An Assessment of Anti-Ganglioside Antibodies for the Diagnosis of Avian Ganglioneuritis and Potential Correlation with Gross Lesions, Microscopic Findings and Serologic Titers in Cockatiels Challenged with Parrot Bornavirus

Avian ganglioneuritis is one of the most widespread diseases of psittacines and is caused by parrot bornavirus (PaBV). It has been suggested that PaBV causes a T-cell-mediated immunopathology comparable to Borna disease virus 1 (BoDV-1). However, the factors involved in progression from infection to clinical disease in psittacines remain poorly understood. It has been proposed that autoantibodies directed against endogenous gangliosides of the central and peripheral nervous systems contribute to disease development. These anti-ganglioside antibodies have been suggested as potential diagnostic markers for birds developing clinical avian ganglioneuritis independent from the causing infectious agent. In this study, 257 plasma samples from cockatiels (Nymphicus hollandicus) experimentally infected with PaBV, with known infection status as well as defined clinical and postmortem outcomes, were submitted in a blinded manner to a commercial laboratory for anti-ganglioside antibody testing. The results were compared with the presence of anti-PaBV antibodies, clinical signs, gross pathological findings, and histopathological results. Among 25 birds with dilated proventriculi at the time of necropsy, 9 (36%) tested positive for anti-ganglioside antibodies, whereas 16 (64%) tested negative. Of 56 birds with histopathological avian ganglioneuritis, 26 (46.43%) tested positive and 30 (53.57%) tested negative. Among 33 birds without histopathological inflammatory lesions, 19 (57.58%) tested negative and 14 (42.42%) tested positive. These results indicate that no association between the occurrence of avian ganglioneuritis and the detection of anti-ganglioside antibodies was seen.