Abstract: The first cases of orogenital sessile papillomas associated with a novel gammaherpesvirus and papillomavirus were recently reported in freeranging Atlantic bottlenose dolphins (Tursiops truncatus). The tumors appear to be sexually transmitted and are now occurring in epidemic proportions in some coastal areas. This study describes the hematological, biochemical, and immunological findings in free-ranging bottlenose dolphins with orogenital papillomas from the coastal waters of South Carolina and Florida. Blood samples were obtained from 22 dolphins with papillomas and 86 healthy dolphins. Few statistically significant differences were found for hematological and serum chemistry variables. Serum iron was significantly lower and serum bicarbonate significantly higher in dolphins with orogenital papillomas compared with healthy dolphins. However, dolphins with tumors had multiple abnormalities in serum proteins and immunologic parameters. Serum protein electrophoresis results demonstrated significantly elevated levels of total globulin, total alpha globulin, and alpha-2 globulin in dolphins with orogenital papillomas. Gamma globulins were also elevated in dolphins with orogenital papillomas although not significantly. Innate immunity was up-regulated in dolphins with tumors. Granulocytic and monocytic phagocytosis and superoxide respiratory bursts were significantly higher in dolphins with orogenital tumors compared with healthy dolphins. Adaptive immunity appeared to be relatively intact with an up-regulated humoral immune response; statistically significant increases were found in B-lymphocyte proliferation and antibody titers to the common marine microorganisms Escherichia coli, Erysipelothrix rhusiopathiae, Mycobacterium marinum, Vibrio cholerae, V. carchariae, V. vulnificus, and V. parahemolyticus. The only adaptive immune system variable significantly lower in dolphins with tumors was the percentage of lymphocytes expressing MHC class II molecules, suggesting possible impaired or down-regulated expression as has been noted in humans with viral infections. The clinically relevant results indicate that dolphins with orogenital papillomas demonstrate hypoferremia, hyperglobulinemia, and hyperalphaglobulinemia likely associated with an acute-phase inflammatory response and up-regulated innate and humoral immunity, all possible responses to the tumors and/or the viruses associated with the tumors. Also, dolphins with orogenital papillomas may have enhanced innate and humoral adaptive immunity because of increased exposure to other directly transmitted pathogens.
Key Words: Atlantic bottlenose dolphin, Tursiops truncatus, orogenital papilloma, emerging disease, hematology, serum analytes, immunology
Document Type: Research article
Page Numbers: 166-177