Separation of Anti-inflammatory and Immunosuppressive Activities in Heterologous Antilymphocyte Serum

HETEROLOGOUS antilymphocyte serum (ALS) has both anti-inflammatory and immunosuppressive properties 1 . Although ALS significantly suppresses graft rejection, its suppression of humoral antibody formation is more variable and often less effective 2 . Because non-immunosuppressive anti-inflammatory agents can delay graft rejection 3,4 , it seemed important to determine if ALS delays graft rejection by primarily anti-inflammatory or immunosuppressive, or a combination of both mechanisms. In addition, an analysis of methods by which these activities may be separately induced should provide insight into the mechanism of action and specificity of the antisera.