abstract

Immune testing was performed on a weekly basis to assess its potential use as a diagnostic or prognostic tool to help in the management of stranded marine mammals. Twenty four animals representing four species were tested over two years, for a total of 161-181 tests (depending on the assay). Immune functions assessed included T and B lymphocyte proliferation, as well as neutrophil phagocytosis and respiratory burst. General trends in immune functions were not consistently associated in time with changes in leukocyte counts (WBC), termination of antibiotic therapy, or other significant events. Deviation from "normal" immune parameters, determined as the mean +/- 1, 1.5 or 2 standard deviations, were determined from the samples tested, and the odds of "abnormal" immune functions determined when leukocyte counts were normal, high or low. In grey, harp and harbor seals, high leukocyte counts were associated with increased odds of low T cell proliferation, suggesting the possibility of recruitment of relatively immature T cells that may not be fully capable of responding to mitogen stimulation. Elevated WBC in grey seals increased the odds for high B cell proliferation and phagocytosis, suggesting a response of both the innate and acquired immune responses to extra-cellular pathogens (such as bacteria), which commonly result in elevated WBC. Elevated WBC in harp seals increased the odds for high B and T cell proliferation and respiratory burst. This may be compatible with a chronic response to difficult to destroy pathogens (such as those associated with abscesses or granulomas) that might involve both a B and T cell response in addition to an innate immunity. Animals that died usually had several low immune test results. Overall, immune testing might be useful in understanding the pathophysiology and management of stranded marine mammals.

acknowledgements

This work was supported by a grant from the NOAA Prescott grant program.