Development, validation and use of ELISA for antibodies to human alpha-1 antitrypsin.

ABSTRACT

Evaluation of human antibody responses to alpha-1 antitrypsin (AAT) in clinical trials and clinical practice has been limited by the lack of a validated assay. Here we describe the development and validation of an ELISA method for quantification of human and nonhuman primate antibody responses to human AAT. A reference anti-human AAT serum standard was generated using sera from a cynomolgus macaque injected with a recombinant adeno-associated virus vector expressing human AAT. The ELISA was validated for use with human serum dilutions as low as 110 and was able to distinguish between specific responses in cynomolgus serum and non-specific increases in apparent antibody titer in serum from subjects in a clinical trial of an AAT gene therapy vector.