[Significance of molecular diagnostics in allergen immunotherapy : Practical tips for the application in various groups of allergens with exemplary cases]. / Bedeutung der molekularen Diagnostik für die Allergenimmuntherapie : Praktische Tipps zur Anwendung bei verschiedenen Allergengruppen mit Fallbeispielen.

The basis of allergen immunotherapy (AIT) is the diagnosis of the eliciting allergen sources, which is a challenge, especially in the case of multiple sensitizations. Molecular allergy diagnostics can be of special help, since detection of "marker allergens", usually important major allergens, allows to distinguish between primary sensitization and cross-reactions. Thus, the indication and extract selection for AIT can be facilitated. While molecular diagnosis is particularly useful for double-sensitized hymenoptera venom and polysensitized pollen allergic patients, the benefit is probably lower in case of house dust mite allergy.

Omalizumab response correlates with reduced IFN-γ-, IL-10- and IL-31-secreting cells in chronic spontaneous urticaria.

BACKGROUND: The anti-IgE antibody omalizumab has been approved for the treatment of chronic spontaneous urticaria (CSU) in patients insufficiently responding to antihistamines. However, its mode of action in CSU is not clearly understood. OBJECTIVES: The aim of this study was to get a better insight in the immune mechanisms involved in clinical improvement of CSU patients treated with omalizumab. METHODS: Chronic spontaneous urticaria patients (n = 15) were followed for 5 months after initiation of omalizumab treatment. Clinical symptoms were assessed by UCT and CU-Q2 oL. Cell-bound IgE was quantified on both FcεRI- and FcεRII-expressing cell populations in peripheral blood. In addition, IgE and IgG as well as their receptors were measured on basophils, and basophil activation was assessed with different concentrations of anti-FcεRI and fMLP. Furthermore, the frequencies of different T-cell subsets secreting IL-5, IL-10, IL-31 or IFN-γ were analysed by ELISpot assay. RESULTS: Seven patients showed a full, five a partial and three no clinical response to omalizumab. Cell-bound IgE was reduced on FcεRI-bearing cells, but not on FcεRII-expressing cells. Likewise, the expression of FcεRI declined. Basophil activation increased upon FcεRI-stimulation while their sensitivity was not affected. Both basophil and T-cell frequencies remained unchanged. However, when comparing the individual response to omalizumab treatment with distinct T-cell subsets, a significant correlation was found between improved UCT and decreased frequencies of IL-10-, IL-31- and IFN-γ-secreting T cells. CONCLUSIONS: We here show that besides addressing IgE-dependent immune mechanisms, omalizumab treatment of CSU patients has effects on distinct T-cell subsets, which correlate with clinical improvement.

[Personalized medicine in allergology]. / Personalisierte Medizin in der Allergologie.

BACKGROUND: Personalized medicine offers new perspectives for diagnostic measurements and medical treatment, but also puts greater demands on the physician. OBJECTIVES: Developments, potentials and potential pitfalls of personalized medicine in allergology. METHODS: Overview, evaluation and discussion of the current state of science on the basis of selected examples. RESULTS: Allergic diseases like allergic rhinitis, atopic eczema or anaphylaxis can be classified into various clinical phenotypes, which are based on different immunological endotypes. These can be captured and categorized by a wide variety of omics technologies. The identification of endotype specific biomarkers holds promising opportunities of more precise diagnostics, the implementation of novel targeted therapies or the development of optimized preventive strategies. However, individualized analysis and assessment of the significance of the measurements represent special challenges. CONCLUSIONS: Findings of the complex omics technologies need to be evaluated by comprehensive prospective studies in order to validate their clinical relevance and suitability for personalized medicine in allergology.

Functional and phenotypic analysis of basophils allows determining distinct subtypes in patients with chronic urticaria.

BACKGROUND: Chronic urticaria (CU) is a frequent skin disease characterized by relapsing appearance of pruritic hives. While clinical symptoms are due to the release of histamine by cutaneous mast cells, the underlying pathophysiology is still unknown. However, previous studies indicate that basophils might be of relevance. Besides, the occurrence of autoantibodies against IgE or its receptor, FcεRI, and the therapeutic efficacy of anti-IgE antibodies imply that IgE-mediated mechanisms also play an important role in CU. METHODS: Reactivity of CU patients' peripheral blood basophils (n=60) to specific anti-FcεRI and IgE-independent fMLP stimulation was determined by basophil activation test in comparison with patients suffering from IgE-mediated allergic rhinitis (n=10) and healthy controls (n=10). In addition, immunoglobulin receptor (FcεRI, FcγRII) expression and surface bound antibodies (IgE, IgG) were quantified on basophils. Furthermore, the autoreactive capacity of CU sera was evaluated and urticaria-related symptoms were assessed by both UCT and CU-Q2 oL. RESULTS: Stimulating CU patients' basophils via FcεRI, we identified three distinct immunologic phenotypes. One subgroup of patients' basophils reacted to FcεRI stimulation, whereas the others had anti-FcεRI nonreactive basophils. Among the latter, a subgroup with pronounced basopenia was identified. Of note, this group was characterized by augmented serum-induced basophil activation, increased levels of autoantibodies against thyroid peroxidase, and also exhibited the strongest disease impact on their quality of life. CONCLUSIONS: Patients with CU can be categorized into three immunologic subgroups based on their basophil reactivity and frequency. These phenotypes are associated with different clinical characteristics, pointing to basophils as important players in CU pathophysiology.

Decline of Ves v 5-specific blocking capacity in wasp venom-allergic patients after stopping allergen immunotherapy.

While allergen-specific immunotherapy (AIT) is very efficient in hymenoptera venom (HV)-allergic patients, long-term outcome after finishing AIT is not well investigated, especially regarding mechanisms that are suggested to contribute to allergen-specific tolerance. Here, we analyse the Ves v 5-inhibitory activity of sera from wasp venom-allergic patients using the novel cell-free enzyme-linked immunosorbent facilitated antigen binding (ELIFAB) assay. Compared to pre-AIT, sera from patients undergoing AIT displayed an increased ability to inhibit Ves v 5 binding by IgE antibodies. In contrast, this inhibitory activity was reduced in patients having finished AIT 5-12 years ago. Allergen-blocking capacity correlated with serum concentrations of Ves v 5-specific IgG4 which rose during AIT but almost reached pretreatment levels in patients who had stopped AIT more than 5 years ago. These data raise questions about how long allergen tolerance is maintained in AIT-treated HV-allergic patients and suggest that the ELIFAB assay might be an easy-to-use tool assessing long-term tolerance in patients treated with HV-AIT.