Cyanobacteria: an unrecognized ubiquitous sensitizing allergen?

This study was designed to investigate the prevalence of skin sensitization using detoxified cyanobacterial reagents in a chronic rhinitis population. Subjects ≥6 years of age who presented for allergy consultation to a community allergy practice and required skin-prick testing (SPT) to common seasonal and perennial aeroallergens were enrolled after signing an informed consent. Detoxified cyanobacteria species were used for skin testing. Skin testing of unexposed, nonsensitized control subjects using these detoxified cyanobacterial skin test reagents was performed to identify irritant threshold responses. All subjects signed an Institutional Review Board-approved informed consent before participation. Two hundred fifty-nine patients ranging in age between 7 and 78 years old underwent testing. The majority were white female patients and over two-thirds (73.4%) were atopic. Seventy-four (28.6% of the population) patients were SPT(+) to at least one of the cyanobacteria species. Positive SPTs were present in 86% of patients to Microcystis aeruginosa and 12% of patients to Aphanizomenon-flos aquae. There was a strong association between severity of atopy (number of positive SPTs), having allergic rhinitis and sensitization to one or more cyanobacteria species (p < 0.001). This is the first study to show that cyanobacterial allergenicity resides in nontoxin-containing components of this organism.

The health effects of non-industrial indoor air pollution.

BACKGROUND: There is growing public awareness regarding the risk associated with poor indoor air quality in the home and workplace. Because Americans spend approximately 22 hours every day indoors, susceptible individuals are at much greater risk of adverse health effects from chronic low levels of exposure to indoor air pollutants over time. Along with particulate matter, gases such as ozone, nitrogen dioxide, carbon monoxide, and sulfur dioxide; microbial and chemical volatile organic compounds; passive smoke; and outdoor ambient air are the most common types of air pollutants encountered indoors. OBJECTIVE: To provide the allergists with necessary information that will assist them in making useful recommendations to patients seeking advice regarding indoor environmental triggers beyond traditional perennial allergens. METHODS: Review of the literature pertaining to indoor exposure and health effects of gaseous and particular matter. RESULTS: Indoor pollutants act as respiratory irritants, toxicants, and adjuvants or carriers of allergens. CONCLUSION: The allergist should be prepared to evaluate patient exposure to allergic and nonallergic triggers and understand how outdoor air pollution is affecting indoor environments. This requires being familiar with methodologies for monitoring and interpreting indoor air quality and interpreting results in the context of the patients exposure history and advising patients about rational environmental control interventions.

Clinical and laboratory investigation of allergy to genetically modified foods.

Technology has improved the food supply since the first cultivation of crops. Genetic engineering facilitates the transfer of genes among organisms. Generally, only minute amounts of a specific protein need to be expressed to obtain the desired trait. Food allergy affects only individuals with an abnormal immunologic response to food--6% of children and 1.5-2% of adults in the United States. Not all diseases caused by food allergy are mediated by IgE. A number of expert committees have advised the U.S. government and international organizations on risk assessment for allergenicity of food proteins. These committees have created decision trees largely based on assessment of IgE-mediated food allergenicity. Difficulties include the limited availability of allergen-specific IgE antisera from allergic persons as validated source material, the utility of specific IgE assays, limited characterization of food proteins, cross-reactivity between food and other allergens, and modifications of food proteins by processing. StarLink was a corn variety modified to produce a (Italic)Bacillus thuringiensis(/Italic) (Bt) endotoxin, Cry9C. The Centers for Disease Control and Prevention investigated 51 reports of possible adverse reactions to corn that occurred after the announcement that StarLink, allowed for animal feed, was found in the human food supply. Allergic reactions were not confirmed, but tools for postmarket assessment were limited. Workers in agricultural and food preparation facilities have potential inhalation exposure to plant dusts and flours. In 1999, researchers found that migrant health workers can become sensitized to certain Bt spore extracts after exposure to Bt spraying.

Is burning semen syndrome a variant form of seminal plasma hypersensitivity?

OBJECTIVE: To identify an index population of Gulf War couples with burning semen syndrome and to determine whether burning semen syndrome was secondary to seminal plasma hypersensitivity. METHODS: Questionnaire surveys, screening laboratory testing for underlying medical disorders, including sexually transmitted diseases and immunoglobulin G and E immunoassays specific for seminal plasma protein, were performed. If subjects met the criteria for seminal plasma hypersensitivity, the Gulf War male veteran's seminal plasma proteins were used to desensitize his female sexual partner. RESULTS: Eighty-nine percent (188 of 211) of respondents had either personally experienced burning after contact with their own semen or had a sexual partner who had burning after contact with their semen. Asymptomatic female partners (three of five) of Gulf War veterans who exhibited specific immunoglobulin E skin and antibody responses to seminal plasma proteins responded successfully to rapid desensitization. Treatment results were confirmed by a provocative office challenge, consisting of instillation of whole seminal fluid into the female's vaginal vault and, if negative, subsequently by natural coitus. CONCLUSION: The results of this study indicate that seminal plasma hypersensitivity may present as burning semen syndrome in a subpopulation of Gulf War couples. Proper screening of Gulf War couples with clinical features of burning semen syndrome should include assessment for seminal plasma hypersensitivity reactions, as seminal plasma protein desensitization may induce remission of burning semen syndrome.

Irritant-induced airway disorders.

Thousands of persons experience accidental high-level irritant exposures each year but most recover and few die. Irritants function differently than allergens because their actions proceed nonspecifically and by nonimmunologic mechanisms. For some individuals, the consequence of a single massive exposure to an irritant, gas, vapor or fume is persistent airway hyperresponsiveness and the clinical picture of asthma, referred to as reactive airways dysfunction syndrome (RADS). Repeated irritant exposures may lead to chronic cough and continual airway hyperresponsiveness. Cases of asthma attributed to repeated irritant-exposures may be the result of genetic and/or host factors.

A case of progesterone-induced anaphylaxis, cyclic urticaria/angioedema, and autoimmune dermatitis.

OBJECTIVE: Women have exhibited anaphylaxis, urticaria/angioedema, and autoimmune progesterone dermatitis (APD) coinciding with the progesterone premenstrual rise. We report a detailed immunological evaluation of such a woman responsive to a gonadotropin hormone-releasing agonist (GHRA). METHODS: Skin testing, enzyme-linked immunosorbent assays (ELISAs), leukocyte histamine release (LHR), and inhibition assays were performed to demonstrate progesterone immunoresponsiveness. RESULTS: Serum specific-progesterone immunoglobulin G (IgG) and IgE were detected initially and disappeared 6 months after GHRA treatment. Dose-response LHR using patient basophils was observed for different hormones but after 3 months persisted only for 5ß-pregnanediol. Preincubation with mouse antiprogesterone monoclonal antibody (PmAb) or mifepristone, a progesterone inhibitor, over a range of doses inhibited specific progesterone-induced LHR. Experiments with varying progesterone concentrations and a fixed dose of anti-IgE resulted in 100% LHR at a concentration as low as 0.016 nmol/mL, which, without anti-IgE, failed to release histamine. CONCLUSIONS: This is the first report of combined recurrent anaphylaxis, cyclic urticaria/angioedema, and APD induced by immunoresponsiveness to progesterone.

Hereditary angioedema: a current state-of-the-art review, II: historical perspective of non-histamine-induced angioedema.

OBJECTIVE: To review the evolution of our understanding of hereditary angioedema (HAE) from the first historical reference to the present day. DATA SOURCES: MEDLINE and PubMed were searched using the following keywords: history of HAE, C1 inhibitor, complements system, genetics of HAE, mechanisms of HAE, and treatment of HAE. STUDY SELECTION: Information was selected that outlines the advances made in complementology, the first report of HAE, and subsequent studies that elucidated the underlying mechanisms of this disease, leading to current therapy of this orphan disease. RESULTS: Generational research efforts in HAE have focused on the following: (1) several new clinical presentations, (2) acquired forms of non-histamine-induced angioedema, (3) the genetic basis for the inherited forms, (4) the effects of C1 inhibitor on contact phases of coagulation-fibrinolytic pathways, and (5) various therapies for short- and long-term control of the disease. CONCLUSION: The progress made in understanding the pathogenesis and treatment of HAE is an excellent example of the "bench to the bedside" paradigm involving the collaboration between clinicians and researchers.

A novel case of mealworm-induced occupational rhinitis in a school teacher.

A 47-year-old African American female elementary schoolteacher presented with itchy, watery eyes, rhinorrhea, postnasal drainage, and nasal congestion complicated by recurrent epistaxis for 2 months. She had similar symptoms the previous year from September to May but was symptom free during the summer. Her symptoms began within 1 hour after entering the classroom and improved in the evening at home, on weekends, and vacation. She denied symptoms around dust, freshly cut grass, or pets and had no prior history of underlying allergic rhinitis and asthma. She had a 20-pack-a-year smoking history but quit 1 1/2 years ago. A detailed history of her classroom environment revealed the presence of mealworms that were used to teach the children about life cycles. Physical exam revealed swollen, erythematous nasal turbinates but was otherwise unremarkable. Prick skin testing was positive for oak tree, grasses, feathers, and cockroaches. Mealworm whole body extracts were prepared using standard methodology. Titration intracutaneous skin testing revealed a positive reaction at a 1:1000 concentration associated with a large delayed reaction 8 hours later that persisted for 24 hours. Specific nasal provocation using acoustic rhinometry revealed a dose response change in nasal volume (48% decrease at 1:100; 53% decrease at 1:50) and cross-sectional area (32% decrease at 1:100; 48% decrease at 1:50) in response to mealworm challenge compared with a saline control. Removal of the mealworms from the classroom resulted in complete relief of her symptoms. This is the first reported case of mealworm-induced rhinitis in a schoolteacher. Because mealworm demonstrations are now part of the standard curriculum in public school elementary classrooms in Ohio, it is important that school administrators recognize the sensitizing nature of these insects and their potential for causing allergic rhinitis and asthma in the workplace.

Evaluation of the clinical efficacy and safety of grapeseed extract in the treatment of fall seasonal allergic rhinitis: a pilot study.

BACKGROUND: Herbal products are widely used by consumers as alternatives to prescription drugs in treating symptoms of allergic rhinitis. However, there have been few placebo-controlled clinical trials that have examined the efficacy or safety of these products. Although grapeseed extract (GSE) is an herbal that is marketed for treating allergic rhinitis, its efficacy is unproven. OBJECTIVE: The aim of this study was to compare the efficacy and safety of GSE with placebo in the treatment of seasonal allergic rhinitis (SAR). METHODS: This was a randomized, double-blind, placebo-controlled study of GSE 100 mg, twice daily, versus placebo. Patients with SAR and skin prick test sensitivity to ragweed were randomized to 8 weeks of active treatment or placebo which was begun before the ragweed pollen season. Outcomes included: daily symptom diary scores recorded by patients, rhinitis quality of life scores at baseline and after 4 and 8 weeks of treatment; and requirements for rescue chlorpheniramine. Safety was monitored with routine laboratory studies. RESULTS: Over 8 weeks of treatment, no significant differences were observed between active and placebo groups in rhinitis quality of life assessments, symptom diary scores, or requirements for rescue antihistamine. No significant laboratory abnormalities were detected. CONCLUSIONS: This study did not show trends supporting the efficacy of GSE in the treatment of SAR.

Health effects of air pollution.

The general public, especially patients with upper or lower respiratory symptoms, is aware from media reports that adverse respiratory effects can occur from air pollution. It is important for the allergist to have a current knowledge of the potential health effects of air pollution and how they might affect their patients to advise them accordingly. Specifically, the allergist-clinical immunologist should be keenly aware that both gaseous and particulate outdoor pollutants might aggravate or enhance the underlying pathophysiology of both the upper and lower airways. Epidemiologic and laboratory exposure research studies investigating the health effects of outdoor air pollution each have advantages and disadvantages. Epidemiologic studies can show statistical associations between levels of individual or combined air pollutants and outcomes, such as rates of asthma, emergency visits for asthma, or hospital admissions, but cannot prove a causative role. Human exposure studies, animal models, and tissue or cellular studies provide further information on mechanisms of response but also have inherent limitations. The aim of this rostrum is to review the relevant publications that provide the appropriate context for assessing the risks of air pollution relative to other more modifiable environmental factors in patients with allergic airways disease.