CLINICAL AND CLINICO-PATHOLOGICAL ALTERATIONS MAY HELP IN THE DIAGNOSIS OF PRIMARY AND SECONDARY IMMUNE-MEDIATED THROMBOCYTOPENIA?

Background: Immune-mediated thrombocytopenia (IMT) is a disease with a complex etiology in which antibodies bind to the platelets’ surface causing premature destruction by mononuclear phagocyte system. IMT may be primary (ITP, idiopathic thrombocytopenia) or secondary (IMTs) due to bacterial, viral, protozoal or helminth infection, neoplasm or drug administration. Objectives: To evaluate the main clinical and pathological findings in dogs affected by IMT and compare the data between the two groups of IMT (ITP vs IMTs). Materials and methods: Fifty-five dogs affected by IMT referred to the Veterinary Teaching Hospital in the period between May 2010 and December 2017 were included (29 ITP and 26 IMTs). For each case, signalment, history, clinical and clinico-pathological findings were collected including complete blood count, serum biochemical profile, coagulation profile, cytology of bone marrow, serology. Data were assessed statistically by Chi square or Fisher test. Results: The study confirmed that Cocker Spaniel breed is predisposed to development of IMT (p <0.0001) and that the presence of petechiae is observed in subjects with a platelet value below 20,000/μL (p = 0.0196). The results showed no statistically significant difference between alterations observed in the two groups except for the remarkable presence of normal leukogram in subjects affected by ITP compared to those affected by IMTs (P= 0.031). Conclusions: This study confirms that clinical or clinicopathological alterations cannot distinguish ITP from IMTs. The ITP diagnosis is based on ruling out secondary causes of IMTs.