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.