Alum-ragweed precipitate: Preparation and clinical investigation: Preliminary report

Abstract

1. 1. Alum-ragweed precipitate is an alum-modified ragweed extract. The method of its preparation is described. 2. 2. Alum-ragweed precipitate is an effective antigen for sensitizing guinea pigs to ragweed, which confirms the work of previous authors. 3. 3. Local and systemic reactions from intracutaneous and subcutaneous injections of alum-ragweed precipitate in ragweed sensitive patients are similar to those produced by equal protein nitrogen concentrations of aqueous ragweed extracts. 4. 4. A slight delay in the absorption of the active pollen fractions of alum-ragweed precipitate as compared to aqueous ragweed extracts, was noted following subcutaneous injections in a series of normal adults. 5. 5. The preseasonal treatment of a series of 24 ragweed sensitive patients with alum-ragweed precipitate is reported. 6. 6. The active ragweed components of alum-ragweed precipitate are apparently identical to those of aqueous ragweed extract. 7. 7. Further investigations are indicated, particularly: (a) variations in the chemical preparation of alum-ragweed precipitate, using greater concentrations of alum than 1 per cent; (b) variations in the methods of therapeutic administration.