Bronchiolitis Obliterans Organizing Pneumonia in Swine Associated with Porcine Circovirus Type 2 Infection

Abstract

Bronchiolitis obliterans organizing pneumonia (BOOP) is a chronic respiratory disease. Although the pathogenesis of BOOP is still incompletely understood, BOOP is responsive to steroids and has a good prognosis. In our five pigs with chronic postweaning multisystemic wasting syndrome (PMWS), typical BOOP lesions were revealed. All five porcine lungs showed typical intraluminal plugs, and porcine circovirus type 2 (PCV2) was identified. They also exhibited similar pathologic findings such as proliferation of type II pneumocytes and myofibroblasts (MFBs), extracellular collagen matrix (ECM) deposition, and fragmentation of elastic fibers. MFBs migration correlative molecules, for instance, gelatinase A, B and osteopontin, appeared strongly in the progressing marginal area of polypoid intraluminal plugs of fibrotic lesion. These molecules colocalized with the active MFBs. Both gelatinase activity and intercellular level of active MFBs were significantly increased (P < .05). Porcine chronic bronchopneumonia leads to BOOP and it is associated with PCV2 persistent infection. Swine BOOP demonstrates similar cellular constituents with human BOOP. Perhaps their molecular mechanisms of pathogenesis operate in a similar way. Thus we infer that the swine BOOP can be considered as a potential animal model for human BOOP associated with natural viral infection. Moreover, it is more convenient to obtain samples.

Cryptogenic Organizing Pneumonia

“…Models of postinfectious OP have been developed in animals inoculated with viruses, namely the intranasal inoculation of moderate doses of reovirus serotype 1 in a susceptible strain of mice (CBA/J), 24,25 the inoculation of Streptococcus pneumoniae in Wistar rats, 26,27 the slow resolution of pneumonia due to Legionella pneumophila in Toll-like receptor-5-deficient mice, 28 and the persistent lung infection of pigs with circovirus. 29 These experimental observations strongly suggest that the genetic background may participate in the pathogenesis of OP, at least in animals, demonstrate the role of T cells, 30,31 and indicate that the intensity of the initial epithelial injury (especially alveolar epithelial cells type 2) and yet undetermined factors inherent to the host may influence the evolution to either OP or DAD.…”

Current State of Knowledge on Porcine Circovirus Type 2-Associated Lesions

“…PCV2 antigen was also associated with intraluminal polyps in bronchiolitis obliterans organizing pneumonia. 13 In Figure 2. Pig experimentally inoculated with porcine circovirus type 2 (PCV2), lymph node.…”

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

“…PCV2 is the primary causative agent of porcine circovirus‐associated diseases (PCVAD) in swine; PCVAD has been referred to by different names, the most common being postweaning multisystemic wasting syndrome (PMWS). Furthermore, porcine dermatitis and nephropathy syndrome (PDNS), proliferative and necrotizing pneumonia, respiratory disease and enteritis were also linked to PCV2 infections (Allan et al., ; Madson et al., ; Grau‐Roma & Segalés, ; Cheng et al., ; Kim & Chae, ) and have caused a huge economic loss to the pig industry worldwide. PCV3, a novel genotype of PCV, was first reported in pigs with cardiac and multisystemic inflammation in 2016 (Phan et al., ).…”