A new method for detecting histamine release

A comparative study on basophil activation test, histamine release assay, and passive sensitization histamine release assay in the diagnosis of peanut allergy

BACKGROUND

Allergy can be diagnosed using basophil tests. Several methods measuring basophil activation are available. This study aimed at comparing basophil activation test (BAT), histamine release assay (HR), and passive sensitization histamine release assay (passive HR) in the diagnosis of peanut allergy.

METHODS

BAT, HR, and passive HR were performed on 11 peanut-allergic and 14 nonallergic subjects. Blood was incubated with peanut extract or anti-IgE and tests were performed as follows: BAT-CD63 upregulation was assessed by flow cytometry; HR-released histamine was quantified by a glass fiber-based fluorometric method; passive HR-IgE-stripped donor basophils were incubated with participants' serum and histamine release was quantified as HR.

RESULTS

CDsens, a measure of basophil allergen sensitivity, was significantly higher for BAT (80.1±17.4) compared to HR (23.4±10.31) and passive HR (11.1±2.0). BAT, HR, and passive HR had a clinical sensitivity of 100%, 100%, and 82% and specificity of 100%, 100%, and 100%, respectively, when excluding inconclusive results. BAT identified 11 of 11 allergic patients, HR 10, and passive HR 9. Likewise, BAT recognized 12 of 14 nonallergic subjects, HR 10, and passive HR 13. However, the tests' diagnostic performances were not statistically different. Interestingly, nonreleasers in HR but not in BAT had lower basophil count compared to releasers (249 vs 630 counts/min).

CONCLUSION

BAT displayed a significantly higher CDsens compared to HR and passive HR. The basophil tests' diagnostic performances were not significantly different. Still, BAT could diagnose subjects with low basophil number in contrast to HR.

Evolution of diagnostic approaches in betalactam hypersensitivity

INTRODUCTION

Betalactams are the most widely used drugs against infections and the primary cause of antibiotic hypersensitivity reactions. Reaction patterns for different betalactams have been changing in accordance with consumption trends, and vary among countries. As a consequence, in vivo and in vitro tests have had to change with to keep up with new tendencies. Areas covered: This review is focused on advances in betalactam hypersensitivity diagnosis. Changes in in vivo methods have been limited to the inclusion of new haptens. In contrast, major progress has been achieved for in vitro tests since the 1960s, from the first description of immunoassays, the basophil activation test and the lymphocyte transformation test, to the more sophisticated assays developed in last years. Expert commentary: Issues with diagnosis are related to test sensitivity. In vivo tests show higher sensitivity, however they can be risky, especially in severe and life-threatening reactions. Therefore, we believe that in vitro tests should be the preferred method. Current efforts are under way to enhance their sensitivity. Only multidisciplinary approaches involving immunology, proteomics, nanotechnology and chemistry can help us to fully understand conjugate structures and mechanisms involved in hypersensitivity reactions to betalactams, and consequently lead to advances in in vitro methods.

Orthologous Allergens and Diagnostic Utility of Major Allergen Alt a 1

Purpose

Hypersensitivity to fungi is associated with rhinoconjunctivitis and asthma. For some fungi, such as Alternaria alternata (A. alternata), the symptoms of asthma are persistent, increasing disease severity and the risk of fatal outcomes. There are a large number of species of fungi but knowledge of them remains limited. This, together with the difficulties in obtaining adequate standardized extracts, means that there remain significant challenges in the diagnosis and immunotherapy of allergy associated with fungi. The type of indoor fungi related to asthma/allergy varies according to geographic, climatic, and seasonal factors, making their study difficult. The aim of this study was to determine hypersensitivity to indoor fungi in a population from Cuenca, Spain.

Methods

Thirty-five patients with symptoms compatible with rhinitis or asthma who showed clear worsening of their symptoms in their homes or workplace were included. In vivo and in vitro tests were made with a battery of fungal allergens, including the species isolated in the home or workplace.

Results

Ulocladium botrytis (U. botrytis) and A. alternata were the most representative species as a source of home sensitization. These species showed very high concordance in skin tests, specific IgE, and histamine release. The allergen Alt a 1, which was recognized in all patients, was detected in A. alternata, U. botrytis, and Stemphylium botryosum (S. botryosum).

Conclusions

U. botrytis and A. alternata were the most representative species as a source of home sensitization. Alt a 1 was recognized in all patients and may be considered a non-species-specific allergen that could be used as a diagnostic source of sensitization to some species of the Pleosporaceae family.

Role of Histamine Release Test for the Evaluation of Patients with Immediate Hypersensitivity Reactions to Clavulanic Acid

BACKGROUND

Immediate hypersensitivity reactions to clavulanic acid (CLV) seem to be on the increase. Diagnosis is mainly based on skin testing and the drug provocation test (DPT), procedures that are not risk free. The aim of this study was to evaluate whether the histamine release test (HRT) could help evaluate patients with selective hypersensitivity to CLV.

METHODS

Eighteen patients with immediate selective hypersensitivity reactions to CLV (positive skin tests to CLV but negative to the major and minor determinants of benzylpenicillin and amoxicillin; negative DPT to benzylpenicillin and amoxicillin) and 21 controls with tolerance to CLV were included. Direct and passive HRT, using patient whole blood or 'IgE-stripped' donor blood sensitized by patient serum, respectively, were performed by stimulating the blood with CLV, and basophil histamine release was detected by fluorometric determination.

RESULTS

The clinical symptoms were anaphylaxis (n = 6), urticaria (n = 9) and urticaria-angioedema (n = 3). The median time interval between the reaction and the study was 225 days (interquartile range, IQR: 120-387.5) and between drug intake and the development of symptoms 30 min (IQR: 6.25-30). We obtained similar data for both the direct and passive HRT, with a sensitivity and specificity of 55 and 85%, respectively, a positive predictive value of 76% and a negative predictive value of 69%.

CONCLUSIONS

The sensitivity of both the direct and passive HRT for diagnosing patients with immediate allergy to CLV is less than 60%. However, the passive HRT has the advantage that it is based on the testing of serum samples that can be handled more easily than fresh blood samples.

Inability to detect significant absorption of immunoreactive soya protein in healthy adults may be relevant to its weak allergenicity

Soya and peanut are botanically closely related and share cross-reacting antigens, but compared to soya, peanut allergy has a higher prevalence with more severe allergic reactions. Furthermore, the threshold dose for eliciting reactions is higher for soya. A difference in undigested protein absorption between the two foods, might explain this diversity.

In the current study the amount of soya protein absorbed after soya bean ingestion in healthy adults was estimated. Ten subjects ingested 100 grams of soya beans (40 grams of soya protein) and blood was drawn before and 1, 3 and 24 hours after administration. Serum was analysed by ELISA and histamine release (HR). In all serum samples the soya protein concentration was below quantification limit (1.6 ng/ml which corresponds to 4.8 μg or 0.12 parts per million absorbed soya protein.

We could not detect any significant absorption of soya protein. While we cannot totally exlude technical reasons, it may also reflect a true poor absorption in healthy adult volunteers. This could, in turn, be relevant to the apparently weak allergenicity of soy protein by comparison with peanut protein in allergic subjects.

Clinical characteristics of patients with drug hypersensitivity in Norway: a single-centre study

BACKGROUND

Drug hypersensitivity reactions (DHRs) represent an important public health problem. Knowledge of their clinical characteristics will provide improved diagnostic approaches to this topic.

OBJECTIVES

The aim of the present study was to describe the clinical characteristics of patients with suspected DHRs.

METHODS

The medical records of 206 outpatients with suspected DHRs, who consulted a Norwegian allergy centre from January 2005 to December 2009, were investigated in a retrospective study.

RESULTS

Mean age (range) was 44.3 (11-84) years, and 72% of the patients were women. The most common underlying diseases justifying the use of drugs were infections (49%) and pain-related diseases (23%). Antibiotics (53%), non-steroidal anti-inflammatory drugs (NSAIDs) (32%), paracetamol (15%) and other drugs (46%), used as monotherapy or combinations, were the most often suspected drugs. Cutaneous symptoms were the most frequently reported symptoms (83%). Hospitalisation or prolonged hospitalisation was needed in 38% of the cases, and anaphylaxis was reported in 28% of all the patients. Skin prick tests were performed in 185 patients, of which 14 patients had positive test results. Drug provocation tests (DPTs) were performed in only 86 patients, six of which had positive reactions. DHRs were confirmed in 24 and rejected in 81 patients. Unsettled cases (39%) were mainly due to not performing DPTs.

CONCLUSIONS

Suspected DHRs occur predominantly in women. The most common manifestations are cutaneous symptoms, but life-threatening reactions justifying hospitalisation may occur. Antibiotics and NSAIDs are the two drug families most frequently suspected. DPTs need to be included in diagnostic protocols in order to evaluate suspected DHRs.

Symptoms after ingestion of pig whipworm Trichuris suis eggs in a randomized placebo-controlled double-blind clinical trial

Symptoms after human infection with the helminth Trichuris suis have not previously been described. Exposure to helminths has been suggested as immune therapy against allergy and autoimmune diseases. We randomized adults with allergic rhinitis to ingest a dose of 2500 T. suis eggs or placebo every 21 days for 168 days (total 8 doses) in a double-blind clinical trial. In a previous publication, we reported a lack of efficacy and a high prevalence of adverse gastrointestinal reactions. The aim of the present study was to present a detailed description of the adverse event data and post-hoc analyses of gastrointestinal reactions. Adverse events and severity (mild, moderate, severe) were recorded daily by subjects, classified by organ using MedDRA 10.0, and event rates compared between subjects on T. suis treatment vs. subjects on placebo. T. suis-specific serum IgG antibodies were measured by a fluoroenzymeimmunoassay (Phadia ApS). During 163 days complete follow-up, subjects ingesting T. suis eggs (N = 49) had a three to 19-fold higher rate of events (median duration, 2 days) with gastrointestinal reactions (moderate to severe flatulence, diarrhea, and upper abdominal pain) compared with placebo subjects (N = 47). The highest incidence of affected subjects was seen from the first few days and until day 42 (3(rd) dose): 63% vs. 29% for placebo; day 163: 76% vs. 49% for placebo. Seroprevalences increased concurrently in the T. suis group: Day 59, 50%; day 90, 91%; day 170, 93%. The combined duration of episodes with onset before day 42 was ≤ 14 days in 80% of affected subjects. Age, gender, total IgE, and recent intestinal symptoms at baseline did not predict gastrointestinal side effects. In conclusion, during the first 2 months, repeated ingestions of 2500 T. suis eggs caused frequent gastrointestinal reactions lasting up to 14 days, whereas 4 months further treatment mainly provoked a subclinical stimulation.

TRIAL REGISTRATION

University hospital Medical Information Network trial registry Reg. no. R000001298, Trial ID UMIN000001070.

Expression of enzymatically inactive wasp venom phospholipase A1 in Pichia pastoris

Wasp venom allergy is the most common insect venom allergy in Europe. It is manifested by large local reaction or anaphylactic shock occurring after a wasp sting. The allergy can be treated by specific immunotherapy with whole venom extracts. Wasp venom is difficult and costly to obtain and is a subject to composition variation, therefore it can be advantageous to substitute it with a cocktail of recombinant allergens. One of the major venom allergens is phospholipase A1, which so far has been expressed in Escherichia coli and in insect cells. Our aim was to produce the protein in secreted form in yeast Pichia pastoris, which can give high yields of correctly folded protein on defined minimal medium and secretes relatively few native proteins simplifying purification.

Residual amounts of enzymatically active phospholipase A1 could be expressed, but the venom protein had a deleterious effect on growth of the yeast cells. To overcome the problem we introduced three different point mutations at the critical points of the active site, where serine137, aspartate165 or histidine229 were replaced by alanine (S137A, D165A and H229A). All the three mutated forms could be expressed in P. pastoris. The H229A mutant did not have any detectable phospholipase A1 activity and was secreted at the level of several mg/L in shake flask culture. The protein was purified by nickel-affinity chromatography and its identity was confirmed by MALDI-TOF mass spectrometry. The protein could bind IgE antibodies from wasp venom allergic patients and could inhibit the binding of wasp venom to IgE antibodies specific for phospholipase A1 as shown by Enzyme Allergo-Sorbent Test (EAST). Moreover, the recombinant protein was allergenic in a biological assay as demonstrated by its capability to induce histamine release of wasp venom-sensitive basophils.

The recombinant phospholipase A1 presents a good candidate for wasp venom immunotherapy.

Display of wasp venom allergens on the cell surface of Saccharomyces cerevisiae

BACKGROUND

Yeast surface display is a technique, where the proteins of interest are expressed as fusions with yeast surface proteins and thus remain attached to the yeast cell wall after expression. Our purpose was to study whether allergens expressed on the cell surface of baker's yeast Saccharomyces cerevisiae preserve their native allergenic properties and whether the yeast native surface glycoproteins interfere with IgE binding. We chose to use the major allergens from the common wasp Vespula vulgaris venom: phospholipase A1, hyaluronidase and antigen 5 as the model.

RESULTS

The proteins were expressed on the surface as fusions with a-agglutinin complex protein AGA2. The expression was confirmed by fluorescent cytometry (FACS) after staining the cells with antibody against a C-tag attached to the C-terminal end of the allergens. Phospholipase A1 and hyaluronidase retained their enzymatic activities. Phospholipase A1 severely inhibited the growth of the yeast cells. Antigen 5 - expressing yeast cells bound IgE antibodies from wasp venom allergic patient sera but not from control sera as demonstrated by FACS. Moreover, antigen 5 - expressing yeast cells were capable of mediating allergen-specific histamine release from human basophils.

CONCLUSIONS

All the three major wasp venom allergens were expressed on the yeast surface. A high-level expression, which was observed only for antigen 5, was needed for detection of IgE binding by FACS and for induction of histamine release. The non-modified S. cerevisiae cells did not cause any unspecific reaction in FACS or histamine release assay despite the expression of high-mannose oligosaccharides.In perspective the yeast surface display may be used for allergen discovery from cDNA libraries and possibly for sublingual immunotherapy as the cells can serve as good adjuvant and can be produced in large amounts at a low price.

Trichuris suis ova therapy for allergic rhinitis: a randomized, double-blind, placebo-controlled clinical trial

BACKGROUND

Parasitic helminth infections can protect against allergic airway inflammation in experimental models and have been associated with a reduced risk of atopy and a reduced course of asthma in some observational studies. Although no clinical evidence exists to support the use of helminth therapy for allergic disease, the helminth Trichuris suis has demonstrated efficacy in treatment of inflammatory bowel disease.

OBJECTIVE

To determine efficacy of helminth therapy for allergic rhinitis.

METHODS

We conducted a double-blind, placebo-controlled, parallel group trial in which 100 subjects age 18 to 65 years with grass pollen-induced allergic rhinitis were randomly assigned to ingest a total of 8 doses with 2500 live T suis ova or placebo with an interval of 21 days. The primary outcome was a change in mean daily total symptom score for runny, itchy, sneezing nose (maximum change, 9.0) or in percentage of well days during the grass pollen season.

RESULTS

Treatment with T suis ova (N = 49) compared with placebo (N = 47) caused transient diarrhea peaking at day 41 in 33% of participants (placebo, 2%), and increased eosinophil counts (P < .001) and T suis-specific IgE (P < .05), IgG (P < .001), IgG(4) (P < .003), and IgA (P < .001), whereas there was no significant change in symptom scores (0.0; 95% CI, -0.5 to 0.4; P = .87), well days (3%; 95% CI, -9% to 14%; P = .63), total histamine (P = .44), grass-specific IgE (P = .76), or diameter of wheal reaction on skin prick testing with grass (P = .85) or 9 other allergens.

CONCLUSION

Repeated treatment with the helminth T suis induced a substantial clinical and immunologic response as evidence of infection, but had no therapeutic effect on allergic rhinitis.

Risk assessment of clinical reactions to legumes in peanut-allergic children

Peanut-allergic children might be at risk for reactions to other legumes. However, it is not always possible to perform multiple oral food challenges in children. On the basis of patient case history, in vitro diagnostic tests, and eventually food challenges, we aimed at developing an algorithm for risk assessment of possible clinical reactions to other legumes (soybean, lupine, fresh, and blanched green pea). Seventy-five consecutive patients with a positive oral food challenge to peanut were included in the study. All tests were run as part of the routine allergy examination. A high proportion of patients and/or caretakers refused the administered legume oral food challenges. Obtained diagnoses from histamine release did not correlate significantly to the outcome of the algorithm. Interestingly, threshold from peanut challenges did not correlate with the risk assessment.

The algorithm presented in this study can be used when advising peanut-allergic children and their caretakers about what other legumes to avoid in the diet.

The prevalence of food hypersensitivity in an unselected population of children and adults

A rising prevalence of food hypersensitivity (FHS) and severe allergic reactions to food has been reported the last decade. To estimate the prevalence of FHS to the most common allergenic foods in an unselected population of children and adults. We investigated a cohort of 111 children <3 yr of age, 486 children 3 yr of age, 301 children older than 3 yr of age and 936 adults by questionnaire, skin prick test, histamine release test and specific immunoglobulin E followed by oral challenge to the most common allergenic foods. In total, 698 cases of possible FHS were recorded in 304 (16.6%) participants. The prevalence of FHS confirmed by oral challenge was 2.3% in the children 3 yr of age, 1% in children older than 3 yr of age and 3.2% in adults. The most common allergenic foods were hen's egg affecting 1.6% of the children 3 yr of age and peanut in 0.4% of the adults. Of the adults, 0.2% was allergic to codfish and 0.3% to shrimp, whereas no challenges with codfish and shrimp were positive in the children. The prevalence of clinical reactions to pollen-related foods in pollen-sensitized adults was estimated to 32%. This study demonstrates the prevalence of FHS confirmed by oral challenge to the most common allergenic foods in an unselected population of children and adults.

The prevalence of peanut sensitization and the association to pollen sensitization in a cohort of unselected adolescents--The Odense Adolescence Cohort Study on Atopic Diseases and Dermatitis (TOACS)

In the last decade an increased occurrence of peanut hypersensitivity and severe anaphylactic reactions to peanut have been reported. However, few prevalence studies have been performed in unselected populations. This study evaluated the point prevalence of peanut hypersensitivity in Danish adolescents. The point prevalence of peanut allergy confirmed by oral challenge was estimated to 0.5%. The number of adolescents sensitized to peanut by specific immunoglobulin E (IgE) (CAP FEIA) and skin prick test (SPT) were higher (5.8% resp. 3.4%). In adolescents without clinically relevant peanut sensitization most cases were sensitized to grass pollen and the IgE class for grass was higher than for peanut. A correlation between peanut and pollen (grass) sensitization is therefore plausible. Before a positive SPT or specific IgE measurement to peanut is considered clinically relevant in a patient, the case history should be evaluated together with examination for pollen sensitization.

Allergy assessment of foods or ingredients derived from biotechnology, gene-modified organisms, or novel foods

The introduction of novel proteins into foods carries a risk of eliciting allergic reactions in individuals sensitive to the introduced protein and a risk of sensitizing susceptible individuals. No single predictive test exists to perform a hazard assessment in relation to allergenic properties of newly expressed proteins in gene-modified organisms (GMOs). Instead, performance of a weighted risk analysis based on the decision tree approach has been suggested. The individual steps of this analysis comprise sequence homology to known allergens, specific or targeted serum screens for immunoglobulin E (IgE) cross-reactions to known allergens, digestability studies of the proteins in simulated gastric and/or intestinal fluids, and animal studies. These steps are discussed and five examples of risk evaluation of GMOs or novel foods are presented. These include ice-structuring protein derived from fish, microbial transglutaminase, GMO-soybeans, amylase and the Nangai nut.

The clinical relevance of sensitization to pollen-related fruits and vegetables in unselected pollen-sensitized adults

BACKGROUND

Previous studies have described cross-reactivity between fresh fruits, vegetables and pollen. However, no data demonstrates the clinical relevance of sensitization to pollen-related fruits and vegetables in unselected pollen-sensitized adults with and without symptoms in the pollen season.

OBJECTIVE

The aim of this study was to estimate the clinical relevance of sensitization to pollen-related fruits and vegetables in unselected pollen-sensitized adults and to examine the diagnostic value of skin-prick test (SPT), histamine release and specific IgE compared with the outcome of oral challenge.

METHODS

In total, 936 unselected adults (female : male 479 : 457, median age 33.7 years) were examined for pollen sensitization and clinical cross-reactivity with pollen-related fruits and vegetables by questionnaire, SPT, histamine release, specific IgE and oral challenge.

RESULTS

The prevalence of pollen sensitization was 23.8% (n = 223). The probability of a clinical reaction to pollen-related foods in the respective pollen-sensitized groups was: 24% (birch), 4% (grass), 10% (mugwort), 35% (birch + grass), 8% (grass + mugwort) and 52% (birch + grass + mugwort). The odds ratio of a clinical reaction to pollen-related fruits and vegetables in symptomatic pollen-sensitized adults was as high as four times (birch + grass) the odds ratio of a clinical reaction in asymptomatic pollen-sensitized adults.

CONCLUSION

This study not only demonstrates a high prevalence of clinical reactions to fruits and vegetables in pollen-sensitized adults, but also a discrepancy between the prevalence of sensitization to fruits and vegetables and the clinical relevance in different pollen-sensitized groups with symptoms in the pollen season as a significant factor.

Prediction of allergenicity of gene-modified foods by serum-based testing

On the basis of applying the IFBC/ILSI decision tree in a number of cases, a refinement of the scheme is suggested. Large differences in allergenic potential may be obtained by altering the route of administration of an allergen. Because an inhalation allergen can induce symptoms at different threshold doses depending on whether it is introduced via the inhalation or oral route, we propose that double-blind, placebo-controlled food challenges be performed in all cases of inhalation allergens being present in foods. Even proteins never previously ingested may cause IgE binding and elicit clinically relevant symptoms.

Food-dependent exercise-induced anaphylaxis: influence of concurrent aspirin administration on skin testing and provocation

BACKGROUND

Provocation tests in patients with food-dependent exercise-induced anaphylaxis (FDEIA) are often negative, even after a sufficient quantity of the implicated food and exercise have been taken.

OBJECTIVES

To investigate the effect of aspirin in provocation tests and in skin prick testing (SPT) of patients with FDEIA. Gluten as a major allergen in wheat-dependent FDEIA was also investigated.

METHODS

Provocation tests and SPT with suspected foods were performed in 12 patients with FDEIA. Provocation tests were performed with combinations of foods, exercise and aspirin. Detection of gluten-specific IgE was also performed by the CAP System FEIA radioallergosorbent test, SPT and a histamine release test.

RESULTS

The SPT reaction was enhanced by pretreatment with oral aspirin in five of eight (62.5) patients. Aspirin facilitated provocation in five of seven (71%) patients tested. Ingestion of wheat and aspirin without exercise provoked symptoms in two patients. Aspirin provoked symptoms even with a small amount of wheat and exercise in one patient. Only the combination of aspirin, wheat and exercise provoked anaphylaxis in one patient. Specific IgE, SPT and/or the histamine release test with gluten were positive in nine of 11 patients with wheat-dependent FDEIA.

CONCLUSIONS

Aspirin enhances symptoms of FDEIA, and prior ingestion of aspirin under controlled conditions can be used to confirm FDEIA. In practice, such patients should avoid aspirin ingestion. Gluten appears to be the major allergen in these patients with wheat-dependent FDEIA.

Frequency of food-dependent, exercise-induced anaphylaxis in Japanese junior-high-school students

BACKGROUND

Food-dependent, exercise-induced anaphylaxis (FEIAn) is classified among the physical allergies. The pathophysiology of FEIAn remains unknown, as does the frequency of FEIAn in the general population.

OBJECTIVE

We sought to study the epidemiology of FEIAn, especially its frequency in junior-high-school students in Yokohama, Japan.

METHODS

A questionnaire asking about the occurrence of FEIAn in school students was sent to all 145 public junior-high-school nurses in Yokohama.

RESULTS

One hundred thirty-two junior-high-school nurses responded to the questionnaire, and 13 (11 boys and 2 girls) cases of FEIAn among 76,229 junior-high-school students were reported. In addition, 24 (12 boys and 12 girls) subjects with exercise-induced anaphylaxis (EIAn) were detected. From this survey, the frequency of FEIAn was 0.017% in this population, and its frequency was significantly higher in boys than in girls (P < .05). The frequency of EIAn was 0.031%, and there was no difference according to sex. Only one third of junior-high-school nurses had any knowledge of FEIAn. We also performed provocation tests in 5 of the 13 cases with FEIAn after obtaining informed consent from the students and their parents and were able to confirm the diagnosis.

CONCLUSION

This study showed that FEIAn and EIAn are relatively rare diseases among junior-high-school students in Yokohama. To avoid serious outcomes, we believe it is important that not only physicians but also school nurses and teachers of physical education be aware of these diseases.

The necessity for dual food intake to provoke food-dependent exercise-induced anaphylaxis (FEIAn): a case report of FEIAn with simultaneous intake of wheat and umeboshi

BACKGROUND

Food-dependent exercised-induced anaphylaxis (FEIAn) is classified among the physical allergies. Many different food allergens have been reported, but the pathophysiology of FEIAn remains unknown. Furthermore, provocation tests with a suspected food do not always succeed in patients with FEIAn.

OBJECTIVE

We sought to clarify and investigate causative foods and mechanisms of FEIAn in a 14-year-old boy. In addition, we tested in vivo and in vitro effects of cromolyn sodium in the same patient.

METHODS

We used open challenge tests for the provocation of FEIAn and measured changes in plasma histamine levels and FEV1. In addition, we investigated the mechanism of FEIAn in this case with in vitro histamine release testing.

RESULTS

The patient was diagnosed as having FEIAn by provocation testing with a simultaneous intake of wheat and umeboshi, but not when each food was eaten singly, followed by exercise. In addition, his plasma histamine level increased transiently and forced expiratory volume 1, expressed as a percentage change from baseline, decreased significantly. A synergistic effect on in vitro histamine release testing with 2 kinds of the causative foods was shown. Administration of cromolyn sodium proved to be effective on both the in vitro and in vivo tests.

CONCLUSION

This is the first report of FEIAn provoked by the test with a simultaneous intake of 2 kinds of food. This case might in part explain negative challenge test results in patients with FEIAn.

In vivo and in vitro techniques to determine the biological activity of food allergens

Methods for determination of the biological activity of food allergens comprise both determination of the allergenic potency, i.e. the capability to elicit an allergic reaction in an already sensitized individual, and the allergenic potential, i.e. the risk for sensitizing a hitherto non-allergic individual. Several methods are discussed for determination of potency including the double-blinded placebo-controlled food challenge, skin testing, in vitro effector cell assays such as basophil histamine release, and IgE-based techniques such as RAST and RAST inhibition. No reliable methods have yet been developed which can predict the allergenic potential of a food or a food allergen. The progress in the areas of stability studies and animal models for food allergy are discussed.

Histamine release test and measurement of antigen-specific IgE antibody in the diagnosis of allergic conjunctival diseases

Although systemic allergic laboratory tests for the quantification of allergen-specific serum IgE antibody have been widely used, in these tests a high titer of serum specific IgE does not necessarily indicate evidence of allergy. We evaluated the diagnostic value of the glass microfiber-based histamine release test (HRT) using small amounts of whole blood, in 36 cases of allergic conjunctival diseases: 17 cases of allergic conjunctivitis and 19 of atopic keratoconjunctivitis. The patients were evaluated by HRT, capsulated hydrolic carrier polymer (CAP)-RAST, and conjunctival provocation test (CPT) against ten allergens. The positive rates for all allergens were higher in CAP-RAST than in HRT. The mean concordance of HRT with CAP-RAST results was 0.789. The mean concordance of HRT with CPT was 0.892 and that of CAP-RAST with CPT was 0.693. A significantly higher concordance was observed in HRT than CAP-RAST for Japanese cedar and mite antigen. The mean sensitivity, specificity, and efficiency of HRT were higher than those of CAP-RAST. These results indicate that CAP-RAST is good for the screening of allergens and that HRT has an advantage in the confirmation of clinical allergens in allergic conjunctival diseases because of its high sensitivity, specificity, efficiency, and higher concordance with CPT.

Calreticulin is an interleukin-3-sensitive calcium-binding protein in human basophil leukocytes

BACKGROUND

IL-3 enhances basophil histamine release upon stimulation with any known secretagogue. The molecular mechanism behind this regulation is not known, although some observations suggest that IL-3 modulates the calcium part of the signal transduction mechanism. The inhibitory action of glucocorticoids on basophils can be reversed by stimulation with IL-3.

METHODS

Calcium-binding proteins in the basophil cell line KU812 were identified by two-dimensional gel electrophoresis, Calcium-overlay assay, N-terminal sequence analysis, and mass spectometry. The presence of the same proteins in purified human basophil leukocytes was established by comigration of KU812 and human basophil proteins on the two-dimensional gels. The expression of the calcium-binding proteins in the absence and presence of IL-3 and/or anti-IgE was determined by densitometric measurement of the spots on the two-dimensional gels.

RESULTS

Calreticulin was identified on the two-dimensional gel of KU812 proteins. A protein with exactly the same migration pattern was found on the gels of proteins from purified human basophils. Immunoblotting with a specific antihuman calreticulin antibody confirmed that this protein was calreticulin. Subsequent analysis showed that the expression of calreticulin in the basophils is upregulated twofold upon stimulation with rhIL-3, even in doses below those needed for enhancement of histamine release.

CONCLUSIONS

The expression of calreticulin in human basophil leukocytes is regulated by IL-3. Calreticulin is known to modulate IP3-dependent Ca2+ influx in different cell systems, and calreticulin overexpression inhibits steroid-induced transcriptional activation. Therefore, modulation of calreticulin expression may be one mechanism by which IL-3 exerts its effects on human basophils.

A new method for histamine release from purified peripheral blood basophils using monoclonal antibody-coated magnetic beads

A new method for evaluating histamine release from purified basophils was developed. Basophil-containing leukocytes were directly purified from a small amount of peripheral blood using monoclonal antibody BA312-coated magnetic beads. The purified basophils still rosetted to magnetic beads maintained a normal response to anti-IgE and to dust mite allergen in comparison with the conventional method using washed leukocytes. This methodology facilitates the purification of basophils, anti-IgE- and allergen-induced histamine release, and subsequent histamine determination within only 3 h. The released histamine was analyzed by an enzyme-linked immunosorbent assay (ELISA) with a characteristic detection profile. Since all steps were performed in 96-well microplates, many clinical samples could be analyzed at the same time, permitting easy applications in routine laboratories.

Diagnosis of allergic bronchopulmonary aspergillosis (ABPA) in cystic fibrosis

BACKGROUND

The diagnosis of allergic bronchopulmonary aspergillosis (ABPA) in cystic fibrosis (CF) patients may be difficult to establish because ABPA shares many characteristics with coexisting atopy or other lung infections in these patients. This study aimed to evaluate the sensitivity and specificity of various paraclinical parameters in the diagnosis of ABPA in patients with CF.

METHODS

Accumulated data from a 5-year period in 238 CF patients were used to divide patients into two groups designated the ABPA group (n=26) and the non-ABPA group (n = 35). Patients in both groups were colonized with Aspergillus fumigatus (Af.), but only the ABPA group consistently demonstrated specific IgE antibodies and specific precipitins. Patients without A. fumigatus colonization were not assigned to either of these groups (n = 177). By this selection as the true diagnosis, 10 patients were selected from the ABPA group and 10 patients from the non-ABPA group.

RESULTS

The groups were comparable as to age, sex, lung function (P=0.6), and presence of chronic Pseudomonas aeruginosa infection (P>0.1). No significant difference between the groups in unspecific atopic parameters such as eosinophil count (P=0.9) or eosinophil cationic protein (ECP) in sputum, plasma, or serum (P=0.9, P=0.59, and P = 0.9, respectively) was demonstrated. Total IgE was significantly higher in the ABPA group (P<0.01). The groups were comparable in skin prick test (SPT) positivity to a standard panel of aeroallergens (pollen, dander, molds, and mites) (P>0.2). Statistically significantly higher levels in the ABPA group were demonstrated in specific IgE to Af. (P < 0.05), SPT positivity to Af. (P < 0.02), and Af. precipitins (P < 0.05). Histamine release (HR) to Af. tended to be higher (P=0.075) in the ABPA group. Specific IgE to Af. was determined by Magic Lite (ML), CAP, and Maxisorp (in-house RAST). The CAP level was one to two classes higher than the ML level; however, the results were comparable (r=0.66, P<0.005). IgE to Af. measured by CAP was the test which offered the highest positive predictive value (PPV) and negative predictive value (NPV). Optimal diagnostic cutoff levels for the diagnosis of ABPA were determined: class 2 for HR to Af., 200 kIU/l for total IgE, and 3.5 (titer) for precipitating antibodies to Af., and class 2 for IgE to Af. (by CAP System).

CONCLUSIONS

Unspecific atopy markers were of limited value for the diagnosis of ABPA. Patients with ABPA do not seem to be more atopic to other aeroallergens than non-ABPA patients. The most valid parameters for the diagnosis of ABPA in CF are SPT to Af., IgE to Af. in combination with precipitating antibodies to Af., and/or total IgE.

Human skin mast cells: in vitro and in vivo studies

OBJECTIVE

This short review surveys our current knowledge on the development and heterogeneity of human mast cells, the distribution of mast cells within human skin and the properties of human skin mast cells both in vitro and in vivo. It also examines the effects of antihistamines in the wheal-and-flare response in the skin provoked by bradykinin.

RESULTS

Mast cells derive from mononuclear precursor cells which undergo their final phase of their differentiation in the tissues. In normal skin, mast cells, which are primarily of the MC(TC) subtype, occur in the greatest density in the superficial dermal zone. Like all other mast cells, human skin mast cells bind IgE with high affinity to specific FcepsilonRI receptors, but unlike those from lung, tonsils, adenoids or intestine, they also express the C5a receptor (CD88) and activation sites for substance P, VIP, somatostatin, and compound 48/80. Both IgE-dependent stimulation by activating tyrosine kinases, and non-immunologic stimulation by activating G-proteins induce a characteristic compound exocytosis resulting in the liberation of the preformed mediators. Production of prostaglandin D2 and leukotriene C4, however, occurs only with IgE-dependent stimulation. In vivo, dermal microdialysis and scanning laser Doppler imaging have been used to assess the role of histamine in the wheal-and-flare response. These techniques were also used to show that low concentrations of intradermal bradykinin release negligible quantities of histamine. The results showed that although the resultant flare was inhibitable by antihistamines, low concentrations of bradykinin released negligible quantities of histamine. This suggests a potentially novel mechanism of action of antihistamines that requires further detailed investigation.

Immediate allergic and nonallergic reactions to Christmas and Easter cacti

BACKGROUND

Occupational exposure to Christmas cacti has been reported as a cause of type I allergy. Therefore, the prevalence of immediate-type mucosal and skin reactions related to cactus exposure was studied in 103 employees in a cactus nursery.

METHODS

The study was based on a questionnaire followed by clinical examination, skin prick tests (SPT) with standard inhalant allergens and cacti, and a histamine-release test (HRT/Refix) using fresh cactus extracts as elicitor.

RESULTS

The questionnaire was answered by 84 (82%) of the nursery employees, and 63 (61%) were interviewed and skin prick tested; 58 of these were tested with HRT/Refix. Furthermore, 22 healthy controls were included and tested in vivo and in vitro. Cactus-related contact urticaria and/or rhinoconjunctivitis were reported by 37% of the cactus workers. Based on a combination of positive history, positive SPT, and positive HRT/ Refix to cactus, 8% of the cactus workers were allergic to cacti. No noncactus workers or controls were allergic to cacti by these criteria. Testing with fresh cactus material elicited positive SPT and negative HRT/Refix in 27 nursery workers and controls, of whom 12 had immediate-type skin and mucosal symptoms.

CONCLUSIONS

Christmas and Easter cacti seemed to be able to induce contact urticaria and rhinoconjunctivitis on both an immunologic and a nonimmunologic basis. Personal atopy was associated with positive reactions to cacti.

Histamine and tryptase in nasal lavage fluid after allergen challenge: effect of 1 week of pretreatment with intranasal azelastine or systemic cetirizine

BACKGROUND

Antihistamines (H1-receptor antagonists) act by competitive antagonism of histamine at H1-receptors. In addition, high concentrations of some antihistamines inhibit allergen-induced histamine release from mast cells in vitro.

OBJECTIVE

The purpose of this study was to determine the effect of intranasal azelastine or systemic cetirizine (both potent antihistamines) on the allergen-induced release of mast-cell mediators from the human nasal mucosa in vivo.

METHODS

Patients allergic to birch pollen (n = 11) and control subjects not allergic to birch pollen (n = 5) were included in a randomized, double-blind, placebo-controlled, 3-way crossover study outside the pollen season. Each subject was treated with azelastine nasal spray 0.14 mg per nostril twice daily, cetirizine tablets 10 mg every day, or placebo for 1 week using a double-dummy design. At the end of each treatment period, nasal allergen challenges were performed, and the number of sneezes were counted. In addition, nasal lavage fluid was collected, and the levels of mast-cell mediators (histamine and tryptase) were measured.

RESULTS

The allergen challenge of patients allergic to pollen produced sneezing and a significant increase in the levels of histamine and tryptase. The challenge of subjects not allergic to pollen produced no such response. Azelastine and cetirizine significantly reduced allergen-induced sneezing and the associated increase in histamine and tryptase levels. No significant differences were found between the azelastine and cetirizine treatments.

CONCLUSION

Pretreatment with azelastine or cetirizine inhibits the allergen-induced release of mast-cell mediators from the human nasal mucosa. Our results are consistent with the hypothesis that both antihistamines reduce mediator release from nasal mucosa mast cells in vivo. However, further studies are necessary to test this hypothesis.

Effect of two different types of vacuum cleaners on airborne Fel d 1 levels

BACKGROUND

Vacuum cleaners may increase the level of airborne allergens by leakage through the cleaners or by disturbance of floor dust by the exhaust air produced.

OBJECTIVE

The aim of this study was to evaluate the short-term effect of vacuum cleaning with two different types of cleaners on airborne cat allergen analyzed by a biologic and by an immunochemical test.

METHODS

Ten homes with cats were cleaned in random order with a 1-week interval by a traditional canister type vacuum cleaner (T) and a semi-stationary vacuum cleaner (S) that conducts the air to the exterior through a valve in the wall. Airborne particles were collected by air sampling for 2 hours and cat allergen, Fel d 1, was quantified biologically by basophil histamine release test (HR test) and immunochemically by enzyme linked immunosorbent assay (ELISA).

RESULTS

Using the S resulted in smaller amounts of airborne cat allergen than the T (mean 2.1 ng/m3 air (range .8 to 12.5) versus 5.2 ng/m3 (1.3 to 13.3), P < .002 measured by ELISA). Results from ELISA and HR test correlated well (r = .91, P < .001).

CONCLUSIONS

The use of S with exhaust to the outside of the dwelling gave rise to less airborne low particle size allergen during the cleaning procedure than a T method. The basophil histamine release test could be a valid alternative method to establish allergen content in environmental samples especially in allergen systems with no available monoclonal antibodies.

Identification of a basophil leukocyte interleukin-3-regulated protein that is identical to IgE-dependent histamine-releasing factor

This study aimed to identify basophil leukocyte proteins associated with interleukin (IL)-3 and/or anti-IgE activation by two-dimensional (2-D) gel electrophoresis. We noticed one particular protein showing increased synthesis after recombinant human (rh)IL-3 and, to a lesser extent, anti-IgE stimulation. The protein was also present in the culture medium in increased amounts after rhIL-3 stimulation. On the basis of comigration with proteins in published 2-D gel electrophoresis databases and immunoblotting with a specific monoclonal antibody, we identified this protein as translationally controlled tumor protein (TCTP), also known as p23 or IgE-dependent histamine-releasing factor. The antibody was shown to be specific for TCTP/IgE-dependent histamine-releasing factor by blotting on 2-D gels of proteins from human lymphocytes and the human basophilic cell line KU812, followed by N-terminal amino-acid sequencing of the bound protein. Densitometric analysis of the gels showed that the synthesis of IgE-dependent histamine-releasing factor in human basophil leukocytes was dose dependent upon rhIL-3 stimulation with an optimum of 100 ng/ml. The level of the protein in the medium was also highest at an optimal rhIL-3 concentration of 100 ng/ml. Supernatants from cultured basophils were able to stimulate histamine release from other basophils. This histamine release was decreased by precipitation of TCTP/IgE-dependent histamine-releasing factor from these supernatants.

Purification of human colonic and gastric mast cells

We have developed a method to purify mast cells from enzymatic isolates of human colonic mucosa (HCM) and submucosa/muscle (HCS), and gastric mucosa (HGM) and submucosa/muscle (HGS). The purification of mast cells from these enzymatic isolates involves positive affinity-magnetic selection of mast cells using a monoclonal antibody specific for the c-kit receptor tyrosine kinase (CD117). The monoclonal antibody is coupled to Dynabeads for positive affinity selection of c-kit receptor positive cells which includes mast cells. This selection procedure generates preparations of mast cells from HCM, HCS, HGM and HGS that are 80% pure. The purified mast cells were microscopically normal and viable (> 85%). The functionality of purified mast cells was examined by studying the effect of anti-human IgE, Concanavalin A (Con A) and calcium ionophore A23187 on histamine release. These results show that this purification procedure generates microscopically normal, viable and functional mast cells. This method of purifying human gastrointestinal tissue mast cells may be a valuable tool for the further study of mast cell heterogeneity and the role of mast cells in the gastrointestinal tract.

Factors determining spontaneous histamine release from human basophils purified with Percoll gradients and Dynabeads

Identification of factors influencing histamine release from purified and cultured basophil leukocytes is important for proper interpretation of results obtained on histamine release. This paper describes factors that influence spontaneous histamine secretion from human basophil leukocytes purified on Percoll gradients, followed by negative selection with Dynabeads. Anti-IgE and recombinant human interleukin-3 were used as model stimulants, and the purified basophil leukocytes were stimulated for 10 min and 6 h. The effect of the following conditions was examined: Percoll temperature, cell-suspension density, and serum in the media. The results showed that low Percoll temperature, high cell-suspension density, and the presence of serum in the media decreased spontaneous histamine release and increased maximal net histamine release upon stimulation.

Histamine and tryptase in nasal lavage fluid following challenge with methacholine and allergen

BACKGROUND

The level of histamine in nasal lavage fluid has been used as an index of mast cell/basophil activation in a number of studies. Obviously, such an index can only be valid if changes in the secretory activity of nasal glands do not affect the level of histamine in lavage fluid (i.e. hypersecretion, without a simultaneous activation of mast cells/basophils in the nasal mucosa, must not increase the level of histamine).

OBJECTIVES

To asses the effect of nasal hypersecretion on histamine levels in lavage fluid.

METHODS

Nasal challenges were performed with methacholine and allergen in grass pollen-allergic patients and non-allergic controls. Nasal lavage fluid was collected before and repeatedly for nine hours after nasal challenge, and the level of histamine was compared with that of a specific mast cell-derived enzyme, tryptase. In addition, the effect of methacholine on basophils was examined in vitro.

RESULTS

Allergen challenge of allergic patients produced sneezing and a significant increase in histamine and tryptase levels, whereas challenge of non-allergic subjects produced no such response. Interestingly, challenge with methacholine also induced a significant increase in histamine levels. This increase was seen in both allergic and non-allergic subjects and it was not associated with any sneezing or increase in tryptase levels, indicating that mast cells were not activated. Furthermore, stimulation of basophils with methacholine did not induce any histamine release in vitro.

CONCLUSIONS

Apparently, there exists a pool of histamine in the human nose that can be transferred to lavage fluid during glandular hypersecretion. The source of this histamine is yet to be identified. As the level of histamine seems to be affected by the secretory activity of nasal glands, we question the use of this single mediator as an index of mast cell/basophil activation in nasal lavage studies.

A method for production and determination of histamine releasing activity from human peripheral blood mononuclear cells

Histamine releasing factors, i.e. cytokines capable of inducing histamine release from basophils or mast cells, have been suggested to be involved in the pathogenesis of, for example, allergic late-phase reactions. Here we describe a controlled method for production and determination of histamine releasing activity (HRA) from human peripheral blood mononuclear cells (MNC). MNC were incubated with concanavalin A (Con A) for 2 h and cultured for another 40 h in fresh serum free medium. The culture supernatants were concentrated 19-25 fold by ultrafiltration (molecular weight cut-off: 3000 Da). The preparations of HRA induced dose- and Ca2+-dependent histamine release from leukocytes. Supernatants of parallel cultures of unstimulated MNC did not induce histamine release. The HRA was neither due to exogenous histamine releasing compounds (e.g. Con A) nor to residual histamine in the preparations of HRA. The kinetics of HRA induced histamine release (half-maximal release after > 40 min) were slower and more protracted than those of anti-IgE induced histamine release. However, based on a comparison between HRA induced histamine release from leukocytes and purified (97%) basophils, this did not appear to be due to an indirect effect on the basophils. Finally, neither the production of nor the response to HRA was dependent on the allergic status of the donor.

Allergenic properties of kiwi-fruit extract: cross-reactivity between kiwi-fruit and birch-pollen allergens

Our investigation aimed to produce and characterize a kiwi extract and to use this extract to investigate a possible cross-reactivity with birch pollen. Kiwi was extracted in two buffers: phosphate-buffered saline (PBS) and borate-buffered saline (BBS). Extraction in BBS produced a double amount of protein, and a more stabile extract. Tandem crossed-immunoelectrophoresis showed that the BBS and PBS extracts had several common, but also a few individual, proteins. The mixture of both extracts was assumed to represent the most complete allergen extract. The allergenic properties of the kiwi extract were investigated by immunoblotting (IB), RAST, and histamine-release (HR) test in 15 birch-pollen-allergic patients (eight of them with clinical kiwi allergy) and one with clinical monoallergy to kiwi. All eight birch-pollen-allergic patients with kiwi allergy and the kiwi-monoallergic patient were positive in kiwi IB binding most frequently to proteins of 10-12 and 20-25 kDa. With our extract, RAST was positive in four kiwi-allergic and one non-kiwi-allergic patient, whereas the HR test was positive in five kiwi-allergic patients and negative in all non-kiwi-allergic patients. RAST and IB inhibition demonstrated cross-reactivity between birch-pollen and kiwi allergens due to a 10-12 kDa protein. In conclusion, a kiwi extract with allergenic properties was produced, and, by the methods used, cross-reactivity was demonstrated between birch-pollen and kiwi allergens.

Use of a new glass microfibre histamine release method to study the modulation of the host response in human schistosomiasis mansoni. Individuals with different degrees of exposure to the disease show differing antibody biological function

A new glass microfibre histamine release method was used to study the modulation of the host response in human schistosomiasis mansoni to improve our understanding of the role of basophils in the development of immunity in schistosomiasis mansoni. The histamine release from umbilical cord blood basophils sensitized with sera from Sudanese individuals infected with Schistosoma mansoni was measured. Schistosomiasis sera (n = 113) were able to passively sensitize basophils and induce a positive histamine release in response to whole worm homogenate (WWH) (chi 2 = 40.5, P < 0.0001) and soluble egg antigen (SEA) (chi 2 = 16.3, P < 0.0001). However, worm antigen induced significantly higher histamine release in adults than egg antigen (Z = 4.83, P < 0.0001). Basophil cell sensitivity to WWH was inversely related to the intensity of infection. A correlation was observed between basophil cell sensitivity and IgE antibodies in response to WWH. Chronically infected canal cleaners (n = 16) showed a significant increase in basophil cell sensitivity 3 months after praziquantel treatment (Z = 1.73, P < 0.05). Normally exposed adults (n = 29) showed a significant decrease in basophil cell sensitivity 1 year after treatment. When serum fractions were used, chronically infected canal cleaners showed a significant increase in histamine release after IgG removal (P < 0.05) Comparison between the different study groups with regard to resistance and susceptibility to reinfection, their basophil sensitizing ability and antibody response showed a difference in the biological function of the IgE to WWH in the different groups. Direct histamine release results from S. mansoni infected individuals from outside the endemic area (Danish) showed the possibility of using the glass microfibre histamine release method in the diagnosis of schistosomiasis.

Histamine release in intact human skin by monocyte chemoattractant factor-1, RANTES, macrophage inflammatory protein-1 alpha, stem cell factor, anti-IgE, and codeine as determined by an ex vivo skin microdialysis technique

BACKGROUND

The chemokines monocyte chemoattractant factor-1, RANTES, and macrophage inflammatory protein-1 alpha release histamine from human basophils, as well as rat and mouse mast cells. The purpose of this investigation was to determine whether these chemokines release histamine from human skin mast cells in situ.

METHODS

A microdialysis technique was used to measure histamine release in skin. First, the model was validated by using anti-IgE, codeine, and stem cell factor (SCF); then the histamine-releasing effects of the chemokines were investigated. A total of 47 skin specimens from 41 donors were investigated. Hollow microdialysis fibers were inserted intradermally, and each fiber was slowly perfused (3 microliters/min). Anti-IgE, codeine, SCF, or chemokines were injected intradermally above individual fibers, and dialysate was collected at 2-minute intervals for 20 minutes. Each series of investigations comprised five to eight single experiments.

RESULTS

Anti-IgE (4 to 4000 U/ml), codeine (0.001 to 1 mg/ml), and SCF (5.4 x (10(-11) to 10(-8) mol/L)) released histamine in a dose-dependent manner; maximum histamine release was 97.4, 116.3, and 9.5 pmol/20 min, respectively. Monocyte chemoattractant factor-1, RANTES, and macrophage inflammatory protein-1 alpha in concentrations of 10(-10) to 10(-6) mol/L did not release histamine; histamine release by 10(-6) mol/L chemokine was less than 0.2 pmol/20 min. None of the chemokines modulated anti-IgE-induced histamine release. In contrast, SCF significantly potentiated anti-IgE-induced histamine release by 33%. All chemokines, but not SCF, released histamine from human basophils.

CONCLUSION

We conclude that the chemokines monocyte chemoattractant factor-1, RANTES, and macrophage inflammatory protein-1 alpha do not release histamine from human skin mast cells.

The effect of cetirizine and loratadine on codeine-induced histamine release in human skin in vivo assessed by cutaneous microdialysis

OBJECTIVE AND DESIGN

To determine whether or not cetirizine and loratadine inhibit codeine- induced histamine release in human skin in vivo, we conducted a placebo-controlled double-blind trial in which histamine release was assessed by dermal microdialysis.

SUBJECTS

A group of ten normal volunteers were studied, each subject visiting the laboratory on three occasions with intervals of at least 2 weeks between visits.

TREATMENT

Cetirizine, loratadine (both 10 mg) or placebo was given orally 4 h before provocation of weal and flare responses in the skin by intradermal injection of 25 microliters of 3 or 10 mg/ml codeine 1 mm from the centre of individual 216 microns diameter microdialysis fibres inserted in the dermis.

METHODS

Dialysate was collected at 2 min intervals for 4 min before and 20 min after codeine injection and histamine assayed spectrofluorometrically. Weal and flare responses to codeine were assessed in the opposite arm.

RESULTS

Histamine concentrations in the microdialysis fibre outflow with 3 and 10 mg/ml codeine were maximal at 2-4 min when 910 +/- 156 and 1194 +/- 304 nM respectively were found in the placebo group. Cetirizine and loratadine did not modify either the kinetics or total histamine release while significantly (p < 0.01) inhibiting weal and flare responses.

CONCLUSIONS

Neither cetirizine nor loratadine inhibited codeine-induced histamine release or modified the time course of its release in human skin in vivo when given in clinically used doses which are sufficient to significantly reduce weal and flare responses.

Allergen-induced histamine release in intact human skin in vivo assessed by skin microdialysis technique: characterization of factors influencing histamine releasability

BACKGROUND

The purposes of the study were to characterize allergen-induced histamine release in intact human skin in vivo by using a novel microdialysis technique and to study covariates influencing histamine releasability.

METHODS

Hollow microdialysis fibers were inserted into the upper dermis in 15 timothy-sensitivity subjects. Up to 12 fibers were inserted in each subject. Each fiber was perfused with Krebs-Ringer's solution at a rate of 3.0 microliters/min. Three to four serial dilutions of allergen were applied to the skin by intracutaneous injections or skin prick test above individual fibers. Samples were collected in two 2-minute fractions before skin challenge and in 10 consecutive samples for 20 minutes after skin challenge. Histamine was assayed spectrofluorometrically.

RESULTS

A significant dose-response relationship for histamine release was demonstrated with intracutaneous tests and skin prick tests. The time to reach peak histamine release after an intracutaneous test was 4 to 8 minutes, compared with 12 to 14 minutes for a skin prick test. Histamine release correlated significantly with wheal size. Intrasubject coefficient of variation on histamine release was about 20%. A substantial intersubject variation in histamine releasability was observed. Seventy to seventy-five percent of the variation could be accounted for by a combination of gender, total and allergen-specific IgE, and an in vitro basophil histamine release test.

CONCLUSIONS

Using a skin microdialysis technique, we have described in detail histamine release in intact human skin by allergen. The microdialysis method proved to be a reproducible technique for monitoring histamine release in allergic skin reactions and for studying histamine releasability of skin mast cells in vivo.

Methacholine induces wheal-and-flare reactions in human skin but does not release histamine in vivo as assessed by the skin microdialysis technique

A number of investigations have indicated that cholinergic agonists release histamine from isolated mast cells and suggested that cholinergic stimulation releases histamine in vivo. The purpose of this study was to investigate whether the cutaneous wheal-and-flare reaction induced by methacholine challenge in human skin involves histamine release as measured by the skin microdialysis technique. Five hollow dialysis fibers were inserted intradermally in forearm skin in eight healthy subjects. Each fiber was perfused with Kreb's-Ringer bicarbonate at a rate of 3 microliters/min. Dialysates were collected in 2-min fractions before skin challenge and for 20 min after intradermal injection of methacholine 10(-3)-10(-1) M, the vehicle, and a positive control, codeine phosphate 0.3 mg/ml. Histamine was assayed spectrofluorometrically. Methacholine caused a statistically significant dose-related wheal-and-flare reaction, the flare reaction to methacholine 10(-1) M being comparable with that seen with codeine 0.3 mg/ml. No significant histamine release was observed with methacholine, cumulative histamine release of 16 +/- 8 nM by methacholine 10(-1) M being similar to vehicle responses of 15 +/- 9 nM. Histamine release by codeine was 2524 +/- 435 nM. In conclusion, methacholine-induced wheal-and-flare reactions in human skin appeared not to involve histamine release from skin mast cells.

Codeine-induced histamine release in intact human skin monitored by skin microdialysis technique: comparison of intradermal injections with an atraumatic intraprobe drug delivery system

BACKGROUND

The skin microdialysis technique makes it possible to measure histamine release in intact human skin in vivo directly. In this study we have used the microdialysis technique to characterize histamine release by codeine after intracutaneous injections and following skin challenge by a novel atraumatic delivery technique.

OBJECTIVE

The purpose of the study was to compare histamine release in human skin by codeine, delivered by an intraprobe drug delivery system (IPD) and intracutaneous injections (ICT), with respect to dose-response relations, kinetics of histamine appearance and decay, correlations between histamine release and skin responses, and reproducibility.

METHODS

Hollow dialysis fibres were inserted intradermally in 12 healthy subjects. Twelve fibres were inserted in each subject, six fibres in each arm. Each fibre was perfused at a rate of 3 microM/min, and samples were collected in 2 min fractions. By the IPD technique, codeine was administered to the skin by adding codeine to the perfusion medium. Sequential IPD challenges were performed in one arm, and ICTs were done on the other arm.

RESULTS

Sixfold serial dilutions of codeine (0.01-3 mg/mL) caused a significant dose-related histamine release by ICT and IPD. Peak histamine release was found within the first 4 min after skin challenge by ICT and IPD, followed by a fast decline with a dialysate histamine half life of approximately 2-3 min. Peak histamine release was linearly correlated with cumulative release of the 20 min sampling period, and histamine release correlated with weal size. The coefficient of variation on peak histamine release was 18.9% and 4.8% for codeine ICT and IPD, respectively.

CONCLUSION

We have described in detail codeine-induced histamine release in intact human skin in vivo by the microdialysis technique. It was possible to administer codeine atraumatically to the skin by intraprobe delivery. The skin microdialysis technique opens up possibilities for measurement of inflammatory mediators release in normal and diseased skin, and it will be possible to deliver immunopharmacologically active drugs to the skin by intraprobe delivery.