HAEMORRHAGIC REACTIONS ELICITED AT SITES OF PASSIVE CUTANEOUS ANAPHYLAXIS BY INTRAVENOUS INJECTION OF AGGREGATED GAMMA-GLOBULIN

Abstract

In guinea pigs injected intradermally with a small amount of antibody and challenged 2 hrs. later by the intravenous route with a mixture of homologous antigen and aggregated gamma-globulin, hemorrhagic reactions of the Arthus type develop at the sites of intradermal sensitization. This effect was obtained with gamma-globulins of different species (human, rabbit and horse) by using different techniques for aggregation (heat, mercaptoethanol-urea and bis-diazo-benzidine) and was always correlated with the ability of the aggregated globulin to fix complement. Fluorescein labelled aggregates of gamma-globulin were detectable in the wall of vessels at sensitized sites. In experiments with guinea pig antibodies, the localizing effect was observed only with gammai, whereas the gamma2, Arthus-producing fraction was completely ineffective. Histamine and hista-mine liberators are not sufficient for eliciting the effect obtained with sensitizing antibody plus homologous antigen. Other effects occurring at the site of specific sensitization may also be responsible for the phenomenon.