Evolution of occupational asthma: does cessation of exposure really improve prognosis?

AIM

To assess the evolution of occupational asthma (OA) depending on whether the patient avoids or continues with exposure to the offending agent.

METHODS

Study in patients diagnosed with OA using a specific inhalation challenge. Patients underwent the following examinations on the same day: clinical interview, physical examination, forced spirometry, methacholine test and determination of total IgE. Clinical improvement, deterioration or no change were defined according to the changes seen on the GINA severity scale at the time of diagnosis.

RESULTS

Of the 73 patients finally included, 55 had totally ended exposure and 18 continued to be exposed at work. Clinical improvement was observed in 47% of those who had terminated exposure and in 22% of those who remained exposed; clinical deterioration was observed in 14% and 17% respectively (p = 0.805). Logistical regression analysis, including the type of agent and the persistence or avoidance of exposure among the variables, did not show any predictive factors of clinical evolution. Similarly, the changes in FEV1 and in bronchial hyperresponsiveness were not associated with the avoidance or continuation of exposure to the causative agent.

CONCLUSIONS

Avoiding exposure to the causative agent in patients with OA does not seem to improve prognosis in this disease. Despite these findings, there is insufficient evidence to recommend a change in current management guidelines.

Tropomyosin IgE-positive results are a good predictor of shrimp allergy

BACKGROUND

Shrimp is a common cause of food allergy. Our aims were to determine the value of IgE antibodies in the diagnosis of shrimp allergy and to study red shrimp (Solenocera melantho) tropomyosin both as a new allergen and as a cross-reactive IgE-binding protein.

METHODS

We have studied 45 subjects. Skin prick test (SPT) was carried out in all subjects, and specific IgE (sIgE) to shrimp, recombinant and natural shrimp tropomyosins rPen a 1 and nPen m 1, recombinant Der p 10, and Dermatophagoides pteronyssinus was assessed by fluoroimmunoassay and/or immunoblotting. Double-blind, placebo-controlled food challenges were carried out to confirm diagnosis of shrimp allergy. Also, in vitro inhibition tests were performed to evaluate cross-reactivity.

RESULTS

Shrimp allergy was confirmed in 18 shrimp-allergic patients. Skin prick test and IgE antibodies to shrimp were positive in all shrimp-allergic patients; sIgE to rPen a 1 was detected in 98% of these patients. Of the 18 shrimp-tolerant patients, 61% had positive SPT to shrimp, 55% were IgE-positive to shrimp, and 33% showed IgE antibodies to rPen a 1. Determination of IgE to rPen a 1 yielded a positive predictive value of 0.72 and a negative predictive value of 0.91.

CONCLUSION

IgE levels to rPen a 1 provided additional value to the diagnosis of shrimp allergy. Some allergens in mite extract are recognized by patients who are allergic to shrimp, though their clinical relevance remains unknown.

Noninvasive methods for assessment of airway inflammation in occupational settings

The present document is a consensus statement reached by a panel of experts on noninvasive methods for assessment of airway inflammation in the investigation of occupational respiratory diseases, such as occupational rhinitis, occupational asthma, and nonasthmatic eosinophilic bronchitis. Both the upper and the lower airway inflammation have been reviewed and appraised reinforcing the concept of 'united airway disease' in the occupational settings. The most widely used noninvasive methods to assess bronchial inflammation are covered: induced sputum, fractional exhaled nitric oxide (FeNO) concentration, and exhaled breath condensate. Nasal inflammation may be assessed by noninvasive approaches such as nasal cytology and nasal lavage, which provide information on different aspects of inflammatory processes (cellular vs mediators). Key messages and suggestions on the use of noninvasive methods for assessment of airway inflammation in the investigation and diagnosis of occupational airway diseases are issued.

Increased body mass index does not lead to a worsening of asthma control in a large adult asthmatic population in Spain

BACKGROUND

Data on the association between obesity and asthma control are conflicting. We performed an analysis to elucidate the association between body mass index (BMI) and asthma control in a large sample of asthmatics.

MATERIALS AND METHODS

Data were obtained from a previous study in which the Asthma Control Questionnaire (ACQ) and Asthma Control Test (ACT) were validated for a Spanish population. The study sample comprised 607 adult (> or = 18 years) asthmatic patients (61% female), of whom 235 (39%) had mild-persistent asthma, 246 (41%) had moderate-persistent asthma, and 126 (21%) had severe-persistent asthma.

RESULTS

The analysis showed a significant but very low correlation between BMI and ACQ-forced expiratory volume in the first second of expiration (FEV1) (r=0.1, P=.007) and ACQ-peak expiratory flow (PEF) (r=0.1, P=.010), but not ACQ-without lung function (wLF) (r=0.06, P=.116) or ACT. No significant association was found between BMI and asthma control as defined by physicians or according to ACT or ACQ (ACQ-FEV1, ACQ-PEF and ACQ-wLF) scores. We found no significant associations between ACT, ACQs (ACQ-FEV1, ACQ-PEF and ACQ-wLF), and BMI when BMI was classified as low (BMI, <18.5 kg/m2), normal (18.5-24.9 kg/m2), overweight (25-29.9 kg/m2), obesity (BMI, > or = 30 kg/m2), or morbid obesity (BMI, >34.9 kg/m2). However, the percentage of patients with poor control was slightly greater in patients with low BMI and obesity.

CONCLUSIONS

Using specific and validated tools, and in the context of clinical practice, this study did not find a relevant association between BMI and asthma control.

Recombinant lipid transfer protein Tri a 14: a novel heat and proteolytic resistant tool for the diagnosis of baker's asthma

BACKGROUND

Baker's asthma is an important occupational allergic disease. Wheat lipid transfer protein (LTP) Tri a 14 is a major allergen associated with wheat allergy. No panel of wheat recombinant allergens for component-resolved diagnosis of baker's asthma is currently available.

OBJECTIVE

To evaluate the potential role of recombinant Tri a 14 as a novel tool for the diagnosis of baker's asthma, and to test the heat and proteolytic resistance of the wheat LTP allergen.

METHODS

A cDNA encoding Tri a 14 was isolated and sequenced, the recombinant allergen produced in Pichia pastoris and purified by chromatographic methods. Physicochemical and immunological comparison of the natural and recombinant forms of Tri a 14 was carried out by N-terminal amino acid sequencing, matrix-assisted laser desorption/ionization mass spectrometry, circular dichroism (CD) analysis, IgE immunodetection, and specific IgE determination and ELISA-inhibition assays using a pool or individual sera from 26 patients with baker's asthma. Thermal denaturation and simulated gastrointestinal digestion of both Tri a 14 forms were checked by spectroscopic and electrophoretic methods, respectively, and biological activity by basophil activation test (BAT).

RESULTS

Natural and recombinant Tri a 14 were similarly folded, as indicated by their nearly identical CD spectra and heat denaturation profiles. A high interclass correlation coefficient (0.882) was found between specific IgE levels to both Tri a 14 proteins in individual sera from baker's asthma patients, but a slightly lower IgE-binding potency of rTri a 14 was detected by ELISA-inhibition assays. Natural and recombinant Tri a 14 elicited positive BAT in two and one out of three patients, respectively. Heat denaturation profiles and simulated gastrointestinal digestion assays indicated that Tri a 14 displayed a high heat and digestive proteolytic resistance, comparable to those of peach Pru p 3, the model food allergen of the LTP family.

CONCLUSIONS

Recombinant Tri a 14 is a potential tool for baker's asthma diagnosis, based on its physicochemical and immunological similarity with its natural counterpart. Wheat Tri a 14 shows a high thermal stability and resistance to gastrointestinal digestion.

Increased prostaglandin E2 levels in the airway of patients with eosinophilic bronchitis

BACKGROUND

Eosinophilic bronchitis is a common cause of chronic cough, which like asthma is characterized by sputum eosinophilia, but unlike asthma there is no variable airflow obstruction or airway hyperresponsiveness. We tested the hypothesis that the different airway function in patients with eosinophilic bronchitis and asthma could be caused by an imbalance in the production of bronchoconstrictor (LTC(4)) and bronchoprotective (prostaglandin E(2); PGE(2)) lipid mediators.

METHODS

We measured cytokines levels, proinflammatory mediators and eicosanoids concentration in sputum from 13 subjects with nonasthmatic eosinophilic bronchitis, 13 subjects with asthma, and 11 healthy control subjects. Cytokines mRNA levels were measured by real time PCR, proinflammatory mediators, PGE(2), and LTC(4) were measured by enzyme immunoassays.

RESULTS

The median sputum eosinophil count was not statistically different in patients with asthma (7.95%) and eosinophilic bronchitis (15.29%). The levels of mRNA specific to interleukin-5 (IL-5), IL-4, IL-10, IL-13, interferon gamma (IFN-gamma), IL-2, vascular endothelial growth factor and transforming growth factor beta were similar in both conditions. In addition, no differences were found between asthma and eosinophilic bronchitis in proinflammatory cytokines, such as IL-8, IFN-gamma and tumor necrosis factor alpha (TNF-alpha) levels. Sputum cysteinyl-leukotrienes concentration was raised both in eosinophilic bronchitis and asthma patients. We found that induced sputum PGE(2) concentrations were significantly increased in subjects with eosinophilic bronchitis (838.3 +/- 612 pg/ml) when compared with asthmatic (7.54 +/- 2.14 pg/ml) and healthy subjects (4 +/- 1.3 pg/ml).

CONCLUSION

This data suggest that the difference in airway function observed in subjects with eosinophilic bronchitis and asthma could be due to differences in PGE(2) production in the airways.

Modulation of allergic response by gene-environment interaction: olive pollen allergy

This article summarizes the most important advances of recent years in the field of gene-environment interaction in allergic response. It specifically examines sensitization to olive pollen as an example of one of the main causes of allergic disease in the Mediterranean area. The presence of at least 20 proteins with allergic activity has been demonstrated in olive pollen, and 10 of these have been characterized (Ole e 1 to Ole e 10). Ole e 1, which is considered to be the majority allergen (causing sensitization in more than 70% of patients), has been the subject of many studies looking for risk factors and ways to protect against sensitization. Markers of the major histocompatibility complex and other genetic loci associated with the allergic response have been analyzed using population-based, family-based, and functional approaches, which have revealed the involvement of genetic regulation in this type of response. Furthermore, evaluation of environmental factors and their relationship with genetic factors is essential when attempting to understand this type of disease. In this review, we provide examples of how exposure to high doses of olive pollen allergen in a specific genetic context can trigger different allergic conditions (from asthma to nonresponse). We stress the importance of evaluating these factors in order to modulate this response correctly.

Cloning and expression of a major allergen from Cupressus arizonica pollen, Cup a 3, a PR-5 protein expressed under polluted environment

BACKGROUND

This paper describes the cloning and expression of the Cupressus arizonica pollen protein Cup a 3. In addition, we present its modulation under polluted environmental conditions. Species of the Cupressaceae family are important because of their high sensitization prevalence.

METHODS

Cup a 3 cloning is based on the sequence of the homologous protein Jun a 3. Cup a 3 was expressed with good yield in the methylotropic yeast Pichia pastoris.

RESULTS

Recombinant Cup a 3 (rCup a 3) contains 199 amino acids, 10 potential phosphorylation sites and no glycosylation sites. By immunoblot 63% of cypress allergic patients had specific immunoglobulin E antibodies against rCup a 3 (n = 104). This major allergen is homologous to members of the pathogenesis-related proteins (PR-5 group) and contributes to the overall allergenicity of C. arizonica pollen. Our results show that the increased expression of Cup a 3 is dependent on the pollution in the area where the pollen has been collected, being higher under polluted conditions.

CONCLUSIONS

Cup a 3 is a PR-5 protein derived from C. arizonica pollen. The expression of the protein under polluted conditions has a direct incidence on the pollen allergenicity, as has been demonstrated by skin tests and Radioallergosorbent test inhibition.

Allergy to dermatophagoides in a group of Spanish gypsies: genetic restrictions

BACKGROUND

Spanish gypsies have traditionally lived as nomads, a reason why few epidemiological studies were done in this ethnic group. However, the high prevalence of asthmatic diseases demonstrated in a population residing in the North of Spain induces us to analyse whether it was due to the influence of genetic loci previously implicated in other population studies as causing the disorders.

METHODS

DRB1* and DQB1* HLA class II, TCR-Valpha8.1, FcepsilonRI-beta Rsa I exon 7 and intron 2, TNF-beta (LTalpha-Nco I) and CD14, were tested for association with asthma and atopy by multiple regression analysis, in 5 families comprising 87 individuals.

RESULTS

Significant associations were found with DQB1*02 (p = 0.02) and DQB1*0301 (p = 0.008) and elevated levels of total serum IgE. A negative association (p = 0.02) was found between total serum IgE and DRB1*14. FcepsilonRI-beta Rsa I-In2 allele 1 was associated with high levels of total serum IgE (p = 0.04). Levels of Der p 1 IgE antibodies were negatively associated with DRB1*11-DQB1*0301 (p = 0.007), and positively with TCR Valpha-8 allele 1 (p = 0.04) and with FcepsilonRI-beta Rsa I-In2 allele 1 (p = 0.009).

CONCLUSIONS

Our results do not show any association between asthma and the genetic loci studied although they do suggest the existence of multiple genetic influences on the allergic response in these families.

Expression on human eosinophils of CD148: a membrane tyrosine phosphatase. Implications in the effector function of eosinophils

The role of protein tyrosine phosphatases (PTP) is crucial in regulating the phosphorylation status of cells. CD148 is a recently described membrane-type PTP. In this study, we have demonstrated that this molecule is expressed on human eosinophils and eosinophilic cell line EoL-3. Interestingly, our data also showed that this molecule acts as a transduction molecule on these cells. Thus, the crosslinking of CD148 was able to induce the degranulation and the induction of superoxide anion generation. By using specific inhibitor and by western blotting, we have shown that tyrosine kinase activation is involved in this transduction pathway. In addition, we have shown the presence of a serine/threonine kinase activity associated with CD148. In conclusion, the activation capacity of CD148 on eosinophils suggests a potential role of this molecule on inflammatory diseases, such as allergic and parasitic diseases, associated with eosinophilia.

Molecular cloning and characterization of an IgE-reactive protein from Anisakis simplex: Ani s 1

Ingestion of the parasitic nematode Anisakis simplex in undercooked fish can cause severe allergic reactions in some individuals. Using pooled human sera from sensitized patients we have probed an expression library for A. simplex antigens. One positive clone was found to encode a full length 21 kDa protein with strong homology to nematode troponins. The recombinant protein was expressed as a GST-fusion protein and found by immunoblot analysis to react with sera from 20% of allergic patients. The presence of functional EF-hand Ca(2+) binding motifs was demonstrated by gel-shift analysis.

Genetic restrictions in olive pollen allergy

BACKGROUND

The major antigen of olive tree pollen, Ole e 1, produces an IgE response restricted by DQ2.

OBJECTIVE

Our purpose was to further analyze the genetic restrictions associated with IgE and IgG antibodies against Ole e 1 and IgE against the recently described antigen Ole e 3.

METHODS

Twenty-two nuclear olive pollen-allergic families (n = 88) were selected. DRB1 and DQB1, TCR-Valpha 8.1, the high-affinity receptor of IgE (FcepsilonRI-beta) Rsa I exon 7 and intron 2 and TNF-beta (LTalpha-Nco I) polymorphisms were determined by PCR and analyzed for association with allergic traits by the multiallelic transmission disequilibrium test.

RESULTS

Significant associations were found among HLA-DQB1*0201 (n = 29) and high levels of IgG (P =.023) and IgE (P =.0136) antibodies to Ole e 1 and with IgE specific to Ole e 3 (P =.0368). DRB1*0701 was associated with high levels of total serum IgE (P =.04) and IgG against Ole e 1 (P =.025). The FcepsilonRI-beta Rsa I exon 7, allele 1 (n = 39), was associated with high levels of total serum IgE (P =. 01), IgE antibodies against Olea europaea extract (P =.004), and specific antibodies to Ole e 1, IgG (P =.04), and IgE (P =.006). The FcepsilonRI-beta Rsa I intron 2, allele 2 (n = 33), was associated with IgE antibodies to O europaea extract (P =.003) and specific antibodies to Ole e 1, IgG (P =.025), and IgE (P =.05).

CONCLUSIONS

We found a new association between IgE antibody response to Ole e 3 and DQB1*0201 and verified the previously reported association between Ole e 1-specific response and DQB1*0201. Also, the association between FcepsilonRI-beta and IgE antibodies against Ole e 1 was demonstrated.

DR2 antigens are associated with severity of disease in toxic oil syndrome (TOS)

Toxic oil syndrome (TOS) was an epidemic which broke out in Spain in 1981, caused by the ingestion of rapeseed oil denatured with 2% aniline and sold illegally as edible oil. More than 20,000 people were affected and mortality rate was 8.4%. Genetic susceptibility appears to be involved in the pathology of this disease. Several reports have described association between the chronic stage of the disease and DR-DQ antigens (DR3, DR4, DR2 and DQ8). In the present work, we have reassessed the HLA class II antigens in a well-designed case-control study. Triplets of subjects (n=265) composed by chronic patients (n=117), non-affected family members (n=71) and non-related controls (n=77) were studied. Also, HLA class II antigens were analyzed in patients who had died from TOS (n= 34) and in TOS control patients who died from other non-TOS related causes (n=13). Regarding surviving patients no significant association was found between HLA and disease. In contrast, an increase in phenotypic frequency of DR2 antigen, was found in patients who had died from TOS (73.5%) compared with the whole study group: TOS-affected alive patients (25.6%, corrected P<0.001), non-affected family members (28.5%, corrected P<0.001), non-related controls (23.9%, corrected P<0.001) and dead controls (38.4%, P=0.03).

Immunopathogenesis of human gastrointestinal infection by Anisakis simplex

BACKGROUND

Anisakis simplex is a parasite of fish, and in the case of human infestation, it should be considered as a possible cause of gastrointestinal disease, especially in countries where raw or undercooked fish is a frequent food. Clinical features of anisakiasis may simulate acute abdominal pain, such as that found in patients with gastric ulcers, appendicitis, and Crohn's disease. Furthermore, many cases of anisakiasis are diagnosed as eosinophilic gastroenteritis, which is a broad term for a specific disease.

OBJECTIVE

The purpose of this study was to investigate the immunopathogenesis of human gastrointestinal infestation by A simplex.

METHODS

Thirteen intestinal biopsy specimens from patients with anisakiasis were analyzed for the presence of messenger (m)RNA for different cytokines and inflammatory mediators by RT-PCR. Specific IgE, eosinophil cationic protein, eosinophil protein X, and tryptase levels were measured in each patient's serum. Also, cell cultures were set up with lymphocytes from some patients and stimulated in vitro with Anisakis and Ascaris antigens.

RESULTS

We performed immunologic phenotyping in 13 patients. All patients underwent biopsy after emergency surgery caused by episodes of acute abdominal pain. In all cases inflammatory infiltrate composed of eosinophils and lymphocytes was found in the intestinal wall. We demonstrated that after infestation, a T(H2)-type immune response occurred. Also, major basic protein, nitric oxide, and eotaxin were found in the tissue, and eosinophil cationic protein and eosinophil protein X levels were elevated in sera.

CONCLUSION

These data and in vitro lymphocyte cultures indicate that a T(H2) mechanism plays an important role in the inflammatory infiltrate produced by the anchorage of parasites in the gastrointestinal wall.

Aspirin inhibits inducible nitric oxide synthase expression and tumour necrosis factor-alpha release by cultured smooth muscle cells

BACKGROUND

Inflammatory related cardiovascular disease, i.e. cardiac allograft rejection, myocarditis, septic shock, are accompanied by cytokine production, which stimulates the expression of inducible nitric oxide (iNOS).

MATERIALS AND METHODS

The aim of the present study was to examine whether anti-inflammatory doses of acetylsalicylic acid (aspirin) could regulate iNOS protein expression in bovine vascular smooth muscle cells (BVSMCs) in culture.

RESULTS

Interleukin 1 beta (IL-1 beta, 0.03 U mL-1) induced nitric oxide release by BVSMCs. Aspirin inhibited nitric oxide release from IL-1 beta-stimulated BVSMCs in a dose-dependent manner. In addition, aspirin significantly inhibited iNOS protein expression in BVSMCs and reduced the translocation of the nuclear factor-kappa B (NF-kappa B). Furthermore, aspirin and the blockade of NO generation by BVSMCs reduced the production of tumour necrosis factor alpha (TNF-alpha) by these cells.

CONCLUSION

High doses of aspirin inhibited iNOS protein expression in BVSMCs and decreased NF-kappa B mobilization. The inhibition of iNOS expression by aspirin was further associated with a reduced ability of BVSMCs to produce TNF-alpha. This study could provide new mechanisms of action for aspirin in the treatment of the inflammation-related cardiovascular diseases.

Galectin-3 down-regulates IL-5 gene expression on different cell types

Galectin-3 is an animal lectin, formerly named epsilon-binding protein or Mac-2, which has been described to play an important role in some inflammatory processes by the implication of different cells and the increase in cell adhesion functions through laminin binding activity. In this work we analyzed the role of galectin-3 in the modulation of Th2 cytokines that have an important role in the development of the inflammatory response. We have found that the addition of galectin-3 to human eosinophils, the eosinophilic cell line EoL-3, PBMC, and an Ag-specific T cell line (CD4+) produced a selective inhibition of IL-5 transcription. No inhibitory effect was found on the IL-4 mRNA transcription rate. The inhibitory effect on IL-5 transcription was reversed by incubation with lactose and using specific Ab against galectin-3. Galectin-3 is able to induce inhibition of the IL-5 released in the supernatants from PBMC stimulated with phorbol 12,13-dibutyrate and anti-CD3. Similar results were obtained when a T-specific cell line was stimulated with Ag. Also, EoL-3 stimulated with anti-CD32 produced IL-5 protein, the synthesis of which was partially inhibited by galectin-3. The present results demonstrate that galectin-3 induces a selective down-regulation of IL-5 expression in different cell types, opening important new possibilities in the regulation of the allergic reactions.

Autoimmune hepatitis type 2 and hepatitis C virus infection: study of HLA antigens

BACKGROUND/AIMS

Markers for hepatitis C virus are often detectable in patients suffering chronic hepatitis with liver-kidney microsomal type 1 antibodies. Several authors have suggested that two subsets of those patients can be defined: a) hepatitis C virus negative and b) hepatitis C virus positive. The aim of this work was to further analyze the possible genetic association, HLA class I and II, in these two groups of patients.

METHODS

HLA was analyzed in 49 patients. Class I was studied using a standard lymphocytotoxicity test and in class II a reverse hybridization-based test for DRB1 typing and PCR-SSO for DQB1 typing were used. Sixty healthy Spanish subjects and 39 chronic hepatitis C subjects without anti-LKM1 antibodies were used as control groups for the "a" and "b" subsets, respectively.

RESULTS

No significant association was found with class I specificities in either group. DQB1 typing showed a very significant increase of DQ2 in the "a" group (93.3% vs. 48%; RR = 15; Pc = 0.0025), and DRB1 typing from the "b" group revealed a high association with DR7 (82.3% vs. 43.6%; RR = 6; Pc = 0.0086).

CONCLUSIONS

Our studies revealed a strong association with DQ2 for the "a" group and for the first time an extremely high association with DR7 antigen for the "b" subset. Hence it is possible to establish a different genetic profile in these two patient groups.

Cytokine mRNA expression in lung tissue from toxic oil syndrome patients: a TH2 immunological mechanism

In 1981, an epidemic occurred in Spain, toxic oil syndrome (TOS), in people who consumed rapeseed oil denatured with 2% aniline, and it was one of the largest intoxication epidemics ever recorded. In 1989, a similar disease, eosinophilia-myalgia syndrome (EMS) was reported in the USA and was associated with the ingestion of L-tryptophan. The pathologic findings in TOS showed primary endothelial injury, with cell proliferation and perivascular inflammatory infiltrates. Immunologic mechanisms have presumably been operative in the pathogenesis and perpetuation of TOS. Our previous findings pointed to a T-cell activation during acute phase of the disease. In order to analyze which T-cell subset is involved on TOS, we have developed an mRNA extraction procedure from paraffin-embedded lung tissues in patients with pulmonary involvement. We analyzed mRNA expression from different cytokines (IL-1, IL-2, IL-4, IL-5, IFN-gamma, GM-CSF) and CD25 (interleukin 2 receptor) and CD23 (low affinity IgE receptor), using RT-PCR technique. In lung tissues from these patients a T-cell activation was observed. We found a significant increase in Th1 (P = 0.006) and Th2 (P = 0.003) cytokine profile in TOS patients with respect to controls. The increment in TH2 response with respect to TH1 is significant (P = 0.03) in TOS lung specimens. Non-significant differences were obtained in other cytokines and receptors studied as IL-1, CD25, CD23 and GM-CSF. Data presented in this paper are the first clear evidence that an immunological mechanism is directly implicated in this illness.

Study of apoptosis in human lymphocytes by toxic substances implicated in toxic oil syndrome

Toxic Oil Syndrome is a multisystemic disease that occurred in epidemic proportions in Spain in 1981 caused by the ingestion of rapeseed oil denatured with aniline. Several data implicate T cells in the pathogenesis of the disease. We evaluated the mechanisms of cytotoxicity in human lymphocytes of TOS-related products: aniline, 3-(N-phenylamino)-1,2-propanediol and its mono- and di-oleyl esters and eosinophilia myalgia-related product such as 3-(phenylamino)-L-alanine, which is chemically similar to 3-(N-phenylamino)-1,2-propanediol, and has been found in manufactured L-tryptophan. Our results show that only di-oleyl ester of 3-(N-phenylamino)-1,2-propanediol induces apoptosis in human lymphocytes, in a concentration and time-dependent way, confirmed by morphology, expression of phosphatidylserine in membrane and analysis of DNA degradation.

Eosinophils transcribe and translate messenger RNA for inducible nitric oxide synthase

Because of the involvement of nitric oxide (NO) in inflammatory states such as parasitic and hypersensitivity disorders and the fact that eosinophils are one of the cell types implicated, we asked whether eosinophils were able to express mRNA specific to inducible NO synthase (iNOS) and iNOS protein and to secrete nitric oxide. iNOS protein was detected on eosinophil preparations by immunocytochemistry using iNOS mAb. Expression of iNOS protein was also detected by immunoblotting in human purified eosinophils and an eosinophilic leukemia cell line, Eol-3. Nitrite production was detected in the supernatant of human eosinophils and Eol-3 cells cultured for 24 h, and was completely inhibited in the presence of the NOS inhibitor N-methylester-L-arginine. iNOS cDNA was obtained by reverse transcription-PCR. After subcloning, sequencing of the 259-bp fragment from three different human eosinophils cDNAs revealed 97% identity with macrophage/monocyte iNOS. Our studies describe for the first time the presence of iNOS on eosinophil and a putative new role for this cell in inflammatory states such as asthma and parasitic disease.

Eosinophils transcribe and translate messenger RNA for inducible nitric oxide synthase

Because of the involvement of nitric oxide (NO) in inflammatory states such as parasitic and hypersensitivity disorders and the fact that eosinophils are one of the cell types implicated, we asked whether eosinophils were able to express mRNA specific to inducible NO synthase (iNOS) and iNOS protein and to secrete nitric oxide. iNOS protein was detected on eosinophil preparations by immunocytochemistry using iNOS mAb. Expression of iNOS protein was also detected by immunoblotting in human purified eosinophils and an eosinophilic leukemia cell line, Eol-3. Nitrite production was detected in the supernatant of human eosinophils and Eol-3 cells cultured for 24 h, and was completely inhibited in the presence of the NOS inhibitor N-methylester-L-arginine. iNOS cDNA was obtained by reverse transcription-PCR. After subcloning, sequencing of the 259-bp fragment from three different human eosinophils cDNAs revealed 97% identity with macrophage/monocyte iNOS. Our studies describe for the first time the presence of iNOS on eosinophil and a putative new role for this cell in inflammatory states such as asthma and parasitic disease.

Immunological basis of toxic oil syndrome (TOS)

The toxic oil syndrome (TOS), a multisystemic disease, that occurred in Spain in 1981, was caused by the ingestion of rapeseed oil denatured with 2% aniline. Due to the clinical course of the disease, immunopathological mechanisms have been suspected but a direct connection was never demonstrated. To analyse this possibility, we determined several immunological parameters in the sera of patients with TOS and without the disease, using a case-control design: total immunoglobulins, IgG and IgE antibodies against different toxic agents (oleylanilide, aniline, linoleyl-anilide, and 3-phenylaminopropane-1-2-diol), autoantibodies, cytokines (IL-4, IL-6, TNF, GM-CSF) and soluble receptors (sCD23 and sIL-2R). We detected high levels of sIL-2R in TOS patients compared to controls (P < 0.0001). A higher levels of sCD23 and IgE were also found. In addition, the response to oleyl-anilide of peripheral blood lymphocytes from TOS patients was studied and a significant proliferative response in 30% of TOS patients versus 5% controls was observed. Our data support the implication of the immune system in the acute phase of TOS, with a possible activation of T-cells and release of cytokines, that could explain some of the clinical findings in this phase of the disease.

Modulation of the Fc gamma RII and Fc gamma RIII induced by GM-CSF, IFN-gamma and IL-4 on murine eosinophils

Murine eosinophils express the low-affinity Fc gamma receptors recognized by the monoclonal antibody (mAb) 2.4G2, which are involved in the activation of these cells. We have studied the membrane and RNA expression of the low-affinity Fc gamma receptors on murine eosinophils stimulated by granulocyte-macrophage colony-stimulating factor (GM-CSF), interferon-gamma (IFN-gamma), and interleukin-4 (IL-4). Flow cytometric analysis (FACS) of eosinophils incubated with GM-CSF and IFN-gamma showed an up-regulation on the expression of these receptors with a maximal effect at 24 hr. IL-4 failed to induce any positive or negative effect in these cells. To assess the pattern of expression of the low-affinity Fc gamma receptors on eosinophils, Northern blot analyses were carried out using specific cDNA probes encoding for the Fc gamma RII and Fc gamma RIII. Murine eosinophils constitutively express transcripts for Fc gamma RII and RIII. Incubation with GM-CSF from 3 to 12 hr produced a potent induction of the two transcripts studied (Fc gamma RII and RIII). IFN-gamma did not induce any important up-regulation of the two transcripts from 3 to 12 hr of incubation. By contrast, IL-4 produced a marked inhibition of both transcripts at 24 hr of incubation. Expression of the gamma-chain transcript which is associated with Fc gamma RIII has been detected on freshly isolated eosinophils. This study demonstrates a different regulation pattern of these receptors depending on the cytokine or growth factor used to stimulate murine eosinophils.

Ole e I: epitope mapping, cross-reactivity with other Oleaceae pollens and ultrastructural localization

Ole e I is the major allergen derived from olive tree pollen (Olea europaea) and it is composed of two polypeptides with molecular weights (MWs) of 18 and 20 kD. A panel of six monoclonal antibodies (mAbs) has been prepared and used to map antigenic determinants on this molecule. Four epitope determinants have been identified on Ole e I. Using the purified mAbs produced against Ole e I, we have analyzed the common epitope determinants in olive (O. europaea) and different Oleaceae pollens: ash (Fraxinus excelsior); privet (Ligustrum vulgare); lilac (Syringa vulgaris), and forsythia (Forsythia suspensa). ELISA showed three reactivity groups depending on the recognition of monoclonal antibodies: (1) olive and ash; (2) olive, ash, privet and lilac; and (3) olive, ash, privet, lilac and forsythia. Immunoblotting studies on Oleaceae pollen extracts with these mAbs showed a very similar cross-reactivity pattern. The 18- and 20-kD MW proteins were present in each pollen, except in the case of forsythia. In this case the reactivity pattern was associated with 50- to 55-kD protein bands. This band was recognized by a pool of sera from olive-allergic patients. Finally, ultrastructural localization of Ole e I antigen was performed on the mature olive pollen grain. Ole e I was located in association with dilated endoplasmic reticulum cisternae. Pollen grain walls, nuclei and cytoplasmic organelles were totally devoid of the allergen.

DR7 and DQ2 are positively associated with immunoglobulin-E response to the main antigen of olive pollen (Ole e I) in allergic patients

We have studied the relationship between HLA class II haplotypes and alleles, and the IgE antibody response to a highly purified allergen, Ole e I, in allergic patients. Ole e I, is the major antigen from the pollen of olive tree that grows mainly in the Mediterranean. Genomic DNA typing was performed in 40 unrelated patients with seasonal allergic pollenosis who had specific IgE antibodies against Ole e I, detected by double-antibody radioimmunoassay. HLA-DRB and -DQB loci were analyzed by PCR-SSO and RFLP. Phenotypic frequencies were compared with those of 179 healthy unrelated individuals. Significant increases in the phenotypic frequencies of DR7 (pf = 67.5% vs 31.3% in the control population, pc = 0.0023) and DQ2 (pf = 90.0% vs 48.0%, pc = 0.0003) were found, indicating an association between DRB1*0701/2, DQB1*0201 alleles and the IgE antibody response to Ole e I. This is the first time that the HLA-DQ gene has been associated with a positive allergic response.

Members of the alpha-amylase inhibitors family from wheat endosperm are major allergens associated with baker's asthma

We have identified the major antigens or IgE binding components from wheat flour. Thirty-five sera from patients with baker's asthma were used to analyze the reaction with wheat salt-soluble proteins. We found a 15 kDa SDS-PAGE band which reacted with all sera tested. Purified members of the alpha-amylase inhibitor family, which are the main components of the 15 kDa band, were recognized by specific IgE when tested with a pool of reactive sera. Immunodetection after two-dimensional electrophoretic fractionation of crude inhibitor preparations from wheat endosperms also detected several inhibitor subunits as major low-molecular-weight allergens.

Release of O2- and LTC4 by murine eosinophils: role of intra- and extracellular calcium

Using an experimental model of mouse peritoneal eosinophilia, we investigated the role of Ca2+ in the in vitro activation of these cells challenged with specific Mesocestoides corti antigen. We have detected LTC4, a metabolite derived from arachidonic acid by way of 5'lipo-oxygenase and superoxide anion from the oxidative burst, as inflammatory mediators produced by activated eosinophils. Preincubation with hyperimmune mice serum increases the amount of LTC4 and superoxide anion in response to the antigenic extract. Release of O2- is inhibited by Verapamil (a voltage-gated calcium channel) and Quin 2 (an intracellular trapped chelator of calcium). Also, LTC4 produced by preincubated eosinophils challenged with M. corti is dramatically inhibited by Quin 2. Our results suggest an intact mechanism for calcium control for the release of these inflammatory mediators by eosinophils, after specific antigenic stimulation.