Interstitial lung disease associated with Equine Infectious Anemia Virus infection in horses

Pompei Bolfa,Jean-Luc Cadoré,Christine Dolmazon,Caroline Leroux,Marie Nolf,Cornel Catoi,Fabienne Archer,Jean-François Mornex

doi:10.1186/1297-9716-44-113

Abstract

EIA (Equine Infectious Anemia) is a blood-borne disease primarily transmitted by haematophagous insects or needle punctures. Other routes of transmission have been poorly explored. We evaluated the potential of EIAV (Equine Infectious Anemia Virus) to induce pulmonary lesions in naturally infected equids. Lungs from 77 EIAV seropositive horses have been collected in Romania and France. Three types of lesions have been scored on paraffin-embedded lungs: lymphocyte infiltration, bronchiolar inflammation, and thickness of the alveolar septa. Expression of the p26 EIAV capsid (CA) protein has been evaluated by immunostaining. Compared to EIAV-negative horses, 52% of the EIAV-positive horses displayed a mild inflammation around the bronchioles, 22% had a moderate inflammation with inflammatory cells inside the wall and epithelial bronchiolar hyperplasia and 6.5% had a moderate to severe inflammation, with destruction of the bronchiolar epithelium and accumulation of smooth muscle cells within the pulmonary parenchyma. Changes in the thickness of the alveolar septa were also present. Expression of EIAV capsid has been evidenced in macrophages, endothelial as well as in alveolar and bronchiolar epithelial cells, as determined by their morphology and localization. To summarize, we found lesions of interstitial lung disease similar to that observed during other lentiviral infections such as FIV in cats, SRLV in sheep and goats or HIV in children. The presence of EIAV capsid in lung epithelial cells suggests that EIAV might be responsible for the broncho-interstitial damages observed.

Highlights

Equine Infectious Anemia Virus (EIAV) is a retrovirus belonging to the lentivirus genus, which infects equids worldwide
Lesions consistent with interstitial lung disease are present in EIAVPOS horses In contrast to the EIAVNEG horses (Figure 1A), 52% of the EIAVPOS horses displayed a mild inflammation around the bronchioles (Figure 1B), 21.5% had moderate inflammation with inflammatory cells inside the alveolar wall and areas of epithelial bronchiolar hyperplasia (Figure 1C), and 6.3% had moderate to severe inflammation, with destruction of the bronchiolar epithelium and accumulation of smooth muscle cells (Figure 1D)
We explored the potential of EIAV to induce pulmonary lesions in naturally infected equids from 79 EIAVseropositive horses collected in Romania and France

Summary

Introduction

Equine Infectious Anemia Virus (EIAV) is a retrovirus belonging to the lentivirus genus, which infects equids worldwide (reviewed in [1]). Clinical signs of EIA (Equine Infectious Anemia), the EIAV-induced disease, are variable infected equids often experience acute febrile episodes with concomitant thrombocytopenia and wasting syndrome followed by a chronic stage characterized by recurring disease episodes. In most cases, these febrile episodes eventually cease and despite remaining persistently infected the animals enter a prolonged phase with no overt clinical signs (reviewed in [1]). These febrile episodes eventually cease and despite remaining persistently infected the animals enter a prolonged phase with no overt clinical signs (reviewed in [1]) These inapparent carriers are potential reservoirs for transmission to naive equids.

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Conclusion