Allergy Notes

Anaphylaxis to Patent Blue V dye used used for staging procedures in breast cancer

2009-11-06T04:33:00.001-05:00

The dye Patent Blue V (PBV) is increasingly used for staging procedures in breast cancer but is reported to cause adverse reactions.

9 patients with hypersensitivity reactions to PBV who were identified through the Norwegian network for reporting allergic reactions during anesthesia.

There was an incidences of 0.5% for all kinds of PBV reactions and 0.4% for anaphylaxis.

Typical clinical features included:

- cardiovascular and/or cutaneous symptoms
- a delay in symptoms, compared to the time of dye injection
- poor response to ephedrine and intravenous fluid
- need for adrenaline administration, sometimes prolonged, for circulatory stabilization

During anaphylactic reactions, serum tryptase was increased in 6 patients and normal in one.

Skin prick tests to PBV were positive in all 8 patients tested.

The clinical features and the results of follow-up studies strongly suggest that these reactions are IgE mediated.

References:
Anaphylaxis to Patent Blue V. Clinical aspects. A. S. Hunting, A. Nopp, S. G. O. Johansson, F. Andersen, V. Wilhelmsen, A. B. Guttormsen. Allergy. 2009.
Image source: Blue. Wikipedia, public domain.

Fibrin degradation products, D-dimer and CRP for assessment of disease activity of chronic urticaria

2009-11-04T06:27:00.003-05:00

Currently, there is no reliable biomarker for evaluation of disease severity and activity of chronic urticaria (CU).

Markers of blood coagulation and fibrinolysis are elevated in severe cases of CU.

Plasma fibrin degradation products (FDP), d-dimer and serum C-reactive protein (CRP) were measured in 82 patients with CU and 37 patients with acute urticaria, idiopathic angioedema (AE) or inducible types of urticaria (IU).

The levels of FDP in patients with CU were higher than those in patients with IU, but no other differences in FDP, d-dimer and CRP were observed among patients with different types of urticaria.

In 37 patients with CU, levels of all these parameters reduced as their disease condition improved, while they increased when the disease became aggravated.

The study authors concluded that the measurement of plasma FDP, d-dimer and serum CRP may be useful for the assessment of disease activity of CU.

References:
Coagulation/fibrinolysis and inflammation markers are associated with disease activity in patients with chronic urticaria. S. Takahagi et al. Allergy, 2009.
Image source: Urticaria, Wikipedia, public domain.

Triggers of asthma attacks in adults

2009-11-03T06:22:00.000-05:00

131 adult asthma patients were enrolled into a study that assessed asthma triggers via a questionnaire.

Regardless of asthma severity, 59.5 % of the subjects reported to be triggered by more than 10 factors.

The most common triggers were air pollutants (89%) and weather changes (82%).

In the severe group, more frequently mentioned triggers were medications, emotional stress, weather changes and indoor pollutants. Stress was reported more frequently by females than males.

References:
Triggers in adult asthma: are patients aware of triggers and doing right? Göksel O, Celik GE, Oner Erkekol F, Güllü E, Mungan D, Misirligil Z. Allergol Immunopathol (Madr). 2009 May-Jun;37(3):122-8.
Air pollution near the home increases asthma severity in children
Traffic exposure associated with decreased lung function in asthma
Image source: Interstate 80, seen here in Berkeley, California, is a freeway with many lanes and heavy traffic, Wikipedia, GNU Free Documentation License.

CNN video: Peanut-free game highlights food allergy

2009-11-02T06:34:00.002-05:00

At least 120 people die each year in the United States from peanut allergies. Food allergies are becoming more prevalent worldwide.

References:
Peanut-free ballgame highlights food allergy dangers. CNN.

Transcription factor PU.1 regulates TCR expression via GATA-3

2009-10-30T04:40:00.000-04:00

The Ets transcription factor PU.1 is a master regulator for the development of multiple lineages during hematopoiesis. The expression of PU.1 is regulated during early T lineage development in the thymus.

Spi-1 (PU.1) 5' UTR regulatory element. Image source: Wikipedia, public domain.

PU.1 modulates the levels of TCR expression in CD4(+) T cells by regulating the DNA-binding activity of GATA-3.

GATA-3-dependent regulation of TCR expression is also observed in Th1 and Th2 cells.

Increased GATA-3 function in the absence of the antagonizing activity of PU.1 leads to:

- increased TCR expression
- reduced activation threshold
- increased homogeneity in Th2 populations

References:
PU.1 regulates TCR expression by modulating GATA-3 activity. Chang HC, Han L, Jabeen R, Carotta S, Nutt SL, Kaplan MH. J Immunol. 2009 Oct 15;183(8):4887-94.

IL-33 is a new marker of severe and refractory asthma

2009-10-29T08:41:00.000-04:00

IL-33 is a new member of the IL-1 cytokine family that promotes Th2 inflammation.

Video: Interleukin-1 binding to its receptor on a cell surface, created from structural data.

Endobronchial biopsies were obtained from adults with mild, moderate, and severe asthma, and from control subjects.

Higher levels of IL-33 transcripts were detected in biopsies from asthmatic compared with control subjects, and especially in subjects with severe asthma.

Airway smooth muscle cells (ASMC) are a source of the IL-33 cytokine and show IL-33 expression at both protein and mRNA levels.

TNF-alpha up-regulates IL-33 in a dose-dependent manner. Dexamethasone fails to abolish TNF-alpha-induced IL-33 up-regulation. IFN-gamma also increases IL-33.

IL-33 appears to be a novel inflammatory marker of severe and refractory asthma.

References:
Increased expression of IL-33 in severe asthma: evidence of expression by airway smooth muscle cells. Préfontaine D, Lajoie-Kadoch S, Foley S, Audusseau S, Olivenstein R, Halayko AJ, Lemière C, Martin JG, Hamid Q. J Immunol. 2009 Oct 15;183(8):5094-103.
Interleukin 33 (IL-33)

Helminth Trichuris suis (pig whipworm) had no effect as therapy for allergic rhinitis

2009-10-28T04:39:00.002-04:00

Parasitic helminth infections may protect against allergic airway inflammation and have been associated with a reduced risk of atopy.

The helminth Trichuris suis (pig whipworm) has demonstrated efficacy in treatment of inflammatory bowel disease.

The authors conducted a double-blind, placebo-controlled trial in which 100 subjects age 18 to 65 years with grass pollen-induced allergic rhinitis were assigned to ingest 8 doses with 2500 live T suis ova or placebo.

Treatment with T. suis ova caused transient diarrhea peaking at day 41 in 33% of participants and increased eosinophil counts and T. suis-specific IgE, IgG(4) and IgA.

There was no significant change in symptom scores and wheal reaction on skin prick testing with grass or other allergens.

The authors concluded that treatment with the helminth T. suis induced a clinical and immunologic response as an infection, but had no therapeutic effect on allergic rhinitis.

References:
Trichuris suis ova therapy for allergic rhinitis: A randomized, double-blind, placebo-controlled clinical trial. Bager P, Arnved J, Rønborg S, Wohlfahrt J, Poulsen LK, Westergaard T, Petersen HW, Kristensen B, Thamsborg S, Roepstorff A, Kapel C, Melbye M. J Allergy Clin Immunol. 2009 Oct 2.
Image source: Trichuris egg in stool sample (40x). Wikipedia, GNU Free Documentation License, Version 1.2.

20% of children with allergic rhinitis have previously undiagnosed bronchial obstruction

2009-10-27T04:38:00.002-04:00

A relationship exists between upper and lower airways. Bronchial obstruction is a paramount feature of asthma and its reversibility is diagnostic of asthma.

200 children with allergic rhinitis and 150 normal subjects were evaluated with skin prick test, spirometry, and bronchodilation test.

"Rhinitics" showed a significant FEV1 increase after bronchodilation test. More than 20% of rhinitics had reversibility (greather than 12% above baseline levels).

Patients with reversibility had lower FEV1 levels, longer rhinitis duration, and perennial allergy.

This study highlights the close link between upper and lower airways and the relevance of performing bronchodilation test in patients with allergic rhinitis.

References:
Impact of allergic rhinitis on asthma in children: effects on bronchodilation test. M. Capasso, A. Varricchio, G. Ciprandi. Allergy, 2009.
Image source: Flow-Volume loop showing successful FVC maneuver. Wikipedia, GNU Free Documentation License, Version 1.2.

Parvalbumins are the most important fish allergens, mediate cross-reactivity between fish species

2009-10-26T04:36:00.002-04:00

Parvalbumin is a calcium binding protein with low molecular weight structurally related to calmodulin and troponin C. Parvalbumin is localised in fast-contracting muscles, brain and some endocrine tissues.

Parvalbumins are the most important fish allergens. Polysensitization to various fish species is common and linked to the cross-reactivity of their parvalbumins.

Dark-muscled fish such as tuna may be less allergenic.

Total protein extracts and purified parvalbumins from cod, whiff, and swordfish were tested for IgE-binding properties with 16 fish-allergic patients' sera from Spain.

Parvalbumins levels from cod were 20 times higher than from swordfish (whiff 30 times higher).

Parvalbumins were recognized by 94% of the patients in extracts of cod and whiff, but only by 60% in swordfish extracts.

The parvalbumins of cod, whiff and swordfish are highly cross-reactive due to high amino acid sequence.

The low allergenicity of swordfish is due to the low expression levels of its parvalbumin.

References:
Expression levels of parvalbumins determine allergenicity of fish species. U. Griesmeier, S. Vázquez-Cortés, M. Bublin, C. Radauer, Y. Ma, P. Briza, M. Fernández-Rivas, H. Breiteneder. Allergy, 2009.
Image source: Gadus morhua, Atlantic cod. Wikipedia, public domain.

Chlorine and exercise did not affect markers of inflammation in the airway of swimmers

2009-10-23T06:32:00.000-04:00

Chlorine metabolites and training load may produce exercise-induced bronchospasm (EIB) in elite swimmers. The aim of this Scottish study was to assess the combined effects of chlorine and exercise on the unified airway of adolescent elite swimmers.

A squad were assessed during an indoor pool session. Athletes trained at least 8 hr per week and underwent pre and post a 2 hr session:

- tidal (TNO) and nasal (NNO) exhaled NO
- peak nasal inspiratory flow (PNIF)

22% of swimmers had known asthma; 36% had a positive exercise challenge; 50% complained of symptoms suggestive of EIB.

36% who did not have asthma were found to have a positive exercise challenge.

There was no significant association between reported exercise symptoms and positive exercise test.

There was no significant change in TNO or NNO for pre vs postexposure, irrespective of asthma diagnosis or AHR.

The authors concluded that combined exposure to chlorine and exercise did not affect surrogate markers of inflammation in the unified airway. There was a high prevalence of undiagnosed EIB.

References:
Effects of chlorine and exercise on the unified airway in adolescent elite Scottish swimmers. K. L. Clearie, S. Vaidyanathan, P. A. Williamson, A. Goudie, P. Short, S. Schembri, B. J. Lipworth. Allergy. 2009.
Image source: Wikipedia, a Creative Commons License.

Urticaria guidelines by EAACI, EDF and WAO

2009-10-22T06:30:00.000-04:00

Urticaria is a frequent disease with a life-time prevalence of 20%.

Chronic urticaria not only cause a decrease in quality of life, but also affect performance at work and school.

The recommended first line treatment is new generation, nonsedating H(1)-antihistamines. If standard dosing is not effective, increasing the dosage up to four-fold is recommended.
For patients who do not respond to a four-fold increase in dosage of nonsedating H(1)-antihistamines, it is recommended that second-line therapies should be added.

Corticosteroids are not recommended for long-term treatment due to their unavoidable severe adverse effects. This guideline was acknowledged and accepted by the European Union of Medical Specialists (UEMS).

References:
EAACI/GA(2)LEN/EDF/WAO guideline: definition, classification and diagnosis of urticaria.
EAACI/GA(2)LEN/EDF/WAO guideline: management of urticaria.
Zuberbier T, Asero R, Bindslev-Jensen C, Walter Canonica G, Church MK, Giménez-Arnau A, Grattan CE, Kapp A, Merk HF, Rogala B, Saini S, Sánchez-Borges M, Schmid-Grendelmeier P, Schünemann H, Staubach P, Vena GA, Wedi B, Maurer M. Allergy. 2009 Oct;64(10):1417-26.
Image source: Urticaria, Wikipedia, public domain.

"Outside-to-inside, back to outside" paradigm in atopic dermatitis focuses on skin barrier

2009-10-21T06:27:00.000-04:00

Pathogenesis of atopic dermatitis includes:

- Th1/Th2 cell dysregulation
- abnormalities in IgE production and dendritic cell signaling
- mast cell hyperactivity

Current therapy has been largely directed towards ameliorating Th2-mediated inflammation and pruritus.

There is emerging evidence that atopic dermatitis results from inherited and acquired insults to the skin barrier,

There is a strong association between mutations in filaggrin and atopic dermatitis, particularly in Northern Europeans.

Sustained hapten access through a defective skin barrier stimulates a Th1 to Th2 shift in immunophenotype, which in turn further aggravates the barrier.

Secondary Staphylococcus aureus colonization not amplifies inflammation and further stresses the barrier in atopic dermatitis.

There is a new 'outside-to-inside, back to outside' paradigm for the pathogenesis of atopic dermatitis. 'Barrier repair' therapies could be developed in the future.

References:
Abnormal skin barrier in the etiopathogenesis of atopic dermatitis. Elias, Peter M; Schmuth, Matthias. Current Opinion in Allergy and Clinical Immunology, 2009.
Image source: Skin layers. Wikipedia, public domain.

Sulphite hypersensitivity

2009-10-20T06:26:00.000-04:00

Sulphites are widely used as preservative and antioxidant additives in the food and pharmaceutical industries.

Sulfites (also sulphites) are compounds that contain the sulfite ion SO. Sulfites occur naturally in all wines to some extent. Sulfites are commonly introduced to arrest fermentation at a desired time, and may also be added to wine as preservatives to prevent spoilage and oxidation at several stages of the winemaking.

Sulphites can induce a range of adverse clinical effects in sensitive individuals:

- dermatitis
- urticaria
- flushing
- hypotension
- abdominal pain
- diarrhoea
- anaphylaxis
- asthmatic reactions

Exposure to the sulphites arises mainly from the consumption of foods and drinks that contain them.

Studies report a 3-10% prevalence of sulphite sensitivity among asthmatic patients following ingestion.

The mechanisms underlying sulphite sensitivity remain unclear.

A 3-D model of the sulfite anion. Image source: Wikipedia, public domain.

References:
Clinical effects of sulphite additives. Vally H, Misso NL, Madan V. Clin Exp Allergy. 2009 Sep 22.
Sulfite. Wikipedia.

Related:
Allergy to Wine? Correct Diagnosis May be Wine-Induced Anaphylaxis and Sensitization to Hymenoptera Venom
Image source: Wikipedia, Free Documentation License.

Risk factors and prevalence of asthma in schoolchildren in Spain

2009-10-19T04:23:00.003-04:00

In 2002, a cross-sectional population-based study was carried out in Spain, following the International Study of Asthma and Allergies in Childhood (ISAAC) Phase III methodology.

Participation rate was 88 % (4492 of 4872 schoolchildren).

Prevalence of wheeze in the past year, asthma ever, and physician-diagnosed asthma were 8 %, 7 % and 6 %, respectively.

Risk factors independently associated with all three asthma case definitions were:

- history of bronchitis or pneumonia
- allergic rhinitis
- family members with atopic disease
- residing in an industrialised area

Risk factors for asthma:

- male sex
- atopic eczema
- dog at home

Exclusive breast-feeding and the presence of another animal (not a dog or cat) were protective factors.

Maternal age was inversely related to asthma. Residence in an area of heavy truck traffic and the father smoking at home were associated with asthma.

Risk factors for wheeze in the past year were low social class, history of sinusitis and the father smoking at home.

The authors concluded that environmental factors are related to the presence of asthma.
Preventive measures should be directed to improving air pollution, promoting breast-feeding and reducing smoking in the home.

References:
Risk factors and prevalence of asthma in schoolchildren in Castellon (Spain): a cross-sectional study. Arnedo-Pena A, Puig-Barberà J, Bellido-Blasco JB, Pac-Sa MR, Campos-Cruañes JB, Artero-Sivera A, Museros-Recatalá L. Allergol Immunopathol (Madr). 2009 May-Jun;37(3):135-42.
Image source: Wikipedia, public domain.

Hymenoptera venom immunotherapy is a safe and effective in pediatric patients

2009-10-17T06:21:00.000-04:00

Hymenoptera venom allergy is a growing problem. A Spanish study analyzed 21 paediatric patients treated with venom immunotherapy. The maintenance dose administered was 100 mcg (the approximate amount of venom delivered during 2 honeybee stings).

Two systemic reactions (both with an Apis extract) were registered. Both the cutaneous test and specific IgE showed a reduction at the end of treatment.

Seven patients (33 %) suffered a spontaneous re-stung during the maintenance phase or after immunotherapy was completed. In 4 patients there was no allergic reaction and the other 3 children suffered a mild local reaction.

The authors concluded that venom immunotherapy is a safe and effective treatment in pediatric patients with hymenoptera venom allergy.

References:
Hymenoptera venom allergy: characteristics, tolerance and efficacy of immunotherapy in the paediatric population. Carballada González FJ, Crehuet Almirall M, Manjón Herrero A, De la Torre F, Boquete París M. Allergol Immunopathol (Madr). 2009 May-Jun;37(3):111-5.
Images source: Wikipedia, Free Documentation License.

Case Report: Occupational Inhalant Allergy to Pork followed by Food Allergy to Pork and Chicken

2009-10-16T04:20:00.002-04:00

Typically, animal-derived proteins are implicated in food allergies. However, animal proteins can play a role in inhalant allergies with secondary food allergy symptoms.

A 42-year-old female with a history of occupational inhalant allergy to pork reported rhinitis, asthma, dysphonia and conjunctivitis 30 minutes after ingestion of chicken.

Skin tests were positive to chicken meat.

Protein extracts were prepared from chicken meat and the patient showed specific IgE binding to chicken meat proteins. Inhibition studies with chicken and porcine hemoglobin as well as with serum albumins demonstrated cross-reactive IgE antibodies.

This is a case of confirmed occupational inhalant allergy due to pork followed by food allergy to pork and 3 years later by food allergy to chicken.

Porcine and chicken hemoglobin were found to be cross-reactive allergens.

Cross-reactivity between porcine and chicken serum albumin was possibly linked to a prior sensitization to cat serum albumin.

References:
Occupational Inhalant Allergy to Pork followed by Food Allergy to Pork and Chicken: Sensitization to Hemoglobin and Serum Albumin. Hilger C, Swiontek K, Hentges F, Donnay C, de Blay F, Pauli G. Int Arch Allergy Immunol. 2009 Sep 15;151(2):173-178
Meat allergy
Image source: Varieties of meat, Wikipedia, public domain.

What is Sidak correction?

2009-10-15T06:32:00.001-04:00

From Wikipedia:

In statistics, the Bonferroni correction is a method used to address the problem of multiple comparisons.

The Bonferroni correction is derived by observing Boole's inequality

In probability theory, Boole's inequality, named after George Boole, (also known as the union bound) says that for any finite or countable set of events, the probability that at least one of the events happens is no greater than the sum of the probabilities of the individual events.

A related correction is called the Šidák correction. The Šidák correction is derived by assuming that the individual tests are independent. Since we are assuming that they are independent, the probability that all of them are not significant is the product of the probabilities that each of them are not significant.

The Šidák correction gives a stronger bound than the Bonferroni correction but requires the additional condition of independence. Because the Šidák correction requires calculating fractional powers, it is more complicated to do and the simpler Bonferroni correction is often preferred.

Nasal rinsing is effective treatment for pregnant women with allergic rhinitis

2009-10-15T06:18:00.000-04:00

Nasal rinsing appears suitable for the management of pregnant women with seasonal allergic rhinitis since no deleterious effects on the fetus are to be expected.

Pregnant women with seasonal allergic rhinitis were randomized to intranasal lavage with hypertonic saline 3 times daily versus no local therapy during a 6-week pollen season. Patients kept a daily record of rhinitis symptoms.

An improvement in rhinitis score was observed in the study group during all weeks of therapy.

Antihistamines use was reduced and no adverse effect was reported in the active group.

The study authors concluded that nasal rinsing is a safe and effective treatment option in pregnant women with seasonal allergic rhinitis.

SinusRinse video (this post is not sponsored by any person or company).

References:
Nasal Lavage in Pregnant Women with Seasonal Allergic Rhinitis: A Randomized Study. Garavello W, Somigliana E, Acaia B, Gaini L, Pignataro L, Gaini RM. Int Arch Allergy Immunol. 2009 Sep 15;151(2):137-141.
Video: How to do nasal irrigation
Nasal Irrigation with Saline Solution May be Better Than Saline Sprays for Chronic Rhinitis

What is Bioconductor and R statistical environment?

2009-10-14T06:29:00.000-04:00

What is Bioconductor?

Bioconductor is a free, open source and open development software project for the analysis and comprehension of genomic data generated by lab experiments in molecular biology.

What is R statistical environment?

R Project for Statistical Computing or "R" is an open source language and environment for statistical computing and graphics.

R was created by Ross Ihaka and Robert Gentleman at the University of Auckland, New Zealand, and is now developed by the R Development Core Team. It is named partly after the first names of the first two R authors (Robert Gentleman and Ross Ihaka), and partly as a play on the name of S.

S is a statistical programming language developed primarily by Bell Laboratories.

R provides a wide variety of statistical (linear and nonlinear modeling, classical statistical tests, time-series analysis, classification, clustering, and others) and graphical techniques. R, like S, is designed around a true computer language, and it allows users to add additional functionality by defining new functions.

The Bioconductor project, which started in the fall of 2001, provides R packages for the analysis of genomic data.

CD28(null) T Cells Infiltrate Muscles of Patients with Dermatomyositis and Polymyositis

2009-10-14T06:17:00.000-04:00

Dermatomyositis and polymyositis are disabling rheumatic diseases characterized by T cells infiltrating muscle tissue.

Patients with dermatomyositis and polymyositis were screened for frequency of CD4(+)CD28(null) and CD8(+)CD28(null) T cells in peripheral blood by flow cytometry.

Presence of these cells in inflamed muscle tissue from 13 of these patients was analyzed by three-color immunofluorescence microscopy.

Muscle-infiltrating T cells were predominantly CD4(+)CD28(null) and CD8(+)CD28(null) T cells in patients with dermatomyositis and polymyositis.

References:
T Cell Infiltrates in the Muscles of Patients with Dermatomyositis and Polymyositis Are Dominated by CD28null T Cells. Authors: Fasth AE, Dastmalchi M, Rahbar A, Salomonsson S, Pandya JM, Lindroos E, Nennesmo I, Malmberg KJ, Söderberg-Nauclér C, Trollmo C, Lundberg IE, Malmström V. J Immunol. 2009 Sep 14.
Image source: X-Ray of the knee in a patient with dermatomyositis. Wikipedia,
Mrich, Creative Commons Attribution ShareAlike 1.0 License.

Total IgE level predicts asthma only among atopic subjects

2009-10-13T06:02:00.001-04:00

The National Health and Nutrition Examination Survey 2005-2006 examined a representative sample of the US population 6 years of age and older.

The median total IgE level was 40.8 kU/L.

The prevalence of current asthma was 8.8%.

The prevalence of atopy was 42%, as defined by 15 specific IgEs.

Immunoglobulin structures. Image source: Wikipedia, public domain.

The odds ratio (OR) for asthma with a 10-fold increase in total IgE level was 2.18. Total IgE level predicted asthma only among atopic subjects and not among nonatopic subjects. Among atopic subjects, the association between total IgE level and asthma became stronger as the number of positive specific IgE test results increased.

92% of atopic subjects were identified by 6 specific IgEs, but to increase the identification to more than 99% required 11 specific IgEs.

The authors concluded that total IgE levels are associated with asthma only among persons who have positive results for at least 1 allergen-specific IgE.

References:
Total IgE levels and asthma prevalence in the US population: Results from the National Health and Nutrition Examination Survey 2005-2006. Gergen PJ, Arbes SJ Jr, Calatroni A, Mitchell HE, Zeldin DC. J Allergy Clin Immunol. 2009 Jul 31. [Epub ahead of print].

Senicapoc, a novel Gardos channel inhibitor, reduced asthmatic response to inhaled allergen

2009-10-12T06:35:00.004-04:00

Gardos channel is a protein "pump" that expels intracellular potassium when activated by calcium. Gardos channel causes dehydration of sickle erythrocytes, its inhibition may serve as an antisickling strategy. http://bit.ly/O15MF

Oral senicapoc, Gardos channel inhibitor, reduced the late asthmatic response to a challenge of inhaled allergen http://bit.ly/JuvyG

However, on 10/26/2009, Icagen Inc. said senicapoc failed the main goals of a midstage study, and it does not plan to keep developing the drug.

Icagen said that in the study of 69 patients randomly receiving either 40 mg of senicapoc daily or a placebo, the drug didn't improve the patients' exercise-induced asthma symptoms.

References:
Icagen asthma drug senicapoc trial fails. Yahoo Finance, 2009.
Image source: Senicapoc. Wikipedia, public domain.

Updated: 10/27/2009

Antimicrobial peptides and atopic dermatitis

2009-10-09T06:44:00.003-04:00

Our skin is constantly challenged by microbes but is rarely infected.

How is that possible?

Cutaneous production of antimicrobial peptides (AMPs) is a primary system for protection.

Cathelicidins are unique AMPs that protect the skin through 2 pathways:

- antimicrobial activity
- cytokine release, inflammation, angiogenesis, and reepithelialization

Cathelicidin dysfunction may be a central factor in the pathogenesis of several cutaneous diseases:

- atopic dermatitis - cathelicidin is suppressed
- rosacea - cathelicidin is abnormally processed to induce inflammation
- psoriasis - cathelicidin converts self-DNA to stimulate an autoinflammatory cascade

Vitamin D3 is as a major factor involved in the regulation of cathelicidin.

Therapies targeting cathelicidin and other AMPs might be beneficial in inflammatory skin diseases.

References:
Antimicrobial peptides and the skin immune defense system. Schauber J, Gallo RL. J Allergy Clin Immunol. 2009 Sep;124(3S2):R13-R18.
Image source: The modes of action by Antimicrobial peptides. Wikipedia, Ymahn, Creative Commons Attribution-ShareAlike 3.0 License.

5% of packaged foods with an advisory label had detectable levels of allergens

2009-10-08T06:41:00.003-04:00

Some of the "culprits" in food allergy. Image source: Mcclatchy-Tribune.

From The Great Falls Tribune:

5% of packaged foods with an advisory label had detectable levels of several common allergens.

2% of packaged foods without warning labels contained an allergen.

3 of the most commonly used terms to label food allergens and what they really mean:

"May Contain"

No allergen in the product's ingredients. There may be small amounts present because of cross-contamination — sharing a production facility with a product that contains allergens.

"Manufactured on the Same Line As"

The food was produced in machines used to make other products containing an allergen, such as peanuts. Major food companies tend to have better allergy controls in place than smaller companies.

"Gluten-Free"

These products shouldn't contain gluten, a main component of wheat, but some have low levels. The FDA is working to develop standards for this label.

References:
Food-allergy lingo. Great Falls Tribune.

Allergy to preservatives in topical ophthalmic therapies

2009-10-07T06:39:00.002-04:00

Ocular hypersensitivity reactions to ophthalmic preservatives are:

- IgE-mast cell mediated
- cell mediated
- irritant (toxic)

Quaternary ammoniums (benzalkonium chloride) are most commonly associated with irritant toxic reactions (8% of cases).

Organomercurials (thimerosal) and alcohols (chlorobutanol) have the highest association with allergic responses.

References:
Allergy to ophthalmic preservatives. Hong, Jison; Bielory, Leonard. Current Opinion in Allergy and Clinical Immunology: October 2009 - Volume 9 - Issue 5 - p 447-453.
Image source: Benzalkonium chloride, Wikipedia, public domain.