Serum protein profiles, circulating immune complexes and proteinuria in dogs naturally infected with Anaplasma phagocytophilum

- Immune mediated mechanisms in Anaplasma phagocytophilum infection in dogs were evaluated.
- Correlations between thrombocytopenia and serum protein profile alterations were found.
- Dogs with higher circulating immune complexes concentrations had lower platelets and higher gammaglobulins.
- A correlation is suggested between high CIC concentration and the presence of proteinuria.

Alterations in serum protein profile, presence of circulating immune complexes (CIC) and proteinuria were investigated in a large group of dogs naturally infected with the Anaplasma phagocytophilum bacterium. Our aim was to evaluate the presence of hypergammaglobulinaemia, CIC and proteinuria as a possible result of an immune-mediated disease following infection by or exposure to A. phagocytophilum. Dogs were divided into three groups - IFA positive (188 dogs with confirmed exposure to A. phagocytophilum), PCR positive (31 dogs with confirmed infection), and control (IFA and PCR negative) (19 dogs). Serum and urine protein patterns were determined by electrophoresis and CIC concentrations by absorbance nephelometry. No significant differences in hypergammaglobulinaemia were observed between the different groups, as shown by the presence of acute phase proteins α2 and β1-2 globulins. CIC concentrations in the IFA and PCR positive groups were, on average, higher than in controls by 151.3 μg/ml, though the differences were not significant. The proportion of dogs with proteinuria did not differ significantly between groups. Our results confirm the assumption that anaplasmosis in dogs is most probably a disease with an acute course, with a good prognosis under the right treatment.