Skin-sensitizing antibody titer: III. Relationship of the skin-sensitizing antibody titer to the intracutaneous skin test, to the tolerance of injections of antigens, and to the effects of prolonged treatment with antigen

Abstract

1. 1. The intracutaneous skin test tends to vary directly with the skin-sensitizing antibody titer. However, individual variations are so great that titer cannot be determined from the skin test. 2. 2. The doses of aqueous ragweed extract tolerated by patients vary inversely with the skin-sensitizing antibody titer. 3. 3. Development of blocking antibody increases the tolerance for injected extracts. 4. 4. Patients with high titers of skin-sensitizing antibody are more likely to have constitutional reactions to emulsions of ragweed pollen extract even with lower doses of antigen. The titer of skin-sensitizing antibody is a helpful guide in determining the dose of emulsified pollen extract to be used. 5. 5. Prolonged treatment with injections of aqueous ragweed extract is accompanied by a decrease in the titer of skin-sensitizing antibody. This decrease is greatest between the first and fifth year of treatment but continues up to 20 years. Comparative studies of untreated patients and of patients who, after 1 or 2 years of treatment, were untreated for an average of 9 years suggest that this decrease in titer of skin-sensitizing antibody results directly from the treatment and not from the increasing age of the patient or duration of hay fever.