Ten-year follow-up study of allergen-specific immunoglobulin E and immunoglobulin G4, soluble interleukin-2 receptor, interleukin-4, soluble intercellular adhesion molecule-1 and soluble vascular cell adhesion molecule-1 in serum of patients on immunotherapy for perennial allergic rhinitis

Interleukin-4 enzyme-linked immunospot assay may be useful for diagnosing sensitization to house dust mite

BACKGROUND

The skin prick test (SPT) is considered a standard test for identification of allergens, but it has some limitations in clinical practice. The multiple allergen simultaneous test (MAST), which measures allergen-specific immunoglobulin E in patients' serum, is a widely used alternative test, but is limited by its relatively low sensitivity and specificity. As a novel diagnostic test to identify allergens, we investigated the sensitivity and specificity of an interleukin-4 (IL-4) enzyme-linked immunospot (ELISpot) assay for Dermatophagoides farinae (Der f) and Dermatophagoides pteronyssinus (Der p).

METHODS

Based on the symptoms and SPT results, 43 house dust mite (HDM) allergic rhinitis (AR) patients and 41 control subjects were included. Peripheral blood was drawn from each subject for IL-4 ELISpot assay and MAST. The receiver operating characteristic (ROC) curve analysis was conducted to determine the cutoff values. Sensitivity, specificity, and positive and neg predictive values were compared between the 2 tests.

RESULTS

The sensitivity, specificity, and areas under the ROC curve (AUCs) of the IL-4 ELISpot assay were 88.4%, 97.6%, and 0.939 for Der f, and 95.3%, 97.5%, and 0.971 for Der p, respectively. However, the sensitivity, specificity, and AUC of MAST were 76.7%, 73.2%, and 0.777 for Der f, and 69.8%, 75.6%, and 0.788 for Der p, respectively.

CONCLUSION

The IL-4 ELISpot assay showed higher sensitivity, specificity, and AUC than MAST, which indicates its clinical feasibility for diagnosing allergy for HDM. A further study is needed to determine the accuracy of the IL-4 ELISpot assay for other common allergens.

Clinico-immunological changes post-immunotherapy with Periplaneta americana

BACKGROUND

Cockroach proteins induce allergies including asthma in predisposed individuals. Well-designed controlled studies are required to show the effect of cockroach immunotherapy (IT). This study is aimed to assess changes in clinical and immunological parameters post-IT with Periplaneta americana extract.

MATERIALS AND METHODS

A double-blind, placebo-controlled trial of cockroach IT was performed for 1year in 50 patients of asthma, rhinitis or both. The efficacy of IT was assessed by change in skin reactivity and clinical parameters such as symptom/drug score, airway reactivity and immunological parameters namely IgE, IgG1 and IgG4, IL-4 and IFN-γ by enzyme-linked immunosorbent assay and western blotting using patients' sera at baseline and after 1year of treatment.

RESULTS

Immunotherapy with cockroach extract demonstrated significant improvement in clinical parameters of active group patients compared with baseline values and placebo group. Specific IgE levels showed a modest reduction, while IgG4 levels increased significantly in active IT group after 1year. IgE immunoblotting demonstrated reduction in intensity and number of specific bands, whereas IgG4 binding showed more number and distinct bands following IT. Active group patients showed correlation between increase in IgG4/IgG1 ratio and reduction in symptom score post-IT.

CONCLUSIONS

Immunotherapy with cockroach extract improved clinical and immunological status of asthma and rhinitis patients. Clinical improvement in patients after IT is associated with immunological changes.

Current immunological approaches for management of allergic rhinitis and bronchial asthma

A large population world over is affected with allergic diseases and asthma. Pharmacotherapy for allergic diseases and asthma is effective in controlling symptoms but on discontinuation of medication, symptoms reoccur. In contrast, immunotherapy modifies and corrects the underlying pathological immune responses in an antigen-specific manner. Immunotherapy shows an increase in IgG (blocking antibody) that competes with IgE for allergen, inhibiting the release of inflammatory mediators. Recent studies suggest that immunotherapy acts by modifying CD4+ T-cell responses either by immune deviation, T-cell anergy and/or both. Current immunological approaches for management of allergies and asthma involve immunization with native allergen, modified allergen, peptides/cDNA of allergen, anti-IgE, adjuvants coupled allergen, including immunostimulatory DNA sequences, cytokines, and bacterial products. These approaches modulate the immune response and are intended to give long-term benefit.

Decreased serum IgE level, decreased IFN-gamma and IL-5 but increased IL-10 production, and suppressed cyclooxygenase 2 mRNA expression in patients with perennial allergic rhinitis after treatment with a new mixed formula of Chinese herbs

A new mixed formula of Chinese herbs containing Shin-yi-san + Xiao-qing-long-tang + Xiang-sha-liu-jun-zi-tang by the weight of 9 + 3 + 3 g/day was prescribed for the treatment of patients with perennial allergic rhinitis for 3 months (the composition of each herb is shown in the tables of the article). We classified the patients into high (H-IgE) and low IgE (L-IgE) groups according to the titer of serum total IgE (> 200 KIU/l in H-IgE vs. < 200 KIU/l in L-IgE) and the presence of house dust mite-specific IgE. The nasal symptomatic score in the high IgE group was significantly improved from 7.19 +/- 0.18 before treatment to 2.67 +/- 0.37 after treatment. In addition, the serum total and house dust mite-specific IgE level were also decreased after treatment. For elucidating the working mechanism of the mixed formula, the Th1 (IFN-gamma) and Th2 (IL-4, IL-5, IL-10 and IL-13) cytokine production by phytohemagglutinin (PHA)-stimulated mononuclear cells (2 x 10(6) cells/ml) and cyclooxygenase type 2 (COX-2) mRNA expression in LPS or IL-13-stimulated PMN were compared before and after 3 months of treatment. We found that the mixed formula treatment significantly enhanced IL-10 but decreased IFN-gamma and IL-5 production by PHA-stimulated mononuclear cells. The IL-5 production was also decreased by PHA-stimulated lymphocyte. In addition, the COX-2 mRNA expression in stimulated PMN was significantly suppressed after treatment. These results suggest that the new mixed formula treatment is beneficial to the patients with perennial allergic rhinitis via modulating the function of lymphocytes and neutrophils.

Clinical and immunologic changes after allergen immunotherapy with Hop Japanese pollen

BACKGROUND AND OBJECTIVE

Hop Japanese (Hop J) pollen has been reported as one of the major causative pollen allergens in the autumn season. There have been no published data regarding the clinical and immunologic effects of Hop J pollen immunotherapy in sensitized patients. In this study, we evaluated clinical and immunologic effects of Hop J immunotherapy.

PATIENTS AND METHODS

Pollens were collected in our area, and "Depo-Hop J" was prepared in the laboratory of Allergopharma (Reinbek, Germany). Fifteen asthmatic patients who had Hop J immunotherapy for > 1 year were enrolled. Their clinical parameters, such as asthma symptom scores, were monitored. Skin reactivity to Hop J and degree of airway hyperresponsiveness to methacholine were measured before and 1 year after the immunotherapy. Sera were collected before the immunotherapy, at the end of initial therapy, and 1 year after the therapy. Serum total IgE levels were compared by radioimmunoassay. Serum-specific IgE, IgG1, and IgG4 levels to Hop J were compared by ELISA. To evaluate the changes of cellular mechanisms, soluble CD30 (sCD30), soluble interleukin (IL)-2 receptor (sIL-2R), soluble CD23 (sCD23), and IL-10 levels were measured by ELISA.

RESULTS

Specific IgG1 and IgG4 levels began to increase at the end of the initial therapy (P < 0.05) with significant decreases in symptom scores (P < 0.05), whereas total and specific IgE levels showed variable responses during the immunotherapy with no statistical significance (P > 0.05). Serum sIL-2R and sCD30 levels decreased significantly (P < 0.05) 1 year after immunotherapy. No significant changes were noted in sCD23, IL-10, skin reactivity to Hop J, or airway responsiveness to methacholine (P > 0.05).

CONCLUSIONS

We are certain that Hop J allergen immunotherapy, if carried out properly according to suitable indications, can favorably influence asthma. Thus, an increase in specific IgG4 and IgG1 antibodies and reduction of a possible Th2 lymphocyte marker (sCD30) may be associated with symptomatic improvements.

Long-term effects of specific immunotherapy, administered during childhood, in asthmatic patients allergic to either house-dust mite or to both house-dust mite and grass pollen

In a retrospective study, asthmatic patients allergic to either house-dust mite (HDM) (Dermatophagoides pteronyssinus) (n = 34) or to both HDM and grass pollen (GP) (n = 14), and who were treated with specific immunotherapy (SIT) during childhood (mean duration of SIT: 61 +/- 9.70 months), were re-evaluated in early adulthood after mean cessation of SIT for 9.3 +/- 2.76 years. The results were compared to those of a control group of asthmatic patients (n = 42) with comparable asthma features, who were treated with appropriate antiasthmatic drugs during childhood, but who never received SIT. Re-evaluation was carried out with a standardized questionnaire, skin prick tests (SPT), and lung-function assessments. At the time of re-evaluation, the mean age in the SIT-treated group was 23.1 +/- 3.50 years; in the control group, it was 22.7 +/- 3.40 years. At re-evaluation, the risk of frequent asthmatic symptoms was three times higher in the control group than in the SIT-treated group (prevalence ratio: 3.43; P = 0.0006). The frequent use of antiasthmatic medication was also more pronounced in the control group, although the difference was not statistically significant (P=0.38). Lung-function parameters and results of SPT with HDM were comparable in both groups. It is concluded that SIT has long-term effects on asthmatic symptoms in young adults.

Suppression of seasonal increase in serum interleukin-5 is linked to the clinical efficacy of immunotherapy for seasonal allergic rhinitis

Although immunotherapy is recognized as a highly effective form of treatment for allergic rhinitis, especially pollen-induced seasonal allergic rhinitis, the mechanisms have not been fully established. In the present study, we investigated whether immunotherapy could affect the seasonal increase in interleukin-5 (IL-5) in the serum of patients with seasonal allergic rhinitis and whether the effect on IL-5 in serum is related to the clinical efficacy of immunotherapy. Venous blood was collected twice from each patient with seasonal allergic rhinitis due to Japanese cedar pollens, before and during the cedar pollen season in 1997, to determine the cedar pollen-specific IgE and IL-5 in serum. Both specific IgE and IL-5 in serum were significantly increased during the pollen season, not only in the poor responders to antihistamines but also in the good responders. Neither the rate of seasonal increase in specific IgE nor the rate of seasonal increase in IL-5 differed significantly between the good responders and the poor responders to antihistamines. Both specific IgE and IL-5 were significantly increased during the pollen season in the poor responders to immunotherapy, whereas neither specific IgE nor IL-5 was increased during the pollen season in the good responders to immunotherapy. The rate of seasonal increase in specific IgE as well as IL-5 was significantly smaller in the good responders than in the poor responders to immunotherapy. The rates of seasonal increase in specific IgE and in IL-5 were inversely correlated with the length of time on immunotherapy. However, the rate of seasonal increase in specific IgE was not significantly correlated with the rate of seasonal increase in IL-5. In conclusion, the suppression of the seasonal increase in IL-5 in serum is a working mechanism of immunotherapy related to the clinical efficacy of the treatment.

Allergen-specific immunotherapy for allergic rhinitis: a new insight into its clinical efficacy and mechanism

Immunotherapy has been used widely for allergic diseases for more than 90 years but, in the opinion of many physicians, it is still a controversial form of treatment. The exact mechanism of action of immunotherapy remains to be determined. In the present study, we review the clinical efficacy and mechanism of action of immunotherapy for allergic rhinitis. Recent double-blind placebo-controlled studies have demonstrated the clinical efficacy of immunotherapy for allergic rhinitis. This therapeutic method has several advantages over conventional pharmacological treatment. Immunotherapy is inferior to pharmacological treatment in the short term, but in the long term it is substantially superior with respect to clinical efficacy. Immunotherapy has the potential permanently to alleviate the abnormal immunological responses of allergic rhinitis and to cure the nasal symptoms in the long term, even after discontinuation of injections. In addition, immunotherapy can prevent the onset of new sensitizations in allergic patients and may prevent the progression of rhinitis to asthma. It may therefore be possible for immunotherapy to alter the natural history of allergic sensitization and its clinical manifestation. These lines of clinical evidence could affect strategies of long-term therapy for allergic rhinitis. Modern molecular biological techniques have suggested that immunotherapy may affect allergen-induced TH responses or cytokine profiles, but there is no general agreement among investigators. However, IL-5 is likely to be the most important cytokine involved in the clinical efficacy of immunotherapy, and the suppression of allergen-induced IL-5 synthesis is most likely to be involved in the mechanism of immunotherapy. Our recent investigations, focusing on specific IgE and IgG4 responses, suggest that immunotherapy-induced changes in these specific antibodies play a clinical role and are involved in the mechanism of action of immunotherapy. It is probable that immunotherapy modulates and affects many different immunological and non-immunological phenomena to produce clinical efficacy and that clinical improvement is a consequence of different mechanisms over time.

Immunotherapy suppresses both Th1 and Th2 responses by allergen stimulation, but suppression of the Th2 response is a more important mechanism related to the clinical efficacy of immunotherapy for perennial allergic rhinitis

Increased attention has recently been directed at the possibility that the clinical efficacy of immunotherapy might be elaborated by alteration of T-cell reactivity. However, there is no general agreement among different investigators regarding the effect of immunotherapy on Th-cell reactivity. Peripheral blood mononuclear cells (PBMCs) from 15 nonatopic subjects and 76 patients with perennial allergic rhinitis (18 untreated patients and 58 patients on immunotherapy) were cultured in the absence and in the presence of a major Dermatophagoides farinae allergen, Der f 1, and the levels of IgE, interleukin-5 (IL-5), interferon-gamma (IFN-gamma) and tumor necrosis factor-alpha (TNF-alpha) in the culture supernatants were determined. The difference between the absence and presence of Der f 1 was calculated to consider the Der f 1-dependent synthesis of IgE, IL-5, IFN-gamma and TNF-alpha. The levels of Der f 1-dependent synthesis of IgE, IL-5 and TNF-alpha were significantly higher in the untreated group than in the nonatopic group, whereas Der f 1-dependent synthesis of IFN-gamma was significantly lower in the untreated group than in the nonatopic group. Immunotherapy decreased the enhanced Der f 1-dependent synthesis of IgE, IL-5 and TNF-alpha, and further decreased the suppressed Der f 1-dependent synthesis of IFN-gamma as the therapy proceeded. The levels of Der f 1-dependent synthesis of IgE and IL-5 did not differ between nonatopic individuals and patients whose duration of immunotherapy was 10 or more years. The levels of Der f 1-dependent synthesis of IgE and IL-5, but not of IFN-gamma and TNF-alpha, were correlated significantly with the levels of symptom scores. In addition, the levels of Der f 1-dependent synthesis of IgE and IL-5, but not of IFN-gamma and TNF-alpha, differed significantly between good and poor responders. In conclusion, immunotherapy for perennial allergic rhinitis may possibly work via induction of tolerance or anergy of both Th1- and Th2 cells. However, our study is likely to support a view that the mechanisms responsible for the clinically beneficial effects of immunotherapy principally involve the tolerance of Th2- rather than Th1 cells. In addition, suppression of IgE synthesis is also likely to be linked to the clinical efficacy of immunotherapy for perennial allergic rhinitis.