Granulomatous Uveitis Associated with Vaccination in the Atlantic Salmon

Abstract

Abstract. This study addressed histologic and immunopathologic changes in ocular tissues and investigated the distribution of major histocompatibility class II (MHC class II)-positive cells in Atlantic salmon (Salmo salar) suffering from severe postvaccination disease. Twenty-nine fish with generalized inflammation, probably a result of vaccination, were investigated. One individual that had escaped vaccination was included in the study. Material was investigated by cultivation methods for fungi and bacteria. Histology using conventional staining procedures and immunohistochemistry with antisera against MHC class II ␤ chain were performed. No growth was observed from the cultivation investigations. Histology revealed occlusion of the lumen in the larger choroid vessels and in the choriocapillaris, inflammatory infiltrations and loss of structure in the choroid rete, and, in some cases, aggregations of multinucleated giant cells (MGC) and Splendore-Hoeppli material. Immunohistochemistry demonstrated massive MHC class II ϩ cellular infiltrations in the uveal tract. Such infiltrations were also seen in the ventral ciliary cleft, a condition that is associated with glaucoma. Immunoreactive cells included dendritelike cells, epithelioid cells, and MGCs. The endothelia of smaller vessels were frequently MHC class II ϩ , and immunoreactive infiltrations were seen in the optic nerve in several individuals. No pathologic changes were detected in the unvaccinated individual. In conclusion, generalized inflammatory reactions in fish may lead to severe ocular inflammation, occlusion of uveal vessels, and perivascular changes with MHC class II ϩ upregulation in cells in the uveal tract and optic nerve.

Comparative cardiac pathological changes of Atlantic salmon (Salmo salar L.) affected with heart and skeletal muscle inflammation (HSMI), cardiomyopathy syndrome (CMS) and pancreas disease (PD)

“…Recently, a CMS transcriptomic study identified the up-regulation of T-lymphocytes (CD3 and CD8), MHC and apoptotic genes, and also correlated with histopathological changes (Timmerhaus et al, 2011). The increased presence of MHC class II + cells have been described in granulomatous uveitis and amoebic gill disease of Atlantic salmon (Koppang et al, 2004;Morrison et al, 2006). These studies were in line with the strong to moderate levels of MHC class II staining observed in diseased hearts in the present study.…”

“…As an antigen presenting molecule, MHC class II has been shown to be expressed on cells of the leucocyte lineage (dendritic cells, macrophages, B and T cells) and epithelial cells (Haugarvoll et al, 2008;Glimcher and Kara, 1992). Previously, cells stained with MHC class II have been suggested as T lymphocytes, epithelial cells, multinucleated giant cells (MGC), macrophages and dendrite-like cells (Koppang et al, 2003a(Koppang et al, , 2004. The MHC class II cells has been indicative of immune cell trafficking and suggested to be involved in antigen presentation in Atlantic salmon affected with amoebic gill disease (Morrison et al, 2006).…”

Vaccine-associated systemic Rhodococcus erythropolis infection in farmed Atlantic salmon Salmo salar

“…isolated in these cases clearly differed phenotypically, the description given by Claveau (1991) may suggest a relationship between that isolate and the R. erythropolis isolates presented here. In conclusion, although further studies are necessary to elucidate the pathogenesis of this vaccinerelated infection, it adds to the growing list of production-related 'diseases' previously described in vaccinated Atlantic salmon (Poppe & Breck 1997, Koppang et al 2003, 2004, 2005 and indicates the potential for further refinement of both vaccines and vaccination procedures.We believe this is the first description of infection in fish by Rhodococcus erythropolis. It is also, to our knowledge, the first demonstration that exposure to oil-adjuvanted vaccine may predispose the vaccinated fish to infection with an otherwise harmless bacterium.…”

Vaccination-Induced Systemic Autoimmunity in Farmed Atlantic Salmon

“…The vaccines commonly used contain an oil-based adjuvant (4), such as mineral hydrocarbon oil and emulsifier (same as IFA, containing mineral oil Bayol F and emulsifier) or animal/vegetable oil that contains pristane (2,6,10,14-tetramethylpentadecane) (5) or squalene (6). A number of undesirable side effects have been attributed to the vaccination of salmon, including retarded growth, chronic peritonitis with pigmentation and adhesion of internal organs (7)(8)(9), granulomatous uveitis (10), and spinal deformities (11).…”