How to design and evaluate randomized controlled trials in immunotherapy for allergic rhinitis: an ARIA-GA(2) LEN statement.

Specific immunotherapy (SIT) is one of the treatments for allergic rhinitis. However, for allergists, nonspecialists, regulators, payers, and patients, there remain gaps in understanding the evaluation of randomized controlled trials (RCTs). Although treating the same diseases, RCTs in SIT and pharmacotherapy should be considered separately for several reasons, as developed in this study. These include the severity and persistence of allergic rhinitis in the patients enrolled in the study, the problem of the placebo, allergen exposure (in particular pollen and mite), the analysis and reporting of the study, the level of symptoms of placebo-treated patients, the clinical relevance of the efficacy of SIT, the need for a validated combined symptom-medication score, the differences between children and adults and pharmacoeconomic analyses. This statement reviews issues raised by the interpretation of RCTs in sublingual immunotherapy. It is not possible to directly extrapolate the rules or parameters used in medication RCTs to SIT. It also provides some suggestions for the research that will be needed. Interestingly, some of the research questions can be approached with the available data obtained from large RCTs.

The biological potency of different extracts for sublingual immunotherapy assessed by skin prick tests.

The standardization of allergen extracts is of primary relevance to the clinical efficacy. Biological standardization procedures are widely used in the commercial production of vaccines. We tested, in grass-allergic patients, the potency of three different grass extracts for sublingual immunotherapy by means of skin prick tests. Specific IgE against Phl p 1, 2, 4, 5, 7, 11 and 12 were also assayed. Allerslit and Sublivac were directly applied as skin test. Grazax, was prepared by dissolving two tablets in 2 mL saline. Thirty-three subjects (mean age 38.8) were studied. The skin response was significantly different among extracts, decreasing from Allerslit to Grazax (t test < 0.01), but all the extract produced a skin response greater than histamine. All the subjects had specific IgE to Phl p 1 and Phl p 4 but 24% did not have specific IgE to Phl p 5. In those subjects the skin response to the three extracts did not differ from that of Phl p 5-positive subjects. Our findings confirm that there is a variability in the biological potency among different extracts. In addition, the standardization of grass extracts based on Phlp 5 only, may be insufficient in some cases.

Administration regimens for sublingual immunotherapy to pollen allergens: what do we know?

The modalities of administration of sublingual immunotherapy (SLIT), including dosing, build-up phase, duration of the treatment, and frequency of the maintenance dose are largely variable. In the case of pollen (SLIT), the complexity increases, since preseasonal, coseasonal and pre-coseasonal regimens can be used. The administration regimens are of relevance from a practical point of view, but can also have economic implications. We review herein the available literature (randomized double blind controlled studies) on pollen SLIT, in order to derive experimentally-supported suggestions about the regimens of administration that should be preferred.

The safety of sublingual immunotherapy with one or multiple pollen allergens in children.

BACKGROUND: Since the majority of allergic patients are polysensitized, it is often necessary to prescribe immunotherapy with multiple allergens. It is crucial to know if the administration of multiple allergens with sublingual immunotherapy (SLIT) increases the risk of side-effects in children. METHODS: Consecutive children with respiratory allergy because of pollens, receiving SLIT for multiple or single allergens were followed-up in a postmarketing survey. Inclusion criteria were those for prescribing SLIT according to guidelines. Parents recorded in a diary card the side-effects (eye symptoms, rhinitis/ear itching, asthma, oral itching/swelling, nausea, vomiting, abdominal pain, diarrhoea, urticaria, angioedema and anaphylaxis). The side-effects were graded as mild, moderate and severe. RESULTS: Four hundred and thirty-three children (285 male, age range 3-18 years) receiving SLIT were surveyed. Of them, 179 received a single extract, and 254 multiple allergens. The total number of doses given was 40 169 (17 143 with single allergen). Overall, 178 episodes were reported. Of them, 76 occurred with the single allergen (42.46% patients, 4.43/1000 doses) and 102 (40.3% patients, 4.42/1000 doses) with multiple allergens (P = NS). 165 episodes (92.5%) were mild and self-resolving and were equally distributed in the two groups. In 13 cases, the events were judged of moderate severity and medical advice was required. Three patients discontinued SLIT, despite the local side-effects being mild. No emergency treatment was required at all. CONCLUSION: The use of multiple allergens for SLIT does not increase the rate of side-effects in children.

Effect of statins on fibroblasts from human nasal polyps and turbinates.

BACKGROUND: Statins are serum cholesterol-lowering agents used for the prevention and treatment of atherosclerotic vascular disease. There is, however, growing evidence that statins have immunomodulatory and anti-inflammatory activities and may prove invaluable in the treatment of immunological and inflammatory disorders. OBJECTIVE: On these basis we evaluated the effect of statins on the proliferation of fibroblasts derived from human nasal polyps and turbinates and determined their ability to modulate airway remodelling. METHODS: Fluvastatin (0.01-0.1-1 microM), Atorvastatin (0.1-1-10 microM) and Simvastatin (0.1-1-10 microM) were tested on cultured fibroblasts derived from human nasal polyps and turbinates stimulated or not with Fibroblast Growth Factor beta (10 ng/ml). All cultures were treated with 3H-Thymidine (1 microCi/ml) to test cell proliferation. RESULTS: Our results show that proliferation of turbinate-derived fibroblasts is significantly inhibited by the three statins. Fluvastatin is already effective at the lowest dose (0.01 microM), whereas Atorvastatin and Simvastatin act at the plasmatic peak concentration (1 microM). No significant effect was found on fibroblasts derived from nasal polyps, except for Simvastatin which was effective after 144 hours of stimulation. CONCLUSIONS: These drugs show a remarkable antiprolhferative effect and their different outcome depending on the different kind of fibroblasts in vitro is prompting news in the studies about statin use for the treatment of chronic inflammatory diseases.

The type of sensitizing allergen can affect the evolution of respiratory allergy.

BACKGROUND: Numerous factors affect the evolution of respiratory allergy, in children, but little is known in adults. We assessed in a prospective study the influence of the type of allergen on the progression of disease. METHODS: Outpatients, with respiratory allergy underwent skin tests and pulmonary function/methacholine challenge at baseline and after 3 years. Patients were subdivided in pure rhinitis or rhinitis + bronchial hyperreactivity (BHR). In polysensitized subjects a single relevant allergen (mites, grasses, birch, Parietaria) was identified based on symptom distribution and when needed on nasal challenge. RESULTS: 6750 patients (age range 12-46) were studied. Of them, 17.8% were monosensitized but this percentage decreased to 10.4% after 3 years (P < 0.05). Subjects with pure rhinitis were 81% at the beginning and 48% at the end. After 3 years, the patients with bronchial responsiveness increased from 18% to 58% for mites, 22% to 49% for birch, 18% to 44% for grasses, 17% to 32% for Parietaria, with a significant difference among allergens (P < 0.05). Almost the same was seen in monosensitized subjects, being mites most likely to cause a worsening. All patients with BHR at baseline received immunotherapy. In these patients the onset of new sensitizations was significantly lower than in the group (pure rhinitis) receiving drugs only and lower airways symptoms disappeared more frequently. CONCLUSION: The different type of allergen influences the course of the disease, as well as the use of immunotherapy.

In vitro and in vivo biological activities of old and fresh Cupressus arizonica pollen.

BACKGROUND: Respiratory allergy to the pollen of Cupressaceae is becoming more and more common every year in the Mediterranean area. OBJECTIVE: The purpose of this study was to see whether the allergenic potency of Cupressus arizonica pollen diminished after a 6-year period (1994-2000). MATERIALS AND METHODS: Among the Cupressaceae, we selected the pollen of C arizonica. The mode of sampling in 1994 and in 2000 was the same and the pollen was collected on the same tree and stored at room temperature. To compare its biological and allergenic activities data was collected with the following methods: cytohistology of Alexander, 2,3,5-triphenyltetrazolium chloride enzyme staining, skin testing, nasal provocation test, radioallergosorbent test (RAST), RAST inhibition, sodium dodecyl sulfate polyacrylamide gel electrophoresis, and immunoblotting to detect protein content. Thirty-eight patients with respiratory allergy to Cupressaceae were selected. RESULTS: We found no decrease in the allergenic potency of the pollen, but did find that viability and germinating power had disappeared completely after 30 to 40 days. Moreover, the amount of protein in the old pollen was half the amount found in the fresh one. Skin prick testing showed identical results with the old and the fresh pollens. CONCLUSIONS: The allergenic in vivo and in vitro activity of cypress pollen is retained for years after its collection. This activity seems to be independent of the viability of pollen grains and of the total protein content. This may explain the presence of clinical symptoms in patients out of the pollen season.

Randomized double-blind controlled study with sublingual carbamylated allergoid immunotherapy in mild rhinitis due to mites.

BACKGROUND: The clinical efficacy of sublingual immunotherapy (SLIT) in mite allergy and in mild disease is still a matter of debate, thus we performed a long-term clinical trial. METHODS: The study was randomized, double-blind and placebo-controlled. After a 1-year assessment, 68 patients with mild rhinitis with/without asthma due to mites were randomized to drugs + placebo or drugs + SLIT for 2 years. Sublingual immunotherapy was given as soluble tablets of monomeric carbamylated allergoid. Clinical scores for asthma and rhinitis (0, absent to 3, severe) and drug consumption were assessed by diary card in the period November-February. Quality of life was assessed before and after each observation period and pharmaco-economy data were evaluated as well. RESULTS: Fifty-six patients completed the study. The rate of dropouts was similar in the two groups. No relevant side effect was reported. There was a significant reduction of total clinical scores (P < 0.05) in the active group vs placebo at the first year, but not at the second whereas nasal obstruction significantly improved in both years (P < 0.05). The reduction of drug intake score was significant only at the first year. No change was observed concerning most of the Short Form-36 items, because at baseline all patients displayed a normal profile. A significant change in SLIT group was seen for the item 'change in health status'. The need for extra visits was significantly lower in the active group (25%vs 43%). CONCLUSIONS: Sublingual immunotherapy was clinically effective and safe in mite-induced mild disease.

Complementary and alternative medicine for the treatment and diagnosis of asthma and allergic diseases.

The use of Complementary/Alternative Medicines (CAM) is largely diffused and constantly increasing, especially in the field of allergic diseases and asthma. Homeopathy, acupuncture and phytotherapy are the most frequently utilised treatments, whereas complementary diagnostic techniques are mainly used in the field of food allergy-intolerance. Looking at the literature, the majority of clinical trials with CAMS are of low methodological quality, thus difficult to interpret. There are very few studies performed in a rigorously controlled fashion, and those studies provided inconclusive results. In asthma, none of the CAM have thus far been proved more effective than placebo or equally effective as standard treatments. Some herbal products, containing active principles, have displayed some clinical effect, but the herbal remedies are usually not standardised and not quantified, thus carry the risk of toxic effects or interactions. None of the alternative diagnostic techniques (electrodermal testing, kinesiology, leukocytotoxic test, iridology, hair analysis) have been proved able to distinguish between healthy and allergic subjects or to diagnose sensitizations. Therefore these tests must not be used, since they can lead to delayed or incorrect diagnosis and therapy.

Seasonal and perennial allergic rhinitis: is this classification adherent to real life?

BACKGROUND: Allergic rhinitis is traditionally subdivided into seasonal (SAR) and perennial (PAR), although the new definitions of persistent and intermittent were recently proposed. We assessed the validity of the traditional classification in a large group of subjects suffering from allergic rhinitis alone. METHODS: Young males referred to a Navy Military Hospital for routine fitness visit, and reporting symptoms of rhinitis alone were selected. According to the sensitization they were subdivided into (i) sensitized to pollens only (seasonal, SAR), (ii) to perennial allergens only (perennial, PAR) and (iii) to both (mixed, MAR). Spirometry, methacholine challenge, severity and characteristics of symptoms were assessed in all participants. RESULTS: Of 19 325 subjects, 2347 had allergic rhinitis. Seventy-two percent of the subjects had MAR, 17% SAR and 11% PAR. Ocular involvement and irritative symptoms were more frequent in SAR (P < 0.03), whereas obstruction was predominant in PAR (P < 0.01). Nasal symptoms varied according to the period of the year in SAR (P < 0.01) and PAR (P < 0.03). An overt bronchial obstruction was detected in 12% of PAR patients, in 7.8% of MAR, and in 4.2% of SAR. forced expiratory volume/1 s was significantly lower during season in SAR patients only (P < 0.05). The FEF25-75 was impaired in 22.5% MAR patients, 21% PAR, and 14% SAR, with a seasonal change in SAR (P < 0.05) and PAR (P < 0.001). Bronchial hyperreactivity was present in 82.2% of PAR, 73.6% of MAR, and 53.5% of SAR, with a seasonal change in SAR (P < 0.001) and MAR (P < 0.05). CONCLUSIONS: This study provides evidence that up to 80% of allergic rhinitics have a mixed form, and SAR and PAR definitions are poorly adherent to real life. Lung involvement is frequent in patients reporting nose symptoms alone.

Evaluation of food-pollen cross-reactivity by nose-mouth cross-challenge in pollinosis with oral allergy syndrome.

BACKGROUND: Oral allergy syndrome (OAS) is often associated with pollen-induced rhinitis, and there are preferential associations between causative substances. If OAS and rhinitis are both immunoglobulin (Ig)E-mediated and there are cross-reacting proteins, it is expected that similar reactions can be elicited in the nose and mouth. In order to test this hypothesis we performed a series of 'cross-challenges' with foods and pollens in both the nose and the mouth. METHODS: Nine patients with ascertained OAS due to vegetables and rhinitis due to pollens were studied. On the first day a nasal challenge with pollen extracts and an oral challenge with fresh food was carried out. After a week, washout nasal challenge with food and an oral challenge with pollens were performed. Immediate symptoms, mucosal tryptase and soluble eosinophil cationic protein (ECP) were assessed after each challenge. RESULTS: The administration of pollen into the nose and food into the mouth elicited symptoms as expected, but the cross-challenge had no clinical effect. In parallel, tryptase and ECP increased after nasal challenge with pollens, whereas foods did not elicit a measurable response. CONCLUSION: The cross-reactivity between foods and pollens, when evaluated at the shock organ, was not clinically evident. This data can be explained with a low concentration of cross-reagent epitopes in pollen extracts and food homogenized because of degradation. The different behaviour upon challenge suggests that different immunological mechanisms may act in the nose and mouth.

Measurement of nasal IgE in an epidemiological study: assessment of its diagnostic value in respiratory allergy.

BACKGROUND: Specific questionnaire and skin prick test (SPT) are the most used methods in epidemiological studies on respiratory allergy. SPT, however, can be positive in many subjects without evidence of any allergic disease. Nasal IgE determination has been suggested by some authors as a valuable diagnostic method, which may overcome this lack of specificity. OBJECTIVE: The aim of this study was to evaluate sensitivity and specificity of nasal specific IgE for the seven most common inhalant allergens in order to verify its reliability as a screening test. METHODS: 126 children, involved in an epidemiological study on prevalence of respiratory allergic disease, were evaluated. All children were assessed with a specific questionnaire, SPT and nasal specific IgE. Nasal specific IgE were determined with a previously described method modified for screening purposes, in order to test seven allergens at the same time. When discordant results were obtained between questionnaire, SPT and nasal IgE, an allergen specific nasal challenge (ASNC) was performed and nasal tryptase was also determined before and after challenge. RESULTS: The questionnaire was positive for respiratory allergy in 28/126 children. SPT was positive in 21 of the 28 children, but also in 5/10 children with atopic dermatitis (AD), and in 12/88 children without allergic symptoms. Nasal IgE were positive in 22/28 and also in 2/10 with AD. Nasal challenge and tryptase confirmed the negativity of nasal IgE in 12/17 children with positive SPT but totally negative for allergic respiratory disease. Moreover nasal IgE was found to be positive to dermatophagoides in one of seven children with negative SPT despite a clinical history suggestive for mite respiratory allergy. In this patient and in 2 of the 5 children with AD the positive nasal IgE to mites was confirmed by a positive ASNC and tryptase. CONCLUSIONS: Nasal IgE have shown a specificity significantly higher than SPT (98% vs. 83%) and a good sensibility. This screening test may also be useful to detect the beginning of upper airways sensitization in patients with AD.

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.