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Cristobalina Mayorga

Publications and source records attributed to Cristobalina Mayorga.

18 recordsLinked to original sources
PubMed2006

Interferon receptor expression in multiple sclerosis patients.

To determine the gene expression of IFNAR1, IFNAR2 and MxA protein and the association with IFNbeta treatment response in MS patients. MS patients treated with IFNbeta had a significant decrease in IFNAR1 and IFNAR2 expression, and a significant increase in MxA compared to non-treated patients and healthy controls. Also, those patients who had a good response to treatment had a significant decrease in IFNAR1 and IFNAR2 expression compared to non-responders, non-treated patients and healthy controls. IFNbeta influences the expression of its receptors, and is greater in patients who respond to IFNbeta treatment. This down-regulation could be indicative of the response to IFNbeta.

Adult↗
PubMed2006

Potential involvement of dendritic cells in delayed-type hypersensitivity reactions to beta-lactams.

BACKGROUND: Although the involvement of T cells in delayed reactions to drugs has been studied, little is known about the interaction between the drug and the antigen-presenting cells. Dendritic cells (DCs) are professional antigen-presenting cells essential for initiating T-cell responses. Their ability is regulated in a process known as maturation, by which they modulate the effector immune response. OBJECTIVES: We studied the role of DCs in subjects who had a delayed-type hypersensitivity reaction to amoxicillin to assess the effect on the pattern of maturation and determine the capacity of DCs to activate T lymphocytes. METHODS: We examined the consequences of the interaction between monocyte-derived DCs, lymphocytes, and amoxicillin by means of phenotypic and functional studies, including endocytosis, proliferation, and cytokine production. RESULTS: Amoxicillin drove DCs from hypersensitive subjects to a phenotypic and functional semimature status, inducing a T-cell proliferation response. CONCLUSIONS: In delayed reactions to amoxicillin, DCs play a relevant role in inducing the T-cell responses. These results are useful not only to understand the mechanism but potentially as a possible approach to diagnosis. CLINICAL IMPLICATIONS: A better understanding of T-cell and DC involvement in delayed-type hypersensitivity reactions is needed. This in vitro assay might provide clues to the diagnostic evaluation of patients allergic to penicillins.

Adult↗
PubMed2006

Immediate allergic reactions to cephalosporins: evaluation of cross-reactivity with a panel of penicillins and cephalosporins.

BACKGROUND: Allergy to cephalosporins has mainly been evaluated in the context of patients with confirmed penicillin allergy. The problem of studying cross-reactivity in subjects primarily sensitized to cephalosporins and potentially allergic to penicillins has not been sufficiently addressed. OBJECTIVE: To evaluate the in vitro IgE response and cross-reactivity to betalactams in patients with immediate allergic reactions to cephalosporins. METHODS: The study included 24 patients with immediate allergic reactions to cephalosporins and RAST-positive to at least 1 cephalosporin. Skin testing and RAST were performed with a panel of penicillins and cephalosporins. RAST inhibition assay with different monomeric conjugates of penicillin and cephalosporin was performed to establish cross-reactivity. RESULTS: The culprit cephalosporins were cefaclor (N = 7), cefonicid (N = 1), cefotaxime (N = 2), ceftazidime (N = 2), ceftriaxone (N = 3), and cefuroxime (N = 9). Two patients had a positive skin test result to penicillin determinants, and 22 patients had a negative result to penicillin determinants and tolerated benzylpenicillin administration. Of these 22, 19 had a positive skin test result to cephalosporins and divided into patients reacting only to the culprit cephalosporin (63.2%) and those reacting to more than 1 cephalosporin (36.8%). RAST and RAST inhibition studies confirmed that the side chain at the R1 position is crucial for recognition. CONCLUSION: The R1 side chain rather than the betalactam structure, shared by penicillins and cephalosporins, seems to play a dominant role in determining the specificity of immunologic reactions to cephalosporins. Thus, penicillin can be administered safely to patients allergic to cephalosporins and with a negative skin test result to penicillin determinants.

Adolescent↗
PubMed2006

Monitoring the acute phase response in non-immediate allergic drug reactions.

PURPOSE OF REVIEW: The aim of this article is to evaluate the advantages of monitoring the immunological response of non-immediate allergic drug reactions in parallel with the affected tissues, skin and peripheral blood, in order to improve our understanding of the immunological response. RECENT FINDINGS: Several studies have shown that in the skin and peripheral blood, the agents that take part in the development of the immunological reaction express a number of markers that parallel the evolution of the disease process. These markers include cytokines, chemokines, and cytotoxic factors, as well as many other markers involved in such mechanisms as drug metabolism and signal transduction. SUMMARY: Monitoring the acute phase response to a drug in the skin with parallel studies in the blood provides clues that increase our understanding of the underlying pathological mechanisms in adverse reactions to drugs with an immunological basis. This approach, together with molecular biology techniques such as microarrays and genomic studies may be useful in future, in better characterizing the clinical subtype and prognosis of nonimmediate allergic drug reactions and generating targeted treatment regimens.

Acute-Phase Reaction↗
PubMed2006

Cytokine production, activation marker, and skin homing receptor in children with atopic dermatitis and bronchial asthma.

T cells are known to develop a critical role in the pathogenesis of atopic dermatitis (AD) and bronchial asthma. T cells involved in AD express the skin homing receptor CLA, but no lung homing receptor has been identified in bronchial asthma. We compared different cell markers and the cytokine production in T cells from children with AD or bronchial asthma. We studied the involvement of CLA+ and CLA- T-cell subpopulations in these diseases. We studied 20 children with acute AD lesions, 15 with mild persistent asthma, and 15 non-atopic controls. All patients were sensitized to house dust mite (DP) and evaluated during the acute phase. Total and specific IgE were measured by immunoassay and the expression of different cell markers and the cytokine production was analyzed by flow cytometry in peripheral blood mononuclear cells. Total IgE was significantly higher in AD children and IgE to DP in the asthmatic children. There was a significant increase in CD25+ CD4+ cells in asthmatic children and in HLA-DR+ CD4+ and HLA-DR+ CD8+ cells in AD. In the CD4+ subsets, there was an increase in IL-13, IL-5 and TNF-alpha in AD compared to controls, a decrease in IFN-gamma in asthmatic children compared to controls, and an increase in IL-13, IL5, IL2, TNF-alpha, and IFN-gamma in the AD compared to asthmatic children. Changes in cytokine production were mainly detected in CLA+ cells in AD and in CLA- cells in asthma. Differences exist in total and specific IgE, activation markers, and cytokine patterns between AD children and children with asthma, with the former expressing a Th2 pattern whereas in asthmatic children we only detected a decrease in IFN-gamma. Moreover, the subpopulations (CLA+ vs. CLA-) expressing these changes were different, indicating that the underlying mechanisms in the two diseases are not exactly the same.

Adolescent↗
PubMed2006

Allergic reactions to beta-lactams.

Allergy to beta-lactam antibiotics is the most frequent cause of drug-induced immunological reactions, although the prevalence is not exactly known. IgE- and T-cell-dependent responses are the main mechanisms involved, although other immunological mechanisms can also participate, especially in haematological abnormalities, such as immune haemolytic anaemia or thrombocytopoenia. Aside from their frequency, the clinical entities reported nowadays have changed little since penicillin was first used. The variation in beta-lactams consumption through the year has modified the pattern and specificities of allergic reactions for IgE and T cell responses. Benzylpenicillin is no longer the beta-lactams most frequently prescribed and other chemical structures, with new or modified haptens, have progressively replaced it. This is relevant for the diagnostic evaluation and management of beta-lactam hypersensitivity.

Anti-Bacterial Agents↗
PubMed2005

IFNAR1 and IFNAR2 polymorphisms confer susceptibility to multiple sclerosis but not to interferon-beta treatment response.

We investigated the role of three polymorphisms in the IFNAR1 (SNPs 18417 and -408) and IFNAR2 (SNP 11876) genes in multiple sclerosis (MS) susceptibility and in the IFNbeta treatment response in a group of 147 patients and 210 controls undergoing interferon therapy during the last 2 years. Only the 18417 and the 11876 SNPs showed an association with disease susceptibility (p=0.001 and 0.035, respectively) although no differential genotype distribution were observed between interferon responders and non-responder MS patients. No alteration of the expression level of IFNAR-1 was observed with respect to the -408 genotypes or to interferon treatment response. These data suggest a role for the IFNAR pathway in susceptibility to MS.

Adolescent↗
PubMed2005

Cephalosporin chemical reactivity and its immunological implications.

PURPOSE OF REVIEW: The aim of this article is to analyze the chemical reactivity of cephalosporins resulting in the epitope responsible for recognition by IgE antibodies and to establish the basis of the allergenicity. RECENT FINDINGS: Increasing evidence supports the role of cephalosporins in IgE hypersensitivity reactions. Third and fourth generation cephalosporins appear to be more involved in specific IgE reactions and often no cross-reactivity with traditional benzyl penicillin determinants exists. In some instances selective responses to unique cephalosporins occur and in others common side-chain similarities exist. SUMMARY: Lack of knowledge of the exact chemical structure of cephalosporin antigenic determinants has hindered clinical interpretation of allergic reactions to these drugs and hampered understanding of the specific recognition by IgE molecules of these determinants. Data indicate that R2 is not present in the final conjugate and that recognition by IgE antibodies is mainly directed to the R1 acyl side chain and to the beta-lactam fragment that remains linked to the carrier protein in the cephalosporin conjugation process.

Cephalosporins↗
PubMed2003

Improvement of toxic epidermal necrolysis after the early administration of a single high dose of intravenous immunoglobulin.

BACKGROUND: Toxic epidermal necrolysis (TEN) is a severe disease often induced by drugs. Treatment is controversial, although intravenous immunoglobulins (IVIGs) have been effective. OBJECTIVE: To report the case of a child with TEN after lamotrigine treatment, who improved 24 hours after IVIG administration. METHODS: Sequential blood and blister fluid samples were obtained for flow cytometry and reverse transcriptase-polymerase chain reaction analyses. RESULTS: The first blood sample, taken before IVIG administration, showed normal levels of lymphocyte subsets and CLA (4.0%) but high levels of activated lymphocytes (CD69) (18.0%). After treatment, the CLA+, CD69+, and memory cells increased until day 7, decreasing to normal values at days 15 and 30. In the blister fluid samples, taken on day 1, there were high levels of CD8+ (70.2%; CD4/CD8 ratio, 1:5), CLA+ (18.8%), and CD69+ (70%) cells, decreasing 24 hours after IVIG administration. In the blood samples, there was a Th1 cytokine pattern initially, tending to Th0 with time. Perforin, granzyme B, and Fas ligand were only observed before IVIG administration. CONCLUSIONS: A single high dose of IVIG interrupted the progression of skin disease and reduced the expression of the apoptotic markers. The immunologic changes, first seen in blister fluid and remaining several days in peripheral blood, indicate that T cells were first recruited to the skin and then recirculated to blood.

Anticonvulsants↗
PubMed2003

Immediate allergy to tetanus toxoid vaccine: determination of immunoglobulin E and immunoglobulin G antibodies to allergenic proteins.

BACKGROUND: Adverse reactions to tetanus toxoid (TT) vaccine are mostly mild and limited to the injection site. However, immunoglobulin (Ig)E-mediated reactions may occur, and the incidence of anaphylactic responses to TT immunization is 0.001%. When TT induces an allergic reaction, the potential causative agents can be TT antigens, thimerosal or aluminum phosphate. OBJECTIVE: We studied four children who developed immediate urticaria after TT vaccine, soon after the reaction and 5 years later. METHODS: Skin tests were performed separately with TT vaccine and two vaccine components, thimerosal and aluminum phosphate, and the diagnosis was confirmed by provocation test. IgE and IgG antibodies to TT and their specificities were determined. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis and immunoblotting were performed to characterize the antigenic proteins. RESULTS: All four children were immediate skin test-positive to TT, but negative to thimerosal and aluminum phosphate; 3 developed a reaction after intramuscular provocation using increasing doses of TT vaccine; and 1 refused to be tested. All these tests were negative in five controls, all of whom received TT vaccine and developed only local swelling at the site of application 24 hours after vaccine administration. After 5 years the IgG antibodies were still high in all cases and the IgE antibody values fell by 50%. Patients allergic to TT vaccine produced IgE and IgG antibodies, which decreased at different rates but remained for at least 5 years. The pattern of antibody decrease was confirmed by radioallergosorbent test, enzyme-linked immunoadsorbent assay, or immunoblotting assay. IgE and IgG antibodies recognized two proteins derived from TT, of 150 and 50 kDa, corresponding to the intracellular form and to a chain of the extracellular form of the tetanus neurotoxin. CONCLUSIONS: In children with immediate allergic reactions to TT vaccine, antibodies may persist for at least 5 years, requiring evaluation by skin and/or in vitro tests before subsequent treatment.

Adolescent↗
PubMed2002

Combination therapy with interferon beta-1b and azathioprine in secondary progressive multiple sclerosis. A two-year pilot study.

Combination therapy may benefit the subgroup of patients with secondary progressive multiple sclerosis (SPMS) who do not respond to interferon beta (IFNB). We performed a two-year study of azathioprine (AZA) combined with IFNB-1b in SPMS patients who had not responded well to IFNB-1b alone. Patients with SPMS were eligible for this non-controlled prospective study if they had two or more relapses requiring corticosteroid treatment or deteriorated by at least 0.5 points on the Expanded Disability Status Scale (EDSS) while on IFNB-1b in the year preceeding the study. Patients were to continue treatment with IFNB-1b (8 MIU qod, subcutaneous) and received AZA (50 mg tid, oral). Safety was assessed in terms of adverse reactions and laboratory measures graded according to the WHO toxicity scale. Efficacy was explored by changes in relapse rate, EDSS, 9-hole peg test (9-HPT), neuropsychological scores, and magnetic resonance imaging (MRI) results. Neutralizing antibodies (NAB) were measured. Ten SPMS patients (6 females) with a median EDSS score of 4.5 were enrolled. One patient withdrew because of gastrointestinal complaints, one was withdrawn owing to poor compliance, and 8 patients completed therapy. The only frequent side effect was lymphopenia, reported at least once in all patients. Annual relapse rate was reduced by approximately 50 % in the second year. There was a significant trend for EDSS increase. Total lesion load measured by MRI decreased at 12 and 24 months; only one patient had active lesions. No changes were seen in the 9-HPT. There was a significant improvement in neuropsychological tests after 24 months ( p = 0.045). One patient tested positive for NAB throughout the study, and transient NAB were detected in 4 patients. In conclusion, combination therapy with IFNB-1b and AZA was safe and generally well tolerated in patients with SPMS. Strict clinical and laboratory monitoring is recommended during this combination therapy.

Adjuvants, Immunologic↗
PubMed2002

Boosted IgE response after anaphylaxis reaction to cefuroxime with cross-reactivity with cefotaxime.

BACKGROUND: Cefuroxime is a second-generation lactamase-stable cephalosporin. Its use is on the increase, and in recent years several reactions to this compound have been reported. OBJECTIVE: To describe a case of selective reaction to cefuroxime, showing a boosted immunoglobulin (Ig)E response after administration of this drug. METHODS: Specific serum IgE antibodies to several cephalosporins were monitored in a 52-year-old man after a selective systemic anaphylaxis attributable to cefuroxime, who showed a good tolerance to penicillin V during a single-blind, placebo-controlled challenge. RESULTS: Specific IgE levels to cefuroxime were not detected at the moment of the reaction but became positive 1 day after, increasing to peak at day 51, and still positive after 115 days. Through radioallergosorbent test inhibition, cross-reactivity between cefuroxime and cefotaxime was demonstrated. CONCLUSIONS: IgE-mediated reaction attributable to cefuroxime with cross-reactivity to cefotaxime was reported. A prompt evaluation undertaking skin tests and additional radioallergosorbent test studies with different betalactam derivatives improves the evaluation of subjects with allergic reactions to betalactams.

Anaphylaxis↗
PubMed2002

Delayed reactions to drugs show levels of perforin, granzyme B, and Fas-L to be related to disease severity.

BACKGROUND: Drugs can induce different immunologic reactions; T-cell mediated responses produce the most severe reactions. Although in vitro studies show that T cells recognize drugs or their metabolites and induce an effector cytotoxic response, direct in vivo evidence of involvement is lacking. T lymphocytes produce cytotoxic markers that are responsible for 2 major pathways to cell death: granule-mediated exocytosis (perforin and granzyme B) and Fas/FasL interaction. OBJECTIVE: The purpose of this investigation was to establish the role of proinflammatory TNF-alpha and cytotoxic markers in subjects with delayed responses to drugs. METHODS: We assessed expression levels by quantitative-competitive PCR of TNF-alpha, perforin, granzyme B, and FasL in mononuclear cells from peripheral blood and blister fluid from subjects with delayed reactions to drugs. Samples were obtained within 24 hours of the reaction and 30 days later. Fifteen patients were included and classified according to severity of the reaction, as follows: (A) maculopapular exanthema, (B) desquamative exanthema, (C) Stevens-Johnson syndrome, (D) toxic epidermal necrolysis. RESULTS: At the acute stage, there was a large increase in TNF-alpha (9-fold), perforin (6-fold), and GrB (7-fold) in patients in comparison with control subjects. FasL was expressed in PBMCs only in Stevens-Johnson syndrome and toxic epidermal necrolysis. A high association between cytotoxic markers and disease severity was seen (P <.001). CONCLUSION: our data show that TNF-alpha, perforin, GrB, and FasL are increased in the early stage of disease, suggesting that a cytotoxic mechanism might be taking part. These findings support the role of T cells in allergic drug reactions and provide further clues pertaining to therapeutic interventions.

Adult↗
PubMedDate not supplied

Synthesis, characterization and immunochemical evaluation of cephalosporin antigenic determinants.

Lack of knowledge of the exact chemical structure of cephalosporin antigenic determinants has hindered clinical interpretation of adverse reactions to these drugs and delayed understanding of the mechanisms involved in the specific recognition and binding of IgE molecules to these antigenic determinants. We further resolve the relationship between structure and activity of proposed antigenic chemicals, including the rational design and synthesis of these haptenic structures. Comparative RAST inhibition studies of the synthesized molecules revealed that they were recognized by IgE antibodies induced by cephalosporin antibiotics. Thus, these data indicate that recognition is mainly directed to the acyl side chain and to the beta-lactam fragment that remains linked to the carrier protein in the cephalosporin conjugation course.

Adult↗
PubMedDate not supplied

Gene expression levels of cytokine profile and cytotoxic markers in non-immediate reactions to drugs.

Drugs can induce IgE mediated or T cell dependent immunological reactions. T cell dependent reactions are poorly understood, although T lymphocytes have been proposed as a protagonist in a number of non-immediate immunological reactions (NIR). The objective was to study in vivo different regulatory and proinflammatory cytokines and cytotoxic markers in patients with NIR to drugs. Twenty patients with NIR after drug intake were classified into two groups: Group A (severe), Stevens-Johnson syndrome and toxic epidermal necrolysis; and Group B (mild), maculopapular exanthema and desquamative exanthema. Another 25 subjects taking the same drugs but without reactions formed a control group. Samples were obtained within 24 hours of the reaction and 30 days later. IL-2, IL-4, IFN, TNF, perforin, granzyme B (GrB), and FasL mRNA expression levels were determined in peripheral blood mononuclear cells by competitive RT-PCR. There were 9 patients in Group A and 11 in Group B. The drugs involved were betalactams (8), anticonvulsants (6), allopurinol (1), sulfamethoxazole (1), amiodarone (1) dypirone (2), and erythromicine+paracetamol (1). At the acute stage there was a high increase of IL-2, IFN, and TNF mRNA expression in both groups vs. controls, perforin and GrB varied in each group with patients in Group A having the highest values, and FasL was only expressed in Group A. Relationships between the cytokines were only significant in Group B (p < 0.05). Only the relation between IFN-gamma and TNF-alpha was significant in Group A. There was a significant correlation between cytotoxic markers in both groups (A: p < 0.001, B: p < 0.01). These data demonstrate the complexity of the Th1 phenotype in NIR after drug intake. In patients with mild NIR, cytokines appear to play a closely related role, whereas cytotoxic markers appear more relevant in severe reactions.

Adult↗
PubMedDate not supplied

Dendrimers as carrier protein mimetics for IgE antibody recognition. Synthesis and characterization of densely penicilloylated dendrimers.

The synthesis of benzylpenicilloyl-containing dendrimers has been achieved by a convenient procedure involving quantitative functionalization of the terminal amino groups of the three Starbust PAMAM generations used (G(n); n = 0, 1, 2). All these densely penicilloylated dendrimers (G(n)P) exhibit similar, simple NMR spectroscopic data suggesting highly symmetric structures and a monodisperse nature, and the results obtained from MALDI-TOF-MS demonstrate their exact chemical composition. The use of PAMAM dendrimers has allowed us to synthesize, for the first time, carrier benzylpenicilloyl conjugates (G(n)P) of precisely defined chemical structure. The attempts to synthesize G(2)P show that forced experimental conditions are not always useful for the functionalization of the dendrimer, especially in introducing bulky groups. The initial results with sera from patients with different RAST levels were positive and thus suggestive that inhibition occurs, so recognition exists; we can therefore conclude that the hapten-carrier (dendrimer) conjugates studied mimic recognition with natural hapten-carrier (protein) conjugates.

Benzeneacetamides↗