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Biomedical subjects

E Fernández-Caldas

Publications and source records attributed to E Fernández-Caldas.

At least 19 recordsLinked to original sources

House dust mite species and allergen levels in Galicia, Spain: a cross-sectional, multicenter, comparative study.

BACKGROUND AND OBJECTIVES: Mites are important sources of allergens in Galicia, Spain. The objective of this study were to identify the main mite species and to determine allergen levels in mattresses from different locations in Galicia. MATERIAL AND METHODS: Dust samples were collected with a portable vacuum cleaner for 2 minutes from 2 m2 of the surface of the mattress used by mite allergic patients and controls. After collection, samples were immediatel frozen. Mite species were collected, identified, and counted, and the results expressed as mites per gram of dust. Mite allergen levels (Der p 1 and Der f 1) were measured using monoclonal antibodies. All individuals answered a questionnaire about the characteristics of their homes. RESULTS: A total of 332 dust samples were collected (112 from mite allergic patients and 220 from controls). Thirty-two species were identified. The mean age +/-SD of all the participants was 32.4 +/- 20.8 years and of the mattresses 7.6 +/- 5.9 years. The geometric mean of the total mite counts was 910.2 mites per gram (896.2 mites per gram in the mattresses of mite allergic patients and 917.3 in the mattresses of control subjects; P > .05). The main species was Dermatophagoides pteronyssinus, which was present in 97.6% of the samples (geometric mean, 584.7 mites per gram). The geometric mean level of Der p 1 was 13.1 microg/g of dust: 11.9 in the mattresses of mite allergic patients and 13.8 in the mattresses of control subjects. The geometric mean level of Der f1 was 1.1 microg/g: 1.5 in the mattresses of mite allergic patients and 0.8 in the mattresses of control subjects. Environmental risk factors associated with high mite counts included obvious signs of humidity in the bedroom and the age of the mattress. CONCLUSIONS: The mite fauna in Galicia is comprised of many species, several of which are known to be of allergologic importance. The total population is exposed to very high levels of mite allergens.

Adolescent↗

Safety of an ultra-rush immunotherapy build-up schedule with therapeutic vaccines containing depigmented and polymerized allergen extracts.

BACKGROUND: Four administration schedules of immunotherapy have been reported: conventional, cluster, rush and ultra-rush. OBJECTIVES: To evaluate the safety and the clinical advantage of using standardized modified allergen extracts in an ultra-rush protocol without premedication and/or hospitalization. MATERIAL AND METHODS: One thousand and sixty-eight patients with rhinoconjunctivitis and/or asthma sensitized to mites and/or pollen were included in a prospective observational study. Patients received a therapeutic vaccine containing depigmented and glutaraldehyde-modified extracts (mites and/or pollens) adsorbed onto alum prescribed by a specialist. The schedule of administration consisted of injecting 0.2 and 0.3 ml of the vial of maximum concentration during the first day of immunotherapy, separated by a time interval of 30 min. All patients reached the maximum dose (0.5 ml) after 2 injections. Tolerance was assessed by recording all side reactions related to immunotherapy, classified according to the criteria of the EAACI. RESULTS: The total number of injections was 2,136. All patients reached the maximum established dose on the 1st day. No premedication was used. Seven clinically relevant local reactions were recorded. The systemic reactions were 5 grade-1 (2 immediate and 3 delayed) and 3 delayed grade-2 reactions. CONCLUSIONS: The therapeutic vaccines containing chemically modified extracts can be administered using an alternative ultra-rush schedule in an immunotherapy unit, reaching the maximum dose on the 1st day with 2 injections, without the need of premedication and/or hospitalization.

Adult↗

Double-blind study of tolerability and antibody production of unmodified and chemically modified allergen vaccines of Phleum pratense.

BACKGROUND: The physicochemical modification of allergen extracts provides a chance for administering higher doses of allergen vaccines. OBJECTIVE: To evaluate the safety of a chemically modified (depigmented-glutaraldehyde polymerized) therapeutic vaccine of Phleum pratense administered at doses that are 10 times higher than those used in clinical practice, in comparison with conventional doses of the corresponding non-modified alum-adsorbed vaccine. MATERIALS AND METHODS: The design of the study was randomized, double-blind, parallel and included two groups of patients. Twenty-three patients were treated weekly during nine visits for the build-up phase, followed by two weekly maintenance doses (a total of 11 injections per patient). Twelve patients received a vaccine containing the standardized unmodified extract, at a maximum concentration of 308.5 mcg of freeze dried material/mL (Group A). Eleven patients received a standardized modified allergen extract (Group B). The maximum dose used was 2400 mcg/mL. Safety was evaluated recording all adverse events. Skin test results and specific antibody levels were evaluated at the beginning and at the end of the study. RESULTS: Group A patients experienced three local immediate (two clinically irrelevant and one with a diameter>5 cm) and 18 delayed reactions (15 irrelevant and three with a diameter>10 cm), while Group B experienced six local immediate and 12 delayed reactions (all clinically irrelevant). Nine Group A patients experienced 12 systemic reactions (one immediate of grade 1, one of grade 2; and one delayed of grade 1; four of grade 2 and three of grade 3), while Group B patients experienced one immediate systemic reaction of grades 1, and 1 delayed reaction of grade 1. CONCLUSIONS: The modified extract of P. pratense is safe to treat sensitive patients, even at concentrations that are 10 times higher than those regularly administered in clinical practice. The majority of the local reactions were clinically irrelevant. No systemic reactions of grade 2, 3 or 4 were reported using the modified extract.

Adult↗

Allergenic composition of the mite Suidasia medanensis and cross-reactivity with Blomia tropicalis.

BACKGROUND: Mites of the genus Suidasia are commonly found in house dust and may play an allergenic role in exposed populations. However, the allergenic potential and clinical impact of this genus has not been well established. The main objective of this project was to evaluate the allergenic role of the mite Suidasia medanensis. METHODS: An extract of S. medanensis was prepared and the allergen composition determined by immunoblot. Specific IgE antibody levels to S. medanensis and Blomia tropicalis were evaluated by radioallergosorbent (RAST) in the sera of 97 allergic asthmatic patients and 50 nonallergic subjects. Cross-reactivity between S. medanensis and the mite species B. tropicalis and Dermatophagoides farinae was investigated by RAST and immunoblot inhibitions. RESULTS: Seventy-one asthmatic patients sera (73.2%) had positive IgE reactivity to S. medanensis; 14 allergens with molecular weights ranging from 7.5 to 105 kDa were detected. The most frequently detected had molecular weights of 30-31 (54.8%), 24.5 (42%), 21 (38.7%), 47 (35%) and 58 kDa (35.5%). Blomia tropicalis extract inhibited IgE binding to nine of these identified allergens. Four B. tropicalis allergens were inhibited by S. medanensis extract. RAST inhibition results demonstrated a high degree of inhibition by B. tropicalis (87.2%) and D. farinae (90.9%) than by S. medanensis (32%). CONCLUSIONS: Sensitization to S. medanensis is common in asthmatic allergy patients in Cartagena. An important degree of cross-reactivity was established between S. medanensis and B. tropicalis, and D. farinae.

Animals↗

Skin tests with native, depigmented and glutaraldehyde polymerized allergen extracts.

INTRODUCTION: Dose-response skin prick tests are an important tool to standardise allergen extracts and to evaluate changes in skin test response as a consequence of allergen modifications. OBJECTIVES: To evaluate in vivo and in vitro characteristics of 3 different types of extracts of Phleumpratense, Olea europaea, Parietaria judaica and Dermatophagoides pteronyssinus. MATERIAL AND METHODS: Three types of extracts were used: native unmodified extracts (N), depigmented extracts (DP) (extracts subjected to a mild acid treatment under controlled conditions and dialysis), and a depigmented glutaraldehyde polymerised extract (DPP). Adult patients were skin tested in duplicate with the 3 types of extracts. The dose-response relationship between the geometric mean of the wheal areas and the allergen concentrations was calculated for each patient using regression line analysis. The amount of freeze-dried allergen preparation needed to produce the same wheal size as histamine was calculated in each patient (individual 10 HEP) and for each of the 3 types of extracts. In vitro analysis consisted of major allergen determinations and specific IgE and IgG inhibitions. RESULTS: The respective 10 HEP values for N, DP and DPP preparations were 0.20 mg, 0.15 and 2.11 for D. pteronyssinus. For P. pratense, these values were 0.02 mg, 0.02 and 0.99; for O. europaea 0.15, 0.44 and 4.9; and for P. judaica 0.01, 0.008 and 1.78 mg. CONCLUSIONS: The polymerised depigmented extracts are significantly less allergenic than the corresponding native and depigmented extracts. This could provide a greater safety margin for the administration of higher doses of immunotherapy in a shorter period of time.

Adult↗

Mite allergen exposure, sensitisation and clinical symptoms in Valdivia, Chile.

One hundred consecutive asthmatic paediatric patients were evaluated and skin tested with a battery of skin prick test reagents, including 8 different standardized house dust mite extracts. Asthma severity was graded according to the Global Initiative for Asthma (GINA) document in mild persistent (52 patients), moderate persistent (39) and severe persistent (9). Sixty patients had asthma and allergic rhinitis, 12 asthma and eczema, and 8 asthma, allergic rhinitis and eczema. The patient population was divided into 2 different socioeconomic groups (50 patients per group) based on a standardized, validated questionnaire. A dust sample was collected with an adapted vacuum cleaner from the mattress of each patient and analysed for Der p 1, Der f 1 and Der p 2 allergen content using monoclonal antibodies. Eighty patients were skin test positive to at least one mite species. All positive skin test patients were positive to Dermatophagoides pteronyssinus, 99% to D. farinae, 92% to Euroglyphus maynei, 80% to Lepidoglyphus destructor, 73% to Tyrophagus putrescientae, 72% to Blomia tropicalis; 70% to Acarus siro and 68% to Chortoglyphus arcuatus. All patients with severe persistent asthma had a positive skin test to mites, 85% in the moderate group, and 73% in the mild group (p < 0.01). 95% of patients with asthma and allergic rhinitis had a positive skin test to mites, 92% of patients with asthma and eczema and 100% of patients with asthma, allergic rhinitis and eczema; (p < 0.01). Mean Der p 1, Der f 1 and Der p 2 allergen concentrations were 18.3, 0.6 and 5.6 microg/g of mattress dust, respectively. Mean Der p 1 allergen levels in the middle-low socioeconomic group were significantly higher than in the middle high group (p < 0.01). There is a high rate of allergic sensitisation among pediatric asthmatic patients in Chile. More than one species are implicated, although sensitisation and exposure to D. pteronyssinus predominates. Mite allergic patients are exposed to high mite allergen concentrations, exceeding previously established risk levels for sensitisation and symptoms.

Adolescent↗

Correlation between Chenopodiacea/Amaranthacea pollen counts and allergic symptoms in Salsola kali monosensitized patients.

UNLABELLED: We performed a prospective observational study to establish a relationship between pollen counts of Chenopodiacea/Amaranthacea and clinical symptoms of rhinoconjunctivitis and asthma in a group of monosensitised patients. MATERIAL AND METHODS: A total of 60 patients (19 with asthma) were included in the study. All patients collected daily symptom scores during the summer months of 1999, 2000 and 2001. The questionnaire included ocular, nasal and pulmonary symptoms. Pollen counts were expressed as pollen grains/m3. Symptom scores and pollen counts were correlated using correlation coefficients and Log transformed variables. RESULTS: In the 3 seasons studied we identified a peak of pollen and clinical symptoms in the second half of August and first half of September. In 1999, there was a significant positive correlation between total symptoms and daily pollen grains/m3 (p<0.005, r = 0.347). This correlation was not significant for the summers of 2000 and 2001. After further analysis, and by displacing one of both variables between 11 to 17 days, the correlation coefficients for total symptoms, improved for 1999 (r = 0. 744; p < 0.0001) and became significant for 2000 (r = 0. 521; p < 0.0001) and 2001 (r = 0.635; p < 0.0001). CONCLUSION: We identified a significant time lag between pollen counts and symptom scores in S. kali monosensitized patients.

Adolescent↗

Allergenicity and cross-reactivity of Russian olive pollen (Eleagnus angustifolia).

BACKGROUND: The purposes of this study were: to determine the prevalence of sensitization and immunochemical characterization of Eleagnus angustifolia pollen (Russian olive) that belongs to the family Eleagnaceae. METHODS: A total of 134 patients with rhinoconjunctivitis and/or asthma were studied. Its allergenicity, cross-reactivity with olive pollen and the presence of Ole e 1 and Ole e 4-like molecules were evaluated. RESULTS: Eleagnus angustifolia pollen was detected from May to June. Seventy-three of 134 (30.5%) had positive skin test to E. angustifolia, all of them were positive to olive. There was a good correlation between specific immunoglobulin (Ig)E levels to E. angustifolia and Olea europaea (r = 0.77, P = 0.002). Sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) immunoblots revealed major IgE-binding bands in the E. angustifolia extract of 43 and 63.7 kDa. The E. angustifolia extract was not able to inhibit olive, whereas O. europaea inhibited E. angustifolia up to 41%. The presence of Ole e 1- and Ole e 4-like allergens in E. angustifolia extract was confirmed by enzyme-linked immunosorbent (ELISA) inhibition assays. Nasal challenge with E. angustifolia was positive in three of six patients with positive skin test to both pollens and negative in five patients with positive skin test only to O. europaea. CONCLUSIONS: This study confirms that E. angustifolia is capable of sensitizing individuals in Madrid. A minimal-to-moderate cross-reactivity with olive pollen was established, suggesting some cross-reactivity but not excluding co-sensitization.

Air Pollution↗

Immunochemical characterization of Russian thistle (Salsola kali) pollen extracts. Purification of the allergen Sal k 1.

BACKGROUND: Salsola kali (Russian thistle) is a weed which belongs to the Chaenopodiacea family. It is widely distributed along the coasts of Europe, North Africa, USA and Australia. The objectives of this study were to study the allergenic composition of S. kali pollen and to purify an important allergen from the pollen extracts of this plant. METHODS: A population of 66 individuals with specific IgE-mediated allergic symptoms and positive skin tests to S. kali were included in the study. Specific IgE to S. kali was determined by direct enzyme-linked immunosorbent assay (ELISA). The antigenic and allergenic profile of S. kali was evaluated by sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE), isoelectric focussing (IEF) and immunoblot. Allergen purification was conducted by preparative SDS-PAGE. The allergenicity of the protein was evaluated by skin testing, direct ELISA, ELISA inhibition and immunoblots. RESULTS: Specific IgE to S. kali was detected in 39 of the 66 individuals (59%). An allergen with a molecular weight of approximately 43 kDa was purified. This allergen was termed Sal k 1. A partial sequencing was obtained and no homology was found with other known proteins/allergens. The allergenicity of Sal k 1 was tested in vitro and in vivo. Of the 39 individuals with a positive specific IgE determination to S. kali, 26 (66.6%) had detectable specific IgE to Sal k 1. Twenty of these 39 individuals were skin-prick tested with the purified allergen (0.5 mg/ml) and all of them had a positive skin test to the purified allergen. Ten additional individuals, used as negative controls, had a negative response. CONCLUSIONS: Sal k 1, an important allergen of S. kali, is recognized, in vitro, by approximately 67% of the patients sensitized to S. kali. Twenty patients with a positive skin test to a standardized S. kali extract had a positive reaction to the purified allergen.

Allergens↗

Identification of Cucumisin (Cuc m 1), a subtilisin-like endopeptidase, as the major allergen of melon fruit.

BACKGROUND: Allergenic components in melon extracts have not been described in spite of the fact that melon (Cucumis melo) is a frequent allergy-eliciting fruit. The aim of this study was to evaluate allergenic components in melon extract and to report the identification of cucumisin as a major melon allergen. MATERIALS AND METHODS: Sera from 35 patients allergic to melon were selected on the basis of clinical symptoms, skin prick tests and oral challenge test. Allergenic components were detected by sodium dodecyl sulphate polyacrylamide gel electrophoresis and immunoblotting. Molecular characterization of IgE-binding bands was performed by N-terminal amino acid sequencing. RESULTS: More than 10 IgE-binding bands, between 10 and 80 kDa, were identified in melon extract. Out of them, four IgE-binding bands were major allergens: 14 kDa, 36 kDa, 54 kDa and 67 kDa. These major allergens, except 14 kDa band, showed the same N-terminal sequence: T-T-R-S-W-D-F-L. Research conducted with protein databases identified this N-terminal sequence as cucumisin, an alkaline serine protease, which shares structural homology with microbial subtilisin. The molecular mass of the identified bands corresponds with different molecular forms of cucumisin produced during the processing or degradation of the enzyme: 67 kDa native cucumisin, 54 kDa mature cucumisin and 36 kDa NH2-terminal cucumisin fragment. CONCLUSION: Cucumisin (Cuc m 1) and several N-terminal cucumisin fragments are the major allergens of melon. The ubiquitous distribution of this protein family (cucumisin-like proteases) in many plant species and its high structural similarity suggest its potential role as a new panallergen in plant foods.

Adolescent↗

Characterization of allergens of Anisakis simplex.

BACKGROUND: Anisakis simplex is an intestinal parasite of sea mammals. The larvae infect crustaceans, cephalopods and fish. Humans may consume A. simplex third stage larvae (L3) when eating infected raw or under-cooked fish. Consumed larvae cause an inflammatory reaction when they penetrate the digestive mucosa. The larvae or their secretory/excretory products can sensitize humans and induce an immunoglobulin E (IgE)-mediated allergic reaction. This parasite is now being implicated in numerous cases of allergic reactions after eating fish. The purpose of this study was to evaluate the allergenicity of proteins present in an extract of the third stage larva. METHODS: Rabbit antiserum raised to A. simplex somatic extract (L3) was reacted by crossed immunoelectrophoresis (CIE) with the same somatic extract. Crossed radioimmunoelectrophoresis (CRIE) was also performed by incubating CIE gels first in the sera of 13 individuals with positive immunoCAP to A. simplex and then in radiolabeled anti-human IgE. RESULTS: Twelve to 16 antigen-antibody precipitin peaks were visualized on Coomassie blue stained CIE gels in which somatic extract was reacted with somatic-antiserum. Autoradiography of CRIE gels showed that 18 different proteins bound IgE in patient sera. Individual patients had serum IgE directed at two to 10 different allergens. Five of these allergens were recognized by >/=50% of the patients. No allergen was recognized by every patient and no patient had serum IgE directed at all 18 allergens. CONCLUSION: Somatic extracts of A. simplex L3 larva contain a large number of allergenic molecules and there is significant variability between patients in their sensitivity and reactivity to these allergens.

Adult↗

Skin tests and conjunctival and bronchial challenges with extracts of Blomia tropicalis and Dermatophagoides pteronyssinus in patients with allergic asthma and/or rhinoconjunctivitis.

BACKGROUND: Blomia tropicalis and Dermatophagoides pteronyssinus are important mite species in Tenerife, Canary Islands, Spain. Several studies have demonstrated a variable degree of allergenic cross-reactivity in vitro. However, only a few have addressed their allergenic cross-reactivity using challenge tests. OBJECTIVE: The objective of this study was to conduct conjunctival and bronchial challenge tests with B. tropicalis and D. pteronyssinus extracts in a group of 42 patients with allergic asthma and/or rhinoconjunctivitis sensitised to house dust mites (31 females, 11 males; mean age 21.7 +/- 7.02 years). METHODS: Prick tests using standardised extracts and specific IgE determinations using the CAP system were performed. Bronchial and/or conjunctival challenges were conducted using freeze-dried extracts of both mite species. A patient was considered sensitive to a mite species if she/he had a positive prick and/or CAP test result. A total of 32 conjunctival and 15 bronchial challenges were performed with both mite species. RESULTS: Prick tests were positive to B. tropicalis in 23 patients (54.7%) and to D. pteronyssinus in 41 (97.6%). One patient (2.4%) was exclusively sensitive to B. tropicalis. The CAP test was positive for B. tropicalis in 28 patients and for D. pteronyssinus in 41. Conjunctival challenges to B. tropicalis were positive in 20 patients (18 sensitised and 2 non-sensitised) and negative in 12 (5 sensitised and 7 non-sensitised patients). Conjunctival challenges with D. pteronyssinus were positive in all 31 D. pteronyssinus-sensitised patients who underwent conjunctival challenges. Bronchial challenges with B. tropicalis were positive in 9 sensitised patients and negative in 6 patients (2 sensitised and 4 non-sensitised). Bronchial challenges with D. pteronyssinus were positive in all patients except 1, who only reacted to B. tropicalis. CONCLUSIONS: Allergens of the mite species B. tropicalis induce positive conjunctival and bronchial challenges in B. tropicalis-sensitised individuals. Our results suggest that although there is a low to moderate degree of in vivo cross-reactivity between B. tropicalis and D. pteronyssinus, B. tropicalis seems to be a relevant source of allergens in areas where patients are exposed.

Acari↗

Allergenicity and immunochemical characterization of six varieties of Olea europaea.

BACKGROUND: The inhalation of Olea europaea pollen is one of the most important causes of allergic respiratory diseases in the Mediterranean basin. The objective of this study was to investigate the antigenic and allergenic composition of six different O. europaea varieties collected in southern Spain. METHODS: The varieties included in the study were: Acebuche (wild olive), Carrasqueño, Nevado, Hojiblanco, Manzanillo and Picual. Extracts of these six varieties were prepared. Twenty-nine olive individuals with an immunoglobulin(Ig)E-mediated allergy to olive pollen were skin tested with these extracts. The antigenic profile of these extracts was evaluated by SDS-PAGE; the allergenic profile was investigated by immunoblotting using the serum of these 29 individuals. The Ole e 1 content was established by ELISA inhibition using purified Ole e 1 and rabbit polyclonal antibodies and by scanning densitometry. RESULTS: The extracts that induced the smallest wheal size were Acebuche and Hojiblanco, being significantly different from the rest of the extracts. The antigenic and allergenic profiles of the extracts also varied. The Ole e 1 content ranged from 0.050 in Hojiblanco to 0.232 in Manzanillo, measured by ELISA inhibition and from 0.153 in Hojiblanco to 0.677 in Nevado, measured by scanning densitometry. CONCLUSIONS: The different varieties of O. europaea pollen studied demonstrated great differences in the in vivo and in vitro potency of the extracts. There were significant differences in the Ole e 1 content, while the protein content remained very similar in these extracts. This study confirms previous observations of a great variability in the antigenic and allergenic composition of O. europaea pollen extracts and establishes significant differences in Ole e 1 content.

Allergens↗

Rapid release of Ole e 1 from olive pollen using different solvents.

BACKGROUND: Solubility is an important characteristic of allergenic molecules. The aim of this study was to investigate the solubility of Ole e 1, a major allergen of Olea europaea, using different solvents. MATERIAL AND METHODS: Olea europaea pollen was placed in a glass column and extracted using three different solvents: deionized water, phosphate buffer 0.01 M (PBS) and normal saline (NaCl 0.9%). Several fractions were collected after extraction with each solvent and pooled based on individual protein content. Each fraction corresponded to a different elution profile, as determined by linear regression analysis. After 130 min of extraction, the pollen that remained in the column was further extracted overnight. A control olive pollen extract was also prepared with each solvent. The antigenic and allergenic profiles of all the eluted and pooled fractions were analysed by SDS-PAGE and inmmunoblots. Protein and Ole e 1 content and the amount of protein needed to produce 50% inhibition were also calculated. Ten patients were skin prick tested with the fractions obtained with deionized water. RESULTS: Four elution profiles were obtained using deionized water as the extracting solution and three with the two other solvents. The three solvents produced different kinetics of allergen release. Ole e 1 was rapidly released when water was used, obtaining a total of 256 micro g of Ole e 1/ml after only 7 min of extraction (fraction EC1). Using PBS, or NaCl 0.9%, the release of Ole e 1 started after 4 and 9 min of extraction, respectively. The highest amount ofOle e 1 was eluted after 44 and 26 min, with a total concentration of 162 and 203 micro g of Ole e 1/ml, respectively. The presence of Ole e 1 in each phase was verified by SDS-PAGE and immunoblot analyses. CONCLUSIONS: The extracting solution seems to determine the antigenic profile of olive pollen extracts. Ole e 1 is rapidly released from the pollen grain after extraction in deionized water. The solubility seems to be affected by the use of other solvents. These techniques could be used to manipulate the Ole e 1 content in O. europaea extracts.

Allergens↗