Clinical and Immunoiogical Studies Following Immunotherapy with Aqueous and Alum Precipitated Ragweed Fraction A

Abstract

Fraction A contains all of the major antigens and allergenic properties of whole ragweed extract, but lacks the yellow pigment and some low molecular weight substances. In a double blind study, the clinical and immunoiogical responses were observed following administration of aqueous and alum precipitated extracts of fraction A to 21 previously nonimmunized ragweed sensitive patients. Both preparations of fraction A were clinically effective. The reactions which occurred after the alum and aqueous extract injections were similar in incidence and character. The immunoiogical response following both extracts was also quite similar. In the majority of patients, serum total IgE levels rose, both as the result of immunotherapy and seasonal exposure. Ragweed radioallergosorbent (RAST) antibody levels, a measure of reagin, dropped in two thirds of the patients following therapy and remained unchanged in all patients during inhalant pollen exposure. Hemagglutinating antibody titers generally rose. Aqueous and alum precipitated fraction A extracts were clinically and immunologically effective. However, further studies are needed to establish any advantage of fraction A over present whole ragweed extract preparations.

Relationship of Immunotherapy, Seasonal Pollen Exposure and Clinical Response to Serum Concentrations of Total IgE and Ragweed-Specific IgE

“…The discrepancy in changes in IgE antibodies and total serum IgE, parti cularly as a result of seasonal exposure confirms our earlier studies [13]. To date the reason for this discordance is not clear.…”

“…The effect of seasonal exposure to ragweed pollen upon these parameters is shown in table V. Three groups of patients are compared: (1) 18 patients with ragweed pollenosis who did not receive specific injection therapy; (2) 43 patients treated during 1972, and (3) 21 patients treated with high doses of ragweed fraction A during 1971 [13]. Untreated patients generally had a rise in both parameters concomitant with seasonal exposure.…”

“…The third group of patients was treated in 1971 with high doses of ragweed fraction A, a ragweed preparation which contains all major antigens and allergenic properties of whole ragweed extract but lacks the yellow pigment and some low molecular weight substances [13], These patients were quite comparable to those treated in 1972. They had classical histories of pollenosis, were highly skin reactive when tested and had never received previous immunotherapy.…”

Immunoregulatory Function of Specific IgG

“…This effect may be dramatically contrasted with the expected anamnestic rise of specific IgE antibody levels in untreated ragweed patients after clinical exposure to ragweed pollen during the pollination season [15]. Similar treatment effects upon RAST titers after short-term immunotherapy with alumadsorbed extracts were reported by two different groups of investigators [13,16]. Of further immunologic interest is the observa tion that simultaneous treatment with ac tive and passive immunotherapy did not in terfere with rises of PHA titers to ragweed allergen in many patients.…”

Fraction A: a New Immunotherapeutic Approach for Ragweed Pollinosis

“…Fraction A, a partially purified derivative of WSR, may be a more acceptable product because it retains all the known protein and peptide allergens of WSR. Soon after a preliminary trial of alum-precipitated fraction A indicated that it was both effective and safe in the treatment of ragweed hay fever [8] , a collaborative multicenter clinical investigation in five different lo calities was undertaken. A total of 148 ragweed hay fever patients agreed to participate in a 2-year controlled study, the objectives of which were to determine the effectiveness and safety of immunotherapy with alumadsorbed fraction A given preseasonally during 1972 and perennially during 1973.…”