Expression of Fibroblast Activation Protein in lungs of dogs with idiopathic pulmonary fibrosis and dogs with lung cancer

peer reviewedCanine Idiopathic Pulmonary Fibrosis (CIPF) is a progressive fibrotic interstitial lung disease of unknown aetiology, affecting predominantly the West Highland White Terrier (WHWT) breed. Currently, there is no curative treatment option available. Fibroblast Activation Protein (FAP) is a cell surface protease usually absent from normal tissue but specifically expressed in areas of active tissue remodelling such as in fibroblast foci in human idiopathic pulmonary fibrosis. In humans, it is also upregulated in various types of cancers, either in cancer-associated fibroblasts (CAFs), in cancer cells or in both, depending on the tumour type. The aim of this study was to assess the expression and localization of FAP in the lungs of WHWTs affected with CIPF, in comparison with WHWTs with healthy lungs and dogs with lung cancer. Post-mortem formalin-fixed lung biopsies prepared from WHWTs with CIPF (n=17, age from 10 to 15y), control WHWTs exempt from lung disease (n=4, age from 11 to 15y) and dogs from various breeds with lung cancer (n=8, age from 8 to 14y) were retrospectively used. Included lung neoplasia were adenocarcinomas (n=6), histiocytic sarcoma (n=1) and metastasized mammary adenocarcinoma (n=1). Immunohistochemistry (IHC) was performed using a rabbit anti-human FAP monoclonal antibody (#ab207178). An IHC staining index (absent, low, moderate or high) was attributed according to the percentage of positive cells combined with the staining intensity. FAP was identified in the lungs of 16 out of 17 (94%) WHWTs with CIPF (IHC index high, moderate, or low in respectively 10, 4 and 2 dogs), 2 out of 4 (50%) WHWTs with healthy lungs (1 of each moderate and low), and 7 out of 8 (88%) dogs with lung cancer (high and moderate in respectively 6 and 1 dogs). FAP was expressed by fibroblasts in areas of active fibrosis in CIPF and by CAFs (all types of cancer) and cancer cells (adenocarcinomas only, n=5) in lung tumours. Results of this study showed that FAP is moderately to markedly expressed by fibroblasts in most dogs affected with either CIPF or lung cancer. Accordingly, FAP should be considered as an interesting potential therapeutic target for both diseases and should encourage further studies in the future. The expression of FAP in healthy lungs of WHWTs should be further investigated, particularly in comparison with FAP expression in dogs from other breeds, as it might serve as an indicator of early fibrosis

Detection of specific bacterial agents by quantitative PCR assays in the bronchoalveolar lavage fluid of dogs with eosinophilic bronchopneumopathy vs. dogs with chronic bronchitis and healthy dogs

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Prevalence and risk factors for Mycoplasma spp. positivity in cat blood donor units from Portugal, Spain and Belgium in 2022: retrospective study on 7573 blood donations from 4121 healthy donor cats

peer reviewedHaemotropic mycoplasmas are epi-erythrocytic parasitic bacteria that can cause haemolytic anaemia. Prevalence for haemoplasma infection varies geographically among Mycoplasma species. Male adult outdoor non-pedigree cats are at increased risk for infection. Some studies identified an association between haemoplasmas and retroviruses. As Mycoplasma spp. can be transmitted via blood transfusion, routine quantitative polymerase chain reaction (qPCR) screening of donor cats is recommended. This retrospective study assessed prevalence and risk factors for Mycoplasma spp. positivity in cat donor units from Portugal, Spain, and Belgium. A private blood bank database of cat donations performed in 2022 was reviewed. Studied risk factors for Mycoplasma spp. positivity included age, sex, pedigree, blood type, geographic area, season, and retroviral co-infection (FeLV and FIV). A multiple generalised estimation equation model was used to account for repeated blood donations on a same cat. A total of 7573 blood donations from 4121 privately-owned mixed breed donor cats from Portugal (n=4034, 97.9%), Spain (n=70, 1.7%), and Belgium (n=17, 0.4%) were studied. Most cats donated blood once (n=1996, 48.4%); the remainder donated twice (n=1099, 26.7%), three (n=725, 17.6%) or four (n=301, 7.3%) times. Two-hundred and twelve Portuguese cats tested positive at least once for Mycoplasma spp. leading to an estimated prevalence of 5.3% (95% CI: 4.6-5.9). The prevalence did not significantly differ between Portuguese regions (P=0.28). Two cats in Spain had positive Mycoplasma spp. qPCR, whilst all Belgian cats were negative. The small sample sizes in these countries prevented robust prevalence estimation. Among positive Portuguese cats, 30 cats donated blood >1 time in 2022: 26 cats were negative first then subsequently tested positive, 3 cats were positive on two occasions, and 1 cat was initially positive and subsequently tested negative. Blood units collected from male cats were at higher risk for Mycoplasma spp. positivity (OR 1.9, P<0.001). Increased risk was also observed for blood units that tested positive for FeLV either by serology and/or qPCR (OR 2.9, P=0.0018) and for blood donations performed in winter (OR 2.5, P<0.0001). None of the other studied risk factors was associated with Mycoplasma spp. positivity. European cat blood donors displayed a low prevalence of Mycoplasma spp. with an increased risk in cats affected with FeLV and male cats. The seasonality for Mycoplasma spp. positivity, with an increased risk in winter, remains to be elucidated. Positive Mycoplasma spp. qPCR results identified in previously negative donors emphasizes the importance of testing on every donation instead of annually

Biomolecular investigation for Capillaria spp. infections on bronchoalveolar lavage fluid of owned domestic dogs presented for chronic cough in Belgium

peer reviewedThe trichuroid parasitic nematode Capillaria aerophila (syn. Eucoleus aerophilus) is responsible for lower respiratory infections and Capillaria boehmi (syn. Eucoleus boehmi) for sino-nasal infections in wild and domestic carnivores. Animals become infected by eating environmental embryonated eggs or earthworms. The adult worms live embedded in the epithelia of the bronchioles, bronchi, and trachea or in the nasal sinuses, respectively. Infections with C. aerophila can be sub-clinical or lead to chronic bronchial inflammation, rarely bronchopneumonia. C. boehmi may cause nasal discharge, sneezing or olfactory impairment. Knowledge about prevalence and distribution of both parasites beyond Eastern Europe and Mediterranean countries is lacking. The aim of this study was to assess the prevalence of C. aerophila infection in coughing, client-owned, domestic dogs in Belgium. Stored bronchoalveolar lavage fluid (BALF) from 125 dogs (median age 7.3 years, range: 0.3-17.2 years) from March 2018-2022 was retrieved. All dogs had history of chronic cough (> 2 weeks duration) and underwent BALF collection for microbiologic testing of common respiratory pathogens. DNA extracted from BALF samples was stored at -80°C until further analysis. A conventional polymerase chain reaction targeting a region internal to the cox1 gene of C. aerophila, a Capillarinae consensus sequence, was performed on BALF samples in duplicate and in batch analysis using previously published primers sequences. DNA of adult C. boehmi specimens was included as a positive control. Molecular grade water was used as a negative control. Neither DNA of C. aerophila nor C. boehmi were detected in the BALF samples. Sixty-seven dogs (54%) had a recent history of deworming against lungworms with either moxidectin or fenbendazole (deworming protocol not standardized), 9 dogs (7%) were not up to date with deworming therapy, and the remaining 49 dogs (39%) had unknown deworming status. Result of this study suggest that C. aerophila infection is not prevalent in Belgium in dogs with chronic cough. This might be explained by recent deworming therapy in half of the included dogs. Epidemiosurveillance of capillarid infection may be considered in wild canids, such as foxes, to determine whether these parasites are a potential risk for domestic animals

Assessment of SPP1 and FN1 in serum, BALF and lung tissue samples from dogs affected with CIPF

Background: Canine idiopathic pulmonary fibrosis (CIPF) is a chronic disease affecting West Highland white terriers (WHWTs)1,2. Osteopontin (SPP1) and fibronectin (FN1) are associated with pulmonary fibrosis in men3-6 and are overexpressed in bronchoalveolar lavage fluid (BALF) macrophage clusters in CIPF7. Study premise: The aim is to investigate whether these molecules are potential disease markers. SPP1 and FN1 serum and BALF concentrations were measured using canine ELISA kits in CIPF WHWTs (n=24), healthy aged-matched WHWTs (n=13) and healthy terriers (n=15). Proteins were also localized in lung tissue by immunohistochemistry. Results: SPP1 serum concentrations were higher in CIPF compared with healthy WHWTs and terriers, and in healthy WHWTs compared with terriers. There were negatively correlated with PaO2 in WHWTs. Higher SPP1 BALF concentrations were found in CIPF and healthy WHWTs compared with terriers. Intense labelling was reported in all groups in ciliated epithelial cells, smooth muscular cells surrounding large vessels and some macrophages. Moreover, in all CIPF WHWTs, the pneumocytes II and the extra cellular matrix were labelled, while it was the case in only 57% of healthy WHWTs and not present in terriers. FN1 serum concentrations were lower in CIPF and healthy WHWTs compared with terriers. No difference was found between groups in BALF. There was no evidence of differences in FN1 labelling. Conclusions: The results suggest that SPP1 is involved in CIPF pathogenesis and could predispose that breed to the disease. However, further studies are required to determine its interest as biomarker or potential therapeutic target

Utility of Computed Tomographic Angiography for Pulmonary Hypertension Assessment in a Cohort of West Highland White Terriers With or Without Canine Idiopathic Pulmonary Fibrosis

West Highland white terriers (WHWTs) affected with canine idiopathic pulmonary fibrosis (CIPF) are at risk of developing precapillary pulmonary hypertension (PH). In humans, thoracic computed tomography angiography (CTA) is commonly used to diagnose and monitor patients with lower airway diseases. In such patients, CTA helps to identify comorbidities, such as PH, that could negatively impact prognosis. Diameter of the pulmonary trunk (PT), pulmonary trunk-to-aorta ratio (PT/Ao), and right ventricle-to-left ventricle ratio (RV/LV) are CTA parameters commonly used to assess the presence of PH. Pulmonary vein-to-right pulmonary artery ratio (PV/PA) is a new echocardiographic parameter that can be used in dogs to diagnose PH. The primary aim of this study was to evaluate the use of various CTA parameters to diagnose PH. An additional aim was to evaluate the correlation of RV/LV measurements between different CTA planes. CTA and echocardiography were prospectively performed on a total of 47 WHWTs; 22 affected with CIPF and 25 presumed healthy control dogs. Dogs were considered to have PH if pulmonary vein-to-right pulmonary artery ratio (PV/PA) measured on 2D-mode echocardiography was less than to 0.7. WHWTs affected with CIPF had higher PT/Ao compared with control patients. In WHWTs affected with CIPF, PT size was larger in dogs with PH (15.4 mm) compared with dogs without PH (13 mm, p = 0.003). A cutoff value of 13.8 mm predicted PH in WHWTs affected with CIPF with a sensitivity of 90% and a specificity of 87% (AUC = 0.93). High correlations were observed between the different CTA planes of RV/LV. Results suggest that diameter of the PT measured by CTA can be used to diagnose PH in WHWTs with CIPF

The prevalence of pulmonary hypertension assessed using the pulmonary vein‐to‐right pulmonary artery ratio and its association with survival in West Highland white terriers with canine idiopathic pulmonary fibrosis

Background: Pulmonary hypertension (PH) is a known co-morbidity in West Highland white terriers (WHWTs) affected with canine idiopathic pulmonary fibrosis (CIPF). The pulmonary vein-to-right pulmonary artery ratio (PV/ PA) has recently been described for the detection of pre-capillary PH in dogs. The objective of the present study was to estimate the prevalence of PH at diagnostic, in WHWTs affected with CIPF, by using PV/PA, in comparison with a group of healthy breed-matched controls (CTRLs). Additional study objective was to expl

Chronic idiopathic lymphoplasmacytic rhinitis (CILPR): Double-masked RCT with Lokivetmab (Cytopoint®)

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