[Pharmacological aspects of immunostimulants]

Immunostimulants are chemical substances capable of increasing the overall activity of a normal immune system as well as normalizing the function of an impaired immune system (immune restauration). This review is concerned with substances of microbial or chemical origin and excludes the so-called physiological inductors or regulators, e.g. thymic factors, interferon etc. During the last decade considerable progress has been achieved with respect to the isolation of effective compounds and the elucidation of their chemical structure. However, the knowledge of their mechanism of action and their effects in the living organism is still poor because of the complexity of the immune system, lack of appropriate standardization methods, lack of internationally agreed test conditions or diseases in intact animals or conditions for controlled clinical trials in man.