Efficacy and safety of subcutaneous immunotherapy with a biologically standardized extract of Ambrosia artemisiifolia pollen: a double-blind, placebo-controlled study.

BACKGROUND: The allergological relevance of Ambrosia in Europe is growing but the efficacy of the injective immunotherapy for this allergen has been documented only in Northern America. OBJECTIVE: We sought to study the safety and efficacy of injective immunotherapy in European patients sensitized to Ambrosia artemisiifolia. METHODS: Thirty-two patients (18 M/14 F, mean age 36.78, range 23-60 years) suffering from rhinoconjunctivitis and/or asthma and sensitized to Ambrosia were enrolled and randomized in a double-blind, placebo-controlled (DBPC) study lasting 1 year. A maintenance dose corresponding to 7.2 microg of Amb a 1 was administered at 4-week intervals after the build-up. During the second and the third year, all patients were under active therapy in an open fashion. Symptom and medication scores, skin reactivity to Ambrosia (parallel line biological assay), and pollen counts were assessed throughout the trial. RESULTS: Twenty-three patients completed the trial. No severe adverse event was observed. During the DBPC phase, actively treated patients showed an improvement in asthmatic symptoms (P=0.02) and drug (P=0.0068) scores days with asthmatic symptoms (P=0.003), days with rhinitis symptoms (P=0.05), and days with intake of drugs (P=0.0058), as compared to before therapy. No improvement for any of these parameters was detected in the placebo group. Moreover, the number of days with rhinitis and asthma was significantly higher in the placebo as compared to the active group (P=0.048 and P<0.0001, respectively). Patients who switched from placebo to active therapy improved in rhinoconjunctivitis, asthma, and drug intake. The skin reactivity decreased significantly (12.2-fold, P=0.0001) in the active group whereas a slight increase (1.07-fold, P=0.87) was observed in the placebo group after the DBPC phase. After switching to active therapy, patients previously under placebo showed a significant decrease of this parameter (4.78-fold, P=0.002). CONCLUSION: Injective immunotherapy is safe and clinically effective in European patients sensitized to Ambrosia.

Sublingual immunotherapy abrogates seasonal bronchial hyperresponsiveness in children with Parietaria-induced respiratory allergy: a randomized controlled trial.

BACKGROUND: The use of immunotherapy in asthmatic children is still controversial. Sublingual immunotherapy (SLIT) may represent an advance, due to the good safety profile, but little is known about its effects on lung function and nonspecific bronchial responsiveness. OBJECTIVE: The aim of this study was to assess the effects of SLIT on these parameters, in children with Parietaria pollen-induced asthma. METHODS: Thirty children with asthma solely due to Parietaria who participated in a previous randomized, placebo-controlled trial with SLIT were studied: pulmonary function test and methacholine challenge were carried out at baseline in winter 1999 (out season), during the 1999 season (before randomization), and during the 2001 season. RESULTS: Before randomization, there was a significant fall in methacholine provocation concentration during the pollen season vs baseline in both groups (SLIT group 9.78 +/- 5.95 mg/ml vs 3.37 +/- 2.99 mg/ml; placebo 8.70 +/- 6.25 mg/ml vs 2.44 +/- 2.25 mg/ml; P =.005). In the second pollen season, the response to methacholine returned to baseline values in the active group (9.10 +/- 7.7 mg/ml; P = NS vs baseline), whereas in the placebo group a significant increase in reactivity was still present (2.46 +/- 2.26; P = 0.008 vs baseline). No significant difference in FEV(1) and FEF(25-75) between the two groups was observed at all times. CONCLUSIONS: Our data show that SLIT abrogates the seasonal bronchial hyperreactivity in children with asthma due to Parietaria. This may be regarded as an indirect evidence of the effect on bronchial inflammation.

[Indoor allergens in office. Evaluation of the work station]. / Il rischio da allergeni indoor negli uffici. Valutazione delle postazioni di lavoro.

House dust mite and other indoor allergens play a prominent role in the pathogenesis of asthma and other allergic diseases. Several studies have shown a close relationship between sensitisation and/or onset of asthmatic symptoms and levels of indoor allergen exposure. Aim of the study was to investigate the concentration of specific markers of the indoor allergenic pollution, such as Der p 1, Der f 1, Mite Group 2, Fel d 1 and Bla g 2. Dust samples were taken using a standard method by means of a 1200 W vacuum cleaner connected with a dust-sampling device (MITEST). A standard A4 size area has been vacuumed four times during 2 min. The concentrations of Der p 1, Der f 1, Mite Group 2, Fel d 1 and Bla g 2 were determined in dust samples from 53 different sources (office chair and carpet) using a commercial kit (DUSTSCREEN). House dust mite allergens were not always detectable in the offices. Indoor allergen concentrations (Der p 1, Der f 1, Mite Group 2, Fel d 1) were significant higher in the work station (chair) than in the carpet (p < 0.0001). Der 1 exceeded the current threshold for sensitization in about 1/4 of the samples. Der f 1 was predominant over Der p 1 according to other studies. A good correlation between the results of Der p 1 and Der f 1 was observed both in carpet and work station. Cat allergen was ubiquitous and predominantly detected in the chairs because of the employees' clothes. No appreciable levels for Mite Gr 2 and Bla g 2 were detected. Such an exposure for 8 hours in every working day may be an important occupational risk for the development of sensitization/elicitation symptoms to house dust mite. To reduce mite allergen levels are necessary preventive measure by means of specific techniques and products as barriers for preventing the direct contact with allergens.

Tolerance and effects on skin reactivity to latex of sublingual rush immunotherapy with a latex extract.

BACKGROUND: Specific immunotherapy could be a therapeutic tool for the increasing problem of sensitisation to Natural Rubber Latex (NRL). OBJECTIVE: To investigate the tolerability of SLIT for Latex and its effects on skin reactivity. METHODS: Twenty-six patients (mean age 35.5 years) with an average history of 7.5 years of cutaneous symptoms plus respiratory symptoms (23/26) due to NRL were studied. All underwent rush sublingual therapy (4 days) with a standardized NRL extract followed by a 9-week maintenance treatment. Local and systemic adverse reactions were monitored throughout the treatment. Skin reactivity to NRL extract was evaluated before, during and at the end of the treatment by latex glove-use test, rubbing test and skin prick test. RESULTS: All patients reached the maintenance dose. Out of 1044 administered doses, 257 (24.6%) produced adverse reactions from which 21.4% were local. Only 10.1% of cases required treatment, mainly with antihistamines alone (5.8%), with 2-agonists alone (0.8%) or associated to antihistamines and/or corticosteroids (2.7%). One patient was precautionary treated twice with adrenaline but completed the treatment without further problems. The glove-use test improved significantly after 5 days and 10 weeks of treatment (p = 0.003, p = 0.0004 respectively), whereas the rubbing test improved significantly only after 10 weeks of treatment. Doctor's assessments confirmed the results obtained with the glove-use test (p = 0.003 after 5 days, and p = 0.004 after 10 weeks) but not those obtained with the rubbing test. No change was detected for SPTs. CONCLUSION: SLIT for NRL allergy is able to modify skin reactivity to NRL in days as assessed with methods reproducing HCWs normal exposure to the allergen. Tolerance of SLIT is better than tolerance reported for injective therapy with NRL, but the build up phase should be administered under medical surveillance until sufficient experience has been accumulated. The long-term effect of the treatment deserves further investigation.

Impact of sublingual immunotherapy on seasonal asthma and skin reactivity in children allergic to Parietaria pollen treated with inhaled fluticasone propionate.

BACKGROUND: Immunotherapy is a recognized treatment for allergic respiratory diseases. OBJECTIVE: To study the usefulness of immunotherapy in combination with optimal pharmacological therapy. METHODS: Thirty-eight children (8-14 years) suffering from seasonal asthma+/-rhinoconjunctivitis due to Parietaria poorly controlled by anti-allergic drugs treatment were selected. After randomization according to a double-blind placebo-controlled design they received active sublingual immunotherapy (15 children) or placebo (15 children) for 13 months combined with inhaled fluticasone twice a day during the pollen season. Eight children were taken as control, whereas all patients were instructed to take symptomatic drugs on need. Early and late skin response to the allergen were assessed in all patients before and after treatment. Drug and symptom scores, as well as visual analogue scores (VASs) and Parietaria pollen counts were assessed during the pollen season. RESULTS: Groups were well balanced for age, gender, early and late skin response before treatment. Four children dropped out, in one case in relationship with active sublingual immunotherapy (SLIT) administration. Chest and nose symptoms, as well as drug scores and VASs were significantly better in both the active or placebo SLIT+fluticasone (S+F) as compared to the control group (P between <0.001 and 0.043). Eye symptoms were significantly better in the active S+F group as compared to control (P=0.025). The VASs were significantly better in the active S+F group as compared to the placebo S+F group (P=0.037). The early skin response decreased significantly in the active S+F group (P<0.001), whereas the late skin response changed significantly in all groups, with an increase in the placebo+fluticasone group (P=0.019) and in the control group (P=0.037) and a decrease (P<0.0001) in the active S+F group. CONCLUSION: The clinical efficacy of S+F is equal to that of fluticasone alone, but the addition of SLIT has effects also on non-bronchial symptoms.

Variation of the skin end-point in patients treated with sublingual specific immunotherapy.

The reduction in skin reactivity in sensitized subjects is a common finding after injective specific immunotherapy. Few data are, on the contrary, available for sublingual immunotherapy. We assessed the skin reactivity by the end-point titration method in 90 monosensitized subjects (age range 3-50; mean age 19.63) at the baseline and for four consecutive years during the SLIT treatment with two different maintenance regimens. The yearly duration of drug intake was monitored throughout the observation period. Age and skin reactivity to histamine (p < 0.0001; r = 0.871), and age and skin prick end-point (p < 0.0001; r = 0.523) turned out to be statistically positively correlated at baseline. No correlation was on the contrary found between age and the ratio allergen wheal/histamine wheal (p = 0.857; r = -0.019). After 4 years all patients showed at least a significant 4-fold decrease of the skin end-point, whereas 46/90 (51.1%) showed a 16-fold decrease and 29/90 (32.2%) a 64-fold decrease (p < 0.001 in all cases). At the end of the SLIT treatment, 21/90 patients (23.3%) were not using any drug, whereas 16/16 (100%) had given up the use of eye drops, and 34/35 (97%) had given up the use of bronchodilators and bronchial steroids (p < 0.001). After SLIT, 52/90 patients showed a reduction by at least 50% of the yearly duration of drug intake (p < 0.0001). An apparent relationship between the progressively decreasing rate of use of drugs and the decrease in skin reactivity was found, but it did not reach the point of statistical significance (p = 0.081). Patients treated with the daily allergen administration schedule, in spite of a lower cumulative dosage, showed a significantly greater decrease in skin reactivity (p < 0.001) and a higher rate of both no use of any drug (p = 0.013) and of at least a 50% reduction of the yearly duration of drug intake (p = 0.001) as compared to patients treated with three allergen administrations per week.

Mite antigens enhance ICAM-1 and induce VCAM-1 expression on human umbilical vein endothelium.

Although sublingual allergen-specific immunotherapy has been proved to be effective in the treatment of allergic diseases, controversy surrounds the means by which such a local therapy can induce systemic immunological changes. Adhesion molecules are critical in the regulation of leukocyte traffic. It has been hypothesized that allergenic extract, administered locally, may induce an up-regulation of the mucosal vessel vascular adhesion molecules (CAMs) resulting in local recruitment of circulating inflammatory cells. In the present study we investigated whether the mite antigens, Der p1 and Der p2, can modulate CAM expression of human endothelial cells (HEC). To do this, slices of whole human umbilical cord vein underwent short-term (8 hours) cultures in the presence or absence of mite antigen (baseline, unstimulated controls). Cryostatic sections of the specimens were then evaluated immunohistochemically for expression of intercellular adhesion molecule (ICAM-1) and vascular cell adhesion molecule (VCAM-1) molecules. The results revealed that while Der p1 is capable of significantly up-regulating ICAM-1 and VCAM-1 on HEC, Der p2 antigen moderately up-regulates ICAM-1 expression but is ineffective in modulating VCAM-1. Although preliminary, these results clearly support the hypothesis that at least some of the effects of sublingual immunotherapy may derive from inflammatory cell recruitment at the site of allergen release.

A pre-seasonal birch/hazel sublingual immunotherapy can improve the outcome of grass pollen injective treatment in bisensitized individuals. A case-referent, two-year controlled study.

BACKGROUND: The study tests the hypothesis of a reduction of priming due to tree allergy in patients sensitised to both birch/hazel and grass pollen undergoing an associated preseasonal Sublingual/Injective immunotherapy. METHODS: 36 out of 49 bisensitized candidates were pair-matched into 18 case-referent couples. During two years all patients were administered preseasonal grass-SIT and one patient in each couple received also birch/hazel-SLIT. Diary cards were fulfilled for three consecutive grass pollen seasons. Specific Nasal Provocation Test (NPT) for grass and aspecific bronchial challenge were done; sera were analyzed for specific IgE and IgG. RESULTS: During the peak of the grass pollen season both groups showed a significant improvement in total symptom-score. Conjunctivitis and cough improved significantly more in patients with associated therapies. While antihistamine score decreased significantly in both groups, antiasthmatics did only in the SLIT-SIT group. The follow-up documented a significant increase in grass- and birch-specific IgG and a decrease in grass-specific IgE. Grass-NPT threshold was clearly higher in SLIT-SIT-group (p = 0.01) and only in this group PD20 methacholine improved significantly (p < 0.05). CONCLUSIONS: Combined birch/hazel-SLIT and grass-SIT are safe and improve clinical outcomes of SIT alone in young bisensitized patients. Priming reduction is supported by specific NPT and bronchial hyperresponsiveness.

Long-lasting effect of sublingual immunotherapy in children with asthma due to house dust mite: a 10-year prospective study.

BACKGROUND: Subcutaneous immunotherapy for respiratory allergy has shown a long-lasting efficacy after its discontinuation, whereas this evidence is still lacking for sublingual immunotherapy, despite the fact that it is widely used. OBJECTIVE: We aimed to evaluate whether a long-lasting effect of SLIT occurs, in a prospective parallel group controlled study. METHODS: Sixty children (mean age 8.5 years) suffering from allergic asthma/rhinitis due to mites were subdivided into two matched groups: 35 underwent a 4- to 5-year course of SLIT with standardized extract and 25 received only drug therapy. The patients were evaluated at three time points (baseline, end of SLIT and 4 to 5 years after SLIT discontinuation) regarding presence of asthma, use of anti-asthma drugs, skin prick tests and specific IgE. RESULTS: We found that in the SLIT group there was a significant difference vs. baseline for the presence of asthma (P

True multifood allergy in a 4-year-old child: a case study.

BACKGROUND: Food allergy is quite common in children, but it usually trends to improve with ageing. When an individual has specific IgE to a large variety of foods (multifood allergy) the clinical picture may be of remarkable severity and the avoidance of the offending foods may lead to severe dietary impairment. We describe a case of a child with ascertained multifood allergy. METHODS: The prick-by-prick testing with fresh foods and serum IgE tests were used to evaluate the patient's sensitivity to food allergens. The clinical effect of sensitizations were evaluated by DBPCFC which was carried out for egg, fish, peanuts, walnut, fig, asparagus, orange, chicory, medlar, peach, strawberry and cherry. Each challenge was performed on a separate day. Medical assistance and resuscitation facilities were available during the whole challenge procedures. RESULTS: SPT with fresh food gave a 4 mm wheal for fig, asparagus, cherry and walnut; a 5 mm wheal for medlar and orange; a 6 mm wheal for chicory and strawberry; a 7 mm wheal for fish and peanuts; an 8 mm wheal for peach and a 9 mm wheal for egg. The RAST assay confirmed the presence of specific IgE to egg, fish, peanuts, walnut, fig, orange, strawberry, peach, and cherry. The total serum IgE was 730,6 kU/l.The DBPCFC was positive, at various degrees, for all foods tested according to skin sensitizations. CONCLUSIONS: The case herein described is a true multifood allergy, as confirmed by the DBPCFC. Multifood allergy is not common, but when present it can lead to severe dietary limitation.

Clustered schedules in allergen-specific immunotherapy.

BACKGROUND: Injective immunotherapy is traditionally performed with a build-up phase lasting 3 to 4 months. The costs, decreasing compliance from both patients and clinicians and inconveniences due to this schedule may be overcome using different schedules. METHODS AND RESULTS: A revision of the published papers with clustered schedules has been made. Attention has been focussed on tolerance and its relationships with relevant parameters such as kind of extract (aqueous or depot), allergens and their pharmaceutical presentation, schedule followed, use or not of a premedication, clinical manifestations of patients before treatment. For a better revision, papers dealing with clustered schedules have been divided into two groups. The first group includes 20 papers not designed to study the clustered schedule but using it to study other parameters affected by specific immunotherapy. The second group includes 9 papers specifically or mainly designed to study the clustered schedule. A huge difference in the rate of side effects could be assessed among different papers, even in studies run with similar allergens from the same producer and with a similar schedule. CONCLUSIONS: Summarizing the results of the revision, the following conditions seem to lead to the optimal tolerance of the clustered schedule: use of a premedication; use of a depot preparation; use of no more than 4 administrations per cluster; administration of 1-2 clusters per week and of 4 to 6 clusters in total. These results seem promising but further efforts are required to better define the optimal clustered schedule.

CD34+ cells in peripheral blood of healthy human beings and allergic subjects: clue to acute and minimal persistent inflammation.

BACKGROUND: There is compelling evidence that hemopoietic precursor cells (HPC) play a crucial role in establishing cellular inflammation in allergic diseases. Increased levels of circulating CD34+ HPC committed to the myeloid lineage have been extensively reported in allergic rhinitis, asthma and eczema, whereas CD34+ cells have been identified within the cellular infiltrates of tissues, at peripheral sites of inflammation. METHOD: We conducted a pilot study to evaluate CD34+ traffic in the peripheral blood of 22 consecutive patients (13 men and nine women; mean age 28.9 years), independently of treatment. The patients presented rhinitis, asthma, eczema, urticaria and adverse food reactions of suspected allergic origin. Allergic reactions were extrinsic in 18 patients and intrinsic in four. In 12 patients who underwent sublingual specific immunotherapy, CD34+ cells were quantified at enrollment (T0), one year later (T1) and two years later (T2). The severity of symptoms was graded on a five-point scale (0 = absence of symptoms and 4 = severe symptoms). Twenty healthy human subjects (10 men and 10 women; mean age 24.5 years) were evaluated as controls. To obtain information about the total amount of circulating HPC, independently of the lineage commitment (Lin+/-) and the degree of differentiation (CD34bright/dim), we used a modification of the Milan protocol of peripheral blood CD34+ cell estimation. The cells were analyzed using a BD FACScan or FACSCalibur and the results were expressed as the percentage of positive cells. RESULTS: CD34+ cell traffic in the control group was very low since all values were < 0.10 (median value: 0.03 %). Values in the patient group were increased in both extrinsic and intrinsic forms with a median value of 0.25 % (interquartile range: 0.13- 0.33 %). The relationship between CD34+ traffic and the severity score was highly significant (Spearman's rho = 0.954; test of Ho: CD34; independent score: Pr > t = 0.000). CONCLUSIONS: The data reported herein suggest that the method employed is effective in assessing acute allergic inflammation, as well as minimal persistent inflammation underlying an asymptomatic clinical condition. Evaluation of CD34bright/dim peripheral traffic, if confirmed by the outcomes of a multicenter study currently being planned together with traditional study of circulating IgE, could be a reliable non-invasive laboratory tool for monitoring allergic inflammation.

An extensively hydrolysed cow's milk formula improves clinical symptoms of gastroesophageal reflux and reduces the gastric emptying time in infants.

BACKGROUND: About 20 % of infants fed with breast-milk substitutes suffer from Gastro Esophageal Reflux (GER) and 1/3 of them also show Cow's Milk Allergy (CMA) symptoms. METHODS: We planned this study to assess by dynamic echography the usefulness of an Extensively Hydrolysed Cow's Milk Formula (eHF) in infants suffering from GER. Ten infants showing GER symptoms and 10 normal babies, all fed with breast-milk substitutes, were enrolled. Clinical symptom scores related to GER were assessed for one week. The Gastric Emptying Time (GET) was determined by means of dynamic echography after feeding with cow's milk-derived formulae and again after a week feeding with eHF in subjects previously showing GER symptoms. RESULTS: All infants with a clinical diagnosis for GER showed an abnormally high average GET in comparison to normal subjects (205 vs 124 min, p = 0.000). Switching to the eHF led to a significant clinical improvement (p = 0.0039) especially in babies skin-test and RAST positive to cow's milk, and to a significant decrease toward the normal value of the GET (167 min, p < 0.001). CONCLUSIONS: The eHF tested improves GER symptoms in infants suffering from this disease. Our experience confirms and supports the use of dynamic echography as a reliable, simple, and non-invasive diagnostic method for infants with an increased GET associated with clinical symptoms of GER.

Differential diagnosis by the endpoint method in patients skin-reactive to more than one inhalant allergen.

In recent years there has been an increasing number of patients suffering from respiratory symptoms and skin test positive to more than one allergen, and in many cases neither the clinical history nor the specific IgE determination has proved useful in establishing a ranking among two or more positive allergens. This study was designed to test the usefulness of the skin-prick test endpoint technique for the identification of the most important allergen(s) among those skin test positive. To this end, 118 consecutive patients (age range 4-60 years) skin test positive to between 2 and 6 different allergens were selected and submitted to the skin-prick test endpoint technique with serial 1:4 dilutions of standardized commercial allergens. The skin-prick test endpoint technique was unable to establish a ranking in only 7 patients sensitized to two allergens, whereas a difference in the range 2-10 between the highest and the lowest endpoint dilution in the same patient could be established in all other cases. Some allergens known to be widely crossreactive (D. farinae and D. pteronyssinus; cultivated and common grasses; birch and hazel) showed a similar skin reactivity only in few cases when tested according to the skin-prick test endpoint technique. This finding suggests a specific sensitization only for one allergen (or mixture) of each crossreacting couple. Moreover, in 60/118 patients the allergen able to evoke the largest skin reaction with the standard diagnostic did not have the highest skin-prick endpoint, suggesting that the ranking of allergens on the basis of the dimension of the wheal obtained with the standard diagnostic is a concept that should be revised and updated.

Sublingual tryptase and ECP in children treated with grass pollen sublingual immunotherapy (SLIT): safety and immunologic implications.

BACKGROUND: The clinical safety of sublingual immunotherapy (SLIT) has been repeatedly confirmed; nevertheless, the possible onset of local oral symptoms is still a concern, and nothing is known about the pathogenesis of this effect. We aimed to determine whether the administration of SLIT in allergic children can evoke an IgE-mediated reaction, by measuring the levels of sublingual tryptase and ECP. METHODS: Thirty children (7-12 years old) with allergic rhinitis/asthma due to grass pollen were prescribed SLIT. In these children, an allergen-specific nasal challenge was performed, and nasal tryptase and ECP were measured before and after. Sublingual ECP and tryptase were also assessed before the SLIT, after 1 month, and after 6 months of treatment. Ten matched allergic children and 10 healthy ones served as controls for the baseline levels of sublingual ECP and tryptase. RESULTS: The levels of nasal tryptase and ECP significantly increased after nasal challenge (P<0.001), whereas no change during the SLIT course (at the beginning, after 1 month, and after 6 months) could be detected in sublingual tryptase either before or after SLIT administration. The sublingual ECP significantly decreased after 6 months of SLIT. The baseline levels of nasal tryptase and ECP were significantly higher in allergic subjects than in healthy controls, as was the level of sublingual ECP. CONCLUSIONS: In the presence of an IgE-mediated reaction (ASNC), a significant increase of tryptase and ECP can be seen. When SLIT is administered, such a phenomenon does not occur; therefore, SLIT does not elicit any IgE reaction in the mouth. It is noteworthy that allergic subjects display higher levels of nasal ECP and tryptase than healthy subjects, even when symptom-free, and these observations may indicate the presence of subclinical inflammation.

The safety and efficacy of immunotherapy with aluminum hydroxide-adsorbed venom extract of Vespula spp. An open, retrospective study.

BACKGROUND: specific immunotherapy for Hymenoptera Venom (VIT) is considered a life-saving treatment in insect sting allergy. A few studies with depot VIT have been published, but they are mainly focussed on patients sensitized to Apis. METHODS: this retrospective study was designed to evaluate both efficacy and safety of depot VIT for Vespula. Thirty-six patients (age range 6-73 years) with a history of systemic reactions (grade III to IV according to Mueller) after a Vespula sting, and specific sera IgE RAST to Vespula at least class 2, were administered a depot preparation of venom reaching 50 microgram as monthly maintenance dose. After the first year the maintenance dose was administered every other month. Thirty-three patients were treated for a minimum of 5 years. Reactions to any new field sting of the relevant insect were recorded during the treatment and for 6 to 24 months after its interruption. RESULTS: the treatment showed an excellent tolerance, with only a few local side effects. Thirteen patients (11 Grade IV according to Mueller before VIT) under treatment showed only local reactions after each field sting (18 field stings in total) by the relevant insect. Four patients (3 Grade IV according to Mueller before VIT) had a total of 6 field stings after the interruption of the 5-year treatment, with only local reactions. CONCLUSIONS: according to our results, and in agreement with previous published studies, VIT for Vespula spp. with depot extracts has an excellent tolerance and is clinically effective.

Prevention of new sensitizations in asthmatic children monosensitized to house dust mite by specific immunotherapy. A six-year follow-up study.

BACKGROUND: Specific immunotherapy (SIT) is a recognized way of treating IgE-mediated respiratory diseases. The clinical outcome is usually better in allergic children than in adults. OBJECTIVE: To increase our knowledge of the ability of SIT to prevent the onset of new sensitizations in monosensitized subjects, so far poorly documented. METHODS: 134 children (age range 5-8 years), who had intermittent asthma with or without rhinitis, with single sensitization to mite allergen (skin prick test and serum-specific IgE), were enrolled. SIT was proposed to all the children's parents, but was accepted by only 75 of them (SIT Group). The remaining 63 children were treated with medication only, and were considered the Control Group. Injective SIT with mite mix was administered to the SIT Group during the first three years and all patients were followed for a total of 6 years. All patients were checked for allergic sensitization(s) by skin prick test and serum-specific IgE every year until the end of the follow-up period. RESULTS: Both groups were comparable in terms of age, sex and disease characteristics. 123 children completed the follow-up study. At the end of the study, 52 out of 69 children (75.4%) in the SIT Group showed no new sensitization, compared to 18 out of 54 children (33.3%) in the Control Group (P < 0.0002). Parietaria, Gramineae and Olea were the most common allergens responsible for the new sensitization(s). CONCLUSIONS: According to our data, SIT may prevent the onset of new sensitizations in children with respiratory symptoms monosensitized to house dust mite (HDM).