Immunoregulatory function of specific IgG. I. Results in nonatopic subjects

Nonatopic subjects immunized with short ragweed developed both reaginic IgE and blocking IgG antibodies to the antigen. Administration of 250 microgram-specific ragweed IgG antibodies 1 week before, simultaneously, or up to 2 weeks after start of immunization with ragweed extract abrogated the production of anti-ragweed reaginic antibodies which was measured by skin reactivity. Formation of specific ragweed IgG antibodies was unaffected by IgG treatment. These results indicate selective regulation of an immune response in humans by IgG.

Possible role of IgG4 in discordant correlations between intracutaneous skin tests and RAST

Comparison of intracutaneous skin tests and RAST in 2 groups of patients, one consisting of 16 individuals having multiple allergies to pollen, mold and animal dander and the other of 10 patients allergic to mold only, revealed that skin tests were more sensitive than RAST. Skin reactions of 3+ to 4+ were frequently associated with negative RAST results. This was observed more so in mold-allergic patients. In a few cases (6%) RAST showed 2+ reactions while the skin tests were negative. Leukocytes from allergic individuals who had positive skin tests and negative RAST released a significant amount of histamine upon challenge with specific allergen as well as antihuman IgG4, suggesting that this immunoglobulin is a functional component of some immediate hypersensitivity reactions.

Platelet thrombopathy in asthmatic patients with elevated immunoglobulin e

Abnormalities of second-wave platelet aggregation were demonstrated in 17 of 33 asthmatic patients in whom drug and diet intake were controlled in the hospital. Mean abnormal responses were significantly greater after epinephrine- (p less than 0.001), adenosine diphosphate-(less than 0.001), collagen- (p = 0.01), and thrombin- (p less than 0.001) induced platelet aggregation in patients with immunologically mediated asthma and serum IgE levels greater than 250 U/ml as compared to patients without immunologic factors and/or normal controls. Mean pollen-specific radioallergosorbent (RAST) binding was also significantly higher in patients with abnormal aggregation as compared to normal platelet responders (p = 0.02). Release of serotonin generally reflected abnormal aggregation patterns in asthmatic patients. Platelet factor 4 release was significantly decreased in the same groups of patients. These results suggest that the allergic state may affect platelet membrane responsiveness to multiple aggregating agents.

Non-responder basophils in highly ragweed-sensitive subjects

12 of 93 patients with untreated seasonal ragweed rhinitis, strong skin sensitivity and 2+ to 4+ RAST gave insignificant (less than or equal to 14%) histamine release from their leukocytes on challenge with ragweed allergen.

In vitro demonstration of specific IgE in phthalic anhydride hypersensitivity

Clinical sensitization to phthalic anhydride occurred in a worker who developed symptoms of rhinorrhea, lacrimination, and wheezing after exposure to this chemical. Positive skin tests, provocative bronchial challenges, and a high serum titer of specific IgE (by the radioallergosorbent test) to phthalic anhydride corroborated his clinical hypersensitivity. Bronchial provocation studies using alcoholic-saline solutions of phthalic anhydride and phthalic anhydride dust resulted in immediate airway obstruction. The successful identification of specific IgE by the radioallergosorbent test demonstrates that this can be a useful in vitro technique for corroborating sensitization to this chemical.

Possible asbestos hazards in clinical allergy

The potential hazards of biological products contaminated by asbestos fibers are quite properly being reviewed by the food and pharmaceutical industries. We have demonstrated that glycerinated saline solutions can be contaminated with asbestos fibers under certain conditions of simulated clinical use of asbestos-packed syringes. Because the fibrogenic and carcinogenic effects of asbestos are subtle and may not be manifest for a long latent period, the future use of asbestos containing materials in allergy practice might be more harmful than now realized.

In vitro cross-allergenicity of major aeroallergenic pollens by the radioallergosorbent technique

Cross-reactivity between major classes of aeroallergenic pollens has been estimated by comparing the inhibitory effects of selected allergens upon the reaginic activity of other native and non-native varieties, as measured by the radioallergosorbent technique (RAST). Common allergenic determinants were demonstrated in indigenous and nonindigenous ragween species. Although patterns of inhibitory capacity were less uniform among grass pollens, endemic species tended to have more common allergenic properties than nonendemic species. Tree pollens exhibited the greatest degree of heterogeneity, confirming the previous view that these pollens tend to be less cross-reactive. Concomitant skin test threshold studies utilizing the same groups of pollens were in general agreement with in vitro results. Because, threshold skin testing was affected by a number of uncontrollable variables, however, the current modification of RAST in estimating cross-allergenicity was more accurate and reliable than data based upon cutaneous tests. It was concluded that reagin neutralization by the RAST method is the best currently available method of assessing cross-allergenic properties of pollens.

Fraction A: a new immunotherapeutic approach for ragweed pollinosis

Fraction A, a concentrate derived from short ragweed extract by (NH4)2SO4 precipitation, contains all major allergens including antigen E. Therapeutic efficacy and safety of this alum-adsorbed product was evaluated in a multicenter double-blind clinical trial by comparing it to placebo in 131 randomly matched ragweed hay fever patients who were not treated for at least 1 year. Therapeutic response to fraction A injections was more significant than placebo (p less than 0.05) by investigators' evaluation, by average daily symptom score (1.097 vs. 1.378, p less than 0.05) during the peak ragweed season, or by average proportion of days in which medication was required (0.411 vs. 0.584, p = 0.01). Fraction A patients exhibited a significantly higher (p less than 0.0005) increase in hemagglutinating titer after treatment than placebo controls. Radioallergosorbent binding, evaluated in a subgroup of 31 patients before and after the ragweed season, was unchanged or decreased in 12 of 15 patients treated with fraction A. In contrast, 9 of 16 placebo-treated patients showed an increase in this index. Systemic effects were noted after 42 (1.5%) of 2.641 injections, while local reactions occurred at the rate of 2.3%. It is concluded that a single course of preseasonal immunotherapy wih alum-adsorbed fraction A is effective and relatively safe.

Effect of force-feeding upon basal insulin levels of rats

Rats were over- or under-fed to achieve a wide range of body weights. The effect of this treatment on basal insulin levels, with and without pretreatment with atropine, was examined. Basal insulin was positively correlated with body weight and this relationship was essentially unchanged in the presence of atropine.

Predictability of the radioallergosorbent test (RAST) in ragweed pollenosis

The radioallergosorbent test was compared with currently accepted allergy diagnostic techniques in ragweed-sensitive and unselected patients. The radioallergosorbent test was positive in 28 of 30 patients with proved histories, positive scratch tests, and positive nasal provation tests to ragweed. The radioallergosorbent test was also positive in 69 per cent of 40 clinically sensitive patients whose diagnoses were corroborated by scratch tests alone. In unselected patients evaluated by intracutaneous testing with short ragweed extract, 10 minus 3 g per ml, the incidence of positive radioallergosorbent test scores was reduced to 43 per cent. No false positive results were encountered in these studies. A good relationship was observed between radioallergosorbent test scores and the maximal tolerable dose of ragweed administered during a course of "rush" immunotherapy in clinically allergic patients. These results suggest that the radioallergosorbent test has several unique advantages in assessing clinical sensitivity to ragweed.

Leukocyte migration inhibition in nickel dermatitis

Leukocyte migration inhibitory factor assay was employed as an in vitro diagnostic aid in nickel dermatitis, the second most common contact dermatitis in North America. 15 patch test-positive and 5 patch test-negative patients, all giving a past history suggestive of nickel dermatitis, were investigated. Significant inhibition of leukocyte migration in both groups of patients was obtained only with nickel sulfate-albumin conjugate and not with unconjugated nickel sulfate. Specificity of this system was tested by utilizing an unrelated metallic albumin complex, and no inhibition was found. When patch testing is equivocal or contraindicated, this in vitro technique may be a practical alternative.