Serum, Immune

a preparation made from animal or human blood and containing antibodies against the causative agents of infectious diseases or the products of the agents’ activity. Immune serum is used in serodiagnosis, seroprophylaxis, and serotherapy. In preparing immune serum, blood serum is taken from animals, human donors, or convalescents that have been immunized by specific antigens against a particular disease. The blood serum is processed in various ways, depending on the type of immune serum and its intended purpose: it is purified to remove neutral substances and isolate the active (chiefly globulin) protein fractions and is then concentrated.

The introduction of immune serum from animal blood into the human body may cause such complications as serum sickness and anaphylactic shock. These complications are almost never caused by concentrated immune serums from human blood, called gamma globulins, or, more precisely, immunoglobulins, since they retain the various globulin fractions. Such concentrated serums are retained in the body longer than other serums.

Immune serums may be therapeutic, prophylactic, or diagnostic. The therapeutic and prophylactic serums are subdivided into antitoxic, antibacterial, and antiviral serums. Antitoxic serums combat the toxic metabolites of microbes; examples are antitetanic, antidiphtheric, and antigangrenous serums. The antitoxic serums also combat the aftereffects of the bites of poisonous snakes and insects. Antibacterial serums, such as antianthrax gamma globulin, combat microorganisms. Antiviral serums contain gamma globulins that provide immunity against measles and influenza; antirabies serum combats the effects of rabies. Diagnostic immune serums are made from different antigens, depending on the nature of the reaction for which they are used. They are used to identify the causative agents of infectious diseases and in experiments.