E. Cavallucci

Lymphocyte subset changes in blood and gastrointestinal mucosa after oral nickel challenge in nickel‐sensitized women

This study investigates lymphocyte subsets in both the gastrointestinal mucosa and blood, in patients with nickel allergic contact dermatitis, after 10 mg oral nickel challenge (double‐blind, placebo‐controlled). 6 such patients with cutaneous symptoms induced only by skin contact with nickel (group A), 6 with a flare‐up of cutaneous symptoms after food nickel ingestion (group B) and 6 healthy controls (group C) were enrolled. Blood lymphocyte subsets (CD4, CD45RO, CD8) were analyzed before and after 4 and 24 h from the challenge (test 1, 2, and 3), and intestinal biopsies were performed 2 days later. Challenges were positive in group B and negative in group A and controls. Serum and urine nickel levels significantly increased after nickel ingestion, with no differences between the 3 groups. At test 3, a significant decrease of the all CDs studied was found in group B. Biopsies of this group showed higher levels of CD45RO+ cells in the lamina propria and in the epithelium and lower levels of epithelial CD8+ lymphocytes. This study confirms that ingested nickel may induce flare‐up of cutaneous reactions in some nickel‐allergic patients, independently of the degree of sensitization and the intake of metal. In these patients, oral nickel stimulates the immune system, inducing maturation of T lymphocytes from virgin into memory cells; these latter cells seem to accumulate in the intestinal mucosa. The immunoreaction also involves CD8+ cells, whose role is not yet clear.

Steroid and antihistamines modulate RANTES release in cultured peripheral blood mononuclear cells of atopic patients.

RANTES plays a crucial role in cell recruitment in allergic inflammation. We investigated the pharmacological modulation of RANTES release in cultured peripheral blood mononuclear cells obtained from allergic patients with active asthma. Chemokine production was assessed before and after 15 day treatment with histamine-1 receptor antagonists (Loratadine or Cetirizine) and a steroid (Deflazacort), both in unstimulated and PHA-stimulated cell cultures. Results were compared with those obtained from placebo-treated patients. During the treatment period, patients recorded morning and evening peak expiratory flow (PEF) by mini-Wright. PEF absolute values and diurnal variability significantly improved respect to the pre-treatment in steroid-treated patients, in comparison to the placebo and antihistamine-treated groups (p<0.001 and 0.01, respectively). PEF diurnal variability in the antihistamine-treated group were lower than placebo-treated group without statistical significance (p=0.06). No differences could be found in RANTES levels in supernatants of all cultures between the two antihistamines. RANTES release significantly decreased in supernatants of all cell cultures from steroid (p<0.01) and antihistamine (p=0.03 and 0.04) groups after treatments, compared to the basal values; whereas it increased slightly in controls. Co-variance analysis on RANTES levels, adjusting for pre-treatment values, showed a significant reduction of RANTES release by PHA-stimulated PBMCs from steroid (p=0.003) and anti-histamine (p=0.03) groups, with respect to the placebo group. The same statistical tool applied between the steroid and the antihistamine groups showed, after therapy, the lowest levels of RANTES to be associated with steroid treatment (p=0.005). The study shows that steroid is the most effective drug in modulating RANTES release from PBMCs. However, antihistamines, which are able to reduce cell recruitment due to chemokine release, avoiding important side effects, may be useful in long term therapy in controlling and preventing allergic inflammation.

Probiotics and food-allergic diseases

The definition of probiotics is always evolving, since it includes natural live micro‐organisms, cellular subfractions, as well as genetically engineered derivatives or proteins. The scope of probiotic administration is beneficial change of the intestinal microflora, and improvement of non immune or immune resistance in the intestinal tract. Very few controlled human studies have been reported, but many in vitro and experimental animal studies point to their safety and potentially useful applications. We shall review the published reports and discuss mainly the prospective uses in the field of allergic diseases, with reference to the implication of the natural (innate) immune system as regulator of the development of abnormal responses to ingested food antigens.

Influence of total IgE and seasonal increase of eosinophil cationic protein on bronchial hyperreactivity in asthmatic grass‐sensitized farmers

Background: This study correlates biomarkers of atopy (serum total and specific IgE) and inflammation (serum eosinophil cationic protein) with bronchial hyperreactivity assessed after the complete end of pollination, in a group of farmers suffering from grass‐allergic asthma.

Dose-dependent clinical and immunological efficacy of sublingual immunotherapy with mite monomeric allergoid.

Sublingual immunotherapy with monomelic carbamylated allergoid (LAIS) is an effective and well tolerated treatment of respiratory allergy. The aim of the present study was to correlate the efficacy of two maintenance doses (1000 AU vs 3000 AU) of LAIS with the immunological modulation of allergen-driven Th1, Th2 and T regulatory cytokines produced in vitro by PBMCs, in patients suffering from mite allergic rhinitis. Forty-eight consecutive patients with mite allergic rhinitis were recruited. Patients were randomly assigned to group A (n=24) or group B (n=24), respectively receiving 1000 AU or 3000 AU weekly during one-year maintenance phase. Each patient was evaluated for rhinitis severity (ARIA protocol), and for drug consumption at the time of the inclusion and after 6 and 12 months of treatment. Patients were also asked to report the perceived severity of the disease and the tolerability of the treatment in a visual analogical scale (VAS). Before and at the end of the treatment allergen-driven release of cytokines by PBMCs in vitro was measured. After 1-year treatment, a statistically significant reduction of all clinical parameters was observed in all patients, associated with reduction of IL-4 and increase of INF-γ secreted in vitro by mite-challenged PBMCs. Notably, the group treated with the higher dose showed significantly better clinical and immunological results. The efficacy of LAIS is correlated to the immune modulation in a clear dose-dependent effect.

Increase in CD45RO+ cells and activated eosinophils in chronic allergic conjunctivitis.

We assessed the infiltration of CD45RO+ cells in conjunctival biopsies of fifteen subjects affected by seasonal allergic conjunctivitis by means of immunohistochemistry. Correlations between infiltration of CD45RO+ cells and serum and mucosal indices of eosinophilic activation were investigated. The study was performed in autumn and all selected patients showed <<red eyes>> also in absence of sensitising pollens. Fifteen healthy subjects were used as controls. The semi-quantitative count of CD45RO+ cells in biopsy specimens demonstrated that positive cells were higher in allergic patients than in controls (p < 0.001) and EG2+ eosinophils were present only in biopsies of allergic patients. Furthermore, a statistically significant positive correlation (r = 0.73; p < 0.001) between CD45RO+ lymphocytes and EG2 positive eosinophils, was observed in the biopsies of allergic patients. Total serum IgE significantly correlated with CD45RO+ cells (r = 0.61; p < 0.02) and EG2+ eosinophils (r = 0.67; p < 0.01) in the conjunctiva. On the other hand serum ECP did not correlate with any histological and immunohistochemical parameters in the conjunctival biopsies. The present study shows that mild symptoms in SCA patients out of pollen season are associated with inflammation of the conjunctiva as shown by an increased number of CD45RO and EG2 positive cells.

Lymphocyte Differentiation in the Nasal Mucosa

Few cytological studies have investigated the morphologic changes occurring during lymphocyte differentiation in the nose. The aim of the study is to investigate lymphocyte and plasma cell morphology in patients with allergic rhinitis. Nasal cytology was performed in 110 patients (61 men, 49 women) of ages ranging from 12 to 47 years (mean age, 27), 72 of whom were affected by pollen allergic rhinitis (32 allergic to olive, 21 to Parietaria, 13 to grasses, and 6 to cypress) and 38 by perennial allergic rhinitis (allergy to house dust mites). Cytological samples were obtained by scraping with Rhino-Probe™. The samples were collected from the inferior middle turbinate. After fixing and drying, the samples were stained and counted. Cells belonging to the lymphocyte-plasma cell lineage were analyzed. Within this population, 5 different cellular types were identified displaying particular morphologic features of the nucleus and the cytoplasm. These morphological variants constitute various functional stages of B lymphocytes. In allergic inflammation, antigen stimulation induces B lymphocytes to differentiate and become plasma cells. The findings from this strictly morphological study will need to be confirmed by immunohistochemical and immunophenotypic studies.

Fluticasone/formoterol association favors long-lasting decrease in bronchial reactivity to methacholine and weekly PEF variability.

Inhaled corticosteroids (ICS)/long-acting beta-agonists (LABA) association offers a better asthma control than a higher steroid dose with short-acting beta-agonists as needed. In this study, we evaluated the effect of the association on bronchial hyperreactivity (BHR) and peak expiratory flow (PEF) variability, as such parameters are positively correlated with increased asthma morbidity and exacerbations. Thirty-six adult patients with mild persistent asthma were enrolled. After a 7-day run-in, they were randomly assigned to three therapy regimens for 6 weeks: Group 1, fluticasone 125 μg + formoterol 5 μg in the same device; Group 2, fluticasone 125 μg + formoterol 12 μg as needed; Group 3, fluticasone 250 μg + formoterol 12 μg as needed. We evaluated changes induced in weekly PEF variability (measured during the entire study and 4 weeks of follow-up) and pre- and post-study PD20 methacholine (MCH). Weekly PEF variability decreased in all groups during treatment with the greatest reduction in Group 1, followed by Group 3, and finally Group 2. During the follow-up, no significant changes were detected in Group 1, whereas a trend towards an increased variability was found in Groups 2 and 3. Post-treatment PD20 MCH was significantly higher versus the pre-treatment. The increase observed in Group 1 was significantly higher compared to Groups 2 and 3 and that observed in Group 3 in respect to Group 2. The study proves that both BHR and PEF variability are influenced by ICS. This effect was greater with fluticasone/formoterol association compared to fluticasone alone with formoterol as needed even at higher steroid dose.

Omalizumab in Chronic Spontaneous Urticaria: steroid sparing effect

Abstract Omalizumab has been recognized to be effective in the treatment of chronic spontaneous urticaria (CSU). The Italian Medicines Agency authorizes two omalizumab courses, only for patients with CSU unresponsive to antihistamines, and this schedule may limit omalizumab use. Unfortunately, in the majority of CSU, the schedule is unsatisfactory because symptoms usually recur shortly after discontinuation of treatment. A case of a patient needing more than two treatment courses with omalizumab is reported, in order to discuss the rationale for its long-term use. Patient had needed systemic steroids almost continuously for 4 years. Two severe glucocorticoid-associated adverse events (GAEs) occurred during long-term treatment. Omalizumab 300 mg monthly was started with immediate disappearance of the urticarial lesions. Beneficial effects waned shortly after discontinuation of treatment, and further steroid use was needed. A second omalizumab course showed the same clinical pattern, with prompt response and recurrence of symptoms after suspension. Therefore, we decided to repeat the 6 months omalizumab treatment as soon as symptoms recurred, to avoid further emergency steroid treatments and GAEs. This experience suggests that long-term use of omalizumab could be useful. Evidences show that omalizumab is effective and safe for re-treatment and long-term use of responding patients after recurrence.

Systemic Nickel Allergy Syndrome

Nickel is one of the most common skin sensitizers, usually responsible for allergic contact dermatitis (ACD). The ingestion of nickel-rich foods is also able to elicit cutaneous (in the absence of physical contact with nickel) and gastrointestinal symptoms in some subjects with nickel ACD, a condition referred to as systemic nickel allergy syndrome (SNAS). The pathogenesis of this disease involves both Th1 and Th2 cells and cytokines, with involvement of both CD8- and CD4-positive T lymphocytes. Clinical aspects include flares of previous ACD lesions and/or positive nickel patch test reactions, widespread eczema, and gastrointestinal disturbance essentially characterized by meteorism and colic. This diagnosis may be suspected in patients with nickel ACD whose gut and skin symptoms disappear or improve after a low nickel diet. Essential for the diagnosis is to confirm that symptoms reappear after a double-blind placebo-controlled oral nickel challenge. In such cases, the low nickel diet can be used as treatment. Of note, to maintain a nickel-free diet for a long time may strongly impact a patient’s quality of life. Therefore, a desensitization treatment should be considered in these patients. Nickel hyposensitization is effective in patients suffering from SNAS. The majority of such patients can safely ingest nickel-containing foods after 1 year of treatment. Clinical experience in patients with ACD alone, although positive and encouraging, is scarce in terms of the number of patients treated and length of the hyposensitization course, which is usually followed, after a relatively short period of time, by a relapse of cutaneous symptoms. In any case, nickel hyposensitization is able to modulate immune responses to nickel by restoring a state of tolerance that seems to be mediated by T regulatory lymphocytes.