RESUMO
AECA were detected in 25 of 71 patients with type 1 diabetes mellitus and in two of 33 healthy subjects. Patients with diabetes of < 1 year duration and those with long-standing disease had the highest levels of these antibodies. Inhibition studies suggest that at least part of the AECA reactivity is due to cross-reactive anti-ssDNA antibodies. AECA-positive sera were able to increase intercellular adhesion molecule-1 (ICAM-1) and E-selectin on human umbilical vein endothelial cells (HUVEC). Increased binding of polymorphonuclear (PMN) cells was also found to accompany raised E-selectin expression. Soluble ICAM-1 and E-selectin were also found to be increased in the sera of AECA-positive patients. An effect of AECA on endothelial cell function is suggested in diabetes mellitus.
Assuntos
Autoanticorpos/sangue , Diabetes Mellitus Tipo 1/sangue , Endotélio Vascular/metabolismo , Imunoglobulina G/sangue , Molécula 1 de Adesão Intercelular/biossíntese , Adolescente , Adesão Celular/fisiologia , Células Cultivadas , Criança , Pré-Escolar , Diabetes Mellitus Tipo 1/imunologia , Selectina E/sangue , Endotélio Vascular/patologia , Humanos , Molécula 1 de Adesão Intercelular/sangue , Neutrófilos/patologia , Neutrófilos/fisiologiaRESUMO
Subjects with Down's syndrome have several immunological abnormalities. We examined the sera of 29 subjects with Down's syndrome for the presence of Fc gamma receptor blocking and for the presence of anti-ssDNA antibodies by EA rosette inhibition. Fifty-five percent of Down subjects had levels of inhibition above the upper limit of normality in comparison to 7% of normal controls. The finding that after polyethylene glycol precipitation of selected sera giving high levels of EA rosette inhibition there was a reduction or a disappearance of the EA rosette inhibition could indicate that the blocking factors detected behaved as immune complexes. Since almost all subjects with anti-ssDNA antibodies also had elevated values of EA rosette inhibition, a role for immune complexes eventually formed with autoantibodies in an Fc-mediated immunoregulatory system is suggested.
Assuntos
Síndrome de Down/sangue , Síndrome de Down/imunologia , Receptores de IgG/antagonistas & inibidores , Adolescente , Adulto , Animais , Anticorpos/análise , Complexo Antígeno-Anticorpo/análise , Complexo Antígeno-Anticorpo/imunologia , Precipitação Química , Galinhas , Criança , Pré-Escolar , DNA de Cadeia Simples/imunologia , Eritrócitos/imunologia , Humanos , Imunoglobulina A/metabolismo , Imunoglobulina G/imunologia , Imunoglobulina G/metabolismo , Imunoglobulina M/metabolismo , Lactente , Linfócitos/imunologia , Polietilenoglicóis/farmacologia , Receptores de IgG/imunologia , Receptores de IgG/metabolismo , Formação de RosetaRESUMO
A quantitative ELISA procedure using monoclonal and polyclonal antibodies against neoantigens of the terminal C5b-9 complement complex has been developed. The ELISA was demonstrated to be both sensitive and reproducible. The normal range for C5b-9 determinations, defined as 2.5-97.5% interval of the values obtained in 76 healthy blood donors, was 3.12-10.3 AU/ml. The presence of rheumatoid factor did not affect the determination of C5b-9 as demonstrated by immunoabsorption studies.
Assuntos
Complexo de Ataque à Membrana do Sistema Complemento/análise , Ensaio de Imunoadsorção Enzimática/métodos , Anticorpos Monoclonais , Artrite Reumatoide/sangue , Complexo de Ataque à Membrana do Sistema Complemento/imunologia , Humanos , Reprodutibilidade dos Testes , Fator Reumatoide/imunologia , Sensibilidade e EspecificidadeRESUMO
Antibody directed against insulin carries idiotypic determinants that may induce an auto-anti-idiotype (anti-Id) antibody response. We describe a solid-phase enzyme immunoassay which allows specific detection of IgG anti-Id directed against anti-insulin antibodies. Among 36 patients with type 1 diabetes, IgG anti-idiotype was detected in 21 (58%). An inverse significant correlation was found between titers of anti-idiotype and anti-insulin antibodies. These findings suggest that anti-idiotype antibodies may function to regulate the immune response to insulin. Whatever the mechanism of action of the anti-idiotype antibodies, we detected by ELISA, the clinical consequences and the theoretical implications of this determination may be important.
Assuntos
Anticorpos Anti-Idiotípicos/análise , Autoanticorpos/análise , Diabetes Mellitus Tipo 1/imunologia , Imunoglobulina G/análise , Anticorpos Anti-Insulina/imunologia , Animais , Galinhas/imunologia , Criança , Ensaio de Imunoadsorção Enzimática/métodos , Humanos , Valores de ReferênciaRESUMO
An ELISA was used to measure the fluid-phase complement complex in the plasma of 54 patients with insulin-dependent (type I) diabetes mellitus. Sixty-seven per cent of the diabetic patients had increased levels of SC5b-9. In individual diabetic patients, increased SC5b-9 was found to be significantly associated with the occurrence of anti-heparan sulphate cross-reactive anti-ssDNA antibodies and in some cases with circulating immune complexes. There was a significant correlation between levels of SC5b-9 and those of urinary albumin excretion rate (AER) (r = 0.39, P less than 0.01). Levels of AER were 8.4 +/- 2.26 micrograms/min and 2.04 +/- 0.35 micrograms/min in the SC5b-9 positive and negative patients, respectively (P less than 0.01). A relationship was also found between SC5b-9 and plasma von Willebrand Factor (r = 0.45, P less than 0.02), von Willebrand factor was 189.2 +/- 19.3% and 132.3 +/- 19.6% in SC5b-9 positive and negative patients, respectively (P less than 0.05). It may be that the abnormalities found in this study play a role in the pathogenesis of the late diabetic vascular complications.
Assuntos
Albuminúria/urina , Complexo de Ataque à Membrana do Sistema Complemento/análise , Diabetes Mellitus Tipo 1/sangue , Fator de von Willebrand/análise , Adolescente , Complexo Antígeno-Anticorpo/análise , Criança , Pré-Escolar , Ativação do Complemento , Proteínas do Sistema Complemento/análise , DNA de Cadeia Simples/análise , Diabetes Mellitus Tipo 1/urina , Ensaio de Imunoadsorção Enzimática , Humanos , LactenteRESUMO
C3 fixing IgA immune complexes were found to be elevated in 25% of patients with type 2 (non insulin-dependent) diabetes mellitus as compared to healthy subjects (2%). Immune complexes containing both IgA and IgG were found in 42% of the diabetic population but not in controls. The presence of C3-IgA and/or IgA/IgG immune complexes correlated with the occurrence of antiglobulins antibodies of IgA class in particular with autoantibodies reactive with the Fab2 portion of IgG. These immunopathological findings were more frequent in patients that exhibited microvascular complications and in particular in patients with proliferative retinopathy. These and our previous results strongly suggest a role of IgA system abnormality in the pathogenesis of diabetic vascular complications.
Assuntos
Anticorpos Anti-Idiotípicos/análise , Complexo Antígeno-Anticorpo/análise , Complemento C3/imunologia , Diabetes Mellitus Tipo 2/imunologia , Angiopatias Diabéticas/imunologia , Imunoglobulina A/análise , Fragmentos Fab das Imunoglobulinas/imunologia , Imunoglobulina G/análise , Complemento C3/análise , Diabetes Mellitus Tipo 2/sangue , Angiopatias Diabéticas/sangue , Humanos , Pessoa de Meia-Idade , Valores de ReferênciaRESUMO
In insulin-dependent diabetes mellitus (IDDM) several organ-specific autoantibodies are found in addition to pancreatic islet cell autoantibodies. In the present study we researched the presence of thyroid microsomal antibodies (anti-TMS) in 33 young patients with IDDM and evaluated contemporaneously their thyroid function. 5 patients (15.4%) are found with significant levels of circulating anti-TMS, among them 4 (12.1%) were also subclinical hypothyroid. However 6 other patients are found with mildly altered thyroid hormone pattern in absence of circulating anti-TMS. Basal and TRH-stimulated TSH were significantly higher, whereas serum FT4 was significantly lower, in patients with IDDM and circulating anti-TMS than in patients with IDDM but without anti-TMS. These observations indicate a significant incidence of mild or subclinical hypothyroidism in patients with IDDM and anti-TMS. Thus the screening for anti-TMS is recommended in all patients with IDDM, then thyroid hormone pattern of anti-TMS positive patients must be periodically followed.
Assuntos
Autoanticorpos/análise , Diabetes Mellitus Tipo 1/sangue , Microssomos/imunologia , Glândula Tireoide/imunologia , Tiroxina/sangue , Adolescente , Adulto , Criança , Doença Crônica , Diabetes Mellitus Tipo 1/imunologia , Feminino , Humanos , Masculino , Tireotropina/sangueRESUMO
Present study was carried out in order to control if glucose tolerance and insulin secretion changed during nicardipine treatment in healthy or in non-insulin dependent diabetics. In the 8th day of therapy with nicardipine (40 mg/day), glucose tolerance and insulin secretion were unmodified in a group of 20 non-diabetic patients. At the same time glucose tolerance was found improved in the group of 14 non-insulin dependent diabetic without a contemporary variation of insulin secretion. Such a result, note-worthy for a drug frequently administered to diabetics, could be due to inhibited glucagon secretion, or to increased glucose uptake by hepatocytes.