Bronchiolitis obliterans organizing pneumonia in Swine associated with porcine circovirus type 2 infection

Chronic interstitial pneumonia with features of organizing pneumonia in an adult horse

A 22-y-old American Quarter Horse gelding was presented with a history of chronic progressive respiratory problems and a diffuse pulmonary nodular pattern in thoracic radiographs. The horse was euthanized, and 4 formalin-fixed samples of lung were submitted for histopathology. There were multifocal areas of marked thickening of alveolar septa as a result of proliferation of myofibroblasts embedded in fibromyxoid matrix (interpreted as "Masson bodies"), focal areas of fibrosis, and numerous papillary projections of connective tissue into bronchioles. A diagnosis of organizing pneumonia was reached. No etiology was found for this lesion. It is important to consider causes of chronic interstitial pneumonia with fibrosis in horses other than equid herpesvirus 5, such as complicated viral or bacterial pneumonia or chronic toxicoses.

The occurrence of porcine circovirus 3 without clinical infection signs in Shandong Province

Porcine circovirus type 3 (PCV3) was detected in Shandong, China. One hundred and thirty‐two of 222 (59.46%) samples were PCV3 positive, while 52 of 132 (39.39%) samples were co‐infected with PCV2. There were no clinical signs of infection in either multiparous sows or live‐born infants. Two strains of PCV3 were indentified from natural stillborn foetuses. Phylogenetic analysis showed the two strains of PCV3 are 96% identical to the known PCV3/Pig/USA (KX778720.1, KX966193.1 and KX898030.1) and closely related to Barbel Circovirus. Further studies of the epidemiology of PCV3 and the co‐infection with PCV2 are needed.

Clinical Characteristics and Cytokine Profiles of Organizing Pneumonia in Patients with Rheumatoid Arthritis Treated with or without Biologics

OBJECTIVE

It has been reported that organizing pneumonia (OP) develops when patients with rheumatoid arthritis (RA) are treated with biologic disease-modifying antirheumatic drugs (bDMARD). However, the clinical characteristics and pathophysiology of OP in RA remain unknown in patients treated with bDMARD. We investigated the clinical characteristics and cytokine profiles of patients with RA-OP treated with bDMARD or conventional synthetic DMARD (csDMARD).

METHODS

Twenty-four patients with RA who had developed OP were enrolled. These patients included 12 treated with bDMARD (bDMARD-OP subset) and 12 treated with csDMARD (csDMARD-OP subset). We compared the clinical characteristics and cytokine profiles between the patients with OP (OP subset, n = 24) and non-OP patients (non-OP subset, n = 29).

RESULTS

There was no significant difference in clinical characteristics between the OP subset and the non-OP subset. Four patients developed OP within 2 months of bDMARD administration. In the other 8 patients, OP developed more than 1 year after the initiation of bDMARD. OP improved with corticosteroid treatment in all bDMARD-OP patients. After OP improved, bDMARD were readministered in 6 patients, and no OP recurrence was observed in any of these patients. Our multivariate analysis revealed that serum levels of interferon-α (IFN-α), interleukin (IL)-1β, IL-6, IL-8, and interferon-γ-inducible protein 10 were significantly associated with the development of OP, although these cytokines tended to be lower in the bDMARD-OP subset than in the csDMARD-OP subset.

CONCLUSION

OP is unlikely to be fatal in patients treated with bDMARD or csDMARD. IFN-α and proinflammatory cytokines are associated with the pathophysiology of OP in RA.

Rattus model utilizing selective pulmonary ischemia induces bronchiolitis obliterans organizing pneumonia

Bronchiolitis obliterans organizing pneumonia (BOOP), a morbid condition when associated with lung transplant and chronic lung disease, is believed to be a complication of ischemia. Our goal was to develop a simple and reliable model of lung ischemia in the Sprague-Dawley rat that would produce BOOP. Unilateral ischemia without airway occlusion was produced by an occlusive slipknot placed around the left main pulmonary artery. Studies were performed 7 days later. Relative pulmonary and systemic flow to each lung was measured by injection of technetium Tc 99m macroaggregated albumin. Histological sections were examined for structure and necrosis and scored for BOOP. Apoptosis was detected by immunohistochemistry with an antibody against cleaved caspase 3. Pulmonary artery blood flow to left lungs was less than 0.1% of the cardiac output, and bronchial artery circulation was ∼2% of aortic artery flow. Histological sections from ischemic left lungs consistently showed Masson bodies, inflammation, and young fibroblasts filling the distal airways and alveoli, consistent with BOOP. In quantitative evaluation of BOOP using epithelial changes, inflammation and fibrosis were higher in ischemic left lungs than right or sham-operated left lungs. Apoptosis was increased in areas exhibiting histological BOOP, but there was no histological evidence of necrosis. Toll-like receptor 4 expression was increased in ischemic left lungs over right. An occlusive slipknot around the main left pulmonary artery in rats produces BOOP, providing direct evidence that ischemia without immunomodulation or coinfection is sufficient to initiate this injury. It also affords an excellent model to study signaling and genetic mechanisms underlying BOOP.

Histopathological analogies in chronic pulmonary lesions between cattle and humans: basis for an alternative animal model

Most of the natural cases of pneumonia in feedlot cattle are characterized by a longer clinical course due to chronic lung lesions. Microscopically, these lesions include interstitial fibroplasia, bronchitis, bronchiectasis, bronchiolitis obliterans, and epithelial metaplasia of the airways. Herein, the aim was to review, under a medical perspective, the pathologic mechanisms operating in these chronic pneumonic lesions in calves. Based on the similarities of these changes to those reported in bronchiolitis obliterans/organising pneumonia (BO/OP) and chronic obstructive pulmonary disease (COPD) in human beings, calves are proposed as an alternative animal model.