Immunotherapy (IT) was performed for 12 months with a purified and standardized preparation of Dermatophagoides farinae. Twenty adults with rhinoconjunctivitis sensitive to house‐dust mite were given IT, and a similar group of 11 patients served as open controls. A total of 512 injections were given. Twenty‐eight episodes of allergic side‐effects occurred, 13 general and 15 local, most of them during the initial incremental dose period. No severe reactions started later than 30 min after the injection. One patient suffered anaphylactic shock. In this patient, specific antibodies fell immediately, followed by an increase within 1 week. The therapy group improved significantly in relation to the open controls in patients’ subjective evaluation of symptoms (P<0.028) and skin (P<0.0001) and conjunctival (P<0.001) sensitivity. Specific IgE increased in controls (P<0.0001) but not in IT‐treated patients during the “mite season;” that is, there was a significant difference in change during the observation period (P<0.0001). There was also a difference in change of specific IgG between the groups during the first 4–5 months and the whole year (P<0.0001), but not from 4–5 months to 12 months. In contrast to changes in antibody titers (IgG, P=0.04), changes in conjunctival (P<0.01) and especially skin sensitivity (P<0.005) correlated well with subjective improvement. This implies that the skin prick test and the conjunctival test can be recommended for follow‐up of IT. Furthermore, we recommend that changes in skin sensitivity be expressed as change in allergen concentration either inducing the same wheal response before and after IT as evaluated by parallel‐line bioassay, or inducing the same wheal response before and after IT as that induced by histamine tested at the same time. Finally, our findings support the hypothesis of a switch from IgE + to IgE ‐ during successful IT.

Sera from 33 patients with mold allergy proven by bronchial provocation were analyzed for specific IgE against six mold species comparing an improved Phadebas RAST with four other techniques. The new method was more sensitive and gave significantly higher IgE antibody concentrations for all tested molds except Cladosporium herbarum.

In an open study, 21 patients suffering from chronic non-seasonal rhinitis and allergic to house mites (HDM) have been treated for 1 year with either a new extract (Pharmalagen; n = 10) or an allergoid, pyridine denatured, extract (Alavac; n = 11), both precipitated with AlOH3 (depot). The following investigations were performed before and after therapy: clinical scoring (for 4 weeks), quantified skin prick tests (SPT) and nasal provocation tests (NPT) with HDM, and determination in serum of HDM-specific IgE and IgG. Both groups were compared with six patients who remained untreated and underwent the same investigations. Hyposensitization with either extract induced an improvement in clinical scores (P less than 0.05), a decrease in SPT reactivity (Pharmalgen: P less than 0.001; Alavac: P less than 0.01), a marked increase in the nasal tolerance to HDM (P less than 0.001) and in HDM-specific IgG (P less than 0.001). In the group of untreated patients, all these parameters remained unchanged. Compared with the Alavac extract, the Pharmalgen extract was more active in decreasing SPT reactions (P less than 0.05) and inducing a HDM-specific IgG rise (P less than 0.05). Although both extracts induced some untoward allergic reactions, no adrenaline was used at any time during the study. These data suggest that hyposensitization with depot extracts of HDM can be considered a safe and active adjunct to the treatment of allergic rhinitis.

Various immune parameters were examined from a group of venom allergic patients at various stages

Thirty-eight adults with allergic rhinitis have been treated with a new partially purified extract of house dust mite (Dermatophagoides pteronyssinus) in a double-blind placebo-controlled trial. Patients were randomized to active (Pharmalgen, D. pteronyssinus) and placebo (histamine) treatment by sensitivity to D. pteronyssinus on nasal challenge. In the actively treated group nasal symptoms, assessed by visual analogue score, improved (P less than 0.01), sensitivity on nasal challenge with allergen was reduced (P less than 0.05) and weal size on skin-prick test with allergen was reduced (P less than 0.01), compared with the placebo group. These results occurred after 3 months of treatment. Reduction in target organ sensitivity occurred, while the serum level of D. pteronyssinus IgE rose in the active group from 14.2 to 22.5 PRU/ml (geometric mean) but did not change significantly in the placebo group. As anticipated, because of the treatment schedule used, a number of generalized allergic reactions were induced by injections, but all responded promptly and easily to treatment. These results suggest this is an effective form of therapy, which now offers us the opportunity to study the immunological mechanisms of hyposensitization and to devise a modified schedule causing fewer reactions.

A double-blind histamine placebo controlled immunotherapy trial was performed to investigate the clinical effect of a purified and standardized Cladosporium herbarum allergen preparation. Thirty children with a clinical history suggesting mould-induced asthma and/or rhinoconjuctivitis were included. The diagnosis was confirmed by positive skin prick test and Phadebas RAST® as well as positive bronchial and/or conjunctival provocation test to Cladosporium herbarum . Immunotherapy was given for 10 months in a double-blind manner to randomized groups with either Pharmalgen®/ Cladosporium herbarum preparation or histamine placebo. Allergic side effects to injections were common, especially during the peak of the mould season (July-September in Scandinavia). In the active group, 13/16 patients experienced general reactions during the first 10 months of treatment. After 6 months of treatment, eye, nose and bronchial symptom scores and peak expiratory flow rates were similar for the groups, maybe because most of the children were also sensitive to many other allergens, including Alternaria alternala . However, medication scores were significantly lower in the treated group ( P < 0.01). Bronchial ( P < 0.01) and conjunctival sensitivity ( P = 0.01) were significantly reduced in the Cladosporium -treated group but not in the placebo group after 10 mouths of treatment. This is the first double-blind clinical trial showing the clinical efficacy of immunotherapy in children with mould-induced asthma.

In order to screen for mould allergy, extracts of five common atmospheric moulds (Cladosporium, Alternaria, Penicillium, Aspergillus and Mucor) from various manufacturers were investigated in 130 patients (5-60 years old) with clinical symptoms indicating possible mould allergy. The patients were screened by skin prick test (SPT) and radioallergosorbent test (RAST). SPT seemed to be more sensitive than RAST as a diagnostic screening procedure (80% positive reactions to one or more species compared to 50%). With a partially purified, standardized preparation of Cladosporium herbarum more positive reactions were obtained than with crude extracts without evidence of any unspecific reactions. The difference between commercial and standardized extracts is most probably a result of a variation of both the biological potency of allergenic determinants and the allergenic composition. A considerable number of negative RAST reactions with standard discs were found in patients with positive skin reactions to partially purified Cladosporium, but RAST seemed to be more sensitive than SPT with the other commercial mould extracts. Based on the screening, a very convincing tendency to IgE-reactivity to other moulds was found in patients reacting to Cladosporium, the most common cause of mould allergy. The results confirm the inadequacy of most mould extracts used in diagnostic procedures and strengthen the value of using standardized extracts.