RESUMO
In a collaborative study involving 7 laboratories, sera from 53 patients with lung cancer, 37 primary and 16 secondary tumours, and sera of 40 healthy blood donors were tested by 19 different assays or assay modifications used for detecting immune complexes. In 12 out of 19 assays, significantly higher immune complex levels were found in the cancer patients than in the healthy subjects. Assays based on interactions between immune complexes and Fc receptors of different cells (lymphocytes, macrophages of platelets) discriminated between cancer patients and health subjects and a high percentage (47-87%) of positivity was observed in such assays in patients with lung cancer. In contrast, none of the tests based on immune complex-complement interactions discriminated between cancer patients and health subjects. Immunochemical analyses of the PEG precipitates obtained from the sera tested revealed that the concentrations of IgG, IgA and C3 were significantly higher in the precipitates obtained from patients sera than from control sera, but no significant differences were seen in IgM and C1q concentrations. A 100% correct classification of individuals tested was obtained on discriminant analysis of results with 3 assays: EA rosette inhibition, ADCC inhibition and C3 concentration in PEG precipitates. Correlation between results obtained with individual sera by the different assays was very poor: significant correlation coefficients were found in only 13% of all possible paired comparisons. Our results suggest that Fc receptor-dependent assays are more suitable for detection and measurement of circulating immune complexes in lung cancer than tests based on interactions with complement.
Assuntos
Complexo Antígeno-Anticorpo , Neoplasias Pulmonares/imunologia , Adenocarcinoma/imunologia , Adulto , Idoso , Citotoxicidade Celular Dependente de Anticorpos , Carcinoma de Células Escamosas/imunologia , Fenômenos Químicos , Físico-Química , Enzimas Ativadoras do Complemento , Complemento C1q , Proteínas do Sistema Complemento/metabolismo , Feminino , Humanos , Neoplasias Pulmonares/secundário , Masculino , Pessoa de Meia-Idade , Polietilenoglicóis/farmacologia , Receptores Fc , Formação de Roseta , Estatística como AssuntoRESUMO
Circulating immune complex (CIC) levels were serially studied in healthy subjects and in normal rats. In human 3 methods (Clq solubility, complement consumption, and granulocyte phagocytosis tests) were used for the measurement of CIC; in rats, CIC levels were determined by the modified complement consumption test. A marked fluctuation in the CIC level was observed both in healthy human subjects and in normal rats. No correlation between results of the 3 assays used for CIC detection was found indicating that not only the level but the composition of CIC changes continuously in health.
Assuntos
Complexo Antígeno-Anticorpo/análise , Animais , Enzimas Ativadoras do Complemento/metabolismo , Complemento C1q , Proteínas do Sistema Complemento/metabolismo , Ácido Edético/farmacologia , Humanos , Fagocitose , Polietilenoglicóis/farmacologia , Ratos , Ratos EndogâmicosRESUMO
An improved ADCC assay for the detection of cancer-associated serum blocking factors is described. Inhibition of ADCC by sera was performed without preincubation and washing of effector cells. Effects of individual susceptibility of normal effector cells to serum inhibitors and of the background inhibition by normal sera were also avoided. Based on their inhibitory effect on ADCC, normal and tumour sera from lung cancer patients could be distinguished with 81.4 to 100% accuracy, according to effector cell donors and to concentrations of the sera tested.
Assuntos
Citotoxicidade Celular Dependente de Anticorpos , Antígenos de Neoplasias , Neoplasias Pulmonares/imunologia , Animais , Ligação Competitiva , Galinhas , HumanosRESUMO
Sera from 53 patients with unresectable lung cancer were tested for the presence of immune complexes by 12 assays. 5 assays (EA rosette inhibition, ADCC inhibition, platelet aggregation, IgG and C3 concentrations in PEG precipitates) could discriminate cancer patients from healthy subjects with over 80% reliability. On the basis of 3 assays (EA-I, ADCC-I and PEG-C3) a function allowing a 100% correct classification could be formulated:--(EA-I)--0.5 (ADCC-I) + 2.4 (PEG-C3) greater than 69.3, i.e., results higher than 69.3 are characteristic for cancer patients and lower than 69.3 for normal subjects. The relationship between the immune complex levels and the average survival time was not altered by sex, age, histology and treatment. None of the immune complex assays or their combination were useful for the estimation of individual life expectation.