Inflammation and injury influence plasma proteins and immunoglobulins. They respond to noxious agents by a rise of c-reactive protein (CRP), orosomucoid, fibrinogen, haptaglobulin, alpha-1 antitrypsin, ceruloplasmin, C 3 and C 4 components of complement. The rate of rise and return to normal values varies. CRP reacts most'promptly. The following substances react by a decline of the levels: albumin, prealbumin, transferrin, alpha-1 lipoprotein and immunoglobulins. Investigation of the patient's immunological state is of prognostic value. CRP, orosomucoid, albumin and prealbumin are considered the most valuable indicators; from their values the so-called PINI index can be calculated and the patients can be divided into five prognostic zones. To threatened patients all-round care must be devoted incl. aimed provision of ATB and immunoprotective substances.