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Dive into the research topics where Beatriz Tavares is active.

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Featured researches published by Beatriz Tavares.


Allergologia Et Immunopathologia | 2007

Goat's milk allergy

Beatriz Tavares; Celso Pereira; F. Rodrigues; Graça Loureiro; Celso Chieira

BACKGROUND Goats milk (GM) allergy not associated with allergy to cows milk (CM) is a rare disorder. Caseins have been implicated has the major allergens eliciting symptoms. METHODS We report the case of a 27 years-old female patient that experienced two episodes of urticaria related to ingestion of goats cheese (GC). She tolerated CM, dairy products and sheep cheese. Skin prick tests were performed with GM, CM, bovine casein and alpha -lactalbumin and fresh milk and GC. Serum specific IgE to GM, CM and its fractions, and GM and CM immunobloting assays with inhibition were also evaluated. RESULTS Skin tests were positive to GM and GC and negative to CM. GM immunoblot showed an IgE-binding 14 kDa band that was totally inhibited after serum pre-incubation with GM. CONCLUSIONS Allergens other than casein can be involved in allergy to GM. Even small quantities of protein can elicit symptoms.


Cases Journal | 2009

Specific sublingual immunotherapy with peach LTP (Pru p 3). One year treatment: a case report.

Celso Pereira; Borja Bartolomé; Juan A. Asturias; Iñaki Ibarrola; Beatriz Tavares; Graça Loureiro; Daniel Machado; Celso Chieira

IntroductionFood allergy is an increasing problem with limited therapeutic approaches apart from to the eviction diet.Case presentationA 40-year-old female patient with food allergy symptoms was polysensitized to almost all vegetable food since the age of 36; the onset of symptoms was during pregnancy. The allergological study demonstrated positive skin prick tests (SPT) to nuts, legumes, cereals, spices, several fresh fruits including peach, and other groups of vegetable foods however, it was negative to common aeroallergens. Serum specific IgE levels were negative (<0.35 kU/L) to profilin and carbohydrate determinants, but positive to Pru p 3 (3.5 kU/L). Positive double-blind placebo-controlled food challenge to peach confirmed the allergic disease. She received specific sublingual immunotherapy with native Pru p 3 at a concentration of 40 μg/ml with 5 administrations per week and a cumulative dose of 200 μg of nPru p 3 per month. After an ultra-rush build-up phase concluded in one day she continued therapy during a year with 5 administrations per week. The clinical evolution and laboratory studies demonstrated an early reduction on SPT reactions with no relevant changes on serum specific IgE, IgG, IgG1 and IgG4 to Pru p 3 during the immunotherapy period. The challenge test was negative 4 months after the beginning of the SLIT. Regarding clinical response she markedly improved after the first month of treatment, and by the 3th month she had no major vegetable dietary restrictions, except for nuts and pepper.ConclusionThese results demonstrate the excellent efficacy and safety of sublingual specific protein immunotherapy developed according to the patient specific sensitivity profile to Pru p3.


International Archives of Allergy and Immunology | 2013

Different Frequencies of Tc17/Tc1 and Th17/Th1 Cells in Chronic Spontaneous Urticaria

Ana Lopes; Daniel Machado; Susana Pedreiro; Ana Henriques; Isabel Silva; Beatriz Tavares; Maria de Jesus Inácio; Celso Chieira; António Martinho; Maria Luísa Pais; Celso Pereira; Artur Paiva

Background: Chronic urticaria is associated with an immune dysregulation usually mediated by T lymphocytes. Recently, Th17 and Tc17 have been implicated in autoimmune diseases; however, their role in urticaria is not clear yet. Methods: For the study we recruited 20 patients [10 of them had autoreactive chronic spontaneous urticaria (positive autologous intradermal serum test response, ASST+), and the other 10 were nonautoreactive chronic spontaneous urticaria patients (ASST–)] and 17 healthy age- and gender-matched controls (HG). The frequency and functional activity of Th17/Tc17 and Th1/Tc1 cells were evaluated by flow cytometry and type 2 cytokine mRNA by real-time PCR. Results: Our results demonstrated a significant decrease in Th17 frequency in both chronic urticaria groups compared to HG; regarding the amount of IL-17, at the single cell level, it was reduced in ASST– compared to HG. Concerning the Th1 and Th17 cells producing IFN-γ, IL-2, and TNF-α, a lower frequency was noted in chronic urticaria patients compared to HG. In contrast, a significantly increased frequency of Tc1 cells producing these cytokines was noted in ASST+ compared to HG and ASST–. Also, the frequency of Tc17 cells producing TNF-α was increased in ASST+ compared to HG; however, with respect to the amount of TNF-α, at the single cell level, we found a decrease in ASST+ compared to HG. Regarding type 2 cytokine mRNA, a higher expression was verified in ASST+ compared to HG. Conclusion: Our data suggest a probable involvement of cytotoxic T cells, mainly the Tc1 and Tc17 subsets, in chronic urticaria, particularly in the ASST+ group.


Science of The Total Environment | 2008

Sensitization to profilin in the Central region of Portugal.

Beatriz Tavares; Daniel Machado; Graça Loureiro; Jessica Cemlyn-Jones; Celso Pereira

BACKGROUND Profilin is a panallergen found in pollens and fruits. Sensitization to this protein may explain some sensitization to multiple pollen species. We aimed to evaluate sensitization to profilin in patients suffering from respiratory allergy sensitized to pollens, in the Central region of Portugal. METHODS Patients were evaluated for asthma symptoms, rhinitis, conjunctivitis and food allergy. Skin prick tests (SPT) to aeroallergens including 12 different pollens and profilin (nPho d 2) were performed. The patients were divided into two study groups according to the region of residence: A--inland region and B--coastal region. RESULTS A total of 370 patients were evaluated (277-group A; 93-group B). 65.9% showed positive skin prick tests and 76.2% were positive to pollens (87.1%-group A; 42.85%-group B; p<0.0001). All the patients sensitized to pollens had rhinitis (p=0.001). Sensitization to profilin was associated with pollen sensitization (p=0.014). 43 patients were sensitized to profilin (40-group A; 3-group B; p=0.006). 21.0% of patients sensitized to pollens, were also sensitized to profilin. 39 patients were sensitized to at least two pollens (p<0.0001). Four profilin and pollen sensitized patients had oral allergy syndrome complaints to melon. This syndrome was related with profilin sensitization (p=0.001). CONCLUSIONS It is advisable to perform SPT to profilin, particularly in the Inland region, for a better differential diagnosis between cross-reactivity and true sensitization to pollens. The results together with the medical history may support the choice for a specific immunotherapy option.


Allergologia Et Immunopathologia | 2012

Streptococcal tonsillitis as a cause of urticaria: tonsillitis and urticaria.

G. Calado; Graça Loureiro; Daniel Machado; Beatriz Tavares; C. Ribeiro; J. C. Cea Pereira; A.S. Luís

BACKGROUND The primary role of infections in chronic urticaria (CU) is controversial. We hypothesised that streptococcal tonsillitis (ST) could be a primary cause of CU or acute recurrent urticaria (ARU). METHODS Retrospective study of 14 outpatients observed between January 2000 and December 2009, with CU/ARU and clinical and/or laboratorial suspicion of an aetiopathogenic link with ST. Clinical history, objective examination and laboratorial study were looked for. Three groups were defined: spontaneous resolution of urticaria, resolution after tonsillectomy, and still symptomatic. RESULTS In these patients, a causal relationship between ST and urticaria is supported by: markers of streptococcal infection, the perception of a clinical relationship between tonsillitis and urticaria, the decrease of urticaria severity with early antibiotherapy to tonsillitis and urticaria resolution after tonsillectomy. CONCLUSIONS Our study encourages the investigation of tonsillitis in these otherwise idiopathic patients, especially until young adulthood and even in the absence of any symptoms.


Archive | 2012

Nasal Provocation Test in the Diagnosis of Allergic Rhinitis

Graça Loureiro; Beatriz Tavares; Daniel Machado; Celso Pereira

The specific provocation tests, since its introduction by Blackley in 1853, have been widely used in the investigation of pathophysiological mechanisms, immunological and therapeutic aspects of allergic disease, as they mimic the response to allergen exposure, under controlled conditions. However, it has not been broadly used in the diagnosis of allergic disease in clinical practice, because of the lack of standardization of the methodology and the need of other complementary diagnostic tests for monitoring specific provocation tests. Nevertheless, the importance of such test is enormous in many circumstances, since it is the only method that can establish the exact etiology of allergic disease. Although the usefulness of these tests has not been questioned, the need to standardize the methodology for monitoring the response has been stressed. In this review, these aspects will be discussed.


Recent Patents on Inflammation & Allergy Drug Discovery | 2009

Dynamics of CD86 Expression on Allergic Inflammation - New Insights

Celso Pereira; Beatriz Tavares; Graça Loureiro; Artur Paiva; Ana Henriques; Margarida Abrantes; Daniel Machado; Filomena Botelho; Manuel F. Baganha

CD86 is a well-known costimulatory molecule in its interaction with CD28 and/or CTLA present on T cells, and is essential for full activation of naïve T-cell and subsequent differentiation. Usually the B7 molecules are expressed mainly on APCs and B cells and in specific conditions on other activated cells. These costimulatory molecules are involved in the development of allergic inflammation and airways hyperreactivity (AHR) in allergen-challenged mice. Activated T cells, CD4(+)CD25(+), express CD86 in the first 60 minutes after the specific inhalatory exposure. These T cells can be relevant in IgE mediated allergic reaction possibly by an autocrine costimulation via CD28/CTLA activation pathway. The blockage of the expression of CD86 could be a potential therapeutical target to reduce the magnitude or the progression of the allergic reaction. The review article also discussed relevant patents.


Archive | 2012

Specific Immunotherapy and Central Immune System

Celso Pereira; Graça Loureiro; Beatriz Tavares; Filomena Botelho

Despite the current knowledge, the mechanisms by which the specific immunotherapy (SIT) achieves clinical improvement remains unclear. However, it is now clear that the immune tolerance is one of the major targets of this kind of treatment. Immune tolerance depends on different mechanisms, including T-cell anergy, T-cell depletion by apoptosis, and active immune suppression (Akdis & Akdis, 2011). One of the goals of SIT is the induction of tolerance to allergens to which the patient is sensitized. IL-10 is probably a relevant cytokine induced by this treatment and is associated to regulatory T cells (T-regs) that actively control or suppress the function of other cells, generally in an inhibitory pattern (Frew, 2010). The changes in microenvironment due to the decrease in histamine and PGE2 release by mast cell, and the IL-10 and TGF- release by dendritic cells (DC) could switch the T-cell population into T-regs. These alterations will then lead to tolerance (Schmidt-Weber & Blaser 2005). Much of the knowledge about SIT has been based on studies using subcutaneous route of administration (SCIT), but increasing data is now available based on studies using sublingual immunotherapy (SLIT). The sublingual mucosa, where the deposition of the extract occurs, has very particular characteristics, quite different from the cellular subcutaneous tissue. The dendritic cells present in the buccal region are distinct from the Langerhans cells present in the skin. These cells present, constitutively, receptors with high affinity for IgE, FcRI+, MHC class I and II molecules, as well as co-stimulation molecules, namely CD40, CD80/B7.1 and CD86/B7.2 (Allam et al., 2006). There is also expression of CD14, a lipopolysaccharide (LPS) receptor, which is relevant for the modulation of Th2 and Th1. In SLIT, the allergen is captured by the DC cell by C-lectin endocytosis receptors and/or by ligation to the IgE on the surface. After the internalization, the migration to the regional lymphoid nodules occurs, and it is then presented to the T cells (Geijtenbeek, 2006). A study that compares the DC population in the oral and nasal mucosa was able to demonstrate that only the DC myeloid type is profusely present in the oral region, in contrast with the nasal mucosa where both populations are present (Allam et al., 2006). Another very important difference is the high expression levels of FcRI in the oral mucosa, which is almost absent in the skin’s Langerhans cells (Allam et al., 2003). Furthermore, the expression levels of MHC class I and II molecules, CD40, CD80 and CD86 is significantly higher in oral DC than in the skin.


Allergologia Et Immunopathologia | 2006

Home gardening may be a risk factor for contact dermatitis to Alstroemeria

Beatriz Tavares; Graça Loureiro; Celso Pereira; Celso Chieira

BACKGROUND Occupational allergy among florists and people who work in cut flower production of Alstroemeria cultivars (Peruvian lily or Inca lily) has been previously reported. The allergen involved in sensitization is tulipalin A (alpha-methylene-gamma-butyrolactone). CASE REPORT We describe the case of a 65-year-old woman who developed severe dermatitis on her right thumb, index and middle fingers and less severe dermatitis on her left palm and front of forearm with occasional itching of the neck and face after taking up home gardening activities, including cutting flowers such as Alstroemeria. METHODS The patient and three healthy individuals were submitted to epicutaneous tests with the European standard series, the plant series, and stem portions of three suspected ornamental plants (Alstroemeria, Lilium and Zantedeschia), garlic, and onion. RESULTS Patch tests performed in our patient, revealed an extreme reaction (+ + +) to Alstroemeria and alpha-methylene-gamma-butyrolactone, a strong reaction (+ +) to propolis and wood tar mix, a weak reaction (+) to balsam of Peru, an irritant reaction to garlic and negative results to diallyl disulfide and the other components investigated. Patch tests performed in the healthy individuals revealed negative. CONCLUSIONS We stress the importance of Alstroemeria as a cause of allergic contact dermatitis not only in workers involved in the flower trade, but also in other people that come into contact with this plant in their leisure activities.


European annals of allergy and clinical immunology | 2007

Low-dose intravenous gammaglobulin in the treatment of severe autoimmune urticaria

Celso Pereira; Beatriz Tavares; I Carrapatoso; G. Loureiro; Emília Faria; D. Machado; Celso Chieira

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G. Calado

University of Coimbra

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