Preliminary evidence for 'aberrant' expression of the leukocyte integrin LFA-1 (CD11a/CD18) on conjunctival epithelial cells of patients with mite allergy.

BACKGROUND: We have previously shown aberrant expression of the 'leukocyte' integrin LFA-1 on epithelial cells in chronic autoimmune thyroiditis. In the present study we investigated whether conjunctival epithelial cells, which bear the adhesion molecule ICAM-1 on their surface during allergic inflammation, may also aberrantly express its natural ligand, the 'leukocyte' integrin LFA-1. METHODS: We studied 13 patients with rhinoconjunctivitis allergic to mites, chronically exposed to the allergen, 11 patients allergic to pollen tested out of the pollen season and 8 normal volunteers. Single and double immunocytochemical staining of conjunctival smears was employed. RESULTS: LFA-1 staining on epithelial cells was demonstrated in 12/13 patients allergic to mites and not in normal controls or in patients allergic to pollen tested out of the pollen season. The epithelial localization of LFA-1 was confirmed by double staining with anti-LFA-1 and anti-cytokeratin antibodies (both immunocytochemical and immunofluorescence). CONCLUSIONS: Coexpression of LFA-1 and ICAM-1 during persistent allergen stimulation may be relevant for interaction between epithelial cells and activated effector cells, such as eosinophils, which bear on their surface both ICAM-1 and its beta2 integrin ligands.

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.

Allergen-specific conjunctival challenge in asthma. An additional diagnostic tool to define sensitization.

Reversible airway obstruction and airway inflammation following allergen exposure represent crucial pathophysiological features of allergic asthma. In order to investigate these events, bronchial-specific challenge is commonly employed although it may be complicated and may not be free of possible risks. Therefore, we evaluated the applicability of allergen-specific conjunctival challenge (ASCC) in adults with asthma to define the diagnosis of specific sensitization and the grade of specific sensitization, and to detect the presence of allergic inflammation. As recently described, conjunctival challenge represents an easy diagnostic tool in allergic inflammation. We studied 30 symptomless patients with a history of mild asthma, including 20 allergic patients, 10 females and 10 males (18-48 years old), sensitized to Parietaria judaica only, with a history of recurrent asthma attacks during seasonal natural exposure to allergen, 10 nonallergic patients, 7 females and 3 males (28-55 years old), with a history of recurrent asthma attacks unrelated to any allergen exposure, and 10 healthy volunteers as controls. The study was performed outside the pollen season. The ASCC induced a highly significant early-phase clinical reaction and a highly significant inflammatory cell infiltrate in the asthmatic patients sensitized to P. judaica when compared to other study groups (p < 0.001). The ASCC showed as 100% sensitivity, specificity, predictive value of positive and negative results in the group of sensitized asthmatic patients when compared to unsensitized ones and to healthy subjects. The study confirms the reproducibility and usefulness of ASCC to diagnose allergy and to define its grade. These data strongly suggest ASCC employment also in patients with a single history of allergic asthma.

Azelastine eye drops reduce and prevent allergic conjunctival reaction and exert anti-allergic activity.

BACKGROUND: Azelastine is a selective H1-receptor antagonist, which has previously been demonstrated to be effective in the treatment of allergic rhinitis. We have recently demonstrated that nasal azelastine inhibits the clinical and inflammatory events following nasal allergen challenge. Particularly, we focused our attention on ICAM-1 expression on epithelial cells, since it is the natural ligand of LFA-1, an adhesion molecule expressed by leucocytes, including eosinophils. OBJECTIVE: Since azelastine ocular drops are now available, the aim of the present study was the evaluation of the anti-allergic activity in the model of allergen specific conjunctival challenge (ASCC). METHODS: Twenty outpatients with allergic rhinoconjunctivitis due to Parietaria Judaica (Wall Parietary) were included outside the pollen season. The study was designed as randomized, placebo-controlled, double-blind and parallel group, developed in two parts. The former investigated the onset of effect of a single dose of azelastine eye drops administered 20 min after clinical response due to ASCC. The latter evaluated the clinical and inflammatory parameters following ASCC after 7-days treatment with azelastine. Clinical parameters (hyperaemia, itching, lacrimation and eyelid swelling) were evaluated at baseline, 5, 10, 20 and 30 min (i.e. early phase reaction-EPR) and 6 h (i.e. late phase reaction-LPR) after ASCC. Cytological assessment (number of neutrophils, eosinophils. monocytes and lymphocytes) and ICAM-1 expression on conjunctival epithelial cells were evaluated at baseline, 30 min (i.e. early phase reaction-EPR) and 6 h (i.e. late phase reaction-LPR) after ASCC. RESULTS: When administered 30 min after ASCC, azelastine produced a clinical effect ranging between 10 and 20 min after eye drops administration (P < 0.01). After 7 days of treatment, 30 min after ASCC, azelastine induced a reduction of symptom scores during EPR and LPR (P < 0.01), a reduction of inflammatory cell infiltration during both EPR (P < 0.01) and LPR (P < 0.01), and a reduction of ICAM-1 expression during EPR and LPR (both P < 0.01). Placebo did not modify any of the studied parameters. CONCLUSION: Azelastine eye drops exert anti-allergic activity, inducing a rapid improvement of clinical events when administered after ASCC, and reducing both symptoms and cellular infiltration when administered before ASCC. Finally, azelastine down-regulates ICAM-1 expression on epithelial conjunctival cells, confirming the results obtained at nasal level.

Antiallergic activity of topical lodoxamide on in vivo and in vitro models.

Lodoxamide is an antiallergic drug acting as a mast-cell stabilizer, which is effective in the treatment of allergic conjunctivitis. The study aimed to evaluate the effect of lodoxamide eye-drops on the inflammatory early-phase reaction (EPR) changes induced by allergen-specific conjunctival challenge (ASCC). This was a cross-over, double-blind, placebo-controlled, randomized study, including 10 outpatients suffering from allergic rhinoconjunctivitis due to Parietaria judaica. Patients received one drop of lodoxamide tromethamine 0.1% or placebo 30 min before each ASCC. Clinical evaluation and cytologic assessment were done at baseline and 30 min after each ASCC. Lodoxamide induced a reduction in total symptom score and hyperemia during the EPR (P < 0.05). Lacrimation, itching/burning, and eyelid swelling were only slightly (nonsignificantly) reduced. Lodoxamide induced a reduction in the total number of inflammatory cells and neutrophils during the EPR (P < 0.02). Eosinophil and lymphocyte number and ICAM-1 expression showed only a slight, not statistically significant decrease. Placebo did not affect the studied parameters. Lodoxamide reduced early clinical events and cellular changes after ASCC consistently with its activity as mast-cell stabilizer. Moreover, lodoxamide was able to downregulate in vitro ICAM-1 expression on the continuously cultured, differentiated conjunctival cell line WK. This was shown both in basal conditions (P < 0.05) and upon interferon-gamma stimulation (P < 0.03), although at high concentration.

Topical ocular levocabastine reduces ICAM-1 expression on epithelial cells both in vivo and in vitro.

BACKGROUND: Levocabastine is a selective topical H1 antagonist, effective in the treatment of seasonal allergic rhinitis and conjunctivitis. OBJECTIVE: We evaluated the possible effects of levocabastine eye drops on early (EPR) and late phase (LPR) inflammatory changes induced by allergen-specific conjunctival challenge (ASCC). We focused our attention on the possible effect of levocabastine on expression of the intracellular adhesion molecule-1 (ICAM-1) on epithelial cells. Such a phenomenon is likely to play an important role in allergic inflammation. METHODS: The study was a double-blind, placebo-controlled, randomized trial, performed in cross-over, outside the pollen season. Ten out-patients suffering from allergic rhinoconjunctivitis due to parietaria judaica (wall parietary) were enrolled. Patients randomly received levocabastine eye drops (0.5 mg/mL) or placebo eyedrops, one drop in the left eye (right eye as control), 30 min before ASCC. Clinical evaluation (hyperaemia, burning-itching, lacrimation and eyelid swelling) and cytological assessment (number of neutrophils, eosinophils and lymphocytes, and ICAM-1 expression on conjunctival epithelium) were evaluated at baseline, 30 min and 6 h after ASCC. In parallel, we evaluated the in vitro effect of levocabastine at concentrations ranging from 2 x 10(-9) M to 2 x 10(-5) M on ICAM-1 expression and shedding by a continuously cultured differentiated epithelial cell line (WK). RESULTS: Levocabastine reduced symptom scores during EPR (15 min and 30 min, P < 0.002), inflammatory cell infiltration during EPR (P < 0.002 for neutrophils, eosinophils and lymphocytes) and ICAM-1 expression on epithelium both during EPR (P < 0.002) and LPR (P < 0.02). LPR symptom scores and inflammatory cell infiltration were only slightly modified by levocabastine treatment. In vitro levocabastine at 2 x 10(-5) M concentration was able to down-regulate basal ICAM-1 expression, although it exerted no effect on ICAM-1 release by epithelium. CONCLUSION: Levocabastine exerts anti-allergic activity, in that it reduces in vivo inflammatory cell infiltration due to ASCC, and also adhesion molecule expression on conjunctival epithelium. The latter phenomenon may be due, at least in part, to a direct effect of levocabastine on epithelial cells.

Minimal persistent inflammation is present at mucosal level in patients with asymptomatic rhinitis and mite allergy.

The natural exposure to house dust mites causes sensitization in genetically susceptible patients. Persistent exposure of sensitized patients causes chronic inflammation, and consequently, hyperreactivity, thus promoting the development of clinical features. Recently, intercellular adhesion molecule-1 (ICAM-1)/CD54 expression on epithelial cells triggered by allergen has been demonstrated and related to the inflammation caused by the allergic reaction. Therefore we evaluated the possible presence of inflammation (i.e., inflammatory cell infiltrate and ICAM-1/CD54 expression on epithelium) at conjunctival and nasal levels in patients with asymptomatic allergic rhinitis caused by mites, in their relatives living in the same environment, and in healthy volunteers. In addition, the possible relationship between inflammation and house dust mite allergen exposure was evaluated. Conjunctival and nasal scrapings of allergic subjects enrolled in the study showed many inflammatory cells. A mild ICAM-1/CD54 expression on conjunctival and nasal epithelium was detectable in allergic subjects, whereas relatives and healthy volunteers showed few inflammatory cells and no ICAM-1/CD54 expression on epithelial cells. A detectable level of house dust mite, sufficient to cause sensitization, was found in all houses. This study demonstrates a minimal persistent inflammation at conjunctival and nasal levels constantly detectable in patients without symptoms who are sensitized to mites and continuously exposed to the natural allergens.

Oxatomide reduces inflammatory events induced by allergen-specific conjunctival challenge.

BACKGROUND: Allergen-specific conjunctival challenge is a safe and reproducible experimental model to evaluate effectiveness and possible mechanism(s) of action of drugs employed in the treatment of allergic diseases. OBJECTIVE: The protective effect of oxatomide on inflammatory changes that follow allergen-specific conjunctival challenge was assessed in 20 patients with rhinoconjunctivitis due to Parietaria judaica in a double-blind study. METHODS: After a screening allergen-specific conjunctival challenge, patients were randomized into two treatment groups, each being given oxatomide (oral tablets) at 60 mg daily or matching placebo for seven days during off-pollen season. Clinical evaluation, cytologic assessment (number of inflammatory cells and ICAM-1 expression on epithelial cells) were assessed at baseline, 30 minutes, 6 hours, and 24 hours after allergen-specific conjunctival challenge, before and after treatment. In addition, electrocardiograms were obtained before and after treatment. RESULTS: Early phase reaction clinical events as well as total numbers of inflammatory cells were significantly reduced by oxatomide compared with placebo. Late phase reaction clinical events as well as total numbers of inflammatory cells were significantly reduced by oxatomide compared with placebo. ICAM-1 expression was significantly reduced by oxatomide in early phase reactions and late phase reactions compared with placebo. No pathologic cardiac events were detected in any subject. CONCLUSIONS: Oxatomide has a protective effect on clinical and cellular early phase reactions and late phase reactions (including ICAM-1 expression on epithelium) induced by allergen-specific conjunctival challenge and is safe and well tolerated.

Loratadine in the treatment of cough associated with allergic rhinoconjunctivitis.

BACKGROUND: Antihistaminic treatment of allergic asthma or cough-type asthma, including cough associated with allergic rhinocojunctivitis, has been recently reconsidered prospectively since new very potent compounds, nonsedating with anti-allergic properties, are available. OBJECTIVE: The possible effectiveness of loratadine in the treatment of allergic cough was assessed in 20 patients with allergic rhinoconjunctivitis and cough due to Parietaria judaica during the pollen season (April to July 1993). METHODS: Allergic patients were enrolled in a double-blind, placebo-controlled, parallel-group, randomized study, and received loratadine 10 mg/d or placebo in oral tablets for 4 weeks. Occurrence and severity of conjunctival and nasal symptoms, severity and frequency of cough attacks were assessed daily by the patients together with peak expiratory flow evaluation performed twice a day, ie, in the morning and in the evening. Physicians evaluated conjunctival and nasal signs, and spirometry on admission (before treatment), 2 and 4 weeks after treatment. On admission methacholine challenge was also performed to assess PD20. Pollen counts were assessed during the study. RESULTS: According to patients' diary cards, ocular and nasal symptoms were progressively reduced by loratadine treatment (respectively P < .05 and P < .01), as well as cough frequency (P < .05) and cough intensity (P < .01). Peak expiratory flow rate, forced vital capacity, and forced expiratory volume in one second significantly decreased in the placebo-treated group (P < .01), while they were not modified in loratadine-treated patients, who remained normal. CONCLUSIONS: The study suggests that loratadine may be beneficial in the treatment of allergic cough, as well as in rhinoconjunctivitis. Further studies of this may be warranted.

ICAM-1 on epithelial cells in allergic subjects: a hallmark of allergic inflammation.

Allergen-specific challenge was first shown to induce ICAM-1 expression on epithelial cells (ECs) of conjunctiva in allergic patients. The data have also been confirmed in the nose. We then checked for the presence of ICAM-1 consequent to natural exposure to allergens. For both conjunctivitis and rhinitis due to pollen we confirmed, during the pollen season, the presence of ICAM-1 on ECs. We demonstrated the endogenous source of ICAM-1 by in situ hybridization both in vitro and in vivo. ICAM-1 could be an activation marker on ECs, or could, enhanced EC susceptibility to bind offending cells such as eosinophils (LFA-1+). ICAM-1 is also a receptor for the vast majority of rhinoviruses, which are known to provoke, mainly in children, asthma attacks. Since we found that mite allergens can induce ICAM-1 on ECs, even during clinical latency, allergy may be considered as a primary event leading to asthma (through rhinovirus infection) and non-specific hyperreactivity.

Cetirizine reduces inflammatory cell recruitment and ICAM-1 (or CD54) expression on conjunctival epithelium in both early- and late-phase reactions after allergen-specific challenge.

BACKGROUND: Allergen-specific conjunctival challenge (ASCC) is a safe and reproducible experimental model of allergic conjunctivitis and a useful tool in the evaluation of effectiveness and possible mechanisms of action of drugs commonly used in the treatment of allergic diseases. OBJECTIVE: The protective effect of cetirizine on inflammatory changes after ASCC was assessed in 12 patients with rhinoconjunctivitis caused by Parietaria judaica in a double-blind study. METHODS: After a screening ASCC was performed, patients were randomized into two treatment groups; each patient was given cetirizine (oral tablets) 10 mg twice daily, or matching placebo for 3 1/2 days in off-pollen season. Clinical evaluation (itching, hyperemia, lacrimation, and swelling of eyelids) and cytologic assessment (number of inflammatory cells in conjunctival scraping and evaluation of intercellular adhesion molecule-1 (ICAM-1)/CD54 expression on epithelial cells) were performed at baseline, 30 minutes (i.e., early-phase reaction [EPR]), 6 hours, and 24 hours (i.e., late-phase reaction [LPR]) after ASCC, before and after treatment. RESULTS: The EPR clinical events and the EPR total number of inflammatory cells were significantly reduced by cetirizine compared with placebo. The LPR clinical events and inflammatory cell recruitment were reduced by cetirizine in a similar manner. Both eosinophil and neutrophil numbers were decreased by active drug in EPR and LPR. Furthermore, ICAM-1/CD54 expression was significantly reduced by cetirizine in both the EPR and LPR compared with placebo. CONCLUSIONS: This study shows that cetirizine has a protective effect on clinical and cellular EPR and LPR events (including ICAM-1/CD54 expression on epithelium) induced by ASCC.

Lodoxamide treatment of allergic conjunctivitis.

Lodoxamide is an antiallergic compound. The present study evaluated the efficacy on clinical and cytological parameters and safety of topical lodoxamide compared to placebo in the treatment of allergic conjunctivitis. The trial, designed as double-blind, randomized, placebo-controlled and parallel group treatment, was carried out in 30 patients, suffering from seasonal allergic conjunctivitis due to grass pollen, during the pollen season. Patients received lodoxamide tromethamine 0.1% eye drops or placebo eye drops, one drop in each eye t.i.d. for 4 weeks. The clinical and cytological evidence was investigated by clinicians on admission and after 4 weeks' treatment. At the end of the trial, only the lodoxamide-treated group showed a significant clinical improvement, associated with a reduction of inflammatory cells. No serious side effects were observed. The results show the clinical efficacy of lodoxamide in the treatment of pollen-induced allergic conjunctivitis. In addition, lodoxamide exerts its antiallergic activity by reducing inflammatory infiltrate (mainly eosinophils).

Effects of conjunctival hyperosmolar challenge in allergic subjects and normal controls.

Nonspecific hyperreactivity to a number of physical, chemical and pharmacological agents in a common characteristics of allergic subjects, which is strictly related to the inflammatory events consequent to an allergic reaction. Hyperosmolar stimulus has previously been shown to cause an inflammatory response inducing mast cell activation and subsequent mediator release. We investigated the clinical and cytological events following conjunctival challenge using a hyperosmolar agent (i.e. glucose solution) in patients with allergy due to pollen, in patients with allergy due to mites and in healthy individuals in order to investigate the possible existence of 'conjunctival hyperreactivity', similar to the well-known nasal and bronchial nonspecific hyperreactivity in allergic patients. Hyperosmolar stimulus was able to produce an immediate inflammatory response evidenced by clinical symptomatology, inflammatory cell infiltrate and CD54 expression on conjunctival epithelium in all allergic subjects and healthy volunteers. House dust mite-sensitive subjects, but not pollen-sensitive subjects studied out of pollen season, showed conjunctival hyperreactivity as shown by histamine challenge, in that they required lower glucose concentrations to elicit the conjunctival reaction. This is probably related to an underlying although mild, inflammation.

Nedocromil sodium and the immune response.

Chromones are frequently employed in the treatment of allergic rhinoconjunctivitis and asthma. Following our recent investigations concerning the influence of some antiallergic drugs, such as cromoglycate sodium, steroids, oxatomide and ketotifen (H1 antihistamines), and theophylline, on the immune response, in the present study we analyzed the in vitro effects of a new chromone derivative, nedocromil, on the immune response. To this end, the proliferation of peripheral mononuclear cells (PMNCs) induced by mitogen (PHA) and by CD3, CD2 or CD28 monoclonal antibodies (MAbs) has been studied. Since the effects of nedocromil on immunological parameters are achieved at 10(-7) mol/l, in the experiments herein reported the drug was tested in the cultures at concentrations of 10(-8), 10(-7) and 10(-6) mol/l. Furthermore, the effect of nedocromil was evaluated on the surface expression of the following markers expressed by PMNCs upon activation: ICAM-1 (CD54), LFA-1 and alpha 1-acid glycoprotein (alpha 1-AGP). The results of the present investigation showed no effect of nedocromil on these immunological parameters. These data acquire clinical relevance when related to previous reports showing a depression of the immunological response exerted by other compounds, such as ketotifen, theophylline and steroids.

Deflazacort protects against late-phase but not early-phase reactions induced by the allergen-specific conjunctival provocation test.

The protective effects of deflazacort against the inflammation that follows the conjunctival provocation test (CPT) by specific allergen were assessed in 24 patients with rhinoconjunctivitis caused by Parietaria judaica in a double-blind study. After a screening CPT, patients were randomized into four treatment groups, each being given deflazacort (oral tablets) at 6, 30, and 60 mg once daily, or matching placebo, for 3 d, outside the pollen season. Clinical evaluation (itching, hyperemia, lacrimation, and swelling of eyelids) and cytologic assessment (number of inflammatory cells in conjunctival scraping and evaluation of ICAM (intercellular adhesion molecule)-1/CD54 expression on epithelial cells) were performed at base line, 30 min (early-phase reaction (EPR), 6 h and 24 h (late-phase reaction (LPR)) after specific CPT, and before and after treatment. Neither the EPR clinical reactions nor the EPR total number of inflammatory cells was modified by deflazacort. However, the LPR clinical effects were significantly reduced by deflazacort at 30 or 60 mg/d (P < 0.01), as compared with placebo. The total number of inflammatory cells during LPR was significantly reduced by deflazacort at 30 or 60 mg/d (P < 0.01), as compared with placebo. Furthermore, CD54 expression was significantly reduced by deflazacort at 30 or 60 mg/d both in the EPR (P < 0.01) and LPR (P < 0.01), as compared with placebo. None of the studied indicators were modified at the 6 mg/d dose. This study shows that deflazacort has a highly protective action against clinical and cellular LPR effects induced by the specific CPT. In addition, deflazacort markedly reduces CD54 expression on the conjunctival epithelium during both EPR and LPR.

Deflazacort in the treatment of uveitis: a comparative study versus prednisone.

Since corticosteroids represent a fundamental tool in the treatment of uveitis, we evaluate the clinical efficacy and possible appearance of side effects of deflazacort, a new corticosteroid of third generation, versus prednisone at equiactive dosages. Sixty six patients suffering from recurring acute anterior uveitis (RAAU) and/or chronic anterior uveitis (CAU) were treated with deflazacort or alternatively prednisone in an "open" study. Clinical efficacy, ophthalmological parameters and haemato-bioassays were evaluated on admission and during the treatment period. All patients showed a complete remission of clinical signs and symptoms with both treatment and no statistically significant difference was evidenced between the studied groups. Concerning the possible appearance of side effects, the comparison between deflazacort and prednisone a statistically significant difference. These preliminary results are strongly encouraging and suggest further controlled studies on the employment of deflazacort in the treatment of uveitis.