Anti-insulin antibodies in diabetic dogs before and after treatment with different insulin preparations.
BACKGROUND
Anti-insulin antibodies (AIA) occur in diabetic dogs after insulin therapy, although their clinical significance is unclear.


OBJECTIVE
Treatment of diabetic dogs with heterologous insulin is more likely to stimulate production of AIA than is treatment with homologous insulin.


METHODS
Diabetic dogs sampled before insulin therapy (n = 40), diabetic dogs sampled following treatment with porcine (homologous) insulin (n = 100), bovine (heterologous) lente insulin (n = 100), or bovine protamine zinc (PZI) insulin (n = 20), and nondiabetic control dogs (n = 120).


METHODS
Prospective observational study. Sera were analyzed by ELISA for antibodies against porcine insulin, bovine insulin, insulin A, B, or C peptides, and control antigens; canine distemper virus (CDV) and canine thyroglobulin (TG). Canine isotype-specific antibodies were used to determine total and anti-insulin IgG1 : IgG2 ratios.


RESULTS
There was no difference in CDV or TG reactivity among the groups. AIA were detected in 5 of 40 newly diagnosed (untreated) diabetic dogs. There was no significant difference in AIA (ELISA optical density reactivity) comparing control and porcine insulin-treated diabetic dogs (P > .05). Anti-insulin reactivity was most prevalent in bovine PZI insulin-treated dogs (90%; P < .01), and bovine lente insulin-treated dogs (56%; P < .01). AIA induced by treatment were enriched for the IgG1 isotype.


CONCLUSIONS
This study indicates that bovine insulin is more immunogenic than porcine insulin when used for treatment of diabetic dogs.
Davison
L J
LJ
Department of Pathology and Infectious Diseases, Royal Veterinary College, London, UK. lucy.davison@cimr.cam.ac.uk
Walding
B
B
Herrtage
M E
ME
Catchpole
B
B
D000818:Animals; D000906:Antibodies / Q000276:immunology*; D002417:Cattle; D003920:Diabetes Mellitus / Q000188:drug therapy / Q000276:immunology / Q000662:veterinary*; D004283:Dog Diseases / Q000188:drug therapy* / Q000276:immunology; D004285:Dogs; D004334:Drug Administration Schedule; D005260:Female; D007004:Hypoglycemic Agents / Q000008:administration & dosage / Q000276:immunology / Q000627:therapeutic use; D007328:Insulin / Q000008:administration & dosage / Q000276:immunology* / Q000627:therapeutic use*; D008297:Male; D013552:Swine
D000906:Antibodies; D007004:Hypoglycemic Agents; D007328:Insulin