Clinical data, clinicopathologic findings and outcome in dogs with amegakaryocytic thrombocytopenia and primary immune-mediated thrombocytopenia.

OBJECTIVES: The aim of this study was to identify distinguishing characteristics between dogs diagnosed with amegakaryocytic thrombocytopenia and those diagnosed with presumed primary peripheral immune-mediated thrombocytopenia. Presenting clinical and clinicopathologic data and outcomes were compared between the two groups. METHODS: Retrospective study performed on seven client-owned dogs diagnosed with amegakaryocytic thrombocytopenia and 34 client-owned dogs with primary peripheral immune-mediated thrombocytopenia. RESULTS: All dogs in the amegakaryocytic thrombocytopenia group were anaemic on presentation with a median haematocrit of 23% (range 9·4 to 36), while the primary peripheral immune-mediated thrombocytopoenia group had a median presenting haematocrit of 35% (range 10 to 53). Dogs with amegakaryocytic thrombocytopenia had a median of five (range 4 to 7) clinical signs of bleeding compared to a median of three (range 0 to 6) in the primary peripheral immune-mediated thrombocytopenia group with 86% (6 of 7) of amegakaryocytic thrombocytopenia dogs requiring a blood transfusion compared to 41% (14 of 34) of primary peripheral immune-mediated thrombocytopenia dogs. Six of the seven amegakaryocytic thrombocytopenia dogs did not survive to discharge, while only five of the 34 primary peripheral immune-mediated thrombocytopenia dogs did not survive to discharge. CLINICAL SIGNIFICANCE: The clinical presentation of dogs with amegakaryocytic thrombocytopenia and primary peripheral immune-mediated thrombocytopenia is similar, but dogs with amegakaryocytic thrombocytopenia had a more severe clinical course compared to primary peripheral immune-mediated thrombocytopenia dogs. The prognosis for dogs with amegakaryocytic thrombocytopenia is poor.

A prospective randomized clinical trial of vincristine versus human intravenous immunoglobulin for acute adjunctive management of presumptive primary immune-mediated thrombocytopenia in dogs.

BACKGROUND: Dogs with immune-mediated thrombocytopenia (ITP) are at risk of hemorrhage when platelet count is <50,000/µL. Treatment with vincristine (VINC) or human intravenous immunoglobulin (hIVIG) decreases platelet recovery time compared with treatment with corticosteroids alone. OBJECTIVES: To compare the effect of hIVIG versus VINC on platelet recovery in dogs with ITP. METHODS: Prospective, randomized study. Twenty dogs with idiopathic ITP (platelet count <16,000/µL) were enrolled. All dogs were treated with corticosteroids. Dogs were randomly assigned to receive a single dose of hIVIG (0.5 g/kg) or VINC (0.02 mg/kg). Outcome measures were platelet recovery time, duration of hospitalization, and survival to discharge. RESULTS: There was no significant difference in age, sex, weight, or initial platelet count between dogs treated with hIVIG (n = 10) and dogs treated with VINC (n = 10). Median platelet recovery time for both groups was 2.5 days (P = .51). Median hospitalization time for all dogs that survived to discharge was 4 days and not different between groups (P = .29). Seven of 10 dogs in the hIVIG group and 10 of 10 in the VINC group survived to discharge. Survival analysis did not identify any significant difference between the groups at discharge, 6 months, and 1 year after entry into the study. No adverse effects were reported in either group. CONCLUSIONS AND CLINICAL IMPORTANCE: Vincristine should be the first-line adjunctive treatment for the acute management of canine ITP because of lower cost and ease of administration compared with human intravenous immunoglobulin (hIVIG).

Idiopathic immune-mediated thrombocytopenia and recent vaccination in dogs.

BACKGROUND: Vaccination is often cited as a potential cause of immune-mediated thrombocytopenia (ITP) in dogs. Although an association has been documented in humans, particularly in children, this relationship has not been definitively established in dogs. OBJECTIVES: To identify the presence of an association between recent vaccination and ITP in dogs. ANIMALS: Forty-eight client-owned dogs with presumptive idiopathic ITP and 96 age-matched, client-owned dogs with non-immune-mediated disease. METHODS: Retrospective, case-control study. Dogs were identified through the Veterinary Medical Database (VMDB) and Hospital Information System at Purdue University. RESULTS: The median age at presentation for dogs with ITP was 7 years (range: 2-15 years). The majority of the ITP group was comprised of mixed breed dogs (38%); no pure breed was represented by more than 3 cases. The number of dogs that were vaccinated within 42 days of diagnosis of ITP did not differ significantly (P = .361) between cases of presumptive ITP (4/48, 8%) and the control group (13/96, 14%). CONCLUSIONS AND CLINICAL IMPORTANCE: This study failed to confirm the presence of an association between presumptive idiopathic ITP in dogs and recent vaccination; however, the possibility of an association cannot be completely ruled out based on the small sample populations and requires further investigation.

Kinetic studies on insoluble cellulose-cellulase system.

Enzymatic hydrolysis of insoluble amorphous cellulose by Trichoderma viride cellulase was investigated in a batch reactor at several substrate concentrations and three enzyme levels. The reactions were carried out at 50 degrees C and pH 4.8. Enzyme was rapidly adsorbed onto solids on contact, then gradually returned to the liquid phase as the reaction proceeded. A kinetic model that considered the fast adsorption which was followed by the slow reaction, and subsequent product inhibition was developed to interpret the experimental observations. The resulting equation successfully correlated the data for up to 70% conversion. The methods for determining the kinetic parameters are discussed.