Red cell-reactive non-specific immunoglobulins and autoantibodies in the sera of normal and anaemic dogs.
The levels of red blood cell (RBC) membrane-reactive IgG were measured in sera from normal and anaemic dogs using an enzyme-linked immunosorbent assay with erythrocyte ghosts as the target antigen (g-ELISA). The anaemic dogs were classified as cases of primary autoimmune haemolytic anaemia (AIHA), other anaemias with elevated levels of RBC-bound immunoglobulin detected by a direct enzyme-linked antiglobulin test (DELAT), or DELAT-negative anaemias. The g-ELISA detected IgG capable of binding RBC membranes in all the serum samples tested, and the levels were significantly higher (P < 0.05) in dogs with AIHA than in cases of DELAT-negative anaemia or in healthy animals. When sera were preabsorbed with RBC ghosts, g-ELISA readings were reduced in two of three AIHA cases that were tested, but not in dogs from any other group. There was no correlation between g-ELISA results and serum IgG levels in the cases of AIHA, but there was a significant relationship (rs = 0.74, P < 0.001) between these parameters in the dogs with other DELAT-positive anaemias. When spectrin(s) from the internal RBC membrane skeleton was used as the target antigen in the s-ELISA, sera from all groups of anaemic dogs yielded a wide range of values. Although the levels of spectrin-reactive IgG were significantly higher (P < 0.05) in AIHA cases than normal dogs, suggesting that haemolysis provoked production of anti-membrane skeleton antibodies, the highest reading was recorded in a healthy animal. It is concluded that all canine sera contain IgG non-specifically reactive with RBC membranes and that serum antibodies against the erythrocyte surface can also be detected in some dogs with primary AIHA. Distinct spectrin-reactive serum IgG antibodies can also be demonstrated in normal and AIHA positive dogs.
Barker
R N
RN
Department of pathology and microbiology, University of Bristol, UK.
Elson
C J
CJ
D000744:Anemia, Hemolytic, Autoimmune / Q000276:immunology / Q000662:veterinary*; D000818:Animals; D001323:Autoantibodies / Q000276:immunology*; D004283:Dog Diseases / Q000276:immunology*; D004285:Dogs / Q000276:immunology*; D004591:Electrophoresis, Polyacrylamide Gel; D004797:Enzyme-Linked Immunosorbent Assay / Q000662:veterinary; D004910:Erythrocyte Membrane / Q000276:immunology*; D004912:Erythrocytes / Q000276:immunology; D007074:Immunoglobulin G / Q000276:immunology*; D013049:Spectrin / Q000276:immunology
D001323:Autoantibodies; D007074:Immunoglobulin G; D013049:Spectrin