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Biomedical subjects

I Diéguez

Publications and source records attributed to I Diéguez.

At least 19 recordsLinked to original sources
PubMed2003

Use of CD63 expression as a marker of in vitro basophil activation and leukotriene determination in metamizol allergic patients.

BACKGROUND: We assessed the reliability of basophil activation test (FAST) and sulphidoleukotriene production (CAST) in the in vitro diagnosis of allergy to metamizol, evaluating its sensitivity and specificity. METHODS: Twenty-six patients allergic to metamizol and 30 control individuals were studied. Skin tests with metamizol, FAST, and CAST were performed. RESULTS: FAST sensitivity was 42.3% and specificity 100%. The PPV of FAST is 100% and the NPV 99.4%. The likelihood ratio for a positive value cannot be calculated because the specificity is 100% and the likelihood ratio for a negative value is 0.58. CAST sensitivity was 52%, and specificity 90%. The PPV of the test is 5% and the NPV 99.5%. The likelihood ratio for a positive result was 5.2 and that for a negative result 0.53. FAST detects a larger number of cases when patients are studied within the first 6 months after the clinical reaction (chi = 4.2, P = 0.04) than later. Together with skin tests, FAST allowed detection of 69.2% patients allergic to metamizol, the same as CAST 76%. The joint use of the three techniques allowed identification of 76.9% of cases. CONCLUSIONS: FAST and CAST are useful for the diagnosis of allergy to pyrazolones. Its usefulness clearly increases when recent reactions are studied.

Adult↗
PubMed2003

[Basophil activation test in the diagnosis of allergy to medicines].

In this paper we study the reliability of the basophil activation test (BAT) in the "in-vitro" diagnosis of allergy to betalactams and to metamizol, and the sensitivity and specificity of the technique are analyzed. To this end, we studied 58 patients allergic to betalactam antibiotics with a positive cutaneous test facing any derivative of penicillin and 30 healthy controls who tolerated betalactams, and 26 patients allergic to metamizol with an immediate reaction and 30 healthy controls who tolerated the medicine. Sensitivity to BAT in allergy to betalactams was 52.8%, and specificity was 92.6%. For metamizol, sensitivity was 42.3% and specificity was 100%. The positive predictive value of BAT in allergy to betalactams was 18.9% and the negative predictive value was 98.4%. For metamizol, the positive predictive value of the technique was 100% and the negative predictive value was 99.4%. The joint use of BAT and CAP (specific IgE) makes it possible to diagnose some 65% of patients allergic to betalactams. The combined use of cutaneous tests and BAT in allergy to metamizol detects 70% of the cases. BAT is a useful, non-invasive technique in the "in-vitro" diagnosis of allergy to betalactams and metamizol.

Basophil Degranulation Test↗
PubMed2002

Flow cytometric basophil activation test: a review.

Flow cytometry is a technique enabling the analysis of physical and biological characteristics of cells or other biological particles when labeled with antibodies coupled to fluorochromes or other dyes. The basophil activation test (BAT), also called flow-cytometric allergen stimulation test (FAST) [commercially available under the name of Flow CAST (Bühlmann Laboratories) or BASOTEST (Beckton-Dickinson)] is based on the in vitro allergen-induced specific activation of basophils. This assay rests on the demonstration of some membrane protein markers that appear after exposure to the allergen. This paper reviews some of the literature about the use of this technique in the investigation of immediate-type allergies to inhalant allergens, drugs, and foods, as well as our own experience with this diagnostic technique. Flow cytometry is a reliable method for the quantification of basophil activation after allergenic stimulus in vitro and in vivo. It also enables us to detect allergic and pseudoallergic reactions because of other mechanisms than allergen-specific IgE antibodies. Further clinical evaluation of this technique will allow validation and better establishment of its diagnostic value in allergy.

Adult↗
PubMed2001

Variations of serum eosinophil cationic protein and tryptase, measured in serum and saliva, during the course of immediate allergic reactions to foods.

BACKGROUND: Subjective complaints and reactions after placebo administration during food challenges (FC) may make their outcome difficult to interpret. We determined serum ECP and tryptase as tryptase in saliva during FC, looking for markers to support challenge outcomes. METHODS: Twelve patients with systemic reactions after food intake and nine presenting oral allergy syndrome (OAS) underwent skin tests; total and specific IgE determination; double-blind, placebo-controlled FC (DBPCFC); and open challenges. Blood samples were collected before and 1, 2, and 5 h after challenge and saliva before and 5, 30, and 60 min after challenge. ECP and tryptase were quantified by ImmunoCAP (Pharmacia-Upjohn, Sweden). Serum tryptase of > 10 microg/l was considered positive. RESULTS: After positive DBPCFC (n = 8), ECP rose significantly (P < 0.05) at 1-h - 16.03 (12.8) microg/l (mean [standard deviation]) - and 2-h intervals - 17.56 (10.7) microg/l - compared to basal level of 9 (6.4) microg/l. After negative DBPCFC (n = 6), ECP increased from basal 9.63 (3.9) microg/l to 24.84 (14.17) microg/l at the 2-h time point. There were nonsignificant differences in ECP between patients with positive and negative FC. Two patients with positive challenge showed a tryptase level of >10 microg/l and only one patient with OAS showed 5.6 microg/l of tryptase 5 min after FC. CONCLUSIONS: ECP and tryptase in serum and saliva were not useful markers for FC outcomes.

Adolescent↗
PubMed2001

Allergen-induced basophil activation: CD63 cell expression detected by flow cytometry in patients allergic to Dermatophagoides pteronyssinus and Lolium perenne.

BACKGROUND: In this study, we determined by flow cytometry the percentage of basophils activated after in vitro stimulation by allergens and expressing the CD63 marker. The diagnostic reliability of the technique was assessed as well as its correlation with other in vitro diagnostic parameters. METHODS: Fifty-three patients suffering from asthma and/or allergic rhinitis following sensitization to Dermatophagoides pteronyssinus and 51 patients sensitized to Lolium perenne were investigated. Twenty-four atopic patients not sensitive to these allergens and 38 healthy subjects were also selected as controls. The basophil activation test determines the percentage of basophils which express CD63 as an activation marker, by means of flow cytometry, after in vitro stimulation with allergen, using double labelling with monoclonal antibody anti-CD63-PE and anti-IgE-FITC. RESULTS: No differences in basal values (non-activated control) were found between sensitized patients, atopic controls and healthy controls. On the other hand, sensitized patients showed a significantly higher percentage of activated basophils after stimulation by allergens in vitro than both control groups (P < 0.001). We found a significant correlation between skin tests and basophil activation tests (r = 0.72, P < 0.001). We also found a positive and significant correlation between basophil activation tests and histamine release tests (r = 0.80, P < 0.001), allergen-specific sulphidoleukotriene production (r = 0.7, P < 0.001) and the occurrence of serum allergen-specific IgE (r = 0.71, P < 0.001). CONCLUSION: The basophil activation test is a highly reliable technique in the diagnosis of allergy to inhalant allergens. The sensitivity of the basophil activation test was 93.3%, and its specificity 98.4%, when using a cut-off point of 15% activated basophils as positive result.

Adult↗
PubMed2001

Study of the in vitro sulphidoleukotriene production in food-allergic patients.

OBJECTIVE AND DESIGN: To study in vitro sulphidoleukotriene (sLT) production by food allergic patients using cellular allergen stimulation test (CAST)-ELISA and to evaluate the reliability of this technique for diagnosing food allergic reactions. SUBJECTS: Forty patients with adverse reactions after food intake, 20 healthy controls, and 15 individuals sensitized to inhalant allergens as atopic controls. METHODS: Skin tests, serum-specific IgE, histamine release test (HRT), CAST-ELISA and food challenges. One-way ANOVA was used to compare tests results between patients and controls and to study mediator release and specific IgE, related to the severity of clinical pictures. Sensitivity and specificity were analyzed by ROC curves. RESULTS: Food allergic patients showed higher (p < 0.05) Ag-dependent sLT production (836.2 +/- 664.1 pg/ml) (mean +/- standard deviation) than both control groups. After stimulus with anti-IgE antibodies, sLT production was higher (p < 0.05) by atopic controls (1630.8 +/- 696.5 pg/ml) compared to patients and healthy controls. Patients with anaphylactic reactions showed higher Ag-specific and anti-IgE sLT and histamine production than patients with less severe manifestations. Mean serum-specific IgE was significantly lower (p < 0.05) in patients presenting oral allergy syndrome compared to patients with more severe clinical pictures. CAST-ELISA was the most sensitive method. Prick by prick test was the most specific. CONCLUSIONS: CAST-ELISA may provide a useful tool for diagnosing food allergy. Enhanced cell releasability may be linked to the severity of the clinical response to foods.

Adolescent↗
PubMed1998

Study of a case of hypersensitivity to lettuce (Lactuca sativa).

BACKGROUND: Allergic reactions to lettuce (Lactuca sativa) are not too frequent and few cases of systemic adverse reactions after its ingestion have been described. OBJECTIVE: We report a case of clinical sensitization to lettuce on a patient who presented mucocutaneous manifestations after its ingestion, with positive skin tests, histamine release test and serum specific-IgE to lettuce. The allergens responsible for this sensitization were also characterized by means of SDS-PAGE immunoblotting. MATERIALS AND METHODS: We performed skin tests, histamine release test, serum specific IgE determination and CAP inhibition with lettuce and mugwort (Artemisia vulgaris) extracts. An aqueous and enriched lettuce (from loose leaf type) extract was subjected to SDS-PAGE immunoblotting for determination of its IgE-binding components. RESULTS AND CONCLUSIONS: CAP inhibition showed antigenic community between lettuce and mugwort. Four protein bands from the lettuce extracts with molecular weights of 50, 43, 39 and 16 kDa exhibited IgE-binding properties.

Adult↗
PubMed1997

Serum eosinophil peroxidase (EPO) levels in asthmatic patients.

Eosinophil granular proteins are a useful eosinophilic activation marker in asthmatic patients. In this study, the eosinophil peroxidase (EPO) levels were assessed in different stages of bronchial asthma, in 123 patients suffering from asthma, classified as mild (n =49), moderate (n = 49), and severe (n = 25), according to the International Consensus Report of Diagnosis and Treatment of Asthma, as well as in 27 healthy controls, with the aim of evaluating the importance of this protein as a severity marker in bronchial asthma, and its possible correlation with parameters such as anamnesis, respiratory function tests, and peripheral blood eosinophil count, and also with some allergologic diagnostic tests, both in vivo and in vitro. The geometric mean serum level of EPO was 9.3 +/- 11.3 ng/ml (median +/- SD) in controls, 28 +/- 37.8 ng/ml in the asthmatic patients. Depending on the asthma severity, the EPO levels were 25 +/- 30.5; 29 +/- 37.1, and 41 +/- 47.3 ng/ml in mild, moderate, and severe asthmatics, respectively, being the significant differences between the group of patients with mild and severe asthma (P < 0.001). The number of eosinophils (eos) in peripheral blood was 157 +/- 20 eos/mm3 in the controls, 334/35 eos/mm3 in mild asthmatics, 510 +/- 87 eos/mm3 in moderate asthmatics, and 658 +/- 72 eos/mm3 in severe asthmatics, with significant differences between all groups (from P < 0.05 to P < 0.001). Both the serum levels of EPO and the number of eosinophils were greater in patients with active asthma patients with inactive asthma (P < 0.001). Significant negative correlations (P < 0.001) were found between serum levels of EPO and FEV1 (rs = 0.30), MEF25-75 (rs = -0.33) and MEF50 (rs = -0.34), and a good positive correlation (rs = 0.80, P < 0.001) was found between EPO levels and the number of eosinophils in peripheral blood. We also found a significant positive correlation between eosinophil number and clinical score (rs = 0.54, P < 0.001) and between EPO levels and the mentioned score (rs = 0.46, P < 0.001).

Adolescent↗
PubMed1991

Influence of seasonal variations on histamine release and other immunological parameters in pollinosis.

One hundred and fifty-six pollen-sensitive patients with sensitization to grass pollen only were chosen for this study; 65 patients were allergic to Dermatophagoides, while 45 were non-allergic subjects with no atopic history. The following tests were carried out on all patients: histamine release of total blood, basal histamine, total histamine, determination of total IgE and specific IgE (RAST) serum levels, serum hemagglutinating antibodies and skin tests. Seasonal increase of IgE was observed, with post-seasonal fall; 50% of the cases reached normal values. However, RAST as a semiquantitative method did not prove to be useful in the detection of variations in specific IgE levels. During pollination, an increase in titers in pollen-sensitive subjects was seen. This was attributed to a humoral immune response epiphenomenon which was independent of IgE. The histamine release test was significantly greater during pollination in pollen-sensitive subjects. The total of stored histamine increased during the months of allergenic exposure.

Animals↗
PubMed1989

Results of the in vitro follow-up of immunotherapy.

With the advances made in allergological diagnosis, thanks to the application of various in vitro immunological techniques, we have also learnt more about the immunological modifications produced during the course of the immunotherapy. Among the techniques which will detect immunological changes is the histamine release test, which will show a decrease in antigen-specific histamine release. On the other hand, both total IgE and IgG4 are modified in the course of this immunotherapeutic treatment.

Follow-Up Studies↗
PubMedDate not supplied

Serum ECP levels in asthmatic patients: comparison with other follow-up parameters.

In recent years, eosinophil cationic protein (ECP) has been considered as a useful eosinophilic activation marker in asthmatic patients. In this study, serum ECP levels in different stages of bronchial asthma were evaluated. We studied 123 patients suffering from asthma, which was classified as mild (n = 49), moderate (n = 49), severe asthma (n = 25), and also 31 healthy controls. Serum ECP levels were 13.22 +/- 1.11 ng/mL (mean +/- s.e.m.) in controls, and 30.15 +/- 2.38 ng/mL in asthmatic patients. By subgroups, ECP levels were 24.23 +/- 3.37 ng/mL, 31.69 +/- 4.21 ng/mL and 37.61 +/- 4.52 ng/mL, in mild, moderate and severe asthmatic patients, respectively, being the differences among the three groups statistically significant (P < 0.01-P < 0.001). Peripheral blood eosinophil numbers were 157 +/- 20 eos/mm3 in controls, and 334 +/- 35 eos/mm3, 510 +/- 87 eos/mm3, and 658 +/- 72 eos/mm3, in mild, moderate, and severe asthmatic patients, respectively, with significant differences among all groups (P < 0.05-P < 0.001). The serum ECP levels as well as the eosinophil numbers were higher in symptomatic patients than in the asymptomatic ones (P < 0.01). Moderate negative correlations, although highly significant (P < or = 0.001), were found between serum ECP levels and forced vital capacity (FVC) (rs = -0.27), FEV1, MEF25-75 (rs = -031), and MEF50 (rs = -0.32). There was also a good positive correlation between ECP levels and peripheral blood eosinophil numbers (rs = 0.67, P < 0.001).

Adolescent↗
PubMedDate not supplied

Eosinophil soluble protein levels, eosinophil peroxidase and eosinophil cationic protein in asthmatic patients.

Eosinophil granular proteins are useful eosinophil activation markers in asthmatic patients. In this study, eosinophil peroxidase (EPO) and eosinophil cationic protein (ECP) levels were assessed in different stages of bronchial asthma in 123 patients suffering from intrinsic (n = 42) and extrinsic (n = 81) asthma, with the aim of evaluating the difference in the protein levels between both types of asthma and their importance as a severity marker of the disease. The geometric mean serum level of EPO was 12.3 +/- 2.17 ng/ml (mean +/- SD) in controls, and 38.6 +/- 3.4 ng/ml in the asthmatic patients. Mean ECP levels were 13.22 +/- 1.11 ng/ml in controls and 30.5 +/- 2.38 ng/ml in patients. Depending on the asthma severity, the EPO levels were 30.4 +/- 4.35, 38.7 +/- 5.29, and 54.46 +/- 9.46 ng/ml in mild, moderate and severe asthmatics, respectively, with the differences being significant between the groups of patients with mild and severe asthma (p < 0.001). ECP levels were 24.23 +/- 3.37 in mild, 31.69 +/- 4.21 in moderate, and 37.61 +/- 4.52 ng/ml in severe asthma. There were significant differences in ECP levels between mild and moderate asthma (p < 0.001) and between mild and severe asthma (p < 0.001). Peripheral eosinophil count was 157 +/- 20 eosinophils/mm3 in controls, 334 +/- 35 eosinophils/mm3 in mild asthmatics, 510 +/- 87 eosinophils/mm3 in moderate asthmatics and 658 +/- 72 eosinophil/mm3 in severe asthmatics, with significant differences between all groups (p < 0.05-p < 0.001). Serum EPO and ECP levels and peripheral eosinophil count were significantly greater in patients with active asthma than in patients with silent asthma (p < 0.001). Significant negative correlations (p < 0.001) were found between serum EPO levels and FEV1 (rs = -0.30), MEF25-75 (rs = -0.33), MEF50 (rs = -0.34). There was also a significant (p < 0.001) and negative correlation between ECP levels and FEV1 (rs = -0.31), MEF25-75 (rs = -0.31), MEF50 (rs = -0.32). A good positive correlation was found between peripheral eosinophil count and EPO levels (rs = 0.80, p < 0.001), and ECP levels (rs = 0.67, p < 0.001). We also found a significant positive correlation between clinical score and peripheral eosinophil count (rs = 0.54, p < 0.001), EPO levels (rs = 0.46, p < 0.001) and ECP levels (rs = 0.52, p < 0.001).

Adolescent↗
PubMedDate not supplied

Schnitzler syndrome: a case study.

Schnitzler syndrome is a clinical entity of unknown etiopathogenesis and is an unusual cause of chronic urticaria. It is characterized by the presentation of a monoclonal band, especially IgM, as well as fever, asthenia and arthralgia. We present the case of a 48-year-old man with 5 years of recurrent urticarial lesions, slight itching, as well as lip, face and occasional pharyngeal edema. The patient had also suffered from fever and right hip and left knee arthralgia. The protein electrophoresis and the immunoelectrophoresis presented an IgG band and a slight lambda band, which is suggestive of a monoclonal gammopathy. The bone marrow examination showed a slight increase in the lymphoplasmatic cells. The marrow biopsy was negative. In order to rule out tumorous, infectious and rheumatic processes as well as collagen diseases, other complementary examinations were performed with negative results. The diagnosis of Schnitzler syndrome as a cause of chronic urticaria requires a thorough study in order to rule out other systemic processes provoking the same symptoms.

Humans↗
PubMedDate not supplied

Skin manifestations of a case of phenylbutazone-induced serum sickness-like reactions.

Serum sickness consists of a systemic reaction resulting from the formation of soluble circulating immunocomplexes after the introduction of a foreign substance into the body We studied a 38-year-old woman diagnosed with anxiety, depression and right sacroileitis who was treated with phenylbutazone, ranitidine, clomipramine and levomepromazine. After taking this treatment for 1 month, she presented with fever, diarrhea, localized edemas, generalized pruritic papular and erythematous rash and lymphadenopathies. She presented the same symptoms after oral intake of metamizole. The diagnosis was confirmed following a single-blind, placebo-controlled provocation test with phenylbutazone and a biopsy of the affected skin.

Adult↗
PubMedDate not supplied

Food allergy as a cause of rhinitis and/or asthma.

We studied the histories of patients who had visited our Department during the last 5 years, presenting food allergy with exclusively respiratory symptoms (18.5%). We studied the correlation between IgE levels and the histamine release test and the type of food implicated. Seventy-seven percent of patients presented sensitization to one food, and 23% presented polysensitization. We found that foods such as snails and eggs have a strong predilection for the bronchial tree as the shock organ. High total IgE was found in 85.2% of patients. The histamine release test was positive in 66% of cases. We conclude that this is a highly sensitive method for the in vitro diagnosis of food allergy.

Allergens↗
PubMedDate not supplied

[Study of drug allergies with special reference to skin manifestations].

One hundred and forty four patients, with dermal reactions to different drugs, were chosen from our clinic. The selection criteria was based on a detailed and careful anamnesis in order to be certain of the specific drug responsible for the reaction. We tried to establish a drug-specific reaction pattern for each of the drugs studied. Intradermal skin tests were performed with all drugs to be studied, except with pyrazolones and aspirin, for which patch tests were applied. The drug concentrations were established prior to the tests in order to avoid unwanted unspecific reactions. In every case, immediate and delayed reaction readings were carried out. A three crosses reaction (+++) was considered positive. The skin tests were positive in 44% of the cases, a value higher than those referred to by most authors. The delayed reactions to skin tests and the chloramphenicol-mediated delayed-type "dermatitis-like" manifestations are compared. It is noteworthy to mention that positive delayed reactions were observed more frequently with chloramphenicol than with any of the other studied drugs. The same applies for those patients with a positive history to chloramphenicol. The most common reaction pattern to penicillin and streptomycin in our series (20%) were urticaria and Quincke's edema. Penicillin, pyrazolones and streptomycin were the most common drugs responsible for urticarial patterns, being the pyrazolones related to fixed erythema in many cases. The age group 25-50 was the most frequently involved. No sex predominance was observed. The value of the classic skin tests is discussed, so are history recording and the in vitro tests.

Adolescent↗