ALV-J诱发鸡成红细胞白血病的临床病例分析

2010—2011年检测3批病例,分别来自泰安新泰的110日龄麻鸡、济宁泗水的90日龄麻鸡和济南20日龄蛋雏鸡。病鸡均表现消瘦、精神萎靡、嗜睡、鸡冠稍苍白或发绀等,死亡率分别为20%、12%和18%。剖检,3批病鸡均可见肝脏、脾脏及肾脏严重肿大,胸腺、肌肉、腺胃等组织器官出血。新泰病鸡肝脏和肺脏表面有明显的白色肿瘤结节。血液涂片与骨髓涂片观察发现大量红细胞转变为体积较大,胞质丰富蓝染,胞核大呈圆形、核内有很纤细的染色质、核周围有空泡的成红细胞,以晚幼成红细胞为主;组织学检查发现,在所有组织脏器血管及间质内均可观察到大量聚集的与血涂片中形态相一致的成红细胞,并且可观察到核分裂相,但未见淋巴细胞聚集。通过血液学和组织学观察不仅排除马立克氏病和网状内皮组织增生症,而且排除中毒及代谢性疾病的可能。以肝脏组织DNA为模板,在3批病鸡中利用PCR检测均扩增出J亚群禽白血病病毒(ALV-J)gp85基因924bp的特异性片段,而A亚群禽白血病病毒(ALV-A)、B亚群禽白血病病毒(ALV-B)阴性。免疫组织化学检测结果表明,发病鸡肺脏和脾脏等含血量丰富的组织内发现组织细胞及成红细胞胞质呈ALV-J抗原阳性。根据以上检测结果确定此3批患有成红细胞白血病病鸡均由ALV-J感染引起。ALV-J引起单纯鸡成红细胞白血病在国内为首次发现。ALV-J在我国鸡群中的多潜能致瘤机制需要进一步的研究。

Clinical Cases Analysis of Avian Leukosis Virus Subgroup J Induced Erythroblastosis in Chicken

Erythroblastosis was diagnosed in two flocks of Chinese local breed and one flock of layer chicken during 2010 and 2011.The age of birds was 110-day,90-day and 20-day,respectively.The main symptoms were characterized by emaciation,depressed and lethargy.At necropsy,numerous similar nodular lesions and resembling tumors were observed in one or more tissues.Some organs showed enlargement.A large number of erythrocytoblasts were observed in blood and bone marrow smears.Erythrocytoblasts were larger,basophilic cytoplasm and round nucleus.Histological examination showed that erythrocytoblasts were crowded in both blood vessels and mesenchym.Mitosis of erythrocytoblasts was often seen.No evidences showed Marek’s disease and reticuloendotheliosis,poisoning and metabolic diseases in these sick chickens.The PCR-based diagnosis showed that ALV-J specific fragment of 924 bp was obtained,rather than ALV-A and ALV-B.Immunohistochemistry results showed that a diffuse presence of ALV-J antigen in various tissues.Taken all data together,it demonstrated that erythroblastosis in the three flocks was induced by ALV-J.Erythroblastosis induced by ALV-J was found first time in China flocks.The etiology and mechanism of tumor spectrum expanded of ALV-J need to be further studied.