Katherine L. Bowman

Pertinent factors influencing comparative skin tests on the arm

Abstract 1. 1. The technic which has been found most useful for comparing, by direct skin tests, two solutions differing but slightly in specific activity is described. 2. 2. A dilution of pollen extract which is 25 per cent stronger than another dilution of the same extract can be identified in 66 per cent of the comparative tests performed with the two solutions when the tests are placed vertically on the arm approximately 4 inches apart and when the relative positions of the tests with the two solutions are alternately reversed in one-half of the cases tested. 3. 3. When these same extracts are compared by placing the tests performed with them vertically on the arm only 2 inches apart, the stronger solution elicits the larger reaction in only 47.9 per cent of the cases tested. The two solutions, therefore, cannot be differentiated from each other by this technic. 4. 4. A dilution of pollen extract differing in specific activity by 20 per cent from another dilution of the same extract can be identified in 76.3 per cent of the cases tested when the tests with the two solutions are placed horizontally on the arm approximately 1.5 inches apart and when the relative positions of the tests are alternately reversed in one-half of the cases in the series. 5. 5. The upper position on the arm shows advantage in whealing response to tests with pollen extracts over the lower position and the medial over the lateral, but to a lesser degree in the latter instance than in the former. 6. 6. In these same atopic subjects, the lower position on the arm shows advantage in whealing response to tests with histamine over the upper position. 7. 7. Tests inserted in rows vertically on the arm influence each other more than those inserted in horizontal rows. This point should be taken into consideration in routine cutaneous testing for hypersensitivity.

Passive Local Sensitization in Atopic Individuals.

The technic for studying the absorption of unaltered proteins in humans has been described. 1 A cutaneous site is passively and locally sensitized with a small amount of serum taken from an atopic patient who is extremely sensitive to the protein to be tested. On the following day, the specific protein is fed to the subject on an empty stomach. Within a few minutes to a few hours, a wheal forms at the sensitized site demonstrating roughly the rapidity and, to a certain degree, the amount of unaltered protein absorption in that subject. The results of studies with various proteins and in different types of subjects have already been presented. 2 , 3 The technic may, however, fail completely or may show diminished reactions in atopic subjects. One of the factors which accounts for this is that atopic individuals do not accept passive local sensitization as well as normals. The evidence is submitted herewith. The ability of atopics to accept passive local sensitization was determined by titrating on their skins the sensitizing power of certain atopic sera of known strength. The titrations of these sera were performed according to the method of Coca and Grove 4 . Atopic and normal subjects were sensitized with the serum in a range of dilutions determined to be suitable for that serum by previous titration on normal subjects. Seven days after sensitization the sites were tested with a suitable dilution of the atopen for which the serum in question contained reagins. Control tests on normal skin sites were introduced at the same time. Readings were made according to the method used in the indirect method of testing 5 ; i. e., any definite excess of reaction, either in wheal or in erythema, on the sensitized site over that manifested on the control site was considered a positive transfer.

On the “protein unit” standardization of pollen extracts proposed by Cooke and Stull

Abstract 1.1. Experiments are described which show that two dilutions of pollen extract and of an extract of Ascaris lumbricoides and of histamine differing in activity by 25 per cent can be distinguished from each other in appropriate comparative skin tests. 2.2. Two dilutions of the same pollen extract differing by 15 per cent in specific activity were indistinguishable in comparative skin tests. 3.3. The assertion of Cooke and Stull that the content of P-T-A precipitable substance in pollen extracts diminishes with time pari passu with the loss of specific activity could not be confirmed in a study of five pollen extracts from two to eight years old. 4.4. The present study confirms Cocas finding that the plan of standardizing extracts suggested by Cooke and Stull is fallacious.

Severe allergic reaction caused by silk as a contaminant in typhoid-paratyphoid vaccine

Abstract Reactions to silk extract and to certain biologicals which had been filtered through silk were demonstrated in the serum of a patient who had experienced a severe asthmatic attack shortly after receiving a subcutaneous injection of triple typhoid vaccine. Cross-neutralization tests showed that silk-filtered vaccines exhausted all the silk antibodies in the patients serum, whereas those vaccines not silk-filtered did not affect the reactivity of the serum. The silk antigen in biological products is a potential hazard to any silk-sensitive individual. The presence of this antigen in any parenterally administered biological should be properly indicated and a warning of its potential danger to silk-sensitive individuals should be included in the instructions for administration.

Canine sensitivity to ascaris antigen

Abstract 1.1. Positive cutaneous reactions to extracts of canine and pig Ascaris occurred in twelve of twenty-four dogs. Most of these animals had a nematode infection at the time of the tests or were known to have been so affected previously. 2.2. Constitutional reactions resulted in two dogs from intracutaneous tests with Ascaris extracts. 3.3. Passive transfer of the antibodies in the blood serum of a naturally sensitive dog to other dogs was successful in four of the five attempts made. 4.4. Passive transfer of the antibodies in the blood serum of two naturally sensitive dogs to human beings was successfully demonstrated. 5.5. Active sensitization of two dogs with Ascaris extract was successful. This was indicated by the development of marked cutaneous reactions in both dogs. The blood serum of one of these dogs gave weakly positive Prausnitz-Kustner reactions in human beings. 6.6. Skin-sensitizing antibodies in the serum of a dog naturally sensitive to Ascaris were found to be heat labile, resembling, in this respect, human atopic reagins.

Leukocytic transfer of the immediate types of allergic reaction in man. I. Techniques for the local passive transfer of atopic hypersensitiveness through the use of leukocytes and their derivatives.

Abstract The local passive transfer of the atopic wheal type of skin reaction, which had previously been effected with suspensions of viable leukocytes, has now been accomplished by the use of extracts of fragmented white blood cells. The suspension and extraction techniques have been described in detail. They have thus far been found to be equally successful for passive transfer except in those experiments in which the preservation of cell viability is a prerequisite, in which case the suspension technique is obligatory. The relative merits and disadvantages of both procedures have been reviewed. The absence of a pronounced inflammatory response at passive transfer sites prepared with leukocytic extracts minimizes most of the difficulties encountered in the testing and reading of sites prepared with leukocytic suspensions.

The influence of a single dose of ACTH on the atopic and histamine skin reactions

Abstract Employing a single intramuscular 25 mg. dose of ACTH and testing asymptomatic subjects with dilutions of atopens producing only slight cutaneous reactions, the writers have succeeded in demonstrating, in the majority of subjects, a slight but definite depressive effect of the hormone upon the atopic cutaneous skin reaction. The cutaneous response to histamine was not depressed by ACTH in any subject.

Leukocytic transfer of immediate-type hypersensitiveness in man. V. Transfer of experimental sensitivity to Ascaris antigen.

Summary From a human donor in whom immediate and delayed forms of sensitivity to Ascaris lumbricoides antigen had been experimentally induced, only the immediate type of sensitivity was transferred to one of 3 recipients by use of peripheral blood leukocytes. Markedly positive transfer reactions were obtained.

The response of contact dermatitis sites in atopic individuals to subsequent stimulation with specific wheal-inducing atopens

Abstract 1.1. When an area of skin in an atopic individual is stimulated by contact with a specific excitant and becomes the site of a contact dermatitis, its response to specific wheal-inducing atopens becomes altered. 2.2. When the dermatitis reaction has completely subsided, an intracutaneous test at this site with a specific wheal-inducing atopen, such as pollen or animal dander, tends to induce a wheal formation which is larger than that obtained at a normal site on the same subject. 3.3. The more intense the original dermatitis reaction is, the more pronounced is the tendency to increased wheal formation upon subsequent specific excitation. 4.4. Erythema formation on restimulated sites tends to be less intense than on normal sites.

Leukocytic transfer of the immediate types of allergic reaction in man. II. The correlation of leukocytic transfer with other sensitivity factors.

Abstract In an eight-year study on D. G., an atopic patient with hay fever, an attempt was made to correlate the results of leukocytic transfer tests with his skin reactions, reagin titers, and symptoms. During the early years of observation, while D. G. was having ragweed hay fever and his skin reactions and serum reagin titers for this pollen were pronounced, his reactions to leukocytic transfer tests by both the suspension and the extract techniques were regularly positive. Then as the immunologic status of the patient changed and his skin reactions, reaginic titers, and hay fever symptoms diminished, the leukocytic transfer tests for ragweed became negative. Throughout the major part of this observation period, D. G. showed skin reactions and serum reaginic titers for timothy grass pollen which were as great as or greater than those for ragweed, but his leukocytes never transferred this sensitivity and he never experienced any symptoms attributable to this pollen. Hence, the leukocytic transfer tests more accurately reflected the status of D. G. with respect to his clinical sensitivities to both pollens than did his cutaneous tests or reaginic titers. The transfer principle in the leukocytic preparations bore a close resemblance to the atopic reagin. All findings pointed to the sensitizing substance as a derivative of the leukocytes rather than as a serum component absorbed or adsorbed by these cells.