title: Detection of colostrum-derived alloantibodies in calves with bovine neonatal pancytopenia.
abstract: Bovine neonatal pancytopenia (BNP) is an emerging calf disease of unknown cause characterized by a pronounced susceptibility to bleeding as a result of a pancytopenia and bone marrow depletion. In this study we investigated whether this phenomenon is related to colostrum-derived alloantibodies directed against neonatal leukocytes. In a first experiment and using a flow cytometric approach sera from 6 BNP-dams (had given birth to BNP-calves; vaccinated against bovine viral diarrhea virus [BVDV]) and 6 control-dams (no herd history of BNP; no BVDV vaccination) were analyzed for the presences of alloantibodies (IgG) able to bind to the surface of leukocytes isolated from 7 calves from a herd with no history of BNP (no BVDV vaccination). In a second experiment, 4 neonates from 3 BNP-dams were fed colostrum from their corresponding mothers and sampled on a regular basis from birth up to day 21 of life under clinically controlled conditions. Sample analysis of the 4 neonates included hematology (white blood cell count and platelets), bone marrow cytology and histopathology as well as the flow cytometric detection of the percentage of IgG+-lymphocytes/monocytes in the peripheral blood. Experiment #1 showed that all BNP-dam sera harbored significantly higher alloantibody titers than the control dam sera (p<0.001). In the peripheral blood of the two neonates (Experiment #2), the percentage of IgG+-cells increased dramatically within 12h post colostrum intake (p.c.i.), remaining at over 95% for up to 3 days. Both calves developed BNP-associated clinical symptoms, one died. Both twin calves showed no clinical symptoms accompanied by a minor increase of IgG+ cells for up to 12h. Thus, the level of IgG+-cells and the duration of the detection thereof correlated with the severity of BNP developed by these animals. The results show that BNP-dams harbor alloantibodies against surface antigens of neonatal leukocytes in their sera that are readily transferred to the offspring via colostrum. These alloantibodies probably play a crucial role in the pathogenesis of BNP.
authors.affiliation: Institute for Hygiene and Infectious Diseases of Animals, Justus-Liebig University, Frankfurter Strasse 85-89, 35392 Giessen, Germany.
authors.forename: Philip Simon
authors.initials: PS
authors.lastname: Bridger
authors.forename: Rolf
authors.initials: R
authors.lastname: Bauerfeind
authors.forename: Lisa
authors.initials: L
authors.lastname: Wenzel
authors.forename: Natali
authors.initials: N
authors.lastname: Bauer
authors.forename: Christian
authors.initials: C
authors.lastname: Menge
authors.forename: Heinz-Jürgen
authors.initials: HJ
authors.lastname: Thiel
authors.forename: Manfred
authors.initials: M
authors.lastname: Reinacher
authors.forename: Klaus
authors.initials: K
authors.lastname: Doll
mesh_terms: D000818:Animals; D000831:Animals, Newborn / Q000276:immunology; D002417:Cattle / Q000276:immunology; D002418:Cattle Diseases / Q000276:immunology*; D003126:Colostrum / Q000276:immunology*; D005260:Female; D005434:Flow Cytometry / Q000662:veterinary; D007074:Immunoglobulin G / Q000276:immunology; D007518:Isoantibodies / Q000276:immunology*; D007958:Leukocyte Count / Q000662:veterinary; D007962:Leukocytes / Q000276:immunology; D010198:Pancytopenia / Q000276:immunology / Q000662:veterinary*; D010976:Platelet Count / Q000662:veterinary; D011247:Pregnancy
chemical_list: D007074:Immunoglobulin G; D007518:Isoantibodies