• Open Access

Anti-Insulin Antibodies in Diabetic Dogs Before and After Treatment with Different Insulin Preparations

Authors


  • The preliminary findings of this study were presented in abstract form as a Free Communication at the European College of Veterinary Internal Medicine Annual Forum, Munich, September 2002.

Corresponding author: Lucy J. Davison, MA, VetMB, PhD, DSAM, DipECVIM-CA, MRCVS, Wellcome Trust IntermediateClinical Fellow, Juvenile Diabetes Research Foundation/Wellcome Trust Diabetes and Inflammation Laboratory, Cambridge Institute for Medical Research, WT/MRC Building, Addenbrooke's Hospital, Hills Road, Cambridge CB2 0XY, Cambridge, UK; e-mail: lucy.davison@cimr.cam.ac.uk.

Abstract

Background: Anti-insulin antibodies (AIA) occur in diabetic dogs after insulin therapy, although their clinical significance is unclear.

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

Animals: 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 and Clinical Importance: This study indicates that bovine insulin is more immunogenic than porcine insulin when used for treatment of diabetic dogs.

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