Shwartzman Phenomenon

The Shwartzman phenomenon (Schwartzmann) was discovered in 1928 by the American scientist Shwartzman and consists of the fact that if a small dose of a broth or agar bacterial filtrate (typhoid bacteria, Escherichia coli, meningococcus, etc.) is injected into the skin of a rabbit, and 24–36 hours later the same filtrate is injected into a vein, then after 1–2 hours a sharply defined hemorrhagic reaction appears at the site of the skin injection, which progresses to necrosis. Healing of the necrotic areas occurs in 8–10 days. Reproduction of the Shwartzman phenomenon is possible not only in the skin but also in other organs. Not all rabbits are sensitive to the phenomenon. Shwartzman obtained a positive phenomenon in 75–80% of cases; the Shwartzman phenomenon is non-specific. According to Shwartzman, specific immune sera are capable of neutralizing the Shwartzman reaction. The serum can be administered to the animal mixed with the bacterial filtrate, either during the preparatory intradermal injection or during the provocative intravenous injection. The latter method yields more consistent results. However, in verification experiments, neutralization of the reaction by specific immune sera is observed only in isolated cases (Roginskaya). The hemorrhagic reaction obtained by the above-described method is, in Shwartzman's opinion, the result of the combined synergistic action of the preparatory and toxic factors of the filtrate. The preparatory factors induce a state of sensitization to toxic substances that are not capable of damaging tissue under conditions of normal resistance. Shwartzman denies the anaphylactic nature of his reaction for the following reasons: 1) not every antigen produces the reaction, and, for example, horse serum (the antigen of classical anaphylaxis) does not produce the reaction; 2) the reaction is non-specific; 3) the interval between the preparatory and provocative injections is significantly shorter than in anaphylaxis; 4) in contrast to anaphylaxis, the Shwartzman phenomenon is not passively transferable; and finally, 5) the skin-preparatory and provocative factors can be neutralized by specific serum. Gratia explains the Shwartzman phenomenon differently. Gratia considers the Shwartzman phenomenon to be allergic. In support of this, Gratia states the following: 1) capillary stasis, a drop in blood pressure, thrombocytopenia, and non-coagulability of the blood (restorable by CO₂) are observed in animals during the Shwartzman phenomenon, just as in classical anaphylaxis; 2) rabbits and guinea pigs, animals capable of producing an anaphylactic reaction, also produce the Shwartzman reaction; rats and mice, which are not capable of anaphylactic reactions, do not produce the Shwartzman reaction. Gratia refutes Shwartzman's interpretation, considering the hypothesis of synergistic action to be unlikely for the following reasons: 1) the disproportion between the small dose that is sufficient to inject into a prepared animal to cause a hemorrhagic reaction and the relatively huge doses that unprepared animals tolerate well; 2) a secondary injection made into the prepared area is not active. Gratia investigated the Shwartzman phenomenon in animals infected with smallpox, anthrax, sarcomatous animals, and others. His experiments on rabbits infected with smallpox are particularly demonstrative. Intravenous administration of a filtrate of Escherichia coli cultures caused a sharp hemorrhagic reaction in such rabbits, followed by necrosis of the smallpox pustules. Based on these experiments, Gratia believes that hemorrhagic forms of smallpox in humans should be explained by the same mechanism as the experimental Shwartzman phenomenon. Gratia proposes the same explanation for hemorrhagic reactions observed in humans during other infectious diseases. Thus, the Shwartzman phenomenon, despite the fact that its mechanism is not yet sufficiently clear, already allows us at the present time to approach the pathogenesis of hemorrhagic reactions in the diseased organism from a new point of view.