Bovine insulin immunogenicity

Human insulin (humulin) is prepared by recombinant DNA technology or is synthesized from porcine insulin (enzymatic replacement of the terminal arginine with threonine). Human insulin is preferred to insulin prepared from animals because it is less antigenic. Porcine insulin differs from human insulin by one amino acid (terminal arginine). Bovine insulin is the most immunogenic preparation. A typical dosing... 

Human insulin is less immunogenic than bovine, but not porcine, insulin. When changing from animal to human insulin, patients taking <100 units of animal insulin are likely to require 10% less human insulin, and if taking >100 units animal insulin, 25% less human insulin. 

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