RESUMO
Introducción: Se ha demostrado la participación de moléculas de adhesión, tanto en eritrocitos con hemoglobina SS, como en el endotelio vascular; así como factores plasmáticos en el fenómeno de vasoclusión en la drepanocitosis. La banda 3 se refiere a una familia de intercambiadores aniónicos presentes en la membrana de todas las células y organelos celulares, las que bajo ciertas condiciones se agregan en la superficie del eritrocito y son reconocidos por anticuerpos naturales como parte del mecanismo de eliminación de eritrocitos senescentes u oxidados. Objetivo: Evaluar la posible participación de los anticuerpos naturales antibanda 3 en el fenómeno oclusivo en la drepanocitosis. Métodos: Se realizó la determinación seriada de anticuerpos naturales antibanda 3 en 19 enfermos con drepanocitosis en diferentes estadios clínicos mediante un ensayo inmunoenzimático en microplacas acopladas con la proteína banda 3. Resultados: Se demostró una disminución significativa (p < 0.01) de anticuerpos naturales antibanda 3 en las muestras de los enfermos obtenidas en las fases de crisis vasoclusiva dolorosa, disminución que pudiera estar relacionada con un consumo elevado de estos en el proceso de eliminación de eritrocitos SS oxidados de la circulación sanguínea. Las muestras en estado basal se mantuvieron dentro de los límites normales. Conclusión: Los resultados sugieren la participación de los anticuerpos naturales antibanda 3 como elemento regulador de la no adhesión de los eritrocitos SS al endotelio vascular en esta enfermedad(AU)
Introduction : The involvement of adhesion molecules in erythrocytes with hemoglobin SS, in vascular endothelium and also plasma factors have been shown in the vasoocclusion phenomenon in sickle cell anemia (SCA). Band 3 refers to a family of anion exchangers present in the membrane of all cells and cellular organelles which under certain conditions cluster on the erythrocyte surface being recognized by natural antibodies as part of the mechanism of removal of senescent or oxidized erythrocytes. Objective : To evaluate the possible participation of natural anti band 3 antibodies in the occlusive phenomenon in SCA. Methods : A follow up study to determine the presence of natural band 3 antibodies in 19 patients with SCA in different clinical stages was performed using an enzyme immunoassay in microplates coupled with the band 3 protein. Results : Significant low levels (p<0.01) of natural band 3 antibodies were demonstrated in the samples of patients obtained in painful vasoocclusive crisis stages, decrease which may be related to a high consumption of antibodies in the process of removing oxidized SS erythrocytes from blood circulation. Steady state samples were within normal range. Conclusion: The results suggest the involvement of natural band 3 antibodies in the regulation of the adherence of SS erythrocytes to vascular endothelium in SCA(AU)
Assuntos
Humanos , Masculino , Feminino , Anticorpos , Traço Falciforme/imunologia , Estudos Transversais SeriadosRESUMO
BACKGROUND AND OBJECTIVE: Periodontal diseases are associated with bacterial challenge and the host immune response, and are also modulated by genetic factors. There is evidence that sickle cell anaemia (SCA) does not represent a risk factor for periodontal diseases. However, it is still unclear whether the heterozygous condition [sickle cell trait (SCT)] is associated with periodontal diseases. SCT is a genetic condition that can cause vaso-occlusive events, which may be associated with a propensity to bacterial infections. The aim of this study was to investigate the association of SCA and SCT with periodontal diseases by evaluating clinical and radiographic characteristics. MATERIAL AND METHODS: The sample (n = 369) was selected and divided into two groups: exposed groups [HbSS (SCA genotype) and HbAS (SCT genotype) = 246] and a nonexposed group (HbAA = 123). HbAA consisted of individuals without SCA and SCT. The clinical parameters evaluated were plaque index, gingival index, calculus index, clinical probing depth, clinical attachment level, gingival recession, tooth mobility and furcation involvement. The percentage of alveolar bone loss was measured using a Schei ruler. Binomial and Poisson regressions were used to estimate correlations of interest (α = 0.05). RESULTS: None of the periodontal parameters was associated with SCA. SCT was associated with gingivitis (p = 0.041) and periodontitis (p = 0.002). Individuals with SCT had a lower plaque index (p = 0.044) but a higher calculus index (p = 0.003) and greater alveolar bone loss (p = 0.010) compared with subjects in the HbAA group. CONCLUSIONS: SCT can act as a predictor for establishment of periodontal diseases. There was no correlation between SCA and periodontal diseases.
Assuntos
Anemia Falciforme/complicações , Anemia Falciforme/imunologia , Doenças Periodontais/complicações , Doenças Periodontais/imunologia , Traço Falciforme/complicações , Traço Falciforme/imunologia , Adolescente , Adulto , Perda do Osso Alveolar/complicações , Anemia Falciforme/genética , Brasil , Criança , Pré-Escolar , Estudos de Coortes , Cálculos Dentários , Índice de Placa Dentária , Feminino , Genótipo , Retração Gengival/complicações , Gengivite/complicações , Hemoglobina A/análise , Hemoglobina Falciforme/análise , Humanos , Masculino , Pessoa de Meia-Idade , Perda da Inserção Periodontal/complicações , Índice Periodontal , Bolsa Periodontal/complicações , Periodontite/complicações , Periodontite/imunologia , Fatores de Risco , Traço Falciforme/genética , Mobilidade Dentária/complicaçõesRESUMO
OBJECTIVE: Despite penicillin prophylaxis and vaccination, infection with encapsulated organisms remains a leading cause of morbidity and death in children with sickle cell disease. The role of Fc receptors in the clearance of encapsulated organisms is well documented. The His(H)-Arg(R) polymorphism at amino acid 131 of the Fc gamma RIIA receptor alters binding affinity for human IgG2 and influences infection with encapsulated organisms in children without sickle cell disease. We hypothesized that the genotype for high-affinity human IgG2 binding (H/H131) is underrepresented in children with sickle cell disease who had encapsulated organism infection. DESIGN: We studied 60 black children with sickle cell disease from four participating centers who had a history of encapsulated organism infection. Genomic DNA from peripheral blood was subjected to amplification by polymerase chain reaction and to sequence analysis for identification of the Fc gamma RIIA genotype, and the genotype distribution was then compared with our data from ethnically matched control subjects. RESULTS: Contrary to our hypothesis, the H/H131 genotype was overrepresented in all individuals (p = 0.046) and in particular in the 11 individuals with a history of Haemophilus influenzae type b infection (64% H/H131, 27% H/R131, 9% R/R131; p = 0.002), in comparison with ethnically matched control subjects (14% H/H131, 60% H/R131, 26% R/R131). In the 51 individuals with a history of Streptococcus pneumoniae infection, the genotype distribution was not statistically significantly different from that of the control population. CONCLUSIONS: The H/H131 Fc gamma RIIA genotype is overrepresented in black children with sickle cell disease and a history of H. influenzae type b infection but not in those with S. pneumoniae infection.
Assuntos
Anemia Falciforme/genética , Antígenos CD/genética , População Negra/genética , Infecções por Haemophilus/genética , Infecções Oportunistas/genética , Infecções Pneumocócicas/genética , Polimorfismo Genético/genética , Receptores de IgG/genética , Adolescente , Adulto , Anemia Falciforme/imunologia , Criança , Pré-Escolar , Feminino , Genótipo , Infecções por Haemophilus/imunologia , Humanos , Lactente , Masculino , Infecções Oportunistas/imunologia , Infecções Pneumocócicas/imunologia , Reação em Cadeia da Polimerase , Fatores de Risco , Traço Falciforme/genética , Traço Falciforme/imunologiaRESUMO
A 57-year-old black man with sickle cell disease was admitted to the hospital because of a painful crisis. After a fall with a fracture into the right knee joint, he developed an acutely painful, swollen knee. Synovial fluid from the right knee showed leukocyte counts of up to 154,000/mm3 and was negative for urate and calcium pyrophosphate dihydrate crystals. Gram stains and cultures were negative. Some sickled red cells were seen by light microscopy; electron microscopy revealed crystal-like arrays of sickled hemoglobin tactoids in erythrocytes which were enfolded and phagocytized by the cells of the synovial fluid. We suggest that this phagocytosis of sickled red cells is the likely cause for the otherwise unexplained inflammation.
Assuntos
Artrite/complicações , Fraturas Ósseas/etiologia , Articulação do Joelho , Traço Falciforme/complicações , Traço Falciforme/imunologia , Exsudatos e Transudatos , Humanos , Traumatismos do Joelho , Masculino , Pessoa de Meia-Idade , Osteoartrite/complicaçõesRESUMO
The role of haemolysis in producing deficient complement function in homozygous sickle cell disease was studied by measuring indices of complement activation and of haemolysis in 30 asymptomatic patients. Plasma concentration of C3d (an index of increased C3 turnover) was elevated in 40 percent of patients and modest decreases in serum concentration of C3 and functionally (haemolytically) active factor B were found. There was a positive correlation between C3d and plasma haemoglobin concentration (r = 0.56, p less than 0.005). Reticulocyte count and foetal haemoglobin concentration also contributed to variation in C3d, though to a lesser extent than plasma haemoglobin. Intravascular haemolysis in sickle cell disease may produce activation of complement and thus cause partial depletion of functional factor B and C3. This may reduce the immune function of the alternative pathway. (AU)
Assuntos
Humanos , Adolescente , Adulto , Pessoa de Meia-Idade , Masculino , Feminino , Anemia Falciforme/imunologia , Ativação do Complemento , Hemoglobinas/análise , Traço Falciforme/imunologia , Proteínas do Sistema Complemento/análise , Complemento C3/análise , Testes Hematológicos , Hemólise , Análise de Regressão , Traço Falciforme/sangueRESUMO
Sickled erythrocytes served as a marker for maternal blood in a cell transfer study of placentas from uncomplicated term pregnancies of women with sicklemia. The incidence of concurrent sickling in maternal and fetal blood was 100% in the 44 cases examined. Maternofetal passage of the erythrocytes was found four times more frequently in umbilical or chorionic veins (8.4%) than in arteries (1.9%). Deported chorionic villi were found in the veins in three of 44 cases but not in the arteries. These findings indicate fresh maternofetal leakage of blood during the third stage of labor.