Hp Laurila

Long‐Term Outcome and Use of 6‐Minute Walk Test in West Highland White Terriers with Idiopathic Pulmonary Fibrosis

Background Idiopathic pulmonary fibrosis (IPF) is an incurable interstitial lung disease occurring mainly in West Highland White Terriers (WHWTs). The effects of IPF on survival and on exercise tolerance in WHWTs are unknown. Objectives To evaluate survival, prognostic factors, and exercise tolerance in WHWTs with IPF. Animals Privately owned WHWTs; 15 with IPF and 11 healthy controls. Methods Prospective case‐control study conducted in 2007–2012. For survival, descriptive statistics and Kaplan–Meier (KM) survival curves with Cox proportional hazard ratios were performed. For the prognostic factor study, KM curves, Cox regression analysis, and logistic regression models were used. The 6‐minute walk test (6MWT) was used for measurement of exercise tolerance. Results The median IPF‐specific survival of deceased WHWTs (7/15) with IPF was 32 (range 2–51) months from onset of clinical signs. The risk of death from birth in WHWTs with IPF in age‐adjusted Cox model was significantly higher (hazard ratio 4.6; 95% confidence interval 1.05–19.74, P = .04) than in control WHWTs. No significant prognostic factors were identified. In 6MWT, WHWTs with IPF walked a shorter distance, median 398 m (range 273–519 m), than healthy controls, median 492 m (420–568 m), P = .05, and the partial pressure of oxygen in arterial blood in diseased dogs had a moderate positive correlation with walking distance (Kendall′s tau‐b = 0.69, P = .06). Conclusion and Clinical Importance IPF had a negative impact on life expectancy, but individual survival varied considerably. 6MWT proved to be a well‐tolerated, noninvasive test to evaluate exercise tolerance.

Comparative Study of Transforming Growth Factor-β Signalling and Regulatory Molecules in Human and Canine Idiopathic Pulmonary Fibrosis

Activation of transforming growth factor (TGF)-β is a key event in the progression of fibrosis in human lung tissue. Idiopathic pulmonary fibrosis (IPF) in West Highland white terriers (WHWTs) shares histopathological features of human usual interstitial pneumonia (UIP), the histopathological counterpart of IPF and non-specific interstitial pneumonia (NSIP). The aim of the present immunohistochemical study was to investigate TGF-β signalling activity and its known extracellular matrix (ECM) regulatory proteins, latent TGF-β binding protein (LTBP)-1 and fibrillin-2, in lung tissue of WHWTs with IPF and healthy WHWTs and to compare these with findings in human UIP and NSIP. P-Smad2 immunoreactivity, indicating TGF-β signalling activity, was increased in WHWTs with IPF relative to healthy WHWTs and expression was localized predominantly in the altered alveolar epithelium, as seen in both UIP and NSIP. Increased peribronchial and perivascular LTBP-1 immunoreactivity was seen in WHWTs with IPF compared with controls, possibly indicating the importance of the small airways in the canine disease. Alveolar LTPB-1 immunolabelling in diseased WHWTs was seen mainly in the altered alveolar epithelium, resembling more closely the labelling in UIP than in NSIP. Alveolar interstitial fibrillin-2 immunoreactivity, which is up-regulated in the lungs of people with UIP, was also detected in the lungs of WHWTs with IPF and people with NSIP. However, no significant difference was seen between WHWTs with IPF and control WHWTs. The results suggest that increased TGF-β signalling and expression of the ECM regulatory proteins LTBP-1 and fibrillin-2 are part of the molecular pathophysiology of canine IPF.

Transforming Growth Factor Beta 1 Activation, Storage, and Signaling Pathways in Idiopathic Pulmonary Fibrosis in Dogs

Background The pathogenesis of idiopathic pulmonary fibrosis (IPF) in dogs is poorly understood. In human, transforming growth factor β1 (TGF‐β1) is considered central in the pathogenesis. Objectives To investigate TGF‐β1 pathway in IPF. Animals Lung tissues from 12 affected and 11 control dogs. Serum from 16 affected West Highland white Terriers (WHWTs) and healthy dogs from predisposed (13 WHWTs, 12 Scottish Terriers and 13 Bichons Frise) and nonpredisposed breeds (10 Whippets, 10 Belgian shepherds, 8 Labradors). Methods In this prospective study, immunohistochemistry was used to evaluate expression and localization of TGF‐β1 protein and proteins involved in TGF‐β1 signaling (TGF‐β receptor type I and phospho‐Smad2/3). Pulmonary expression of TGF‐β1 and molecules involved in its storage (latent TGF‐β binding proteins [LTBP] 1, 2, and 4), activation (ανβ6 and ανβ8 integrins, thrombospondin‐1) and signal inhibition (Smad 7) was analyzed by quantitative reverse transcriptase PCR. Circulating TGF‐β1 concentration was measured by ELISA. Results In IPF, high level of TGF‐β1 protein was found in areas of fibrosis, epithelial cells had strong expression of TGF‐β receptor type 1 and phospho‐Smad2/3, gene expression was decreased for LTBP 4 (P = .009) and β8 integrin (P < .001) and increased for thrombospondin‐1 (P = .016); no difference was seen for Smad7, LTBP1 and 2. Serum TGF‐β1 concentration was higher in predisposed compared with nonpredisposed breeds (P < .0001). Conclusions and Clinical Importance This study identified an enhanced TGF‐β1 signaling activity in IPF. TGF‐β1 storage and activation proteins with altered expression represent potential therapeutic targets. Higher circulating TGF‐β1 concentration in predisposed breeds might partly explain their susceptibility for IPF.

Assessment of CCL2 and CXCL8 chemokines in serum, bronchoalveolar lavage fluid and lung tissue samples from dogs affected with canine idiopathic pulmonary fibrosis

Canine idiopathic pulmonary fibrosis (CIPF) is a progressive disease of the lung parenchyma that is more prevalent in dogs of the West Highland white terrier (WHWT) breed. Since the chemokines (C-C motif) ligand 2 (CCL2) and (C-X-C motif) ligand 8 (CXCL8) have been implicated in pulmonary fibrosis in humans, the aim of the present study was to investigate whether these same chemokines are involved in the pathogenesis of CIPF. CCL2 and CXCL8 concentrations were measured by ELISA in serum and bronchoalveolar lavage fluid (BALF) from healthy dogs and WHWTs affected with CIPF. Expression of the genes encoding CCL2 and CXCL8 and their respective receptors, namely (C-C motif) receptor 2 (CCR2) and (C-X-C motif) receptor 2 (CXCR2), was compared in unaffected lung tissue and biopsies from dogs affected with CIPF by quantitative PCR and localisation of CCL2 and CXCL8 proteins were determined by immunohistochemistry. Significantly greater CCL2 and CXCL8 concentrations were found in the BALF from WHWTs affected with CIPF, compared with healthy dogs. Significantly greater serum concentrations of CCL2, but not CXCL8, were found in CIPF-affected dogs compared with healthy WHWTs. No differences in relative gene expression for CCL2, CXCL8, CCR2 or CXCR2 were observed when comparing lung biopsies from control dogs and those affected with CIPF. In affected lung tissues, immunolabelling for CCL2 and CXCL8 was observed in bronchial airway epithelial cells in dogs affected with CIPF. The study findings suggest that both CCL2 and CXCL8 are involved in the pathogenesis of CIPF. Further studies are required to determine whether these chemokines might have a clinical use as biomarkers of fibrosis or as targets for therapeutic intervention.

Evaluation of chemokines CXCL8 and CCL2, serotonin, and vascular endothelial growth factor serum concentrations in healthy dogs from seven breeds with variable predisposition for canine idiopathic pulmonary fibrosis.

The West Highland white terrier (WHWT) is particularly prone to canine idiopathic pulmonary fibrosis (CIPF). We hypothesized that higher circulating concentrations of chemokines CXCL8, CCL2, serotonin (5-HT), or vascular endothelial growth factor (VEGF) could serve as predisposing factors for CIPF development in the WHWT breed. Serum samples from 103 healthy dogs of seven different breeds variably predisposed to CIPF were collected. Serum CXCL8 concentrations were higher in healthy WHWT compared with each of the other groups of healthy dogs. Serum CCL2 concentrations were higher in healthy WHWT and Maltese compared with King Charles spaniels and Malinois Belgian shepherds. No relevant inter-breed differences were observed for serum 5-HT concentrations regarding CIPF predisposition. VEGF values from 89.3% of samples tested were below the kit detection limit. In conclusion, high CXCL8 blood concentrations and possibly CCL2 concentrations might be related to the breed predisposition of the WHWT for CIPF and warrants further investigations.

Analysis of gene expression in canine idiopathic pulmonary fibrosis

Idiopathic pulmonary fibrosis (IPF) in dogs is a rare disease of unknown aetiology, seen in terrier breeds, particularly the West Highland white terrier (WHWT). The aim of this study was to determine pulmonary gene expression in canine IPF in order to gain insights into the pathogenesis of the disease and to identify possible biomarkers. Microarray analyses were conducted to determine gene expression profiles in the lungs of dogs with IPF and control dogs of various breeds. More than 700 genes were identified as having greater than two-fold difference in expression between the two groups. The significant biological functions associated with these genes were related to cellular growth and proliferation, developmental processes, cellular movement, cell to cell signalling and interaction, and antigen presentation. Altered levels of expression were confirmed by quantitative reverse transcriptase PCR for genes encoding chemokine (C-C) ligand (CCL) 2 (+4.9 times), CCL7 (+6.8 times), interleukin 8 (+4.32 times), chemokine (C-X-C) ligand 14 (+3.4 times), fibroblast activation protein (+4.7 times) and the palate, lung and nasal associated protein (PLUNC, -25 times). Serum CCL2 concentrations were significantly higher in WHWTs with IPF (mean 628.1 pg/mL, interquartile range 460.3-652.7 pg/mL) than unaffected WHWTs (mean 344.0 pg/mL, interquartile range 254.5-415.5 pg/mL; P=0.001). The results support CCL2 as a candidate biomarker for IPF in dogs.

Upregulation of Alveolar Levels of Activin B, but not Activin A, in Lungs of West Highland White Terriers with Idiopathic Pulmonary Fibrosis and Diffuse Alveolar Damage

Activins, cytokines belonging to the transforming growth factor-β superfamily, have an important role in inflammation and fibrosis. Activin A has been suggested to participate in the pathophysiology of human idiopathic pulmonary fibrosis (IPF), but studies on the role of activin B are sparse. Canine IPF (CIPF) is an incurable interstitial lung disease occurring particularly in West Highland white terriers (WHWTs). During the disease course there are acute exacerbations (AEs) and the condition has a poor prognosis. Microscopically, AEs of CIPF are characterized by diffuse alveolar damage, which is also a key feature of acute respiratory distress syndrome (ARDS). The aim of this study was to study expression of activin A and B in lung tissue of WHWTs with CIPF and WHWTs with CIPF and concurrent AE, and dogs of various breeds with ARDS and to compare these findings with those of healthy WHWTs. In addition, western blot analysis of activin B from bronchoalveolar lavage fluid (BALF) from WHWTs with CIPF and healthy WHWTs was conducted. Activin B, but not activin A, was strongly expressed in the altered alveolar epithelium in the lungs of WHWTs with CIPF as well as in the lungs of dogs with ARDS. Activin B was detected in the BALF of WHWTs with CIPF, most notably in samples from dogs with AE, but activin B was not detected in BALF from healthy WHWTs. These findings suggest that activin B may be part of the pathophysiology of CIPF and might act as a marker of alveolar epithelial damage.

Reflux aspiration in lungs of dogs with respiratory disease and in healthy West Highland White Terriers

Background Gastroesophageal reflux and microaspiration (MA) of gastric juice are associated with various human respiratory diseases but not in dogs. Objective To detect the presence of bile acids in bronchoalveolar lavage fluid (BALF) of dogs with various respiratory diseases. Animals Twenty‐seven West Highland White Terriers (WHWTs) with canine idiopathic pulmonary fibrosis (CIPF), 11 dogs with bacterial pneumonia (BP), 13 with chronic bronchitis (CB), 9 with eosinophilic bronchopneumopathy (EBP), 19 with laryngeal dysfunction (LD), 8 Irish Wolfhounds (IWHs) with previous BPs, 13 healthy WHWTs, all privately owned dogs, and 6 healthy research colony Beagles Methods Prospective cross‐sectional observational study with convenience sampling of dogs. Bile acids were measured by mass spectrometry in BALF samples. Total bile acid (TBA) concentration was calculated as a sum of 17 different bile acids. Results Concentrations of TBA were above the limit of quantification in 78% of CIPF, 45% of BP, 62% of CB, 44% of EBP, 68% of LD, and 13% of IWH dogs. In healthy dogs, bile acids were detected less commonly in Beagles (0/6) than in healthy WHWTs (10/13). Concentrations of TBA were significantly higher in CIPF (median 0.013 μM, range not quantifiable [n.q.]‐0.14 μM, P < .001), healthy WHWTs (0.0052 μM, n.q.‐1.2 μM, P = .003), LD (0.010 μM, n.q.‐2.3 μM, P = .015), and CB (0.0078 μM, n.q.‐0.073 μM, P = .018) groups compared to Beagles (0 μM, n.q.). Conclusion and Clinical Importance These results suggest that MA occurs in various respiratory diseases of dogs and also in healthy WHWTs.