Increased serum antibody responses to Aspergillus fumigatus and house dust mite antigens in dogs with idiopathic eosinophilic bronchopneumopathy

TL;DR

Dogs with a lung disease called EBP show higher levels of antibodies to Aspergillus fumigatus and house dust mites compared to healthy dogs or those with another lung condition.

Contribution

This study identifies elevated IgG antibody responses to Aspergillus fumigatus and house dust mites in dogs with EBP, suggesting a potential IgG-dependent hypersensitivity mechanism.

Findings

Serum IgG concentrations for Aspergillus fumigatus were higher in EBP dogs compared to CB dogs and healthy dogs.

HDM-specific IgG concentrations were elevated in both serum and BALF of EBP dogs compared to CB dogs.

A fumigatus-specific IgE levels did not differ between groups, indicating EBP is not IgE-mediated.

Abstract

Eosinophilic bronchopneumopathy (EBP) in dogs is an idiopathic disease presumably caused by hypersensitivity to causative allergens that remain unidentified. In humans, allergic bronchopulmonary aspergillosis (ABPA) is a hypersensitivity to Aspergillus fumigatus in uncontrolled asthma in patients.

Investigate potential implications of A fumigatus and other ubiquitous antigens (house dust mites, HDMs) in dogs with EBP compared to healthy dogs and dogs with chronic bronchitis (CB).

Paired serum and bronchoalveolar lavage fluid (BALF) from dogs with EBP or CB and healthy dogs.

Case–control observational study. Quantitative PCR (qPCR) for A fumigatus was performed on BALF and A fumigatus-specific antibodies were investigated using a validated ELISA on serum and BALF. An ELISA also was performed for HDM-specific antibodies.

Aspergillus fumigatus qPCR was weakly positive in BALF in 2 of 23 EBP dogs and negative in all other dogs. Concentrations of A fumigatus-specific immunoglobulin E (IgE) in serum and BALF were very low and did not differ between groups. Concentrations of A fumigatus-specific serum immunoglobulin G (IgG) were higher in EBP dogs than in CB dogs and healthy dogs (P = .01) but concentrations in BALF were not different. Concentrations of HDM-specific IgG were higher in both serum and BALF in EBP dogs compared with CB dogs (P = .01).

Higher concentrations of serum IgG for A fumigatus and HDM observed in EBP dogs might suggest an IgG-dependent disease. Based on our results, EBP is not mediated by A fumigatus-specific IgE.

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