Immunotherapy: Past and present

In 1911, Leonard Noon of London published a short report on immunization treatment of hay fever with a distilled water extract of the pollen of timothy grass, Phleum pratense, which had been sealed in glass tubes and boiled for 10 minutes. Noon tested his patients by dropping dilutions of his extract in their eyes and observing the conjunctival reaction. Through this method he determined "the strength of the extract which is just sufficient to give this reaction." His units represented the material extracted from 0.1 mu g of pollen. He began inoculations at minute doses administered subcutaneously and increased the dose every 1 to 2 weeks, retesting the eye reaction to observe protection against the pollen "toxin." The strength of the extract required to elicit an eye reaction was increased as much as 100-fold, and Noon hoped that the immunity thus demonstrated would be sufficient to carry the patients through a season "without suffering their annual attacks of hay fever." Noon, whose health was failing, turned the matter over to J. Freeman who, later the same year, reported results in 20 individuals with eye reactions to the extract who received doses varying from 4 to 2000 units. One patient dropped out of the study, but the remaining patients had decreased ocular reactivity: nine had "satisfactory" clinical results, five more had "moderately" or "fairly satisfactory" results, and the others had less than satisfactory results. Freeman recognized that "bias" could enter such an evaluation but thought that his patients gave "discriminating judgments." Noon and Freeman thought that hay fever resulted from a pollen toxin to which some people were "hypersensitive" and that their inoculations resulted in an "active immunity".