CD4+ T cell-targeted immunomodulation and the therapy of allergic disease

In recent years there have been considerable advances in our knowledge of the cellular and molecular events following ligation of the T cell receptor. The quantitative and qualitative characteristics of the signal(s) received by a naive or memory T cell largely determine whether receptor ligation results in cell activation, cell death, or the induction of a state of antigen-specific nonresponsiveness. Furthermore, microenvironmental conditions, including the presence of secreted cytokines or the structure of the peptide antigen, strongly influence the differentiation of CD4+ helper cells into functionally distinct subsets. The interregulation of these functional subsets appears pivotal to the development of many immune-mediated disorders, including allergic disease. We suggest that the selective manipulation of the immune response to specific antigens may be an effective strategy for the therapy of such disorders and we review recent studies which support this concept.

Allergic and infective rhinosinusitis: differential diagnosis and interrelationship

Despite the growing emphasis on sinus surgery, the management of chronic or recurrent sinus problems remains multifaceted and should include consideration of contributory, correctable medical factors. Accurate differentiation between infective or allergic rhinosinusitis is often difficult if based only on history and physical examination. The character (and culture results) of mucus obtained from the sinus ostia region by endoscopy may confirm an infective problem, whereas positive results of specific allergy tests, supported by history, will confirm the presence of significant allergy. If complicating infection is not appropriately controlled, allergic management of rhinosinusitis will yield results that are less than optimum. Failure to recognize and treat contributory allergy may jeopardize the results of sinus surgery performed to resolve chronic infection.

Immunology in the pediatrician's office

The development of antibody-mediated immunity is reflected in the maturation of B lymphocytes, in the changing levels of total immunoglobulins, and in the development of specific antibodies first to proteins and then sequentially to different types of polysaccharides. The measurement of anti-pneumococcal antibodies allows us to recognize specific antibody deficiencies, which need to be differentiated from normal developmental phases in the maturation of antibody-mediated immunity. The recognition of the late phase of IgE mediated allergic reactions is important to understanding the chronic manifestations of allergy. Chronic manifestations of allergy are frequently missed because they do not appear to be clearly related to acute triggers of allergic reactions. These conditions can be appropriately diagnosed, prevented, and treated, however, when the mechanisms of the late manifestations of allergy are understood. The integration of knowledge about the development of immunity and of allergic diseases enhances the pediatrician's ability to care for patients with immunologic abnormalities.

[New experimental therapies for type I allergy]

CD4+ T cells play a central role in the development of the immediate-type allergic response. It was shown that T cells from allergic patients exhibit an imbalance on the level of cytokine production which is characterized by increased IL-4- and decreased IFN-gamma production. Different strategies were developed to therapeutically interfere on various levels of the immunological dysregulation. In this article, the use of the immunomodulatory and immunosuppressive drugs methotrexate, cyclosporine, and intravenous immunoglobulin (IVIG) will be discussed. Furthermore, new experimental therapeutic approaches will be presented which are aimed to selectively interfere on the level of cytokine production and regulation. A different approach targets the functional activity of allergen-specific T cells whose functions could be modulated in an animal model system by subcutaneous treatment with peptides.

[Current trends in the specific immunotherapy for allergic syndromes due to Dermatophagoides pteronyssinus]

House dust mites of the species Dermatophagoides pteronyssinus are among the most prevalent perennial allergens. Measurement of allergen exposure is so crucial to establish the natural history of the allergic reaction. The most common clinical manifestations induced by Dermatophagoides are perennial asthma and perennial rhinitis. Recently there are a number of studies indicating that a high degree of exposure to house dust mites may represent a risk factor for severe disease in patients with atopic dermatitis. The diagnosis was performed by in vivo and in vitro tests. Nowadays the treatments regard allergen eradication and specific immunotherapy. Mite specific immunotherapy is only effective under optimal conditions, including an appropriate selection of patients and the use of high-quality standardized extracts. The specific immunotherapy received by subcutaneous injection is the one mostly used until now and the results were really satisfactory, even if its evaluation has been made on clinical data or on bronchial challenges. Immunologic changes were found only when using same extracts. The incidence of systemic reactions during the immunotherapy was low. Recently local immunotherapy was used and it has been shown to be significant by safety, but further clinical investigations are needed to clarify the clinical efficacy in direct comparison with traditional parenteral immunotherapy.

A comparative study of IgG subclass antibodies in patients allergic to wasp or bee venom

IgG1 and IgG4 antivenom antibody responses were compared in groups of patients who had experienced systemic reactions to wasp (Vespula spp.) or bee stings. Pretreatment serum IgG4 antibody levels were low in both groups, but IgG1 antibodies were significantly raised in bee-allergic patients (P < 0.002), probably reflecting their greater exposure to stings than wasp-reactive patients. No direct or indirect relationships were found, in untreated bee or wasp patients, between IgG1, IgG4, or IgE antibody levels and the severity of a patient's last systemic reaction to a sting. After a 12-week course of venom immunotherapy (VIT), IgG1 antibodies increased significantly only in wasp-sensitive patients (P < 0.001), although both groups responded with marked increases in venom-specific IgG4 (P < 0.01). Wasp-allergic subjects who responded to VIT with high production of specific IgG4 showed the greatest increases (pre- to post-VIT) in IgE antibodies (P < 0.05). This group also demonstrated a direct correlation (P < 0.05) between post-VIT levels of IgE and IgG1 antibodies, a finding contrary to an IgE-immunoregulatory role for IgG1. High levels of venom-specific IgG1 alone, or in combination with IgG4, were not protective in three patients who suffered repeated adverse reactions to bee VIT, showing that absolute levels of IgG subclass antivenom antibodies are not reliably indicative of clinical responsiveness in individual patients.

Follow-up of hymenoptera-sensitive patients without active immunotherapy

Presently there is no definitive guideline for the treatment of adult patients suffering from generalized insect sting reactions limited to skin manifestations or purely respiratory compromise who have not been treated with immunotherapy. Previous studies in adults demonstrate that the majority of patients with insect sting anaphylaxis have a decreased reactivity to re-sting with time, suggesting the insect allergy itself may be self-limiting. In this study, we evaluated 63 patients with initial insect sting manifestations limited to the skin and the respiratory system and noted the incidence and degree of natural re-sting reactions to these patients who had not undergone venom immunotherapy. In those patients with mild systemic reactions limited to the skin, none experienced an increase in severity. A local reaction was found on repeat sting in three of five patients in this group, and two of five had an equivalent cutaneous response (i.e., urticaria/angioedema). In five patients who had an initial respiratory reaction, four of the patients had a local reaction while one patient repeated the same respiratory manifestations. None of the patients with cutaneous or respiratory symptoms demonstrated a more severe reaction upon re-sting. This demonstrates that there is a natural progression of tolerance to insect stings in the adult population.

Decreased incidence of stings in venom-sensitive patients following venom immunotherapy

We re-questioned 23 patients from our Venom Referral Clinic after three or more years of venom immunotherapy to determine whether venom immunotherapy makes venom-sensitive patients less susceptible to future stings. They were asked the same questions regarding stings, including: The number of stings in the previous 2 years, insects involved, time spent out of doors per week, and avoidance techniques. The number of patients stung in the previous 2 years dropped from 87% to 30%. Furthermore, the mean number of stings in 2 years per subject was 1.30 compared to 2.26 prior to these patients receiving venom immunotherapy. The average number of hours spent out of doors for this group of patients increased from 16.7 hrs per week to 18.9 hrs per week. Therefore, these patients were stung less frequently despite spending somewhat more time out of doors. We conclude that the process of desensitization during venom immunotherapy makes venom-sensitive patients less susceptible to future stings.

[Studies on metal allergy in the field of dentistry--treatment with application of X-ray fluorescence spectroscope analysis in detection of allergen metals]

The most effective method to treat metal allergy may be allergen elimination. Information on the exact location of the allergens becomes essential for this treatment. An XRFS (X-ray fluorescence spectroscope) was used for the detection of such elements and applied for the treatment of these patients. 1. Evaluation of the apparatus preceding its clinical application proved that the reliability and the detection limit for pure elements were comparative to those of the Electron Probe Microanalyzer. A notable decrease in the emitted X-ray intensity was observed when a sample was analyzed through a medium with thickness of more than 5 mm. 2. The analysis results of the restorations showed that the most frequently used alloys were Ag-Sn-Hg amalgams, Au-Ag-Pd alloys and Ag alloys. Some of the elements with high prevalence rates were Ag, Cu, Zn, Au, Pd, Sn, and Hg. 3. Personal and household items suspected of containing allergen metals were analyzed. Some of the frequently detected elements were Fe, Cu, Mn, Zn, Ni, Cr, and Au. 4. With XRFS, analysis of bulk metals and those samples in various forms became possible. A clinical case with the lesion resolved after the allergen elimination was reported. This proved that the use of XRFS enabled us to deal more definitely and effectively towards metal allergy.

Consumer illness careers: an investigation of allergy sufferers and their universe of medical choices

The concept of the consumer illness career with a focus on allergies is introduced and developed by the authors in terms of a trajectory of five stages over time, the related product-service unities or constellations--including health care treatments and remedies--and various situational and trait factors that influence the course of a consumer's response to his or her disease. Next, they investigate the career's holistic nature and thematic content in an in-depth study of allergy sufferers. The study indicates that allergy sufferers engage ina wide range of strategic behaviors and choices associated with coping with their allergies, much of which can be captured in terms of patterned themes. Finally, the authors offer research, managerial, and public policy implications.

Profound reduction in allergen sensitivity following treatment with a novel allergy vaccine

A novel approach is described for the treatment of IgE-mediated allergic reactions which is based on the induction of a strong anti-IgE response in the host. Vaccination of ovalbumin-sensitized rats with constant domains two and three of rat IgE coupled to a heterologous carrier protein resulted in a profound decrease in serum levels of IgE, and later in a nearly complete block of histamine release from mast cells and basophils upon challenge with either a cross-linking polyclonal anti-IgE antiserum or a specific allergen.

[State of the art on allergy to the cat: a review of the literature]

There are now seven cat allergens. The major, Feld is present in squames, skin and urine, but not in serum albumin. Recent studies have shown that its base is in sebum. It can float in the atmosphere on very small, light particles indefinitely and is deposited on clothes, curtains and carpets in considerable amounts. Immunotherapy, often the cause of collateral accidents, in the best cases only gives a transitory reduction of conjunctival and pituitary sensitisation. It has no proven activity in asthma and the biological data do not change logically during treatment. Prevention consists of total exclusion, which is very difficult to effect.