Does allergen immunotherapy alter the natural course of allergic disorders?

Allergic and immunologic features of Ménière's disease

Ménière's disease (MD), which by definition is idiopathic, has been ascribed to various causes, including both inhalant and food allergies. Patients with MD report higher rates of allergy history and positive skin or in vitro tests compared with a control group of patients with other otologic diseases and to the general public. Recent immunologic studies have shown higher rates of circulating immune complexes, CD4, and other immunologic components in patients with MD compared with healthy controls. Published treatment results have shown benefit from immunotherapy and/or dietary restriction for symptoms of MD in those patients who present with both allergy and MD.

Tolerability and clinical efficacy of oral immunotherapy with house dust mites in a model of canine atopic dermatitis: a pilot study

Atopic dermatitis (AD) is a chronic, life-long disease. In humans, immunotherapy (IT) is the only treatment that can alter the course of AD. Oral IT is appealing owing to the ease of administration and the potential for increased compliance. The purposes of this study were to investigate the tolerability, clinical efficacy and effects on allergen-specific IgE of oral IT using a canine AD model. Thirteen atopic beagles sensitized to house dust mites (HDMs) were randomly divided into two groups. One group received daily oral doses of HDMs while the other group received vehicle only for 7 months. The investigator evaluating the dogs was blinded to the allocation of treatments. Prior to and after 2 and 7 months of IT, dogs were challenged daily with HDMs for 3 days concurrently, and clinical signs were scored using a modified Canine Atopic Dermatitis Extent and Severity Index (CADESI). Prior to and at completion of oral IT, serum was collected for measurement of allergen-specific IgE. Oral IT was well tolerated, and no adverse effects were noted. Analysis of variance showed no significant effect of time, group and group × time interaction for CADESI scores. In addition, there were no significant differences in allergen-specific IgE levels. In conclusion, it appears that oral administration of HDMs is well tolerated in these atopic beagles but that this protocol was not sufficient to induce clinical improvement. Further, longer-term studies will be necessary to explore the potential of oral IT in veterinary medicine.

Diagnosis and management of work-related asthma: American College Of Chest Physicians Consensus Statement

BACKGROUND

A previous American College of Chest Physicians Consensus Statement on asthma in the workplace was published in 1995. The current Consensus Statement updates the previous one based on additional research that has been published since then, including findings relevant to preventive measures and work-exacerbated asthma (WEA).

METHODS

A panel of experts, including allergists, pulmonologists, and occupational medicine physicians, was convened to develop this Consensus Document on the diagnosis and management of work-related asthma (WRA), based in part on a systematic review, that was performed by the University of Alberta/Capital Health Evidence-Based Practice and was supplemented by additional published studies to 2007.

RESULTS

The Consensus Document defined WRA to include occupational asthma (ie, asthma induced by sensitizer or irritant work exposures) and WEA (ie, preexisting or concurrent asthma worsened by work factors). The Consensus Document focuses on the diagnosis and management of WRA (including diagnostic tests, and work and compensation issues), as well as preventive measures. WRA should be considered in all individuals with new-onset or worsening asthma, and a careful occupational history should be obtained. Diagnostic tests such as serial peak flow recordings, methacholine challenge tests, immunologic tests, and specific inhalation challenge tests (if available), can increase diagnostic certainty. Since the prognosis is better with early diagnosis and appropriate intervention, effective preventive measures for other workers with exposure should be addressed.

CONCLUSIONS

The substantial prevalence of WRA supports consideration of the diagnosis in all who present with new-onset or worsening asthma, followed by appropriate investigations and intervention including consideration of other exposed workers.

Allergy and Ménière's disease

Ménière's disease (MD), which by definition is idiopathic, has been ascribed to various causes, including both inhalant and food allergies. Patients with MD report higher rates of allergy history and positive skin or in vitro tests compared to a control group of patients with other otologic diseases and to the general public. Recent immunologic studies have shown higher rates of circulating immune complexes, CD4, and other immunologic components in patients with MD compared to normal controls. Published treatment results have shown benefit from immunotherapy and/or dietary restriction for symptoms of MD in patients with both allergy and MD.

Specific immunotherapy is effective in the prevention of new sensitivities

BACKGROUND

Allergen specific immunotherapy is the only specific and curative approach in the treatment of IgE-mediated allergic diseases such as bronchial asthma and allergic rhinitis. The safety and clinical efficacy of this treatment are well documented but data on the prevention of new sensitizations remain scarce.

OBJECTIVE

To demonstrate the efficacy of specific immunotherapy in allergic respiratory diseases in childhood and to determine whether this treatment prevents the development of new sensitizations in children sensitized to house dust mite or pollen species.

METHODS

Fifty-six patients received specific immunotherapy (43 sensitive to house dust mite and 13 sensitive to pollen). Fifty-one patients not receiving immunotherapy but treated with pharmacotherapy were enrolled in the control group. The patients were followed-up for at least 4 years and treatment efficacy and the development of new sensitizations were compared between the two groups.

RESULTS

The number of patients with symptoms was significantly decreased in both groups at the end of the treatment period. No new sensitizations were found in 35 of the 43 (81.39 %) patients in the house dust mite immunotherapy group and in 10 of 13 (76.92 %) patients in the pollen immunotherapy group. In contrast, 20 of 51 (39.21 %) patients in the control group showed new sensitizations. The difference between the house dust mite and pollen immunotherapy groups and the control group in this parameter was statistically significant (p = 0.033).

CONCLUSION

Our data demonstrate that administration of specific immunotherapy in allergic patients significantly reduced symptoms and the development of new sensitivities.

Autologous whole blood injections to patients with chronic urticaria and a positive autologous serum skin test: a placebo-controlled trial

BACKGROUND

Patients with chronic urticaria (CU) frequently exhibit positive skin test reactions to autologous serum (ASST). Therapies aimed at inducing tolerance to circulating histamine-releasing factors in ASST+ CU patients, e.g. by treatment with autologous whole blood (AWB), have not yet been tested.

OBJECTIVE

To test whether ASST+ CU patients can benefit from repeated low-dose intramuscular injections of AWB.

METHODS

We characterized CU severity and duration, anti-Fc(epsilon)RI and anti-IgE expression, use of antihistamines, and quality of life in 56 CU patients (ASST+: 35, ASST-: 21) and assessed the therapeutic effects of 8 weekly AWB injections in a randomized, placebo-controlled, single-blind, parallel-group trial.

RESULTS

Numbers, size, intensity, and/or duration of CU symptoms, quality of life, as well as expression of anti-Fc(epsilon)RI or anti-IgE were similar in ASST+ and ASST- CU patients. However, CU in ASST+ patients was of longer duration and required markedly more antihistaminic medication. Interestingly, ASST+ patients, but not ASST- patients, showed significantly (1) reduced CU activity, (2) decreased use of antihistamines, and (3) improved quality of life after AWB treatment. Placebo treatment was ineffective in both groups, but differences of AWB and placebo treatment responses did not achieve statistical significance in either group, most likely due to the limited number of patients treated.

CONCLUSION

Our findings suggest that ASST+ CU is clinically different from other CU subforms and that ASST+ CU patients can benefit from AWB therapy.

Hipersensibilidade a fungos em crianças asmáticas de uma comunidade do Recife, Pernambuco

OBJETIVOS: identificar a sensibilização a testes cutâneos de hipersensibilidade imediata para fungos em crianças asmáticas, residentes em comunidade urbana de baixa renda. MÉTODOS: no período de março de 1997 a junho de 1998 foram avaliadas 13 crianças com mais de três episódios de dispnéia nos últimos 12 meses, selecionadas a partir de um estudo transversal, em que todos os 123 escolares de 6 a 10 anos residentes na comunidade responderam ao questionário International Study of Asthma and Allergies in Childhood. Nas 13 crianças com asma em atividade, foram aplicados testes cutâneos de hipersensibilidade imediata para avaliar resposta a seis extratos fúngicos padronizados: Aspergillus mix, Penicillium mix, Hormodendrum cladosporidiodes, Alternaria tenius, Helminthosporium interseninatum e Mold mix. RESULTADOS: dentre as 13 crianças analisadas, 12 apresentaram sensibilididade a pelo menos um dos fungos testados (12/13), cujos extratos com maior frequência de positividade foram: Aspergillus mix (7/13), Penicillium mix (6/13) e Hormodendrum cladosporidiodes (5/13). CONCLUSÕES: a freqüência elevada de hipersensibilidade aos extratos de fungos nas crianças avaliadas sugere a necessidade de estudos analíticos observacionais para esclarecer uma possível associação causal entre fungos e asma.

Double-blind and placebo-controlled study to assess efficacy and safety of a modified allergen extract of Dermatophagoides pteronyssinus in allergic asthma

BACKGROUND

A randomized double-blind, placebo-controlled study was conducted in patients allergic asthma sensitized to Dermatophagoides pteronyssinus.

OBJECTIVE

To evaluate the efficacy and safety after 1-year of immunotherapy with a modified D. pteronyssinus extract compared with placebo.

MATERIAL AND METHODS

Fifty-five patients were randomly allocated to receive the active treatment (n = 29), or placebo (n = 26). The main outcome was the specific bronchial provocation test (BPT). Other parameters analysed were dose-response skin prick test (SPT), symptom and medication scores and asthma quality of life (AQLQ).

RESULTS

At the end of the study, the active group showed a significant increase in the PD(20)FEV(1) compared with placebo (P = 0.0029). Nineteen patients of the active vs 10 of the placebo group needed more than twice the initial amount of allergen extract to have a positive BPT (P = 0.0293); seven patients in the placebo vs one in the active group needed less than half (P = 0.0137). In SPT, a significant improvement (P = 0.0049) was found in the active group. This group also had a median reduction of 91.5% in symptom scores, whereas the placebo group increased by 86%. Medication scores decreased in both groups (56% in the active and 11.4% in the placebo). In AQLQ, the differences between both groups were significant (P = 0.0234) at the end of the study.

CONCLUSION

After 1 year of treatment, the modified extract of D. pteronyssinus demonstrated to be safe and efficacious to treat patients with asthma and allergic rhinoconjunctivitis sensitized to this mite.

Pediatric Allergic Rhinitis: Treatment

Allergic rhinitis, an IgE-mediated disease, is the most common chronic childhood condition and is characterized by nasal sneezing, rhinorrhea, palate and eye itchiness, and congestion. Allergic rhinitis should be diagnosed as early as possible to avoid detrimental effects on the quality of life and comorbid disorders. Treatment initially involves avoidance measures and, when necessary, pharmacotherapy or immunotherapy. Pharmacotherapy generally involves antihistamines or nasal corticosteroids, but other medications such as leukotriene antagonists have demonstrated effectiveness in treating allergic rhinitis symptoms. Immunotherapy generally is reserved for patients unresponsive to therapy or unable to take medications.

Allergic rhinitis in children : diagnosis and management strategies

The incidence of allergic rhinitis has been increasing for the last few decades, in keeping with the rising incidence of atopy worldwide. Allergic rhinitis has a prevalence of up to 40% in children, although it frequently goes unrecognized and untreated. This can have enormous negative consequences, particularly in children, since it is associated with numerous complications and comorbidities that have a significant health impact on quality of life. In fact, allergic rhinitis is considered to be a risk factor for asthma. There are numerous signs of allergic rhinitis, particularly in children, that can alert an observant clinician to its presence. Children with severe allergic rhinitis often have facial manifestations of itching and obstructed breathing, including a gaping mouth, chapped lips, evidence of sleep deprivation, a long face, dental malloclusions, and the allergic shiner, allergic salute, or allergic crease. The medical history is extremely important as it can reveal information regarding a family history of atopy and the progression of atopy in the child. It is also important to identify the specific triggers of allergic rhinitis, because one of the keys to successful management is the avoidance of triggers. A tripartite treatment strategy that embraces environmental control, immunotherapy, and pharmacologic treatment is the most comprehensive approach. Immunotherapy has come to be viewed as potentially prophylactic, capable of altering the course of allergic rhinitis. The most recent guidelines for the management of allergic rhinitis issued by the WHO recommend a tiered approach that integrates diagnosis and treatment, in which allergic rhinitis is subclassified both by frequency, as either intermittent or persistent, and by severity, as either mild or moderate to severe. Oral or topical antihistamines and intranasal corticosteroids are the mainstay of pharmacologic therapy for allergic rhinitis, depending upon its severity, and several agents have been approved for use in children aged 5 years old and younger.

Serum interferon-gamma is associated with longitudinal decline in lung function among asthmatic patients: the Normative Aging Study

BACKGROUND

Cytokines are important mediators of the asthmatic response. A retrospective pilot study showed that serum levels of interleukin (IL)-5 and interferon (IFN)-gamma were related to lung function decline among asthmatic patients over the preceding 3 years. To confirm these findings, we tested the hypothesis that serum cytokines are associated with longitudinal lung function decline.

METHODS

We conducted a prospective, longitudinal study of 25 asthmatic and 50 nonasthmatic men (median age, 63 years; range, 45 to 80 years) participating in the Normative Aging Study. All study subjects completed two consecutive triennial examinations, including spirometry, methacholine challenge testing, allergy skin testing, and phlebotomy. Serum levels were measured for IL-4, IL-5, IL-6, IL-8, IL-10, and IFN-gamma.

RESULTS

Among asthmatic patients, a higher initial serum level of IFN-gamma was associated with a greater rate of decline of forced expiratory volume in 1 second (FEV1; beta = -67 mL/year per log increase in serum IFN-gamma, P = 0.04) and, to a lesser extent, of FEV1/forced vital capacity ratio (beta = -0.91%/year per log increase in serum IFN-gamma, P = 0.07) after adjusting for age, smoking status, and baseline level of lung function. Serum IL-5 level was associated with a rate of decline in FEV1 of borderline significance (beta = -61 mL/year per log increase in serum IL-5, P = 0.08) among asthmatic patients. These relationshipswere not observed among nonasthmatic patients.

CONCLUSIONS

Serum levels of IFN-gamma are associated with subsequent rate of change in lung function among asthmatic patients in this cohort of middle-aged and older men, and may be useful as biologic markers of risk for accelerated lung function decline in population studies.

Benefits of immunotherapy with a standardized Dermatophagoides pteronyssinus extract in asthmatic children: a three-year prospective study

BACKGROUND

Although widely practiced for over 80 years, the role of specific immunotherapy (SIT) in pediatric asthma treatment is still controversial. We assessed the effects of a 3-year period of subcutaneous administration of a standardized preparation of Dermatophagoides pteronyssinus (D pt) on the respiratory health in a group of asthmatic children monosensitized to house dust mite (HDM).

METHODS

A randomized clinical trial was performed after 1-year run-in period. Fifteen children receiving SIT for HDM and 14 controls (four drop-outs), matched for age, allergen sensitization, asthma severity, lung function, and non-specific bronchial reactivity (BHR), were studied during the 3-year treatment period. During the whole trial, respiratory symptoms, pharmacological and respiratory function parameters were regularly evaluated. Skin prick tests and methacholine challenge were performed at the beginning and end of the study.

RESULTS

In the SIT group significant improvement in asthmatic symptoms and marked reduction in drug intake was observed. The SIT group also showed a significant decrease in non-specific bronchial BHR. No new sensitivity occurred during the study period in the SIT group only. No major local or systemic side-effects were reported during the study.

CONCLUSIONS

Our results confirm that SIT is effective in asthmatic children sensitive to mites. It is associated with a decrease in BHR and it may prevent the development of new sensitizations in monosensitized subjects.