STUDIES OF THE PELGER-HUET ANOMALY IN FOXHOUNDS

Abstract

An inbred family of foxhounds with 4 members expressing the Pelger-Huet (P-H) anomaly is described. The disease-free status of all P-H affected dogs suggests a benign disorder, although review of breeding records indicated a lower percentage of pups weaned (63%) by P-H females compared with the percentage of pups weaned (81%) by outcrossed females throughout the foxhound colony. Light microscopic examination of blood films from affected dogs revealed 50-67% neutrophils with round, oval or bean-shaped nuclei and rarely (0.5%) segmented nuclei. Neutrophils examined by EM showed the nuclei to have a fine nuclear cleft and condensed chromatin and the cytoplasm to have mature heterochromatic granulation. Local P-H neutrophil mobilization through a standard skin abrasion into a chamber containing autologous serum was impaired at all time periods evaluated (1, 4, 8 and 24 h) compared with the neutrophil mobilization by normal dogs. Antibody response to sheep erythrocyte immunization was also impaired. In vitro reactivity of normal and P-H lymphocytes stimulated by pokeweed mitogen was depressed when lymphocytes were cultured in plasma from a P-H dog but not when cultured in plasma from a normal dog. Vigorous blastogenic responses to phytohemagglutinin by normal and P-H lymphocytes cultured in P-H or normal plasma suggest the presence of a factor(s) in the P-H plasma which interferes with B[bone marrow-derived]-lymphocyte reactivity.