Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 11 de 11
Filtrar
Más filtros











Intervalo de año de publicación
1.
Immunol Res ; 72(4): 864-873, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-38834764

RESUMEN

Ataxia-telangiectasia (AT) is a rare genetic disorder leading to neurological defects, telangiectasias, and immunodeficiency. We aimed to study the clinical and immunological features of Latin American patients with AT and analyze factors associated with mortality. Referral centers from 9 Latin American countries participated in this retrospective cohort study, and 218 patients were included. Median (IQR) ages at symptom onset and diagnosis were 1.0 (1.0-2.0)  and 5.0 (3.0-8.0) years, respectively. Most patients presented recurrent airway infections, which was significantly associated with IgA deficiency. IgA deficiency was observed in 60.8% of patients and IgG deficiency in 28.6%. T- and B-lymphopenias were also present in most cases. Mean survival was 24.2 years, and Kaplan-Meier 20-year-survival rate was 52.6%, with higher mortality associated with female gender and low IgG levels. These findings suggest that immunologic status should be investigated in all patients with AT.


Asunto(s)
Ataxia Telangiectasia , Humanos , Femenino , Masculino , América Latina/epidemiología , Ataxia Telangiectasia/mortalidad , Ataxia Telangiectasia/inmunología , Ataxia Telangiectasia/diagnóstico , Estudios Retrospectivos , Niño , Preescolar , Adulto , Adolescente , Lactante , Síndromes de Inmunodeficiencia/mortalidad , Síndromes de Inmunodeficiencia/epidemiología , Síndromes de Inmunodeficiencia/inmunología , Adulto Joven
2.
J. pediatr. (Rio J.) ; 91(4): 373-379, July-Aug. 2015. tab
Artículo en Inglés | LILACS | ID: lil-759341

RESUMEN

OBJECTIVES: To evaluate the association between oxidative and inflammatory stress markers with peri-intraventricular hemorrhage (PIVH) in very-low birth weight newborns.METHODS: This was a prospective study conducted in a level III neonatal unit. Basal and stimulated reactive oxygen intermediates (ROIs), reduced glutathione (GSH), and interleukin-6 (IL-6) levels were measured in umbilical cord blood. Newborns underwent serial ultrasound at the bedside, at 6, 12, 24, and 72 hours of life and at seven days for the diagnosis of PIVH, classified as grades I to IV. Two groups were assessed, those with and without PIVH; maternal and neonatal control variables were used for comparison. Univariate and multiple regression analyses were applied.RESULTS: A total of 125 newborns were assessed. PIVH incidence rate was 12.0%. In the univariate analysis, basal ROI, the use of two or more doses of corticosteroids, birth weight < 1,000 g, ventilatory support use, and SNAPPE II value ≥ 22 were significantly associated with PIVH. However, in the multivariate analysis, only antenatal steroid use was independently associated with the disease (OR 0,194; 95% CI: 0,048 to 0,773; p=0,02).CONCLUSION: ROI, GSH, and IL-6 levels were not associated with the occurrence of PIVH in very-low birth weight infants.


OBJETIVOS: Avaliar a associação entre marcadores de estresse oxidativo e inflamatório com a hemorragia peri- e intraventricular (HPIV) em recém-nascidos (RN) de muito baixo peso ao nascer.MÉTODOS: Estudo prospectivo em unidade neonatal nível III. Foi feita dosagem em sangue de cordão umbilical de intermediários reativos de oxigênio (ROI) basal e estimulado, glutationa reduzida (GR) e interleucina-6 (IL-6). Recém-nascidos foram submetidos a ultrassonografia seriada, à beira do leito, com seis, 12, 24 e 72 horas de vida e sete dias para o diagnóstico de HPIV, classificada em graus de I a IV. Foram avaliados dois grupos: com e sem HPIV e variáveis de controle maternas e neonatais foram usadas para comparação. Análise univariada e de regressão múltipla foram aplicados.RESULTADOS: Foram avaliados 125 recém-nascidos. A taxa de incidência de HPIV foi de 12%. Na análise univariada o valor basal de ROI, o uso de duas ou mais doses de corticosteroide, peso ao nascer menor do que 1.000 g, o uso de assistência respiratória e valor de SNAPPE II maior ou igual a 22 foram significativamente associados à HPIV. Porém, na análise multivariada, apenas o uso antenatal de esteroides se mostrou independentemente associado à doença (OR 1,94 IC95% 0,048-0,773 p = 0,02).CONCLUSÃO: ROI, GR e Il-6 não foram associados à ocorrência de HPIV em RN de muito baixo peso ao nascer.


Asunto(s)
Femenino , Humanos , Recién Nacido , Masculino , Ventrículos Cerebrales , Hemorragia Cerebral/sangre , Sangre Fetal , Glutatión/sangre , Estrés Oxidativo/fisiología , Especies Reactivas de Oxígeno/análisis , Corticoesteroides/farmacología , Biomarcadores/sangre , Hemorragia Cerebral , Ventrículos Cerebrales , Recién Nacido de muy Bajo Peso , Inflamación/metabolismo , /sangre , Estrés Oxidativo/efectos de los fármacos , Estudios Prospectivos , Sustancias Protectoras/farmacología
3.
J Pediatr (Rio J) ; 91(4): 373-9, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-25913045

RESUMEN

OBJECTIVES: To evaluate the association between oxidative and inflammatory stress markers with peri-intraventricular hemorrhage (PIVH) in very-low birth weight newborns. METHODS: This was a prospective study conducted in a level III neonatal unit. Basal and stimulated reactive oxygen intermediates (ROIs), reduced glutathione (GSH), and interleukin-6 (IL-6) levels were measured in umbilical cord blood. Newborns underwent serial ultrasound at the bedside, at 6, 12, 24, and 72hours of life and at seven days for the diagnosis of PIVH, classified as grades I to IV. Two groups were assessed, those with and without PIVH; maternal and neonatal control variables were used for comparison. Univariate and multiple regression analyses were applied. RESULTS: A total of 125 newborns were assessed. PIVH incidence rate was 12.0%. In the univariate analysis, basal ROI, the use of two or more doses of corticosteroids, birth weight<1,000g, ventilatory support use, and SNAPPE II value ≥ 22 were significantly associated with PIVH. However, in the multivariate analysis, only antenatal steroid use was independently associated with the disease (OR 0,194; 95% CI: 0,048 to 0,773; p=0,02). CONCLUSION: ROI, GSH, and IL-6 levels were not associated with the occurrence of PIVH in very-low birth weight infants.


Asunto(s)
Hemorragia Cerebral/sangre , Ventrículos Cerebrales , Sangre Fetal , Glutatión/sangre , Estrés Oxidativo/fisiología , Especies Reactivas de Oxígeno/análisis , Corticoesteroides/farmacología , Biomarcadores/sangre , Hemorragia Cerebral/diagnóstico por imagen , Ventrículos Cerebrales/diagnóstico por imagen , Femenino , Humanos , Recién Nacido , Recién Nacido de muy Bajo Peso , Inflamación/metabolismo , Interleucina-6/sangre , Masculino , Estrés Oxidativo/efectos de los fármacos , Estudios Prospectivos , Sustancias Protectoras/farmacología , Ultrasonografía
4.
J Allergy Clin Immunol ; 133(4): 1134-41, 2014 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-24679470

RESUMEN

BACKGROUND: Severe combined immunodeficiency (SCID) is a syndrome characterized by profound T-cell deficiency. BCG vaccine is contraindicated in patients with SCID. Because most countries encourage BCG vaccination at birth, a high percentage of patients with SCID are vaccinated before their immune defect is detected. OBJECTIVES: We sought to describe the complications and risks associated with BCG vaccination in patients with SCID. METHODS: An extensive standardized questionnaire evaluating complications, therapeutics, and outcomes regarding BCG vaccination in patients given a diagnosis of SCID was widely distributed. Summary statistics and association analysis was performed. RESULTS: Data on 349 BCG-vaccinated patients with SCID from 28 centers in 17 countries were analyzed. Fifty-one percent of the patients had BCG-associated complications, 34% disseminated and 17% localized (a 33,000- and 400-fold increase, respectively, over the general population). Patients receiving early vaccination (≤1 month) showed an increased prevalence of complications (P = .006) and death caused by BCG-associated complications (P < .0001). The odds of experiencing complications among patients with T-cell numbers of 250/µL or less at diagnosis was 2.1 times higher (95% CI, 1.4-3.4 times higher; P = .001) than among those with T-cell numbers of greater than 250/µL. BCG-associated complications were reported in 2 of 78 patients who received antimycobacterial therapy while asymptomatic, and no deaths caused by BCG-associated complications occurred in this group. In contrast, 46 BCG-associated deaths were reported among 160 patients treated with antimycobacterial therapy for a symptomatic BCG infection (P < .0001). CONCLUSIONS: BCG vaccine has a very high rate of complications in patients with SCID, which increase morbidity and mortality rates. Until safer and more efficient antituberculosis vaccines become available, delay in BCG vaccination should be considered to protect highly vulnerable populations from preventable complications.


Asunto(s)
Vacuna BCG/efectos adversos , Inmunodeficiencia Combinada Grave/epidemiología , Vacuna BCG/inmunología , Preescolar , Comorbilidad , Femenino , Trasplante de Células Madre Hematopoyéticas , Humanos , Lactante , Recién Nacido , Estimación de Kaplan-Meier , Masculino , Prevalencia , Estudios Retrospectivos , Riesgo , Inmunodeficiencia Combinada Grave/diagnóstico , Inmunodeficiencia Combinada Grave/terapia , Vacunación/efectos adversos , Vacunación/legislación & jurisprudencia
5.
J Pediatr (Rio J) ; 89(1): 40-7, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-23544809

RESUMEN

OBJECTIVE: To compare the immunologic state of 44 pediatric patients with cystic fibrosis (CF) with a control group consisting of 16 healthy individuals. METHODS: CF patients aged 3 to 12 years with moderate to good clinical score were selected for the study. Erythrocytic glutathione, production of reactive oxygen species, cytokines (TNF-a, IFN-g, IL-8, IL-6, IL-10) in peripheral blood mononuclear cells cultures under spontaneous and BCG- or PHA-stimulated conditions, serum concentrations of TGF-b2, IgA, IgG, IgM, IgE, and salivary IgA were evaluated. RESULTS: The spontaneous production of TNF-a, IL-6, and IL-10, the PHA-stimulated production of IL-6, and the serum TGF-b2, IgA, and IgG were increased in samples from CF patients. Healthy subjects had a higher production of TNF-a in response to BCG. CONCLUSION: Although CF patients appeared clinically stable, the results of their peripheral blood examinations demonstrated an impact on the immune system.


Asunto(s)
Fibrosis Quística/inmunología , Citocinas/biosíntesis , Glutatión/biosíntesis , Inmunoglobulinas/sangre , Estudios de Casos y Controles , Técnicas de Cultivo de Célula , Niño , Preescolar , Estudios Transversales , Fibrosis Quística/sangre , Ensayo de Inmunoadsorción Enzimática , Femenino , Humanos , Mediadores de Inflamación/sangre , Leucocitos Mononucleares/química , Masculino , Monitorización Inmunológica , Especies Reactivas de Oxígeno/sangre , Saliva/inmunología , Factor de Crecimiento Transformador beta2/sangre
6.
J. pediatr. (Rio J.) ; 89(1): 40-47, jan.-fev. 2013. ilus, tab
Artículo en Portugués | LILACS | ID: lil-668824

RESUMEN

OBJETIVO: Comparar o estado imunológico de 44 pacientes pediátricos com fibrose cística (FC)a umgrupo-controle formado por 16 indivíduos saudáveis. MÉTODOS: Foram selecionados para o estudo pacientes com FC com idade entre 3 e 12 anos, apresentando um escore clínico moderado e bom. Foram avaliados a glutationa eritrocitária, a produção de espécies reativas de oxigênio, citocinas (TNF-α, IFN-γ, IL-8, IL-6, IL-10) em culturas de células mononucleares do sangue periférico em condições espontâneas e estimuladas por BCG ou PHA, a concentração sérica de TGF-β2, IgA, IgG, IgM, IgE e IgA salivar. RESULTADOS :A produção espontânea de TNF-α, IL-6 e IL-10, a produção de IL-6 estimulada por PHA e TGF-β2, IgA e IgG séricas aumentaram em amostras de pacientes com FC. Indivíduos saudáveis tiveram uma produção mais elevada de TNF-α em resposta a BCG. CONCLUSÃO: Apesar de os pacientes com FC parecerem clinicamente estáveis, os resultados de seus exames de sangue periférico mostraram que houve um impacto sobre o sistema imunológico.


OBJECTIVE: To compare the immunologic state of 44 pediatric patients with cystic fibrosis (CF) with a control group consisting of 16 healthy individuals. METHODS: CF patients aged 3 to 12 years with moderate to good clinical score were selected for the study. Erythrocytic glutathione, production of reactive oxygen species, cytokines (TNF-α, IFN-γ, IL-8, IL-6, IL-10) in peripheral blood mononuclear cells cultures under spontaneous and BCG- or PHA-stimulated conditions, serum concentrations of TGF-β2, IgA, IgG, IgM, IgE, and salivary IgA were evaluated. RESULTS: The spontaneous production of TNF-α, IL-6, and IL-10, the PHA-stimulated production of IL-6, and the serum TGF-β2, IgA, and IgG were increased in samples from CF patients. Healthy subjects had a higher production of TNF-α in response to BCG. CONCLUSION: Although CF patients appearedclinically stable, the results of their peripheral blood examinations demonstrated an impact on the immune system.


Asunto(s)
Niño , Preescolar , Femenino , Humanos , Masculino , Fibrosis Quística/inmunología , Citocinas/biosíntesis , Glutatión/biosíntesis , Inmunoglobulinas/sangre , Estudios de Casos y Controles , Técnicas de Cultivo de Célula , Estudios Transversales , Fibrosis Quística/sangre , Ensayo de Inmunoadsorción Enzimática , Mediadores de Inflamación/sangre , Leucocitos Mononucleares/química , Monitorización Inmunológica , Especies Reactivas de Oxígeno/sangre , Saliva/inmunología , /sangre
7.
J Pediatr (Rio J) ; 88(1): 61-6, 2012.
Artículo en Inglés | MEDLINE | ID: mdl-22344368

RESUMEN

OBJECTIVE: To investigate the association between antenatal maternal corticosteroid administration and blood levels of reactive oxygen intermediates (ROI), reduced glutathione (GR) and interleukin-6 (IL-6) in preterm, very low birth weight infants. METHODS: This was a cohort study in which cord blood samples were used for the following tests: baseline and stimulated granulocyte ROI were measured by flow cytometry; GR was assayed by spectrophotometry; and IL-6 by enzyme-linked immunosorbent assay. Two different comparative analyses of antenatal corticosteroid (betamethasone) were conducted: the first compared administration against no administration and the second compared mothers who received the complete cycle with those given only a partial antenatal corticosteroid cycle. Maternal and neonatal variables were analyzed in order to compare groups. Categorical variables were compared using the chi-square or Fischer tests, and blood marker test results were compared using the Mann-Whitney test. RESULTS: The different corticoid therapy groups were similar in terms of all of the maternal and neonatal variables with the exception of vaginal delivery, which was significantly associated with not receiving antenatal corticosteroid. The results for ROI, GR and IL-6 did not differ when the comparison was based on simple presence or absence of administration of the steroid. However, when the complete cycle was compared against incomplete administration, median ROI and IL-6 were lower among those given the complete cycle. CONCLUSION: Administration of the complete cycle of betamethasone to the mother had a suppressive effect on baseline ROI and IL-6 production in very low birth weight preterm newborn infants.


Asunto(s)
Betametasona/administración & dosificación , Sangre Fetal , Glucocorticoides/administración & dosificación , Recién Nacido de muy Bajo Peso/sangre , Inflamación/sangre , Estrés Oxidativo , Atención Prenatal/métodos , Adolescente , Adulto , Biomarcadores/sangre , Relación Dosis-Respuesta a Droga , Métodos Epidemiológicos , Femenino , Glutatión/sangre , Humanos , Inmunosupresores/administración & dosificación , Recién Nacido , Recien Nacido Prematuro , Interleucina-6/sangre , Masculino , Embarazo/efectos de los fármacos , Especies Reactivas de Oxígeno/sangre , Adulto Joven
8.
J. pediatr. (Rio J.) ; 88(1): 61-66, jan.-fev. 2012. tab
Artículo en Portugués | LILACS | ID: lil-617051

RESUMEN

OBJETIVO: Avaliar a associação entre o uso materno antenatal de corticosteroide e os níveis sanguíneos de intermediários reativos de oxigênio (ROI), glutationa reduzida (GR) e interleucina-6 (IL-6) em recém-nascidos pré-termo de muito baixo peso ao nascer. MÉTODOS: Estudo de coorte. A dosagem foi feita em sangue de cordão umbilical. A dosagem de ROI por granulócitos foi realizada por citometria de fluxo nos estados basal e estimulado; a GR, por espectrofotometria; e a IL-6, por enzyme-linked immunosorbent assay. Foram considerados dois grupos em relação ao uso de corticosteroide (betametasona) antenatal: uso ou não da medicação; e, se presente, se foi de modo completo ou parcial. Variáveis maternas e neonatais foram consideradas para efeito de comparação dos grupos. As variáveis categóricas foram comparadas usando os testes do qui-quadrado ou de Fischer, e as comparações dos valores dos marcadores sanguíneos foram feitas usando-se o teste de Mann-Whitney. RESULTADOS: Os grupos de corticoterapia foram comparáveis em relação às variáveis maternas e neonatais, exceto a ocorrência de parto vaginal, o qual foi associado significativamente à ausência de uso de corticosteroide antenatal. Os valores de ROI, GR e IL-6 não se mostraram diferentes quando se avaliou a presença ou ausência da administração de esteroide; porém, quando o ciclo se fez de modo completo, encontraram-se menores medianas de ROI e IL-6. CONCLUSÃO: A administração de ciclo completo de betametasona à mãe exerceu um efeito supressor sobre a produção basal de ROI e de IL-6 em recém-nascidos pré-termo de muito baixo peso.


OBJECTIVE: To investigate the association between antenatal maternal corticosteroid administration and blood levels of reactive oxygen intermediates (ROI), reduced glutathione (GR) and interleukin-6 (IL-6) in preterm, very low birth weight infants. METHODS: This was a cohort study in which cord blood samples were used for the following tests: baseline and stimulated granulocyte ROI were measured by flow cytometry; GR was assayed by spectrophotometry; and IL-6 by enzyme-linked immunosorbent assay. Two different comparative analyses of antenatal corticosteroid (betamethasone) were conducted: the first compared administration against no administration and the second compared mothers who received the complete cycle with those given only a partial antenatal corticosteroid cycle. Maternal and neonatal variables were analyzed in order to compare groups. Categorical variables were compared using the chi-square or Fischer tests, and blood marker test results were compared using the Mann-Whitney test. RESULTS: The different corticoid therapy groups were similar in terms of all of the maternal and neonatal variables with the exception of vaginal delivery, which was significantly associated with not receiving antenatal corticosteroid. The results for ROI, GR and IL-6 did not differ when the comparison was based on simple presence or absence of administration of the steroid. However, when the complete cycle was compared against incomplete administration, median ROI and IL-6 were lower among those given the complete cycle. CONCLUSION: Administration of the complete cycle of betamethasone to the mother had a suppressive effect on baseline ROI and IL-6 production in very low birth weight preterm newborn infants.


Asunto(s)
Adolescente , Adulto , Femenino , Humanos , Recién Nacido , Masculino , Embarazo , Adulto Joven , Betametasona/administración & dosificación , Sangre Fetal , Glucocorticoides/administración & dosificación , Recién Nacido de muy Bajo Peso/sangre , Inflamación/sangre , Estrés Oxidativo , Atención Prenatal/métodos , Biomarcadores/sangre , Relación Dosis-Respuesta a Droga , Métodos Epidemiológicos , Glutatión/sangre , Recien Nacido Prematuro , Inmunosupresores/administración & dosificación , /sangre , Especies Reactivas de Oxígeno/sangre
9.
AIDS ; 25(17): 2079-87, 2011 Nov 13.
Artículo en Inglés | MEDLINE | ID: mdl-21866040

RESUMEN

OBJECTIVE: To evaluate cell-mediated immune response to Bacillus Calmette-Guérin (BCG) vaccination in uninfected, HIV-1-exposed infants, comparing it with unexposed children. DESIGN: It is designed as a cross-sectional study. METHODS: BCG-specific lymphoproliferation and T-cell subsets (CD4(+), CD8(+) and TCR γδ(+)) by flow cytometry and interleukin-10, interferon-γ (IFN-γ) and tumor necrosis factor-α (TNF-α) concentration by ELISA were analyzed in HIV-exposed and unexposed infants. Whole blood lymphocyte immunophenotyping and blood counts were performed in exposed children. Nonparametric tests were used (P < 0.05). RESULTS: Given the ontogeny of the immune system, exposed infants were separated into three groups according to age: exposed 1 (E1, aged 6.1-8.8 months), E2 (aged 9.1-17.1 months) and E3 (aged 18.1-26.3 months). Unexposed infants (UE group) and E1 were matched for age. Cell proliferation was not different among the three exposed groups, neither for BCG nor for phytohemagglutinin (PHA)-stimulated cultures. Furthermore, BCG-stimulated lymphoproliferation was reduced in the E1 group in comparison with the UE group. T-lymphocyte subpopulations also showed differences, with the youngest HIV-exposed groups (E1 and E2) showing a predominant proliferation of CD4(+) T cells in cultures with BCG, whereas E3 and UE groups had a robust γδ(+) T-cell expansion. There was lower IFN-γ concentration in the samples from E1 group in comparison with all of the other groups. The unexposed infants showed higher TNF-α concentration in cultures with BCG and PHA in comparison with E1 group. CONCLUSION: BCG-specific T-cell proliferation was reduced in HIV-exposed uninfected infants and IFN-γ concentration was lower in younger exposed infants, showing a delay in immune system maturation of HIV-exposed infants.


Asunto(s)
Vacuna BCG/inmunología , Linfocitos T CD4-Positivos/inmunología , Linfocitos T CD8-positivos/inmunología , Seropositividad para VIH/inmunología , VIH-1/inmunología , Interferón gamma/sangre , Factor de Necrosis Tumoral alfa/sangre , Biomarcadores/sangre , Estudios de Casos y Controles , Preescolar , Estudios Transversales , Ensayo de Inmunoadsorción Enzimática , Femenino , Citometría de Flujo , Humanos , Inmunofenotipificación , Lactante , Interleucina-10/sangre , Activación de Linfocitos , Masculino , Receptores de Antígenos de Linfocitos T gamma-delta/sangre
10.
Artículo en Inglés | MEDLINE | ID: mdl-19264724

RESUMEN

HIV-1 infection has increased among women in recent years. The HIV-1 env gene (structural gene) has the greatest variation in all the HIV gene regions. In this study, 58 samples from infants infected with HIV-1 via perinatal transmission were analyzed. All the 58 samples were submitted to Nested-polymerase chain reaction of the env gene region for posterior viral genotyping using EN 70 and EN 85 (first polymerase chain reaction) and EN 80 and EN 95 (second polymerase chain reaction) primers, with the product of the 682 base pair amplification. After Nested-polymerase chain reaction for genotyping, purification of the product, and direct sequencing in a MegaBace 1000 automatic sequencer, 56 genotypes were found in the 58 HIV-1-positive children of the study, where 47 (83.93%) were HIV-1 subtype B infected and 9 (16.07%) were HIV-1 subtype F1 infected. The results demonstrate the predominance of subtype B followed by subtype F in Southeast Brazil.


Asunto(s)
Genes env , Infecciones por VIH/epidemiología , VIH-1/clasificación , VIH-1/genética , Transmisión Vertical de Enfermedad Infecciosa , Secuencia de Bases , Brasil/epidemiología , Genotipo , Infecciones por VIH/transmisión , Infecciones por VIH/virología , VIH-1/aislamiento & purificación , Humanos , Lactante , Datos de Secuencia Molecular , Reacción en Cadena de la Polimerasa , Prevalencia , Análisis de Secuencia de ADN
11.
Rev. bras. alergia imunopatol ; 18(6): 223-7, nov.-dez. 1995. tab
Artículo en Portugués | LILACS | ID: lil-163277

RESUMEN

As plaquetas podem estar envolvidas na fisiopatologia da asma liberando mediadores inflamatórios e/ou espasmogênicos, bem como interagindo com outras células inflamatórias. O objetivo deste trabalho foi investigar a agregaçao plaquetária de crianças com asma crônica grave. Foram selecionadas 16 crianças entre 7 e 15 anos de idade, tratadas com brocodilatadores inalatórios e beclometasona (no máximo 750 mug/dia). Doadores de sangue foram selecionados como controles-sadios. Plasma em plaquetas (PRP) e plasma pobre em plaquetas (PPP) foram preparados de acordo com procedimento padrao. A agregaçao de plaquetas foi estudada em agregômetro Payton de dois canais, calibrados com PRP (0 por cento) e PPP (100 por cento) segundo a transmitância de luz. Os estímulos utilizados para induzir a agregaçao plaquetária foram adrenalina (1-30 muM) ou adenosina bifosfato (ADP,1-30 muM). Os resultados foram expressos como percentagem da transmitância máxima. As medianas da agregaçao plaquetária dos pacientes foram respectivamente (adrenalina/ADP 1,3,10 e 30 muM): 0/0, 30/48/41/52, 45/58. As medianas da agregaçao plaquetária dos controles-sadios foram respectivamente (adrenalina/ADP 1,3,10 e 30 muM): 0/0, 12/44, 29/65, 54/74. A análise estatística demontra que a agregaçao de plaquetas dos pacientes foi significativamente menor que a de controles-sadios quando o estímulo foi ADP nas concentraçoes 10 e 30 muM. Em contrapartida, frente aos estímulos adrenalina (1-30 muM) ou mesmo ADP em concentraçoes menores (1-3 muM), a agregaçao de plaquetas dos pacientes foi similar a de controles-sadios. Concluímos que plaquetas de crianças com asma crônica grave sao hiporresponsivas quando o estímulo é ADP em altas concentraçoes. Os mecanismos bioquímicos e molecular envolvidos nesse fenômeno encontram-se sob investigaçao.


Asunto(s)
Humanos , Masculino , Femenino , Niño , Adolescente , Agregación Plaquetaria/fisiología , Asma/fisiopatología , Adenosina Difosfato/efectos adversos , Asma/sangre , Enfermedad Crónica , Epinefrina/efectos adversos
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA