Thromboelastometry assessment of mycophenolate mofetil effect on thrombotic risk in dogs with primary and secondary immune-mediated hemolytic anemia and by Erhlichia canis infection

ABSTRACT This study aimed to identify, by means of thromboelastometry assessment, altered thrombotic risk in dogs with primary and secondary IMHA by E. canis infection after initiating the immunosuppressive therapy with mycophenolate mofetil. The animals’ screening was based on complete blood count (CBC), biochemical and urine tests. Dogs with moderate to severe anemia (hematocrit ≤ 25%) which showed symptoms of immune-mediated hemolysis, such as spherocytosis, positive saline agglutination, bilirubinuria and/or hemoglobinuria, were included. Blood and urine samples were collected at two different moments. The first sample (M1) was collected at the time of diagnosis, when hematocrit was lower or equal to 25% before treatment with mycophenolate mofetil (Accord ®); the second sample (M2) was collected after treatment with mycophenolate mofetil, when hematocrit was greater or equal to 30%. Five out of the twelve animals selected died before the end of the study. No reduction in thrombotic risk was observed in the animals treated with mycophenolate mofetil. The animals that presented hypocoagulation at the time of diagnosis showed the worst prognosis, and their reticulocyte count displayed a better prognostic value than their erythrocytes count at the time of diagnosis.

摘要
本研究旨在通过血栓弹性描记法（thromboelastometry）评估，明确在使用霉酚酸酯（mycophenolate mofetil）启动免疫抑制治疗后，犬埃利希体（E. canis）感染引发的原发性与继发性免疫介导性溶血性贫血（immune-mediated hemolytic anemia，IMHA）患犬的血栓风险变化情况。受试动物的筛选基于全血细胞计数（complete blood count，CBC）、生化检验与尿液检测。纳入符合以下条件的患犬：存在中至重度贫血（血细胞比容≤25%），且表现出免疫介导性溶血症状，如球形红细胞增多症、盐水凝集试验阳性、胆红素尿及/或血红蛋白尿。在两个不同时间点采集血液与尿液样本：首个样本（M1）于确诊时采集，此时患犬在接受霉酚酸酯（Accord®）治疗前的血细胞比容≤25%；第二个样本（M2）于霉酚酸酯治疗后采集，此时患犬血细胞比容≥30%。入选的12只受试动物中，有5只在研究结束前死亡。接受霉酚酸酯治疗的患犬未观察到血栓风险降低的现象。确诊时表现为低凝状态的患犬预后最差，且其确诊时的网织红细胞计数相比红细胞计数具有更优的预后判断价值。