Optimizing Value in the Evaluation of Chronic Spontaneous Urticaria: A Cost-Effectiveness Analysis.

BACKGROUND: Chronic spontaneous urticaria (CSU) affects approximately 1% of the general population. The cost-effectiveness of routine laboratory testing for secondary causes of CSU has not been formally evaluated. OBJECTIVE: To characterize the cost-effectiveness of routine laboratory screening in adults with CSU. METHODS: A Markov model using cohort analysis and microsimulations was created for adult patients aged 20 years, over a 10-year time horizon, randomized to receive screening laboratory testing or a no-testing approach. Laboratory results were derived from a previously published retrospective analysis of adult patients with CSU. Cost-effectiveness was evaluated at a willingness to pay threshold of $100,000/quality-adjusted life-year using the incremental cost-effectiveness ratio (ICER) in patients with untreated CSU, and patients treated with antihistamines, cyclosporine, or omalizumab. RESULTS: Average laboratory costs per simulated patient with CSU were $573 (standard deviation [SD], $41), with only 0.16% (SD, 3.99%) of tests resulting in improved clinical outcomes. Testing costs per laboratory-associated positive outcome were $358,052 (no therapy), $357,576 (antihistamine therapy), $354,115 (cyclosporine), and $262,121 (omalizumab). Screening tests were not cost-effective, with ICERs of $856,905 (no therapy), $855,764 (antihistamine therapy), $847,483 (cyclosporine), and $627,318 (omalizumab). In the omalizumab-treated subgroup, testing could be cost-effective below $220 or if it resulted in a 0.73% rate of CSU resolution. From a simulated US population perspective, nation-wide screening costs could reach $941,750,741 to $1,833,501,483. CONCLUSIONS: In CSU, the likelihood of clinical improvement from laboratory testing is very low, and testing is not cost-effective. These data support recommendations to not routinely perform laboratory testing in patients with CSU with otherwise normal histories and physical evaluations.

Mastocytosis: from a Molecular Point of View.

Mast cells (MCs) are physiologically activated by binding of stem cell factor (SCF) to the extracellular domains of the Kit receptor. This binding increases the proliferation and prolongs the survival of normal mature MCs, as well as intensifies the release of mediators. In mastocytosis, somatic mutations of the coding Kit gene cause autocrine dysregulation and lead to constitutive KIT activation even in the absence of its ligand SCF. Clinical symptoms are caused by MC-mediator release and/or infiltration of MCs into tissues. Aberrant KIT activation may result in increased production of MCs in the skin and extracutaneous organs. Depending on the affected organ(s), the disease can be divided into cutaneous mastocytosis (CM), systemic mastocytosis (SM), and localized MC tumors. The updated classification of WHO discriminates between several distinct subvariants of CM and SM. While the prognosis in CM and indolent SM (ISM) is excellent with (almost) normal life expectancy, the prognosis in aggressive SM (ASM) and MC leukemia (MCL) is dismal. The symptoms may comprise urticaria, angioedema, flush, pruritus, abdominal pain, diarrhea, hypotension, syncope, and musculoskeletal pain and are the results of MC infiltration and mediator release into target organs, i.e., the skin, gastrointestinal tract, liver, spleen, lymph nodes, and bone marrow. Mastocytosis differs from a lot of other hematological disorders because its pathology is not only based on the lack of normal function of a specific pathway or of a specific cell type but additionally is a proliferative disease. Currently available treatments of mastocytosis include symptomatic, antimediator and cytoreductive targeted therapies.

An inverse relationship between peroxisome proliferator-activated receptor gamma and allergic airway inflammation in an allergen challenge model.

BACKGROUND: Peroxisome proliferator-activated receptor gamma (PPAR-gamma) expression has not been evaluated in bronchoalveolar lavage (BAL) cells from allergic asthmatic patients. OBJECTIVE: To determine whether inappropriate down-regulation of PPAR-gamma in alveolar macrophages may contribute to persistent airway inflammation in allergic asthma. METHODS: We used segmental allergen challenge as a model of in vivo experimental allergic asthmatic exacerbation and airway inflammation. PPAR-y gene expression was evaluated at baseline and 24 hours later in asthmatic patients and controls using real-time polymerase chain reaction. Immunofluorescence was used to determine cellular location of the PPAR-gamma protein. RESULTS: We demonstrate for the first time to our knowledge that PPAR-gamma messenger RNA and protein, which are highly expressed in alveolar macrophages of healthy individuals, are significantly reduced in asthmatic patients after segmental allergen challenge. In allergic asthmatic patients (n=9), PPAR-gamma gene expression decreased significantly from baseline to postchallenge BAL (median decrease, 45%; P = .008). Furthermore, immunofluorescence staining demonstrated that PPAR-gamma protein was associated with alveolar macrophages and not with inflammatory eosinophils and neutrophils. CONCLUSION: Results implicate down-regulation of PPAR-gamma in BAL cells as a potential factor in dysregulation of lung homeostasis in asthmatic patients. The present findings suggest that PPAR-gamma agonists could have a future role in asthma therapy and warrant further study.

Omalizumab: where does it fit into current asthma management?

Omalizumab (Xolair), a monoclonal antibody, is a new agent that blocks the allergic cascade at its primary step. This drug offers substantial promise for patients with moderate-to-severe, persistent allergic asthma that is not well controlled. But due to the cost of the drug, limitations on dosage, and available clinical trial data, it is not a first-line therapy. This review discusses how this drug works, which patients will be candidates for it, and the practical aspects of using it.