Peripheral B lymphocyte percentage as an indicator of subclinical progression of bovine leukemia virus infection.
The relationship between percentage of B cells in peripheral blood and subclinical bovine leukemia virus infection was examined in a herd of 240 Holstein-Friesian cows. Absolute leukocyte count and absolute lymphocyte count were significantly positively correlated with B cell percentage in cows that were seropositive to bovine leukemia virus envelope glycoprotein, but these parameters were not correlated in seronegative cows. The B cell percentage was not affected by age. Cows that had persistent lymphocytosis and hematologically normal seropositive cows had greater mean B cell percentages (78 and 45%, respectively) than did seronegative herdmates (37%). To evaluate B cell percentage as a means of detecting subclinical progression of bovine leukemia virus infection, an index was developed based upon the distribution of B cell percentages in seronegative cows. When this index was compared with a standard hematological key (the European Community's Leukosis Key), which is based on absolute lymphocyte count and age, 29% of seropositive, hematologically normal cows had B cell percentages two standard deviations above the mean of their seronegative herdmates. The B cell percentage was thus shown to be more effective than absolute lymphocyte count for detecting subclinical progression of bovine leukemia virus infection in individual cows.
Lewin
H A
HA
Department of Animal Sciences, University of Illinois, Urbana 61801.
Wu
M C
MC
Nolan
T J
TJ
Stewart
J A
JA
D000818:Animals; D000914:Antibodies, Viral / Q000032:analysis; D001402:B-Lymphocytes; D002417:Cattle; D002418:Cattle Diseases / Q000097:blood* / Q000276:immunology / Q000382:microbiology; D005260:Female; D007938:Leukemia / Q000097:blood / Q000276:immunology / Q000662:veterinary*; D001909:Leukemia Virus, Bovine / Q000276:immunology; D007958:Leukocyte Count / Q000662:veterinary
D000914:Antibodies, Viral