犬免疫性溶血性貧血之診斷與靜脈注射人類免疫球蛋白治療之評估

Abstract

免疫性溶血性貧血(immune-mediated hemolytic anemia; IMHA)是犬重要免疫性疾病之一。本研究收集27隻IMHA患犬基本資料、病史、臨床症狀、血液檢查、及診斷試驗結果，藉以了解此病在台灣之現況，同時靜脈注射人類免疫球蛋白(human intravenous immunoglobulin， hIVIG)治療患犬，評估此藥之治療效果。本研究結果顯示，中年雌犬為好發族群，瑪爾濟斯犬和西施犬為本研究最多之犬種，患犬在初次就診時最常見的臨床症狀與理學檢查結果為嗜睡、厭食、黏膜蒼白，黃疸或尿色變深。就診時血液學檢查會出現貧血(100%)、白血球增多症(77.8%)、以及血小板減少症(71.4%)，其中再生性貧血比例為55.6% ，非再生性貧血為44.4%。確診試驗最常見為真實自體凝集現象(77.8%)，其次為陽性庫姆氏試驗(66.7%)，與球狀紅血球增多症(19%)。庫姆氏試驗的結果，及出現抗體種類、數目多寡與力價高低對預後並無決定性影響，但陽性患犬治療前後力價高低變化可反應治療效果。本研究中患犬使用hIVIG來治療IMHA 6個月以上存活率達63%，無觀察到明顯副作用，且成功治療之患犬可無須再依靠免疫抑制藥物控制。對治療反應之評估，發現hIVIG治療後第7天到第14天紅血球相Hb、PCV、RBC的上升為預後良好指標，選用同廠牌不同濃度hIVIG製劑來治療並無差異，若在治療後不需要或僅需短期使用免疫抑制劑治療的患犬存活時間較長且比率較高。本研究也發現hIVIG有抑制不當輸血後快速及大量溶血的作用。而病因學、治療前血液檢查結果對預後並無影響。綜合所有之觀察，hIVIG為治療犬IMHA一種良好的選擇。

Immune-mediated hemolytic anemia (IMHA) is an important immunological disease in dogs. 27 IMHA dogs treated with human intravenous immunoglobulin (hIVIG) were included in this study. The signalments, histories, clinical findings, and blood examinations results of 27 IMHA dogs were collected to understand the present situation of canine IMHA in Taiwan, and evaluated the theraprutic effects of hIVIG. In this study, middle-age females had higher risk for IMHA than males. Maltese and Shih-Tzu were the most affected breeds. The most frequently encountered clinical signs and presentions of physical examination included lethargy, anorexia, pale mucus membrane, icterus, and pigmenturia. Blood examinations presented anemia (100%) which 55.6% were regenerative and 44.4% were non-regenerative, leukocytosis (77.8%), and thrombocytopenia (71.4%) at presenting. Diagnosis of IMHA showed 77.8% with true autoagglutination, 66.7% with positive Coombs’ test, and 19% with spherocytosis. The positive result, type of antibody and titers of Coombs’ tests could not indicate good prognosis, but the therapeutic effects were corresponded with the variation of titer. Survival rate during the 6-month observation period was 63%, and no obvious side effects were observed. The IMHA dog with good prognosis showed the increasing of Hb, PCV, and RBC during 7th day to 14th day, and without or in short time with others immunosuppressive agent after hIVIG therapy. Different concentration of same product didn’t affect therapeutic effect. Another important point was also observed, that hIVIG maybe can decrese severe hemolysis after inappropriate blood transfusion. Therefore, intravenous administration of hIVIG may be a good alternative therapy for canine IMHA.