Development of a Standard Methodology for Screening Medical Device Materials for Alternative Pathway Complement Activation
Daniel B. Lyle, Grace S. Bushar and John J. Langone, Molecular Biology Branch, OST/CDRH/Food and Drug Administration, Rockville, MD 20857
Complement is a group of blood proteins that are part of the immune system. Inappropriate activation either by the antibody-dependent "classical" pathway or the antibody-independent "alternative" pathway can have serious adverse health effects. Some medical device materials when in contact with patient blood are known to activate complement by the alternative pathway. Materials being considered for new medical devices need to be tested for alternative-pathway complement activation. This paper describes the development of an inexpensive, rapid, function-based standard methodology for screening materials for alternative pathway complement activation based on rabbit RBC hemolysis. Results are validated by immunoassay for C4d and Bb complement pathway-specific components.