Page 1462 - Veterinary Immunology, 10th Edition

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FIG. 43.6 The lymphoid organs of a bony fish.

Box 43.1

Vaccine-Induced Autoimmunity in Fish

Oil-adjuvanted vaccines are widely employed in aquaculture for

the prevention of infections. Under some circumstances
administration of these vaccines to farmed Atlantic salmon can
result in polyclonal B cell activation, the production of multiple

autoantibodies, and the development of a membranoproliferative
glomerulopathy and spondylitis. The autoantibodies are directed
against nuclear and cytoplasmic antigens, immunoglobulins
(rheumatoid factors), ssDNA, chromatin, thyroglobulin,
erythrocytes, and ferritin. These are not non-specific reactions;

rather, each fish develops its own pattern of autoreactivity with
different levels of response against each autoantigen. The kidney
lesions that develop are consistent with immune complex–

mediated reactions. These vaccine-induced reactions may well
have an impact on the continuing use of oil-based adjuvants in
salmon vaccines.

Koppang EO, Bjerkås I, Haugarvoll E, et al: Vaccination-induced systemic autoimmunity
in farmed Atlantic salmon, J Immunol 181:4807-4814, 2008.

The fish kidneys differentiate into two sections. The
opisthonephros or posterior kidney is an excretory organ similar to
the mammalian kidney. In contrast, the pronephros or anterior
kidney is a lymphoid organ containing antibody-forming cells and

phagocytes. Its function is analogous to mammalian bone marrow

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