Frequency of surface immunoglobulin bearing blood lymphocytes in cattle affected with bovine leukosis.

Lymphocytes of the peripheral blood from healthy cows and animals suffering from bovine leukosis (persistent lymphocytosis or leukaemia) were examined for the presence of surface immunoglobulin determinants. Using the immunofluorescence technique an average of 18 per cent of lymphocytes from healthy and 67 per cent from leukotic cows could be recognised as positive. An increase of these positive cells, which are supposed to be B cells or of B cell origin, seems to be a characteristic finding in this disease of cattle.