiratory bronchioles, (14) and it has documented airway narrowing with inflammation and fibrosis, and loss of the
peribronchiolar alveolar attachments.
At 14 days after infection, we observed diffuse granulomatous pneumonia and the severe destruction of lung parenchyma with the
peribronchiolar and perivascular infiltration of macrophages and neutrophils (Figure 5(h)).
This is likely due to the exuberant
peribronchiolar granulomatous response.