Clinical Analysis On Erythroblastosis And Lymphocytic Leukosis Induced By ALV-J In Chicken

ALV-J(Avian Leukosis Virus Subgroup J, ALV-J), is a subtype of avian leukosis virus. It is a member of the family Retroviridae, genus Alpharetrovirus and was first isolated from the meat-type chickens by Payne, a British scholar, in 1989, its prototype strain is HPRS-103. Avian leukosis virus can cause a variety of tumors, including myeloid leukosis, hemangioma,lymphocytic leukosis, erythroblastosis,myeloblastosis, but the most common is myeloid leukosis. There is no phenomenon that lymphocytic leukosis and erythroblastosis caused by ALV-J simultaneously. This paper described a case that lymphocytic leukosis and erythroblastosis was induced by ALV-J.Lymphocytic leukosis is the most common type of clinical tumor. It is a type tumor that bursa lymphoid follicle cells(B cells) cancerate, hyperplasia and metastasis to the liver, spleen and other organs through blood. Erythroblastosis is a type of tumor that erythrocytes(pronormoblast) of the bone marrow cancerate. These two tumors induced by ALV-J in clinical is rare.Our laboratory detects a case of three 220-day-old hens from the farm of Shandong in August 2015. Chickens showed anorexia, weight loss, listlessness, lethargy and drop in egg production, comb slightly pale or cyanosis, the mortality rate of over 10%. Through laboratory testing of autopsy found that serious spleen and kidney enlarge, nipple glandular swell, adhesions disappear, chickens ovary, liver and lung surface have obvious white tumor nodules. Lymphocyte infiltration of liver and erythroblastosis of its blood vessels, and observation of mitotic figures in liver, lymphocyte infiltration and erythroblastosis of ovarian, lung and marrow, erythroblastosis of kidney were revealed by histological examination. By gross necropsy and histological observations, not only exclude reticuloendothelial hyperplasia, Marek's disease, but also exclude the possibility of toxic diseases and metabolic diseases. In liver DNA as a template, with avian leukosis virus subgroup J primers, the target band that is gp85 gene of 924 bp were amplified by PCR, but REV and MDV were negative.Indirect immunofluorescence assay confirmed the presence of ALV-J. Nucleotide sequence analysis showed that the genetic relationship of the strains approachs the British prototype strains HPRS103, up to its homology(97.8%-98.2%). Based on the above test results to determine the chickens suffer from erythroblastosis and lymphocytic leukosis, and infections caused by ALV-J. However, erythroblastosis and lymphocytic leukosis caused by ALV-J in chickens is not reported in our country, this paper identified ALV-J induce lymphocytic leukosis and erythroblastosis for the first time, so the pluripotent tumorigenic mechanism of ALV-J needs further study in our country.