Bovine leukocyte adhesion deficiency in Holstein cattle.

Two Holstein heifers with persistent and recurrent infections including ulcerative gingivitis, periodontitis, pneumonia, loss of teeth and stunted growth associated with marked neutrophilia were evaluated clinically and for neutrophil function, CD18 expression on neutrophils and CD18 genotype analysis by DNA-polymerase chain reaction (PCR) test. Adherence to nylon fibers and phagocytic activity of neutrophils from affected animals were significantly (p < 0.05) impaired as compared with those of controls. Neutrophils from affected heifers had decreased chemiluminescent (CL) responses when stimulated with opsonized zymosan, compared with those of controls. In contrast, neutrophils from affected heifers produced increased CL responses when stimulated with latex beads and phorbol myristate acetate compared with those of controls. The clinical findings, functional leukocyte abnormalities, deficiency in expression of CD18 on neutrophils, and the D128G mutation detected by DNA-PCR testing of affected heifers demonstrated that these heifers have bovine leukocyte adhesion deficiency (BLAD). Although both animals were confirmed to be homozygotes for BLAD by DNA-PCR test, they had differences in clinical, hematological and neutrophil functional characteristics.