Allergen-induced inflammation and the role of immunoglobulin E (IgE)

Population-based efficacy modeling of omalizumab in patients with severe allergic asthma inadequately controlled with standard therapy

Omalizumab, a recombinant humanized monoclonal antibody, is the first approved anti-immunoglobulin E (IgE) agent for the treatment of subjects with moderate to severe persistent allergic asthma that are inadequately controlled by the standard of care. The objective of this study was to quantitatively characterize relationships between serum free IgE and pulmonary function (as measured by forced expiratory volume in 1 s [FEV1]) as well as serum free IgE and airway inflammation (as measured by fractional exhaled nitric oxide [FeNO]) using population-based efficacy models. Data were collected from patients in the EXTRA trial who received omalizumab or placebo 150 to 375 mg subcutaneously every 2 or 4 weeks from week 0 to 48 with constant standard of care as background therapy. None of the covariates evaluated, including demographics, disease status, and baseline pharmacodynamic biomarkers, were significant in explaining the variability in the FEV1 or FeNO response to omalizumab. Results from the efficacy models further confirmed the current omalizumab dosing rationale based on the mean target free IgE level of 25 ng/ml and quantified the variability for the target. In addition, the resulting population models could be used to predict population FEV1 or FeNO response for omalizumab and/or other anti-IgE therapeutics for which PK-IgE models are constructed.

Inflammation, aging, and cancer: tumoricidal versus tumorigenesis of immunity: a common denominator mapping chronic diseases

Acute inflammation is a highly regulated defense mechanism of immune system possessing two well-balanced and biologically opposing arms termed apoptosis ('Yin') and wound healing ('Yang') processes. Unresolved or chronic inflammation (oxidative stress) is perhaps the loss of balance between 'Yin' and 'Yang' that would induce co-expression of exaggerated or 'mismatched' apoptotic and wound healing factors in the microenvironment of tissues ('immune meltdown'). Unresolved inflammation could initiate the genesis of many age-associated chronic illnesses such as autoimmune and neurodegenerative diseases or tumors/cancers. In this perspective 'birds' eye' view of major interrelated co-morbidity risk factors that participate in biological shifts of growth-arresting ('tumoricidal') or growth-promoting ('tumorigenic') properties of immune cells and the genesis of chronic inflammatory diseases and cancer will be discussed. Persistent inflammation is perhaps a common denominator in the genesis of nearly all age-associated health problems or cancer. Future challenging opportunities for diagnosis, prevention, and/or therapy of chronic illnesses will require an integrated understanding and identification of developmental phases of inflammation-induced immune dysfunction and age-associated hormonal and physiological readjustments of organ systems. Designing suitable cohort studies to establish the oxido-redox status of adults may prove to be an effective strategy in assessing individual's health toward developing personal medicine for healthy aging.

Dietary exclusions for established atopic eczema

BACKGROUND

Atopic eczema (AE) is a non-infective chronic inflammatory skin disease characterised by an itchy red rash.

OBJECTIVES

To assess the effects of dietary exclusions for the treatment of established atopic eczema.

SEARCH STRATEGY

We searched The Cochrane Skin Group Specialised Register (to March 2006), The Cochrane Central Register of Controlled Trials (CENTRAL) in The Cochrane Library (Issue 1, 2006), MEDLINE (2003 to March 2006), EMBASE (2003 to March 2006), LILACS (to March 2006), PsycINFO (1806 to March 2006), AMED (1985 to March 2006), ISI Web of Science (March 2006), www.controlled-trials.com, www.clinicaltrials.gov and www.nottingham.ac.uk/ongoingskintrials (March 2006). Pharmaceutical companies were contacted where appropriate for reviews or unpublished trials.

SELECTION CRITERIA

People who have atopic eczema as diagnosed by a doctor.

DATA COLLECTION AND ANALYSIS

Two independent authors carried out study selection and assessment of methodological quality.

MAIN RESULTS

We found 9 RCTs involving a total of 421 participants of which 6 were studies of egg and milk exclusion (N=288), 1 was a study of few foods (N=85) and 2 were studies of an elemental diet (N=48). There appears to be no benefit of an egg and milk free diet in unselected participants with atopic eczema. There is also no evidence of benefit in the use of an elemental or few-foods diet in unselected cases of atopic eczema. There may be some benefit in using an egg-free diet in infants with suspected egg allergy who have positive specific IgE to eggs - one study found 51% of the children had a significant improvement in body surface area with the exclusion diet compared to normal diet (RR 1.51, 95% CI 1.07 to 2.11) and change in surface area and severity score was significantly improved in the exclusion diet compared to the normal diet at the end of 6 weeks (MD 5.50,95% CI 0.19 to 10.81) and end of treatment (MD 6.10, 95% CI 0.06 to12.14). Methodological difficulties have made it difficult to interpret these studies. Poor concealment of randomisation allocation, lack of blinding and high dropout rates without an intention-to-treat analysis indicates that these studies should be interpreted with great caution.

AUTHORS' CONCLUSIONS

There may be some benefit in using an egg-free diet in infants with suspected egg allergy who have positive specific IgE to eggs. Little evidence supports the use of various exclusion diets in unselected people with atopic eczema, but that may be because they were not allergic to those substances in the first place. Lack of any benefit may also be because the studies were too small and poorly reported. Future studies should be appropriately powered focusing on participants with a proven food allergy. In addition a distinction should be made between young children whose food allergies improve with time and older children/adults.

Developmental Phases of Inflammation-Induced Massive Lymphoid Hyperplasia and Extensive Changes in Epithelium in an Experimental Model of Allergy

Direct evidence that inflammation is linked to carcinogenesis has yet to be established. Very few data are available on the developmental phases of inflammation-induced immune dysfunction that may lead to tumorigenesis. In a series of studies conducted in the 1980s and 1990s, an experimental model of acute and chronic inflammation was established in guinea pig conjunctiva by topical application of fluoresceinyl ovalbumin (FLOA) for up to 30 months. In this updated report, some of the findings are reanalyzed and expanded to identify that at lease 3 developmental phases were involved during the entire course of inflammatory responses including (1) an acute response (phase A) involving IgE-mast cell sensitization and degranulation; (2) an intermediate phase (phase B), a desensitization phenomenon and loss of mast cell function and neovascularization; (3) a chronic response (phase C) and induction of massive lymphoid hyperplasia, follicular formation with germinal centers, increased swollen goblet cells, extensive epithelial thickening and thinning, and angiogenesis. The results suggest evidence of a direct association between inflammation and the development of tumor-like lesions in lymphoid tissues and extensive changes in adjacent epithelia. Confirmation that inflammation induces irreversible changes in lymphoid and epithelial tissues leading to lymphoid tumorigenesis and/or carcinogenesis requires further studies. Understanding the developmental phases of immune dysfunction may provide unique opportunities for diagnosis and treatment of inflammatory diseases, autoimmune disorders, and cancers including lymphomas associated with Sjogren syndrome, squamous cell carcinoma of the conjunctiva, and other lymphomas or epithelial cancers. It is suggested that inflammatory mediators are ideal targets (biomarkers) for diagnosis, chemoprevention, and therapy for several cancers.

Modulation of T-cell functions by laser surgery in patients with allergic rhinitis

OBJECTIVE

Potassium-titanyl-phosphate (KTP) laser turbinectomy is an established treatment for hypertrophied inferior turbinates that do not respond to other medical treatments. KTP laser surgery is usually performed with the aim of reducing the size of hypertrophied inferior turbinates. We hypothesized that laser vaporation may also inhibit the allergic reaction in the nasal mucosa of inferior turbinates.

MATERIAL AND METHODS

We examined the effect of KTP laser therapy on T-cell responses using peripheral blood mononuclear cells (PBMCs).

RESULTS

Levels of T-cell proliferation after stimulation with Staphylococcus enterotoxin B (SEB) were higher in post- than pre-surgery patients. Levels of interferon-gamma and IL-2 produced by PBMCs after stimulation with SEB appeared to be higher in post- than pre-surgery patients. Serum levels of house dust-specific IgE were lower in post- than pre-surgery patients. These results indicate that KTP laser therapy modulates T-cell responses and probably tilts the Th1/Th2 balance towards the Th1-dominant state.

CONCLUSION

KTP laser surgery eases or cures allergic rhinitis not only by reducing the volume of the inferior turbinates but also by modulating T-cell functions.

Topical pimecrolimus: a review of its clinical potential in the management of atopic dermatitis

Pimecrolimus (SDZ ASM 981), an ascomycin derivative, is a nonsteroid, has anti-inflammatory activity, and has demonstrated efficacy in reducing symptoms of atopic dermatitis in adult and paediatric patients when applied topically. Compared with vehicle, topical pimecrolimus 1.0% cream was significantly more effective at reducing symptoms of atopic dermatitis, as measured by the Eczema Area and Severity Index (EASI), in infants aged 3 to 23 months, children aged 2 to 17 years and adults. The median reductions from baseline in the total EASI score in adults after treatment with pimecrolimus 1.0% or corresponding vehicle twice daily for 3 weeks were 47 and 0%, respectively. In infants and children, treatment with pimecrolimus 1.0% twice daily for 6 weeks resulted in significant decreases in mean EASI scores compared with vehicle. The severity of pruritus was significantly reduced in patients of all age groups after topical treatment with pimecrolimus 1.0% cream. Compared with vehicle, the incidence of eczematous flares was also reduced by intermittent long-term use of topical pimecrolimus 1.0% in adults, children and infants. Sixty percent of children treated with pimecrolimus for 1 year completed the first 6 months of treatment without experiencing a flare, compared with 35% of patients who received vehicle. Furthermore, the use of topical corticosteroids for the treatment of uncontrolled flares in adults, children and infants was lower in the pimecrolimus groups than in the vehicle groups. Topical pimecrolimus 1.0% cream is well tolerated in atopic dermatitis patients of all age groups. There were no clinically relevant systemic adverse events reported from any of the studies in patients with atopic dermatitis. The most frequently reported adverse events pertained to application site reactions, such as burning and a feeling of warmth. In conclusion, topical pimecrolimus 1.0% cream has shown efficacy in the treatment of mild to moderate atopic dermatitis in infants, children and adults. Although tolerability data concerning infants and children have not yet been published in full, the drug appears to be well tolerated in all age groups, and there have been no reports of clinically relevant systemic adverse events. Furthermore, pimecrolimus 1.0% cream has shown no potential for skin atrophy, a problem commonly associated with treatment with topical corticosteroids. Pimecrolimus 1.0% cream provides a promising and well tolerated treatment option in the management of infants, children and adults with mild to moderate atopic dermatitis.