Serological Studies on Iodinated Sera
Authors: Jacobs John 
Published: January 2023

Discussion and Summary
Of 21 pigs sensitized by various methods to Lugol-guinea pig serum preparations, and injected with iodinated sera 6 died in acute anaphylaxis, and 4 more had sublethal but severe and typical symptoms. It appears that these preparations will produce a definitely anaphylactic state in about half of the pigs injected.
Of 8 pigs sensitized to Lugol + horse serum, 7 died in acute anaphylaxis, indicating a much stronger antigenic effect when the iodine was in combination with foreign serum than in combination with guinea pig serum. This experiment demonstrates clearly that strongly antigenic substances, sensitizing specifically to iodinated sera, may be formed by iodination in neutral solutions.
Of 15 pigs sensitized by the same technic to a Lugol-guinea pig serum preparation, 7 were given a shocking injection of iodinated guinea pig serum, and 8 of iodinated horse serum. In contrast to Friedberger and Ito, (3), who were not able to produce shock with mixtures of iodine and foreign serum, no marked difference was noted in this or other experiments in the ability of iodinated guinea pig serum to produce shock as contrasted to iodinated foreign serum, although preparations containing homologous protein are weak sensitizing agents.
Sensitizations in tubercular guinea pigs by Dienes' method resulted in a somewhat greater sensitivity than that produced in normal pigs.
Evidence was obtained which seemed to show, although in a short series of animals, that diiodotyrosine has an inhibitory effect on iodoprotein anaphylaxis. Potassium iodide did not show any relation to this system. These observations are in accord with Wormall's experiments on precipitating systems (5), but are not in harmony with Friedberger's claim (3) that sodium iodide produces anaphylaxis in pigs sensitized to a “mixture” of iodine and guinea pig serum. Dihalogenated tyrosine seems to be the one type of hapten, as yet observed, which is related to iodinated proteins.
The fact that definite sensitizations can be set up with homologous serum iodinated by the addition of Lugol's solution under conditions comparable to those obtaining in iodine antisepsis indicates the possibility that this type of reaction may be present in cases of human iodine idiosyncrasy. Idiosyncrasies to iodine in other forms, such as potassium iodide, cannot at present be brought into the same category, for they fail to shock or to inhibit shock in animals sensitized to iodo-proteins.
On the other hand drug idiosyncrasies may be due to direct sensitization of the type that Bloch and Steiner-Wourlisch (8) produced in guinea pigs with a crystalline substance obtained from extracts of primrose. The success of Landsteiner, Levine and van der Scheer in producing shock, although not regularly, with a dye of known chemical constitution, points in the same direction. Further evidence is necessary before the relative importance of these possibilities can be evaluated.
Further evidence of guinea pig sensitization to Lugol + guinea pig serum preparations is described. A much stronger specific sensitization is produced by Lugol + horse serum preparations. Animals sensitized by these methods are more or less equally susceptible to shock by iodinated guinea pig and iodinated foreign sera. Evidence is presented which indicates that diiodotyrosine, but not ionic iodine, inhibits shock in these anaphylactic systems.