Assuntos
Autoanticorpos/sangue , Doadores de Sangue , Troponina I/sangue , Troponina T/sangue , Adolescente , Adulto , Idoso , Biomarcadores/sangue , Feminino , Humanos , Imunoglobulina G/sangue , Masculino , Pessoa de Meia-Idade , Valores de Referência , Sensibilidade e Especificidade , Adulto JovemRESUMO
We identified IgG reactive with human cardiac troponin-I (cTnI) in plasma and serum samples (N = 1930) from normal blood donors, and in sample cohorts characterized on the basis of clinical biomarkers associated with cardiac, infectious, and autoimmune diseases. cTnI and brain natriuretic peptide were the biomarkers chosen to reflect myocyte damage or left ventricular dysfunction, respectively. The infectious disease cohorts were serologically positive for antibodies to hepatitis B (natural infection), hepatitis C virus, and Chagas (i.e., T.cruzi). The autoimmune cohorts were represented by samples from diagnosed systemic lupus erythematosus (biomarker: dsDNA) and rheumatoid arthritis (biomarker: rheumatoid factor) subjects. The prevalence of IgG autoantibodies reactive with cTnI was high in the normal donor cohort (95/750, 12.7%). The prevalence in the other sample cohorts was not significantly different from that in the normal blood donors, with the exception of a slight increase in the rheumatoid factor cohort (28/137, 20.4%). The presence of anti-cTnI IgG in highly reactive samples was confirmed by inhibition with the antigen and further by screening with a library of peptides derived from the human cTnI amino acid sequence. Our data suggest that these autoantibodies are polyspecific, encompassing epitopes across the entire cTnI sequence, including the cardiac-specific amino terminal region.
Assuntos
Autoanticorpos/sangue , Imunoglobulina G/sangue , Troponina I/imunologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Sequência de Aminoácidos , Anticorpos Antivirais/sangue , Artrite Reumatoide/sangue , Artrite Reumatoide/imunologia , Doença de Chagas/sangue , Doença de Chagas/imunologia , Criança , Estudos de Coortes , Feminino , Hepatite B/virologia , Hepatite C/virologia , Humanos , Medições Luminescentes/métodos , Lúpus Eritematoso Sistêmico/sangue , Lúpus Eritematoso Sistêmico/imunologia , Masculino , Pessoa de Meia-Idade , Peptídeo Natriurético Encefálico/imunologia , Reprodutibilidade dos Testes , Troponina I/química , Adulto JovemAssuntos
Autoanticorpos/sangue , Imunoglobulina G/sangue , Troponina T/sangue , Troponina T/imunologia , Adolescente , Adulto , Idoso , Animais , Autoanticorpos/imunologia , Feminino , Humanos , Imunoglobulina G/imunologia , Masculino , Pessoa de Meia-Idade , Troponina I/sangue , Troponina I/imunologia , Adulto JovemRESUMO
Hydrogen peroxide generated from the enzymatic oxidation of choline was detected using a chemiluminescent acridinium-9-carboxamide. The dose-response for choline (0-50 microM) was established in buffer and was applicable to the quantification of choline in human plasma. This homogeneous assay was performed in a 96-well microplate format and required minimal sample volume (1 microL) and analysis time (<5 s per well).
Assuntos
Acridinas/química , Colina/sangue , Colina/química , Peróxido de Hidrogênio/análise , Medições Luminescentes/métodos , Betaína/síntese química , Humanos , Estrutura Molecular , Oxirredução , Sensibilidade e Especificidade , Fatores de TempoRESUMO
Choline was oxidized in the presence of choline oxidase and the hydrogen peroxide generated was detected using a chemiluminescent acridinium-9-carboxamide. The dose response for choline (0-150 microM) was established in buffer and was validated for the quantification of choline in human plasma and whole blood. This homogeneous assay was performed in a 96-well microplate format and required minimal sample volume (4 microL) and short analysis time (<5s per well). The new assay(s) correlated well (R>0.98, plasma; R>0.97, whole blood) with LC-MS/MS.
