Minimal persistent inflammation is also present in patients with seasonal allergic rhinitis

BACKGROUND

The allergic reaction is characterized by an inflammatory response, which is correlated to the allergen exposure, and is detectable in mite allergic patients, even when symptoms are absent.

OBJECTIVE

The study was aimed at assessing the presence of inflammation in patients with pollen allergy during a long observation period.

METHODS

Six patients, sensitized only to Betula alba, were enrolled. Evaluated parameters were (1) nasal symptoms, (2) inflammatory markers (ie, neutrophil and eosinophil number and intercellular adhesion molecule-1 expression on nasal epithelial cells), and (3) pollen count. Patients were examined during the pollen season every 4 days for 40 days and were observed 3 times after the pollen season.

RESULTS

A significant inflammatory reaction was evident throughout the pollen season, even during the days with a low pollen count and low or absent symptoms.

CONCLUSIONS

The results of this study indicate that the global therapeutic strategy for allergic rhinitis should be revised and targeted to inflammatory phenomena rather than to symptoms alone.

Oral and sublingual immunotherapy: general aspects and critical considerations

Local routes for immunotherapy (IT) such as oral (OIT) and sublingual (SLIT) have the primary aim of avoiding or minimizing the risk of adverse events and of improving the compliance of the patients with IT itself. About the possible mechanisms of action, only few information are available since local IT has been deeply studied only in the last ten years. The current data about pharmacokinetics are controversial and not conclusive, since they are mostly derived from animal models. However, very recent studies have demonstrated that the sublingual/swallow modality is the most promising way of mucosal immunotherapy. Thus, SLIT could be shown to lead to systemic immunological effects and to a decreased responsiveness of target organs. Furthermore, no severe adverse events were reported in the SLIT-studies. Some studies indicate that SLIT is as effective as subcutaneous IT, whilst OIT is not recommended for the clinical practice. SLIT would appear particularly suitable for pediatric patients. Administration schedules include a build-up phase and a maintenance phase which can be administered either preseasonally or continuously, and rush schedules for preseasonal IT are also available. Furthermore, SLIT reduces time and money expenses usually required by SIT since it is self-administered.

Aeropollinic sampling at three different heights by personal volumetric collector (Partrap FA 52)

BACKGROUND

Aeropollinic sampling is usually performed by volumetric pollen traps located on the top of buildings at a height of 15-20 m. The present study aimed to determine whether pollen concentration is similar, at the same time, at different heights.

METHODS

Pollen concentrations were measured at the same time for 3 days each month (March-October 1997), with three Partrap FA 52 devices respectively located at 1.5, 5, and 15 m above the ground. A Burkard sampler was used as control at the 15-m level.

RESULTS

No significant difference in either the total count or the single pollen counts was observed between the Partrap and Burkard samplers at 15 m. The total pollen count did not differ significantly between the Partrap at 1.5 m and 15 m (130+/-19 and 123+/-18, respectively), whereas the sampler at 5 m collected an amount of pollen (84+/-14) significantly lower than at 1.5 and 15 m (P<0.0001 and P<0.001, respectively). The amount of Urticaceae pollen was significantly higher at 1.5 m (97+/-17) than at 15m (80+/-12) and 5m (58+/-11); P<0.02 and P<0.001, respectively. Regarding grass pollen, the collector at 5 m captured significantly less pollen (4.5+/-0.8) than at 1.5m (9.5+/-1.3) and 15m (7.2+/-1.3) (P=0.002 and P=0.02, respectively). No significant difference was observed between the data obtained from samplers at 1.5 and 15 m. In addition, the Oleaceae, Cupressaceae, and Corylaceae pollen counts were significantly higher when collected at 15 than at 5 and 1.5 m.

CONCLUSIONS

These data show that differences exist in pollen sampling performed at different heights.

Clinical and immunologic effects of a rush sublingual immunotherapy to Parietaria species: A double-blind, placebo-controlled trial

BACKGROUND

The local (noninjection) routes of immunotherapy are presently regarded as viable therapeutic options for respiratory allergy, and their mechanisms of action are currently undergoing investigation.

OBJECTIVE

We evaluated the clinical efficacy of a preseasonal rush sublingual-swallow immunotherapy and its effects on allergic inflammation in patients with seasonal rhinoconjunctivitis caused by Parietaria species.

METHODS

Thirty patients with Parietaria species-induced rhinoconjunctivitis (13 with mild intermittent asthma) were randomly assigned sublingual-swallow immunotherapy or placebo in a rush preseasonal course. We assessed the seasonal symptom-drug intake score by diary card and the inflammatory infiltration and the intercellular adhesion molecule 1 expression on nasal epithelium after specific allergenic challenge before and after treatment.

RESULTS

The investigated immunotherapy was well tolerated, and no side effects were recorded. A significant reduction of the symptom score (P =.016) and drug intake score (P =. 008) after immunotherapy was observed only in the active group. A decrease of the cumulative score was observed also in the placebo group (P =.046), but the significance was clearly higher (P =.006) in the active group. In the active group a reduction of neutrophils (P =.001), eosinophils (P =.01), and intercellular adhesion molecule 1 expression (P =.04) after specific nasal challenge was also detected.

CONCLUSION

The present results suggest that this sublingual-swallow immunotherapy administered through a rush schedule is clinically effective and safe and that it decreases the immune-mediated inflammatory responses to the allergen.

Minimal persistent inflammation may be controlled by cetirizine

OBJECTIVE

Recent pathophysiologic research demonstrated the crucial role played by adhesion molecules in recruiting and activating inflammatory cells during allergic reaction.

DATA SOURCES

Intracellular adhesion molecule (ICAM-1) expression on nasal epithelial cells is involved in two main pathogenetic phenomena. The first is to allow leukocyte infiltration of respiratory mucosa, since they express LFA1 and Mac1, which are ligands of ICAM-1. This point is very important, because it has been demonstrated that patients with mite allergy (ie, continuously exposed to allergen) present a minimal persistent inflammation (MPI) both at nasal and conjunctival levels. This inflammation is characterized by the presence of leukocyte infiltration and ICAM-1 expression on epithelial cells and by a relationship between specific and nonspecific hyperreactivity in the absence of clinical symptoms. The second is that ICAM-1 is also the main receptor of the human rhinoviruses. This fact may partially explain the relationship among allergy, viral infections, and asthma attacks.

STUDY SELECTION

Different studies have been performed to demonstrate the possible effects on the different clinical aspects of MPI exerted by an antiallergic drug.

RESULTS

It has been demonstrated that cetirizine is able to reduce ICAM-1 expression on nasal epithelial cells and conjunctival nonspecific hyperreactivity in asthmatic asymptomatic children with MPI.

CONCLUSIONS

The therapeutical strategy of mite allergy should be targeted to treat minimal persistent inflammation.

Post-marketing surveillance study on the safety of sublingual immunotherapy in pediatric patients

BACKGROUND

Immunotherapy (IT) is the only causal treatment for allergic subjects recognized to be effective and to offer long-lasting efficacy. The noninjective routes, aimed at improving the safety of the treatment, have been validated as effective in adults, but documentation of their safety in children is still poor. The aim of the present survey study was to assess the safety of sublingual immunotherapy in pediatric patients, by evaluating a large population.

METHODS

A total of 268 children (aged 2-15 years), receiving sublingual IT for respiratory allergy, were followed-up over a period ranging from 3 months to 7 years (mean 34 months). The side-effects possibly due to the treatment were recorded on a proper diary card; self-assessment of the clinical outcome was also evaluated.

RESULTS

About 96000 doses of extract were globally administered. Local side-effects were of no clinical relevance. Eight side-effects were reported (3% of patients; 0.083 per 1000 doses). Seven systemic side-effects (abdominal pain, conjunctival itching, and rhinitis) were mild and required no treatment. One case of urticaria was well controlled with oral antihistamines. No life-threatening event occurred. The clinical outcome was judged excellent or good by 80% of the patients.

CONCLUSIONS

The sublingual IT herein investigated appeared to be well tolerated and safe in pediatric patients. The risk/benefit ratio was therefore favorable.

Double-blind placebo-controlled evaluation of sublingual-swallow immunotherapy with standardized Parietaria judaica extract in children with allergic rhinoconjunctivitis

BACKGROUND

Sublingual-swallow immunotherapy was recently recognized in the World Health Organization Position Paper (Allergen immunotherapy: therapeutic vaccines for allergic diseases) "as a viable alternative to parenteral injection therapy to treat allergic diseases" in adults. More controlled studies were required to assess the efficacy and safety of this treatment in children.

OBJECTIVE

This study was carried out to assess the clinical efficacy and safety profile of sublingual-swallow immunotherapy with high-dose allergen in children with allergies.

METHODS

We used a double-blind placebo-controlled design. Forty-one children with Parietaria -induced rhinoconjunctivitis were randomized to receive sublingual standardized Parietaria judaica extract (n = 20) or placebo (n = 21) for 2 years. The cumulative dose of allergen was 375 times higher than that used in parenteral immunotherapy and the cumulative dose of Par j 1 major allergen was 52.5 mg over 2 years. The main efficacy assessment criteria were symptoms and rescue medication scores recorded on the patients' diary cards. Secondary criteria were changes in skin and conjunctival specific reactivity as well as blood parameters, analyzed after 1 and 2 years of immunotherapy. The safety of the treatment was assessed by evaluating the frequency and severity of adverse effects.

RESULTS

A significant reduction in rhinitis symptoms was observed in the active treatment group during the second season (P =.02), with no difference in medication scores. A significant decrease in skin reactivity (P =.002 after 2 years of treatment) and an increase in the threshold dose for conjunctival allergen provocation test (P =.02) were observed in the active treatment group compared with the group receiving placebo. A significant increase in specific IgG(4 ) levels (P =.02) was also observed in the active group. Immunotherapy was well tolerated.

CONCLUSION

Sublingual-swallow immunotherapy in Parietaria -allergic children provided a clinical benefit and a decreased specific reactivity to the allergen. The safety profile of this treatment, which constitutes an important issue, indicated good tolerance and compliance.

Double-blind placebo-controlled evaluation of sublingual-swallow immunotherapy with standardized Parietaria judaica extract in children with allergic rhinoconjunctivitis

BACKGROUND

Sublingual-swallow immunotherapy was recently recognized in the World Health Organization Position Paper (Allergen immunotherapy: therapeutic vaccines for allergic diseases) "as a viable alternative to parenteral injection therapy to treat allergic diseases" in adults. More controlled studies were required to assess the efficacy and safety of this treatment in children.

OBJECTIVE

This study was carried out to assess the clinical efficacy and safety profile of sublingual-swallow immunotherapy with high-dose allergen in children with allergies.

METHODS

We used a double-blind placebo-controlled design. Forty-one children with Parietaria -induced rhinoconjunctivitis were randomized to receive sublingual standardized Parietaria judaica extract (n = 20) or placebo (n = 21) for 2 years. The cumulative dose of allergen was 375 times higher than that used in parenteral immunotherapy and the cumulative dose of Par j 1 major allergen was 52.5 mg over 2 years. The main efficacy assessment criteria were symptoms and rescue medication scores recorded on the patients' diary cards. Secondary criteria were changes in skin and conjunctival specific reactivity as well as blood parameters, analyzed after 1 and 2 years of immunotherapy. The safety of the treatment was assessed by evaluating the frequency and severity of adverse effects.

RESULTS

A significant reduction in rhinitis symptoms was observed in the active treatment group during the second season (P =.02), with no difference in medication scores. A significant decrease in skin reactivity (P =.002 after 2 years of treatment) and an increase in the threshold dose for conjunctival allergen provocation test (P =.02) were observed in the active treatment group compared with the group receiving placebo. A significant increase in specific IgG(4 ) levels (P =.02) was also observed in the active group. Immunotherapy was well tolerated.

CONCLUSION

Sublingual-swallow immunotherapy in Parietaria -allergic children provided a clinical benefit and a decreased specific reactivity to the allergen. The safety profile of this treatment, which constitutes an important issue, indicated good tolerance and compliance.

Effects of H1 antihistamines on adhesion molecules: a possible rationale for long-term treatment

Our knowledge of the mechanisms underlying the allergic reaction has increased rapidly and has revealed a complex network of cells, mediators and cytokines. The intercellular adhesion system (and the ICAM-1 molecule in particular) appeared to play a pivotal role in the accumulation of inflammatory cells at the site of allergic reaction. The new antihistamines have been demonstrated to be capable of affecting several phenomena of the allergic inflammation, including mediator release, cellular activation and adhesion molecule expression. Taking into consideration the central role of adhesion molecules, the modulation of their expression may represent an important therapeutic target. The nasal and the conjunctival challenges represent two useful models for the in vivo study of the antiallergic activity of drugs, as they allow investigation of a wide variety of parameters: inflammatory infiltrate, ICAM-1 expression, concentration of soluble mediators.

Airborne pollens and prevalence of pollenosis in western Liguria: a 10-year study

During the last 15 years aerobiology has become a relevant branch of allergy, making possible the partial clarification of the relationships between clinical diseases and environment. We performed a 10-year survey of pollen counts and pollen sensitization in a confined area on the western Ligurian coast of Italy in order to evaluate possible changes in aerobiological pattern and to correlate them with the prevalence of sensitization. Pollen counts for the area surrounding Bordighera in the period from 1988-1997 were analyzed; the occurrence of skin sensitization in outpatients were also studied during the same period. We considered the following allergens: Parietaria, grasses, Compositae, Cupressaceae, olive and birch. We also examined the possible differences between patients living on the seaside and those living inland. Over the 10-year period a significant increase in the pollen counts was seen for birch and Compositae (p = 0.001); this was accompanied by a parallel significant increase in the rate of sensitization (p = 0.004 and p = 0.01, respectively). Conversely, an increase in sensitization to Cupressaceae (p = 0.001) and olive (p = 0.03) was also seen, although no change in the pollen counts was detectable. Finally, the prevalence of sensitization to Cupressaceae and Compositae was higher in the patients living in the coastal region than those residing inland. These data suggest that a positive correlation between the pollen counts and the rate of sensitization exists for certain pollens. Nevertheless, for other species such a correlation was not apparent, and additional environmental factors maybe involved in the increased prevalence of sensitization.

Asthma controller therapy: role of antileukotrienes, a new therapeutic class

Asthma is a chronic disease and should be treated with both controller and reliever drugs. Asthma controller therapy is not used sufficiently widely, probably due to low compliance with inhaled drugs, lack of response in some patients to low-medium doses of inhaled steroids and possible adverse events. This review analyses a new class of antiasthmatic drugs, leukotriene receptor antagonists (antileukotrienes). At present, two antileukotrienes are available in Italy: zafirlukast and montelukast. Antileukotrienes improve symptoms and also inhibit the effects of some of the inflammatory mediators involved in the pathogenesis of asthma; therefore, antileukotrienes may be used in monotherapy. In addition, the oral administration route is an advantage for compliance. Antileukotrienes significantly improve pulmonary function, asthma symptoms and inhaled and oral steroid and short-acting beta 2-agonist use. Moreover, antileukotrienes produce a 50% mean reduction in the incidence of asthma exacerbations compared with placebo. From the economic point of view, asthma controller therapy using antileukotrienes is associated with a > 50% (compared with placebo) reduction in healthcare costs (hospitalization due to asthma exacerbation, healthcare contact and absenteeism from work or school), which globally account for 93% of asthma-related costs. Antileukotrienes are indicated in the treatment of persistent mild-to-severe asthma, seasonal allergic asthma, exercise-induced asthma and aspirin-induced asthma. Antileukotrienes are well tolerated independently of the duration of treatment and the incidence of the observed adverse events is substantially similar to that observed using placebo. Owing to good tolerability and compliance and the economic advantages, these agents may be considered a valid therapeutic option for the control and management of asthma as a chronic disease.

Long-term treatment with allergoid immunotherapy with Parietaria. Clinical and immunologic effects in a randomized, controlled trial

BACKGROUND

Specific immunotherapy (SIT) is a valuable treatment for respiratory allergy, and the use of chemically modified allergens (allergoids) has improved its safety, as testified by several studies. We evaluated the effects of a SIT course with an allergoid extract of Parietaria pollen in a double-blind, placebo-controlled trial.

METHODS

The study was double-blind in the first year; then it was prolonged up to 3 years with all patients on active treatment. Clinical effectiveness, safety, skin reactivity, systemic immunologic parameters, and subjective assessment were evaluated. We also had available a self-evaluation recorded in a follow-up visit 4 years after the discontinuation of SIT.

RESULTS

A significant reduction of the symptoms plus drug intake scores during the pollen seasons was observed in the patients receiving active SIT. The placebo patients, after switching to active SIT, also showed significant clinical improvement. The clinical efficacy persisted during years 2 and 3 of treatment. After year 1, the actively treated patients reported a significant subjective improvement (frequency of symptoms, P = 0.001; duration of symptoms, P = 0.024; physical performance, P = 0.043) compared with the placebo group. The self-evaluation by visual analog scale showed that all patients maintained a significant clinical improvement up to 4 years after discontinuing SIT (year 1: active=+31.6%, placebo=-15.7%; year 7: active=+35.8%, placebo=+31.3%). The systemic immunologic changes after active SIT paralleled those described elsewhere (IgE decreased from 22 to 9 and from 21 to 8 IU/ml; IgG4 increased from 43 to 87 and from 18 to 60 IU/ml). A significant decrease in skin reactivity to three different allergen concentrations was observed at year 3 compared with pretreatment values (P<0.05).

CONCLUSIONS

The investigational SIT with Parietaria appeared to be effective and safe; a 3-year course of treatment achieved a long-lasting efficacy.

Continuous antihistamine treatment controls allergic inflammation and reduces respiratory morbidity in children with mite allergy

BACKGROUND

Allergic reaction is characterized by a complex inflammatory process. Some of the new antihistamines have antiallergic effects and can affect the inflammatory cell recruitment via adhesion molecule downregulation. We aimed to assess in a 12-month study whether continuous treatment with an antihistamine (terfenadine) can reduce respiratory symptoms and local inflammation in children with mite allergy.

METHODS

The study was double-blind and placebo-controlled: it involved two parallel groups of children suffering from rhinoconjunctivitis and/or mild intermittent asthma due to mite allergy. They received either terfenadine (1 mg/kg per body weight per day) or placebo for 1 year. Nasal, conjunctival, and bronchial symptoms were recorded by diary cards; at each of the programmed control visits, a nasal scraping for inflammatory cells and ICAM-1 was performed. Some additional clinical parameters were also recorded: days of school absence, extra visits for acute respiratory symptoms, and days of hospital admission.

RESULTS

Only children treated with terfenadine achieved significant control of symptoms (P<0.05 in 8 out of 12 months) and allergic inflammation, as shown by inflammatory cell infiltrate and ICAM-1 expression at nasal level (P<0.001), and had significantly fewer extra visits and school absences than the placebo group (P<0.03). No side-effects were reported in either group.

CONCLUSIONS

The present study demonstrates that continuous terfenadine treatment (1 mg/kg body weight per day) could decrease respiratory symptoms and allergic inflammation, and it had an additional antiallergic effect in reducing ICAM-1 expression on nasal epithelial cells. Therefore, the present results confirm the efficacy of a long-term therapeutic strategy in controlling allergic inflammation.

Distinct regulation of HLA class II and class I cell surface expression in the THP-1 macrophage cell line after bacterial phagocytosis

Expression of HLA and CD1b molecules was investigated in the THP-1 macrophage cell line within 2 weeks following phagocytosis of mycobacteria or Escherichia coli. During the first 2-3 days, cell surface expression of HLA class II and CD1b was drastically down-modulated, whereas HLA class I expression was up-modulated. In the following days both HLA class II and CD1b expression first returned to normal, then increased and finally returned to normal with kinetics similar to that observed for the steadily increased HLA class I. The initial down-modulation of HLA class II and CD1b cell surface antigens was absolutely dependent on phagocytosis of bacteria. Further studies indicated that initial HLA class II cell surface down-modulation (1) was not due to reduced transcription or biosynthesis of mature HLA class II heterodimers, (2) was only partially, if at all, rescued by treatment with IFN-gamma, although both mRNA and corresponding intracellular proteins increased up to sixfold with respect to untreated cells, and (3) resulted in failure of THP-1 cells to process and present mycobacterial antigens to HLA-DR-restricted antigen-specific T cell lines. The existence of a transient block of transport of mature HLA class II heterodimers to the cell surface in the first days after phagocytosis of bacteria may have negative and positive consequences: it decreases APC function early but it may increase it later by favoring optimal loading of bacterial antigens in cellular compartments at high concentration of antigen-presenting molecules.

Azelastine eye drops reduce conjunctival hyperresponsiveness to hyperosmolar glucose challenge in children with asymptomatic mite conjunctivitis

Mite allergy is characterized by a continuous allergen exposure. Persistent inflammation is therefore always detectable; and during symptomless periods as well. It has been reported that mite allergic patients also present a nonspecific hyperreactivity to different stimuli, including hyperosmolar solution. Since azelastine was previously demonstrated to be able to reduce allergic inflammation, the aim of the study was to investigate the effects of the drug on nonspecific conjunctival hyperreactivity in mite-allergic patients. Twenty children with mite allergy were studied. A hyperosmolar conjunctival challenge was performed before and after azelastine eye drops or placebo treatment for a period of 2 weeks. It was found that patients treated with azelastine eye drops showed a significant reduction in nonspecific conjunctival hyperreactivity compared to the placebo group (p = 0.018). It was concluded that azelastine eye drops are able to reduce the nonspecific hyperreactivity present in subjects with mite allergy.

Terfenadine and fexofenadine reduce in vitro ICAM-1 expression on human continuous cell lines

BACKGROUND

Epithelial cells and fibroblasts play an important role in allergic inflammation. Modulation of surface expression of adhesion molecules on epithelial cells by antiallergic drugs has been shown by both in vivo and in vitro studies.

OBJECTIVE

The aim of the study was to evaluate the effect exerted by terfenadine and fexofenadine on adhesion molecules expression (CD54/ICAM-1 and CD29) of a human continuously cultured conjunctival epithelial cell line (WK) and a fibroblast cell line (HEL).

METHODS

By means of flow cytometry analysis, we evaluated ICAM-1 and CD29 expression by WK and HEL epithelial cells in basal condition (at baseline) or after IFN gamma or TNF alpha stimulation in the presence or in the absence of terfenadine and fexofenadine. We also performed immunoenzymatic assays in order to evaluate soluble ICAM-1 released by WK cells and procollagen type I and III and IL6 released by HEL cells.

RESULTS

Terfenadine and fexofenadine significantly reduced ICAM-1 basal expression on WK cells at the concentration of 1 microg/mL and 50 microg/mL, respectively. In addition, both terfenadine and fexofenadine were able to decrease soluble ICAM-1 levels in IFN gamma-stimulated WK cells. On HEL fibroblasts, fexofenadine only was able to inhibit ICAM-1 upregulation induced by IFN gamma. Concerning the release of fibroblast products, we observed a dose-dependent decrease of spontaneous IL6 release only in the presence of fexofenadine.

CONCLUSION

This study shows that terfenadine and fexofenadine exert a biologic effect directly on epithelial cells and fibroblasts reducing ICAM-1 expression and partially reducing soluble ICAM-1 release.

Allergic reactions to honey and royal jelly and their relationship with sensitization to compositae

Honey and royal jelly are complex etherogeneous mixtures of flowers' nectar, sugars, proteins and bee's glandular secretions. The existence of a type I hypersensitivity to honey is still matter of debate, while an aetiological role of Compositae pollens in the clinical manifestations following honey ingestion has been envisaged. We describe two cases of severe systemic reactions (anaphylaxis and generalized urticaria/angioedema) due to honey and royal jelly ingestion in patients sensitized to compositae (mugwort). Both patients had a skin and RAST positivity to mugwort and a positive prick-by-prick to the offending foods. Moreover, in one of the two patients the RAST-inhibition assay showed the strong cross-reactivity between the proteins of honey and mugwort and the SDS-PAGE analysis showed that the major proteic bands from honey and mugwort extracts are largely superimposable. Both the clinical data and the laboratory analysis support the hypothesis of a strict link between sensitization to compositae and adverse reactions to honey and jelly.

Serum intercellular adhesion molecule-1 and long-term response to IFN-alpha2b therapy in chronic hepatitis C

We have attempted to correlate the outcome of interferon (IFN) therapy with circulating soluble intercellular adhesion molecule-1 (sICAM-1) and the level of viremia in a sample of patients with chronic hepatitis C virus (HCV) infection. Forty-two patients were studied. Eighteen patients were maintained in long-term remission following IFN therapy, whereas 24 did not respond or relapsed. Serum concentrations of sICAM-1 were measured by enzyme-linked immunoassay. Viremia was measured by branched DNA signal amplification assay. Basal sICAM-1 was significantly higher in long-term responders than in nonresponder/relapsing patients. It was found that very high levels (>1000 ng/ml) were closely associated with long-term clinical response. A quantitative evaluation of viremia in basal conditions, which was significantly lower in long-term responders, gave completely opposite results. During treatment, sICAM-1 concentrations significantly decreased in the group of long-term responders but not in the nonresponders. sICAM-1 reduction was apparent as early as 1 month after treatment started. Serum sICAM-1 may be a useful parameter in evaluating the outcome of patients with chronic hepatitis C infection treated with IFN.

IL-4 and IL-13 specifically increase adhesion molecule and inflammatory cytokine expression in human lung fibroblasts

Subepithelial fibrosis in the bronchi of asthmatics is the result of an irreversible lung fibroblast activation, triggered by cytokines secreted by IL-4- and IL-5-activated inflammatory cells. Here, we provide evidence that human lung fibroblasts (ICIG7 cells) express a single class of high-affinity IL-4 receptor (IL-4R). This receptor is functional and composed of at least the IL-4Ralpha and IL-13Ralpha1 chains in the absence of the IL-2Rgamma chain. The IL-4Ralpha is efficiently internalized at 37 degrees C within 15 min in the presence of IL-4, whereas this process is slower with IL-13. In ICIG7 cells, IL-4 triggers the tyrosine phosphorylation of at least two proteins (110 and 180 kDa), and up-regulates the transcription of c-fos, c-jun and c-myc proto-oncogenes. In addition, the secretion of several cytokines [IL-6, granulocyte colony stimulating factor and granulocyte macrophage colony stimulating factor (GM-CSF)] as well as the expression of beta1 integrin and VCAM-1 adhesion molecules are augmented by IL-4. IL-13 displays similar biological activities, but less effectively than IL-4. On the other hand, ICIG7 cells could constitute a lung fibroblast population defined by the spontaneous release of several pro-inflammatory cytokines (IL-6, IL-11 and GM-CSF) and cell surface phenotype (CD4 and Thy-1). Through this peculiar cytokine pattern and the IL-4/IL-13-dependent activities, these cells could act as effector cells in the pathogenesis of asthma, triggering and maintaining the recruitment, homing and activation of bone marrow-derived inflammatory cells, and playing a role in the remodeling process of the airways.

Interleukin (IL) 4 and IL-13 act on human lung fibroblasts. Implication in asthma

Airway hyperresponsiveness leading to subepithelial fibrosis is mediated by inflammatory cells activated by T helper (Th) 2-derived cytokines such as IL-4 and IL-5. By analyzing the phenotype and response of human lung fibroblasts derived from either fetal (ICIG7) or adult (CCL202) tissue as well as from a Th2-type stromal reaction (FPA) to IL-4 and IL-13, we provide evidence that human lung fibroblasts may behave as inflammatory cells upon activation by IL-4 and IL-13. We show that the three types of fibroblasts constitute different populations that display a distinct pattern in cell surface molecule expression and proinflammatory cytokine and chemokine release. All fibroblasts express functional but different IL-4/IL-13 receptors. Thus, while IL-4 receptor (R) alpha and IL-13Ralpha1 chains are present in all the cells, CCL202 and FPA fibroblasts coexpress the IL-13Ralpha2 and the IL-2Rgamma chain, respectively, suggesting the existence of a heterotrimeric receptor (IL-4Ralpha/IL-13Ralpha/IL-2Rgamma) able to bind IL-4 and IL-13. Stimulation with IL-4 or IL-13 triggers in the fibroblasts a differential signal transduction and upregulation in the expression of beta1 integrin and vascular cell adhesion molecule 1 and in the production of IL-6 and monocyte chemoattractant protein 1, two inflammatory cytokines important in the pathogenesis of allergic inflammation. Our results suggest that when activated by IL-4 and IL-13, different subsets of lung fibroblasts may act as effector cells not only in the pathogenesis of asthma but also in lung remodeling processes. They may also differentially contribute to trigger and maintain the recruitment, homing, and activation of inflammatory cells.

The relationship between clinical efficacy of specific immunotherapy and serum intercellular adhesion molecule-1 levels

The intracellular adhesion molecule-1 (ICAM-1) is a reliable marker of allergic inflammation; its soluble isoform in serum is hypothesized to reflect the severity of the disease, therefore it may be used to monitor the efficacy of specific immunotherapy. We evaluated the levels of soluble ICAM-1 in the serum of 14 patients with grass-induced respiratory allergy before and after 12 months of specific immunotherapy, and correlated this parameter with the clinical outcome, measured using a visual analog scale. We found that in the majority of the patients, soluble ICAM-1 levels paralleled the clinical trend of the disease, with a significant decrease of soluble ICAM-1 in patients with successful specific immunotherapy (Spearman's correlation test: r = 0.57; p < 0.001). Therefore, we hypothesize that soluble ICAM-1 could be regarded as a reliable indirect marker of specific immunotherapy efficacy and that it could be used for monitoring clinical outcome.

Intranasal fluticasone propionate reduces ICAM-1 on nasal epithelial cells both during early and late phase after allergen challenge

BACKGROUND

Allergen specific nasal challenge (ASNC) is an optimal method to study the pathophysiological mechanisms sustaining the allergic inflammation and in particular the adhesion molecule system, which is involved in cellular infiltration of nasal mucosa. Topical steroids have been accepted as a highly effective anti-inflammatory therapy for allergic rhinitis.

OBJECTIVE

The aim of this double-blind placebo- controlled study was the evaluation of clinical and cytological parameters, including ICAM-1 expression on nasal epithelial cells, after a 4 week treatment with nasal fluticasone propionate (200 microg/daily) or placebo, using the model of ASNC.

METHODS

Twenty allergic rhinitics underwent nasal challenge before and after treatment. The following parameters were evaluated: (i) nasal symptoms (rhinorrhoea, itching, sneezing, obstruction), (ii) inflammatory cells (eosinophils and neutrophils), (iii) ICAM-1 expression on nasal epithelial cells at baseline, 30 min (early phase) and 6 h (late phase) after ASNC.

RESULTS

Fluticasone propionate was capable of reducing: (i) clinical symptoms during both early (P<0.001) and late phase (P<0.04), (ii) eosinophil (P<0.002) and neutrophil (P<0.001) infiltrate during late phase, and (iii) ICAM-1 expression on nasal epithelial cells during both early (P < 0.01) and late phase (P < 0.03).

CONCLUSIONS

The present results demonstrate that fluticasone propionate exerts a significant action on early and late phase clinical events following specific nasal challenge, reducing also the cellular influx during the late phase. This event is likely due to the modulation of ICAM-1 expression on epithelial cells.

Randomised controlled trial of local allergoid immunotherapy on allergic inflammation in mite-induced rhinoconjunctivitis

BACKGROUND

Non-injective routes of immunotherapy are thought to be valuable therapeutic options for respiratory allergy. We investigated the clinical efficacy and the effects of sublingual/oral immunotherapy on conjunctival allergic inflammation in patients with mite-induced respiratory allergy.

METHODS

We used a double-blind placebo-controlled design. 20 patients with mite-induced rhinoconjunctivitis (six of whom also had mild asthma) were randomly assigned sublingual/oral immunotherapy (n=10) or placebo (n=10) for 2 years. We assessed symptom score by diary cards and inflammatory-cell infiltrate, and expression of intercellular adhesion molecule 1 (ICAM-1) in the conjunctiva after specific allergen challenge at enrollment and after 12 and 24 months of treatment.

FINDINGS

We found significantly lower symptom scores in the immunotherapy group than in the placebo group in most of the winter months (p=0.05). Compared with the placebo group, inflammatory-cell infiltration after conjunctival challenge, and ICAM-1 expression on conjunctival epithelium decreased significantly in the first year of treatment in the immunotherapy group (p=0.04 and p=0.02, respectively). These effects were also seen for the minimum persistent inflammation, in symptom-free patients exposed constantly to allergens (p=0.02). Serum concentrations of eosinophil cationic protein decreased significantly (p=0.04). Immunotherapy was well tolerated and compliance was good.

INTERPRETATION

Our results suggest that this immunotherapy is clinically effective in rhinoconjunctivitis and that it decreases the immune-mediated inflammatory responses to the allergen.

Allergen-specific nasal challenge: response kinetics of clinical and inflammatory events to rechallenge

Allergen-specific nasal challenge is a valid and reliable tool for studying the pathophysiological mechanisms involved in allergic inflammation. Nasal challenge induces an immediate clinical response in allergic subjects and a concomitant appearance of an inflammatory infiltrate. The mucosal inflammation may persist up to 48-72 h after allergen exposure. If the subjects are rechallenged within this period the response is more pronounced: the so-defined priming effect. The aim of the study was to evaluate the effects of the nasal rechallenge, performed at different time intervals: 3 days, 1, 2 and 4 weeks after the first challenge. Forty allergic subjects underwent two nasal challenges: at baseline and after the periods mentioned above (10/group). Symptoms and inflammatory cells (eosinophils and neutrophils recovered by nasal brushing) were assessed. The 3-day-interval group showed a hyperreactive response (priming effect), the 1- and 4-week-interval groups showed a response similar to baseline, and the 2-week-interval group showed a hyporeactive response ('tolerogenic effect'). The last phenomenon may be due to a possible immunologic response similar to that achievable during local specific immunotherapy. The present results further elucidate the kinetics of allergen-driven inflammatory events and highlight the importance of the time period chosen for rechallenge. The latter fact may be of primary importance in clinical trials involving specific challenge.

Cetirizine reduces conjunctival nonspecific hyperreactivity in children with mite allergy

As mite allergy is characterized by a continuous allergen exposure, persistent inflammation is always detectable even during symptomless periods. It has been reported that mite allergic patients present a nonspecific hyperreactivity to different stimuli, including hyperosmolar solution. Since it has been reported previously that cetirizine is able to reduce minimal persistent inflammation due to mite allergy, the aim of the study was to investigate the effect of cetirizine on nonspecific conjunctival hyperreactivity. Twenty children with mite allergy were studied; two hyperosmolar conjunctival challenges were performed before and after cetirizine or placebo treatment, lasting one week. Patients treated with cetirizine showed a significant reduction in nonspecific conjunctival hyperreactivity compared to the placebo group (p < 0.05). In conclusion, cetirizine was able to reduce nonspecific hyperreactivity related to allergic inflammation.

Continuous versus on demand treatment with cetirizine for allergic rhinitis

BACKGROUND

Cetirizine is an antihistamine used in the treatment of allergic rhinoconjunctivitis, that has antiallergic activity.

OBJECTIVE

The aim of this double-blind, placebo-controlled, parallel group study was to evaluate the clinical efficacy and the antiallergic activity of cetirizine, administered either continuously or on demand over a 4-week period of natural allergen exposure.

METHODS

Twenty patients, with allergic rhinoconjunctivitis due to grass and/or Parietaria pollen, were enrolled. They were randomized into 2 parallel groups: one group received the standard dose of 10 mg cetirizine daily and the other received placebo, all patients were allowed to take an additional daily dose of cetirizine when needed. Variables evaluated were clinical symptoms (recorded on diary cards), number of additional on demand cetirizine doses, nasal inflammatory cells, and pollen counts.

RESULTS

The results of the present study show that patients treated with continuous administration of cetirizine achieved significant symptomatic relief and inflammatory control (decreases in numbers of infiltrating neutrophils and eosinophils) in comparison to patients treated on demand.

CONCLUSION

Continuous treatment with cetirizine is more effective than on demand treatment. Continuous treatment reduces clinical and inflammatory variables more than symptomatic treatment and the on demand therapy can determine acceptable clinical control, but does not reduce allergic inflammation.

Treatment of allergic diseases during pregnancy

Pregnancy may variously modify the natural history of allergic disorders through occurring endocrinologic, functional and immunological changes. A pharmacologic treatment of allergic diseases (mainly asthma) is often necessary during pregnancy. On the other hand, a drug should be not potentially teratogenic and should not have serious side effects, both for the mother and the fetus. This paper reviews current knowledge about allergic diseases during pregnancy, considering the points of view of the different specialists involved in their management. Topical mucosal agents seem to be the safest, due to their minimal or absent absorption which should reflect reduced side effects. Preferred agents should be topical antihistamines (for rhinitis and conjunctivitis), and cromones and topical steroids (for asthma), as they are both safe and effective.

Aerobiologic particle sampling by a new personal collector (Partrap FA52) in comparison to the Hirst (Burkard) sampler

A new personal portable sampler of biologic particles (Partrap FA52, Coppa, Biella, Italy) was used for pollen sampling in comparison with Hirst's (Burkard) fixed device. The aerobiologic samplings were carried out simultaneously outdoors with the two devices coupled on the same axis, during the daytime of 10 dry, nonconsecutive spring days. The total amount and the percentages of the pollens most often trapped by the two collectors were compared by Student's t-test for paired samples. The Partrap FA52 showed a highly significant efficacy, quite comparable to that of the Burkard device, in pollen trapping for both the total number (P < 0.0001) and the percentages of Parietaria (P < 0.0001), pine (P < 0.002), and grass (P < 0.0001) pollens. Therefore, Partrap FA52 proved to be highly effective in obtaining quantitative and qualitative aerobiologic samples in comparison with the commonly used fixed samplers.

Inhibition of adhesion molecules by budesonide on a human epithelial cell line (lung carcinoma)

Inhaled corticosteroids in the treatment of asthma have been shown to produce marked reductions in the number of inflammatory cells (mainly mast cells and eosinophils) and their products at bronchial level (such as cytokines). Recently, it has been demonstrated that epithelial cells express ICAM-1/CD54 in allergic patients both during natural allergen exposure and after allergen challenge. We have previously demonstrated that deflazacort (a systemic steroid) reduces the expression of ICAM-1 on conjunctival epithelial cells. The present study aimed to evaluate the effects exerted by budesonide on adhesion molecule expression by a human epithelial cell line (lung carcinoma: DM) and on soluble ICAM-1. Budesonide was added at concentrations corresponding to 10(-8), 10(-7), and 10(-6) mol/l in cultured epithelial cells, either in the absence of any stimulus or in the presence of interferon-gamma (IFN-gamma) at 500 U/ml. After 24 h of incubation, cytofluorometric analysis was performed for ICAM-1 and CD29/VLA beta 1. The 24-h supernatants of the same cultures were collected and then evaluated for soluble ICAM-1 (sICAM-1). The results showed that budesonide inhibits ICAM-1 and CD29 basal expression on the cells studied (P < 0.05): budesonide was effective in a dose-dependent manner. In addition, budesonide reduced surface ICAM-1 upregulation induced by IFN-gamma at 500 U/ml (P < 0.05). Finally, cell cultures with budesonide showed decreased levels of soluble ICAM-1 in basal condition, but not after IFN-gamma stimulation.

Long-term follow-up of nasal immunotherapy to Parietaria: clinical and local immunological effects

BACKGROUND

Local nasal immunotherapy (LNIT) with extracts in powder has been demonstrated clinically effective and devoid of side-effects in several controlled trials; nevertheless, no data concerning the long-term effects of LNIT are presently available.

METHODS

In a recent double-blind, placebo-controlled study of LNIT to Parietaria pollen we observed, by means of specific nasal provocation test (SNPT) that LNIT is able to modify the local allergic inflammatory response. In the present study we followed up the same patients in open fashion for 2 further years.

RESULTS

The results confirmed the clinical efficacy of LNIT and showed that it is strictly dependent on pre-seasonal administration: in fact, after LNIT discontinuation a clinical relapse was observed. A certain long-lasting protective effect on SNPT parameters (nasal symptoms and neutrophils infiltration) was also observed, whereas an increase of eosinophils count and ICAM-1 expression on nasal epithelial cells appeared as possible markers of clinical relapse.

CONCLUSION

The present study suggests that pre-seasonal LNIT can be taken in consideration in selected subjects as prophylactic treatment for pollen-induced rhinitis. In addition, the results obtained provide informations about the duration of clinical efficacy and add data about the local allergic inflammation and its modulation.

Absorption and distribution kinetics of the major Parietaria judaica allergen (Par j 1) administered by noninjectable routes in healthy human beings

BACKGROUND AND OBJECTIVE

The clinical effectiveness of noninjectable routes for specific immunotherapy has been demonstrated in many studies, but no data are available on the kinetics of allergens administered by these routes. Therefore we studied the kinetics of the radiolabeled purified major Parietaria judaica allergen (Par j 1) after sublingual, oral, and intranasal administration to healthy human beings.

METHODS

After tracer administration (10 to 12.5 microg of Par j 1 labeled with iodine 123) to nonallergic volunteers, scintigraphic images were recorded at various times. Blood samples were also obtained at serial intervals to evaluate the absorption and distribution of radioactivity in plasma and to identify circulating radioactive species by molecular exclusion gel chromatography.

RESULTS

When the sublingual route was used, no circulating radioactivity was detected until the tracer was kept under the tongue. The labeled allergen was rapidly degraded and absorbed in the gastrointestinal tract after swallowing. Plasma radioactivity peaked at about 1.5 to 3 hours and was mostly represented by free radioiodine and small radiolabeled peptides. Some activity not caused by free 123I remained associated with the oral mucosa up to 18 to 20 hours after administration. When the oral route was used, the results were similar to those observed after swallowing the sublingually administered allergen but without any persistence of the tracer in the mouth. When the intranasal route was used, the pattern of plasma radioactivity mimicked that of the sublingual and oral routes, with absorption of activity from the radiolabeled allergen occurring in the gastrointestinal tract after transport to the pharynx by mucociliary clearance. A relevant fraction of the tracer was retained on the nasal mucosa up to 48 hours after administration.

CONCLUSION

The data in this study provide the first experimental basis for exploring the in vivo kinetics of allergen administered through noninjectable routes for specific immunotherapy in human beings.

Cetirizine treatment of allergic cough in children with pollen allergy

Cetirizine, an antihistamine widely used in the treatment of allergic rhinoconjunctivitis, also has antiallergic activity. The present study aimed to evaluate cetirizine as a treatment for children with allergic cough due to pollen allergy. This was a parallel-group, double-blind, placebo-controlled, randomized study. Twenty children with pollinosis were enrolled: they were subdivided into two groups receiving a 1-month treatment during the pollen season. The following variables were monitored: 1) clinical symptoms and respiratory data (spirometry and PEF) evaluated at baseline and at the end of the study by allergists and by a daily diary card, and 2) pollen count. This study shows that cetirizine treatment reduces cough intensity (P < 0.05) and frequency (P < 0.01). In conclusion, cetirizine does clinically improve cough due to pollen allergy.

In situ hybridization analysis of ICAM-1 (CD54) mRNA on conjunctival epithelium during allergic inflammation

BACKGROUND

The intercellular adhesion molecule ICAM-1 has been detected by immunohistochemical methods on epithelial cells of the conjunctiva and nose during allergic inflammation.

OBJECTIVE

The aim of the present study was to evaluate whether ICAM-1 expression on conjunctival epithelium derives from endogenous synthesis or is merely due to passive uptake of soluble ICAM-1 released from inflammatory cells.

METHODS

In situ hybridization was performed using a 3' end dygoxygenin-labelled specific DNA oligonucleotide probe on fixed conjunctival smears from allergic subjects challenged with, or naturally exposed to the allergen, and from healthy subjects. Immunocytochemistry for ICAM-1 was performed by alkaline phosphatase antialkaline phosphatase.

RESULTS

In allergic patients, both naturally exposed to the allergen and after specific challenge, a clear hybridization pattern on epithelial cells was apparent. Out of allergen exposure, some symptomfree pollinosic subjects, as well as a few healthy volunteers showed mild ICAM-1 mRNA cytoplasmic staining in the absence of immunohistochemically detectable ICAM-1. This finding may explain the very early appearance of ICAM-1 on conjunctival epithelium following specific challenge in allergic individuals.

CONCLUSIONS

These results indicate that the presence of ICAM-1 on conjunctival epithelium during allergic inflammation derives from endogenous synthesis and not from uptake of soluble ICAM-1.

Preseasonal specific immunotherapy with modified Phleum pratense allergenic extracts: tolerability and effects

The preparation of chemically modified allergens, with a reduced IgE binding capacity (responsible for side effects with traditional immunotherapy) but with the same or greater immunogenic activity, is one of the paths followed to obtain better results with specific immunotherapy (IT). The aim of the study was to evaluate the tolerability and effects of an extract Phleum pratense, modified with glutaraldehyde and absorbed on aluminium hydroxide, in controlling the seasonal symptomatology induced by grass pollen in a group of 10 monosensitized patients, compared to a group of 10 similar patients not treated with specific IT but with drugs alone. The monitoring parameters were: 1) Clinical: a) symptomatology after specific conjunctival provocation test (pre and post seasonal) and during the natural exposure to the allergen b) drug consumption. 2) Immunological (peripheral blood eosinophils, total and specific IgE, total specific IgG). 3) Cytological, before, during and after the pollen season.

CONCLUSIONS

In subjects treated with specific IT a) both the overall symptomatology and the drug consumption resulted significantly reduced compared to the controls (p = 0.045); b) the phlogistic infiltrate showed a tendency to decrease during the pollen season; c) the peripheral blood eosinophils, total and specific IgE and IgG did not show any significant variation compared to the controls; d) no systemic reactions occurred and there were only two slight local reactions.

Intercellular adhesion molecule-1 on cultured human epithelial cell lines: influence of proinflammatory cytokines

The expression of intercellular adhesion molecule-1 (CD54 or ICAM-1) on epithelial cells during acute or chronic inflammation may favor the interaction between epithelial cells and leukocytes expressing the natural ligands of ICAM-1, LFA-1 (CD11a/CD18), and Mac-1 (CD11b/CD18). We have evaluated in vitro the expression of ICAM-1 by a conjunctival (WK) and an intestinal (I407) human continuous epithelial cell line. Cells were cultured for 24 h in the presence or absence of IFN-gamma, TNF-alpha, IL-1 beta, IL-4, IL-6, IL-8, IL-10, and TGF-beta 1. Both epithelial cell lines showed a constitutive expression of ICAM-1. IFN-gamma at 500 U/ml and TNF-alpha at 200 ng/ml upregulated ICAM-1 expression; IL-1 beta at 100 pg/ml upregulated ICAM-1 on WK cells only. Cells cultured in the presence of both IFN-gamma and TNF-alpha exhibited a mean fluorescence intensity far greater than those cultured with IFN-gamma or TNF-alpha alone. I407 and WK cells were able to release soluble ICAM-1. IFN-gamma and TNF-alpha enhanced the release of sICAM-1. IL-4, IL-6, IL-8, IL-10, and TGF-beta 1 did not affect either ICAM-1 expression or sICAM-1 release. In conclusion, continuously cultured human epithelial cells may express ICAM-1 on their surface and release it in culture medium. These phenomena are upregulated by proinflammatory cytokines.

Nonfatal systemic reactions to subcutaneous immunotherapy: a 10-year experience

The present retrospective study reviews our clinical experience with Subcutaneous immunotherapy (SIT) over a 10 year period (1981-1991), in order to assess both incidence and clinical features of nonfatal systemic reactions due to this treatment. 192,505 injections were globally administered to 2,206 outpatients, following the suggested precautionary guidelines. We observed 115 systemic reactions (5.2% of patients and 0.06% of injections) and no fatalities. The association asthma + urticaria was the most frequent reaction (67%), followed by asthma alone (22%). No risk factor related to age, gender, pollen season or manufacturer was observed. The occurrence of systemic reactions was highly frequent in asthmatic patients, but approximately 1/3 of the patients who presented reactions had never previously suffered from asthma. The largest part of the observed reactions occurred during the maintenance phase of treatment. Almost all adverse events occurred within 30 minutes after the injection and they were promptly controlled by routine therapy. We conclude that subcutaneous immunotherapy, if performed with careful compliance to good clinical practice rules, is a safe treatment for respiratory allergy.

Seasonal rhinitis and azelastine: long- or short-term treatment?

BACKGROUND

Azelastine is a topical antihistamine, clinically demonstrated to be effective in allergic rhinitis.

OBJECTIVE

We evaluated the clinical efficacy and the antiallergic activity of azelastine nasal spray, administered 0.56 mg per day, 0.28 mg per day, or on demand over a 3-month period during natural allergen exposure, in a double-blind, placebo-controlled fashion.

METHODS

Thirty patients, sensitized to grass or Parietaria pollen, were allocated to three treatment groups: those receiving the standard dosage (0.14 mg/nostril two times a day), half the dosage (0.07 mg/nostril two times a day), or placebo daily for 3 months. All patients were allowed to take additional doses of azelastine when needed. Evaluation parameters were as follows: clinical symptoms recorded on a diary card, number of additional, on-demand azelastine puffs, nasal inflammatory cell count, intercellular adhesion molecule-1 expression on nasal epithelial cells, and pollen count.

RESULTS

This study showed the following: (1) the half dose (0.28 mg/day) and the standard dose (0.56 mg/day) were equally effective in reducing clinical symptoms (p = NS), although the standard dosage required fewer additional puffs during times of peak pollen counts (p < 0.05); (2) both dosages were able to reduce the allergic inflammation (p < 0.05 vs placebo); and (3) on-demand use achieved acceptable clinical control but did not significantly reduce allergic inflammation.

CONCLUSION

Continuous treatment was more effective than on-demand use as assessed by both clinical evaluation and antiinflammatory action.