Stephen C. Dreskin

Isoforms of Jun Kinase Are Differentially Expressed and Activated in Human Monocyte/Macrophage (THP-1) Cells

Ten isoforms of c-jun N-terminal kinase (JNK) have been described that arise by differential mRNA splicing of three genes. In that the relative expression and function of these different JNK proteins in human monocytic cells is not known, we have examined the JNK isoforms in THP-1 monocyte/macrophage cells. Differentiation of THP-1 cells by exposure to 10−8 M PMA for 42–48 h enhances cellular responses to LPS, including enhanced activation of total JNK activity and increased phosphorylation of p54 JNK as well as p46 JNK. Examination of JNK proteins on Western blots reveals a predominance of p46 JNK1 and p54 JNK2 proteins. Clearing of lysates by immunoprecipitation of JNK1(99% effective) removes 46% of the JNK enzymatic activity (p < 0.01), whereas clearing of JNK1 plus JNK2 (70% effective) depletes the sample of 72% of the JNK activity (p < 0.01). Further analysis, undertaken with real-time RT-PCR, revealed that 98% of the JNK messages code for three isoforms: JNK1β1, JNK2α1, and JNK2α2. The p54 JNK that is phosphorylated in LPS-stimulated, PMA-differentiated THP-1 cells is most likely JNK2α2 because 97% of the p54 JNK-encoding messages code for JNK2α2. By analogous reasoning, the p46 JNKs that are not heavily phosphorylated, but account for approximately half of the N-terminal c-jun kinase enzymatic activity, are most likely either JNK1β1 or JNK2α1 because they account for 98% of the messages that can code for 46kDa JNKs.

An algorithm for treatment of patients with hypersensitivity reactions after vaccines

Concerns about possible allergic reactions to immunizations are raised frequently by both patients/parents and primary care providers. Estimates of true allergic, or immediate hypersensitivity, reactions to routine vaccines range from 1 per 50000 doses for diphtheria-tetanus-pertussis to ∼1 per 500000 to 1000000 doses for most other vaccines. In a large study from New Zealand, data were collected during a 5-year period on 15 marketed vaccines and revealed an estimated rate of 1 immediate hypersensitivity reaction per 450000 doses of vaccine administered. Another large study, conducted within the Vaccine Safety Datalink, described a range of reaction rates to >7.5 million doses. Depending on the study design and the time after the immunization event, reaction rates varied from 0.65 cases per million doses to 1.53 cases per million doses when additional allergy codes were included. For some vaccines, particularly when allergens such as gelatin are part of the formulation (eg, Japanese encephalitis), higher rates of serious allergic reactions may occur. Although these per-dose estimates suggest that true hypersensitivity reactions are quite rare, the large number of doses that are administered, especially for the commonly used vaccines, makes this a relatively common clinical problem. In this review, we present background information on vaccine hypersensitivity, followed by a detailed algorithm that provides a rational and organized approach for the evaluation and treatment of patients with suspected hypersensitivity. We then include 3 cases of suspected allergic reactions to vaccines that have been referred to the Clinical Immunization Safety Assessment network to demonstrate the practical application of the algorithm.

Allergic skin diseases

The skin is one of the largest immunologic organs and is affected by both external and internal factors, as well as innate and adaptive immune responses. Many skin disorders, such as atopic dermatitis, contact dermatitis, urticaria, angioedema, psoriasis, and autoimmune blistering disorders, are immune mediated. Most of these diseases are chronic, inflammatory, and proliferative, in which both genetic and environmental factors play important roles. These immunologic mechanisms might have implications for potential targets of future therapeutic interventions.

Effector activity of peanut allergens: a critical role for Ara h 2, Ara h 6, and their variants

Rationale An important property of allergens is their ability to cross‐link IgE and activate mast cells and basophils. The effector activity of peanut allergens has not been well characterized.

The thyroid and urticaria.

Purpose of reviewAlthough it is generally accepted that thyroid autoimmunity is more prevalent in patients with chronic urticaria than in the general population, the importance of this finding is unclear. In addition, there are reports that chronic urticaria remits in some but not all patients who have evidence of thyroid autoimmunity and are treated with l-thyroxine. This review will summarize the history of this controversy and suggest a possible role for thyroid autoimmunity in the pathophysiology of chronic urticaria. Recent findingsImportant subsets of patients with chronic urticaria have autoantibodies to the high-affinity receptor for IgE (FcϵRI), anti-IgE, and antithyroid antibodies. Patients with chronic urticaria and biochemical evidence of thyroid autoimmunity may have active thyroid disease or may be clinically euthyroid. These patients are often poorly responsive to conventional therapy of urticaria and may have more chronic disease. New findings on the pathogenic effects of anti-FcϵRI autoantibodies and of antithyroid antibodies have revealed a role for complement activation. SummaryCurrently, there are no compelling arguments to decide whether or not thyroid autoimmunity plays a significant role in the pathogenesis of chronic urticaria. New developments concerning a role for complement activation in the pathogenesis of chronic urticaria may, however, lead to better understanding of this phenomenon in the future.

RBL cells expressing human FcεRI are a sensitive tool for exploring functional IgE–allergen interactions: studies with sera from peanut-sensitive patients

Rat basophilic leukemia cells (RBL SX-38) express the alpha, beta, and gamma chains of human Fc epsilon RI. Following sensitization with IgE from a subset of allergic human donors, these cells can be triggered by exposure to anti-IgE or to very low concentrations of specific allergens. We examined 18 sera from patients who were highly sensitive to peanuts by history and had anti-peanut IgE by in vitro testing. The ability of these sera to sensitize the RBL SX-38 cells for degranulation with peanut allergens correlates very well with the absolute amount of anti-peanut IgE (r=0.95; p<0.001). The most effective sera contained at least 50 kU/l of total IgE and at least 15 kU/l of peanut-specific IgE. RBL SX-38 cells sensitized with these sera degranulated optimally upon exposure to anti-IgE (net degranulation of 40+/-8%, means+/-S.D.; n=8) and to a 10(5)-10(6) dilution of crude peanut extract (CPE) (37+/-7% net degranulation; 93+/-13% of that seen with anti-IgE). This assay is quite sensitive. Cells sensitized with selected sera are activated by exposure to a 1:10(7) dilution of the CPE containing picogram amounts of peanut allergens. This assay is also quite specific. Cells sensitized with sera from patients with anti-peanut IgE and no detectable IgE against soybean, walnut or grass pollen did not degranulate following exposure to these latter antigens. The converse was also true; cells sensitized with sera from patients without anti-peanut IgE did not react to peanut. These data demonstrate that RBL cells expressing human Fc epsilon RI form the basis of a useful model system for the detection of allergens and for the study of IgE-allergen interactions.

The 2S albumin allergens of Arachis hypogaea, Ara h 2 and Ara h 6, are the major elicitors of anaphylaxis and can effectively desensitize peanut-allergic mice.

Ara h 2 and Ara h 6, co‐purified together in a 13–25 kD fraction (Ara h 2/6; 20 kD fraction) on gel filtration chromatography, account for the majority of effector activity in a crude peanut extract (CPE) when assayed with RBL SX‐38 cells sensitized with IgE from human peanut allergic sera.

Redefining the major peanut allergens

Food allergy has become a major public health concern in westernized countries, and allergic reactions to peanuts are particularly common and severe. Allergens are defined as antigens that elicit an IgE response, and most allergenic materials (e.g., pollens, danders, and foods) contain multiple allergenic proteins. This has led to the concept that there are “major” allergens and allergens of less importance. “Major allergens” have been defined as allergens that bind a large amount of IgE from the majority of patients and have biologic activity. However, the ability of an allergen to cross-link complexes of IgE and its high-affinity receptor FcεRI (IgE/FcεRI), which we have termed its allergic effector activity, does not correlate well with assays of IgE binding. To identify the proteins that are the most active allergens in peanuts, we and others have employed in vitro model assays of allergen-mediated cross-linking of IgE/FcεRI complexes and have demonstrated that the most potent allergens are not necessarily those that bind the most IgE. The importance of a specific allergen can be determined by measuring the allergic effector activity of that allergen following purification under non-denaturing conditions and by specifically removing the allergen from a complex allergenic extract either by chromatography or by specific immunodepletion. In our studies of peanut allergens, our laboratory has found that two related allergens, Ara h 2 and Ara h 6, together account for the majority of the effector activity in a crude peanut extract. Furthermore, murine studies demonstrated that Ara h 2 and Ara h 6 are not only the major elicitors of anaphylaxis in this system, but also can effectively desensitize peanut-allergic mice. As a result of these observations, we propose that the definition of a major allergen should be based on the potency of that allergen in assays of allergic effector activity and demonstration that removal of that allergen from an extract results in loss of potency. Using these criteria, Ara h 2 and Ara h 6 are the major peanut allergens.

Contribution of Ara h 2 to peanut-specific, immunoglobulin E-mediated, cell activation.

Background Ara h 2 is a potent peanut allergen but its contribution to the ability of a crude peanut extract (CPE) to cross‐link IgE and activate mast cells has not been rigorously evaluated.

Development of a daily diary for patients with chronic idiopathic urticaria

BACKGROUND Chronic idiopathic urticaria (CIU) is a disease characterized by itching and skin hives or wheals of unknown cause that vary in size and last for at least 6 weeks. The criterion standard for measuring disease activity is the urticaria activity score (UAS). However, content validity of the UAS has not been previously reported. OBJECTIVES To identify outcomes important to patients with CIU, create an urticaria patient daily diary based on the UAS and input from patients, and assess its content validity. METHODS A qualitative research study was conducted in 2 stages using one-on-one telephone interviews of patients with CIU. In stage 1, patients were asked to discuss the impact of CIU on aspects of their life and to evaluate the content of the UAS. On the basis of this information, a patient daily diary, including UAS items, was developed. In stage 2, patients were interviewed to determine whether the urticaria patient daily diary was comprehensive and easily understood. RESULTS Stage 1 interviews showed that CIU has an extensive impact on patients, from the primary symptoms of itching, hives, and angioedema to the broader aspects of sleep and health-related quality of life. Stage 2 interviews demonstrated the content validity of the urticaria patient daily diary and resulted in minor modifications to the diary. When the urticaria patient daily diary was administered in conjunction with the Dermatology Life Quality Index and Medical Outcomes Study Sleep Scale, patients considered the assessment to be comprehensive, although some recommendations were made to include more items on emotional issues and other aspects of angioedema. CONCLUSIONS The final urticaria patient daily diary is an easy-to-administer, comprehensive assessment of symptoms for CIU patients. Future research is needed to establish its additional psychometric properties.