Abstract
Assessing the health status of a population is essential in order to maintain adequate managing plans. Phagocytosis is the most important and initial defense against many pathogens in mammals. In order to verify the efficiency of the immune system it is possible to examine the functionality of the phagocytes. The phagocytosis test enables a quantitative analysis of phagocytic function of neutrophils and monocytes in a blood sample using flow cytometry. Blood was taken from harbor seal pups (Phoca vitulina) at admission to the rehabilitation center and prior to release. The phagocytosis test was performed with the help of a flow cytometer. A Phagotest® test kit produced for human medicine application was applied. At admission it was evident that neutrophils of pups with elevated hemogram values (WBC > 12 g/l) had less phagocytic activity than those of pups with normal hemograms. The innate immune response was obviously very active at admission. Prior to release the 2 ½-3 month old rehabilitated pups showed a considerable decrease of neutrophil phagocytic activity. Kakuschke (2006) identified a significantly higher haptoglobin (Hp) value in pups prior to release than when admitted. One of the functions of this acute phase protein is the binding of free hemoglobin (Hb). Compared to adults, newborns have higher Hb concentrations and RBC with shorter life-spans of the erythrocytes. The latter causes the increase of Hb concentration and at the same time a need for Hp.1,2,4 Hp, however, is known to inhibit phagocytosis and dampen the acute inflammatory response.5 The higher Hp value of pups in their pre-release blood samples found by Kakuschke could be one reason why the phagocytic activity was reduced. It might also denote a development of the immunocompetence. Further investigations should focus on more in-depth studies of why rehabilitated pups show less phagocytosis and if an increased Hp is the only reason. This study is an important contribution for understanding and assessing the health status of harbor seal pups.
References
1. Andersson M, E Sevelius. 2001. Abnormal microheterogeneity of haptoglobin in serum from dogs with various diseases. Veterinary Record 148(1): 14-17.
2. Begemann M. 1998. Praktische Hämatologie. Klinik, Therapie, Methodik. Thieme Verlag, Stuttgart.
3. Kakuschke A. 2006. Einfluß von Metallen auf das Immunsystem von Meeressäugern. Dissertation at the University of Hamburg.
4. Mahlberg R, Gilles A, A Läsch. 2004. Hämatologie. Theorie und Praxis für medizinische Assistenzberufe. Whiley-VCH Verlag GmbH & Co. KGaA, Weinheim.
5. Rossbacher J, Wagner L, MS Pasternack. 1999. Inhibitory effect of haptoglobin on granulocyte chemotaxis, phagocytosis and bacterial activity. Scandinavian Journal of Immunology, 50: 399-404.