Haemagglutinating antibodies to cat dander in relation to exposure and respiratory allergy

Systemic reactions and fatalities associated with allergen immunotherapy

OBJECTIVE

The primary objective of this review is to discuss systemic allergic reactions and risk factors associated with the injection of allergen vaccines.

DATA SOURCES

A review of the literature on anaphylactic reaction, adverse effects, and fatalities associated with allergen immunotherapy (IT) was conducted.

STUDY SELECTION

The expert opinion of the author was used to select relevant data.

RESULTS

Systemic allergic reactions associated with the injection of allergen vaccines usually begin within 20 minutes. However, on occasion, they begin 20 to 30 minutes or longer after an injection. Such reactions can also occur after allergen skin testing. Most reactions associated with skin testing and allergen IT are mild and readily respond to appropriate treatment. However, severe and even fatal reactions have been reported with both skin testing and IT.

CONCLUSIONS

Risk factors for skin testing and allergen IT include: 1) patients, particularly asthmatic patients, suffering with seasonal exacerbation of their symptoms; 2) patients who demonstrate exquisite sensitivity to particular allergen(s); 3) patients on beta-blockers; 4) patients with asthma, especially if their asthma is unstable; 5) patients in whom rush IT is used; and 6) patients in whom high doses of potent standardized allergen vaccines are used. It is essential that strict attention be paid to the risk factors for systemic reactions, and that techniques and management be initiated both before and after skin testing or IT to minimize these risks. Done properly, the risk of skin testing and IT is minimal.

Reaginic and non-reaginic antibodies against mammalian danders

Solid phase enzyme immunoassay (EIA) and passive haemagglutination techniques were used to study the occurrence of IgG-type antibodies against feline and bovine epithelial extracts among RAST-positive patients, senior veterinary students, cat fanciers (representing exposed subjects) and healthy controls. In most groups both techniques exhibited equal sensitivity being positive in about half of the RAST-positive cases. The levels of both EIA-reactive IgG-class and IgA-class antibodies were increased in most of the sera (greater than mean + 2 s.d. of controls), while only a few sera showed increased IgM values.

The hazard of mould hyposensitization in children with asthma

Of thirty-eight children, who were immunized with mould extracts, seven (19%) were withdrawn from hyposensitization due to serious side-effects clinically consistent with a type III reaction. These seven children exhibited a two- to four-fold increase in circulating precipitating-antibodies to the injected extracts, and had shown a slight increase in precipitating antibodies to the mould extracts used before hyposensitization. A further fourteen patients, also hyposensitized with mould extracts but without side effects did not develop precipitating antibodies. It is suggested that hyposensitization with mould extracts may be hazardous in children who may have a primary "immune imbalance' with a risk of provoking type III reactions.

RAST in the diagnostic of dog dander allergy. A comparison between three allergen preparations using two variants of RAST

The results of the skin, bronchial or conjunctival provocation tests and of the radioallergosorbent test (RAST) with dog dander and hair extract preparations from two different producers were compared. 202 asthmatic children were included in the study. The clinical tests, Al-RAST and paper RAST, were performed using only one allergen preparation (Hu073), while two allergen preparations (e2 and e5) were used in Phadebas RAST. A good correlation was generally found between the results of the clinical diagnostic tests, the clinical history and the results of RAST. Phadebas RAST e2 was the most specific but the least sensitive: it gave a class 0 result in 18% and class 3-4 in 34.5% of the subjects with a positive provocation test. The corresponding numbers for e5 RAST were 6.0% and 70.2%, respectively. Al-RAST was equally sensitive, but had lower specificity than Phadebas RAST e5. The correlation between Phadebas RAST e5 and paper RAST Hu 073 was excellent, which indicates a remarkable similarity between these allergen extracts. Using sensitive, immunochemically standardized Phadebas RAST e5 or Al-RAST methods, classes 0-1 can be regarded as negative, class 2 as doubtful and classes 3-4 as clinically positive results.