RESUMO
Whole blood samples (N = 295) were obtained from different locations in Amazonas and Sucre States, in Venezuela. Malaria was diagnosed by microscopy, OptiMAL and polymerase chain reaction (PCR), with Plasmodium vivax, P. falciparum, and P. malariae being detected when possible. We identified 93 infections, 66 of which were caused by P. vivax, 26 by P. falciparum, and 1 was a mixed infection. No infection caused by P. malariae was detected. The sensitivity and specificity of each diagnostic method were high: 95.7 and 97.9% for microscopy, 87.0 and 97.9% for OptiMAL, and 98.0 and 100% for PCR, respectively. Most samples (72.2%) showed more than 5000 parasites/microL blood. The sensitivity of the diagnosis by microscopy and OptiMAL decreased with lower parasitemia. All samples showing disagreement among the methods were reevaluated, but the first result was used for the calculations. Parasites were detected in the 6 false-negative samples by microscopy after the second examination. The mixed infection was only detected by PCR, while the other methods diagnosed it as P. falciparum (microscopy) or P. vivax (OptiMAL) infection. Most of the false results obtained with the OptiMAL strip were related to the P. falciparum-specific band, including 3 species misdiagnoses, which could be related to the test itself or to genetic variation of the Venezuelan strains. The use of the microscopic method for malaria detection is recommended for its low cost but is very difficult to implement in large scale, population-based studies; thus, we report here more efficient methods suitable for this purpose.
Assuntos
Malária Falciparum/diagnóstico , Malária Vivax/diagnóstico , Parasitemia/diagnóstico , Plasmodium falciparum , Plasmodium vivax , Animais , Cromatografia/métodos , Doenças Endêmicas , Humanos , Malária Falciparum/epidemiologia , Malária Vivax/epidemiologia , Microscopia/métodos , Plasmodium falciparum/genética , Plasmodium falciparum/imunologia , Plasmodium vivax/genética , Plasmodium vivax/imunologia , Reação em Cadeia da Polimerase , Prevalência , Sensibilidade e Especificidade , Venezuela/epidemiologiaRESUMO
Whole blood samples (N = 295) were obtained from different locations in Amazonas and Sucre States, in Venezuela. Malaria was diagnosed by microscopy, OptiMAL and polymerase chain reaction (PCR), with Plasmodium vivax, P. falciparum, and P. malariae being detected when possible. We identified 93 infections, 66 of which were caused by P. vivax, 26 by P. falciparum, and 1 was a mixed infection. No infection caused by P. malariae was detected. The sensitivity and specificity of each diagnostic method were high: 95.7 and 97.9 percent for microscopy, 87.0 and 97.9 percent for OptiMAL, and 98.0 and 100 percent for PCR, respectively. Most samples (72.2 percent) showed more than 5000 parasites/æL blood. The sensitivity of the diagnosis by microscopy and OptiMAL decreased with lower parasitemia. All samples showing disagreement among the methods were reevaluated, but the first result was used for the calculations. Parasites were detected in the 6 false-negative samples by microscopy after the second examination. The mixed infection was only detected by PCR, while the other methods diagnosed it as P. falciparum (microscopy) or P. vivax (OptiMAL) infection. Most of the false results obtained with the OptiMAL strip were related to the P. falciparum-specific band, including 3 species misdiagnoses, which could be related to the test itself or to genetic variation of the Venezuelan strains. The use of the microscopic method for malaria detection is recommended for its low cost but is very difficult to implement in large scale, population-based studies; thus, we report here more efficient methods suitable for this purpose.
Assuntos
Animais , Humanos , Malária Falciparum/diagnóstico , Malária Vivax/diagnóstico , Plasmodium falciparum , Plasmodium vivax , Parasitemia/diagnóstico , Cromatografia/métodos , Doenças Endêmicas , Malária Falciparum/epidemiologia , Malária Vivax/epidemiologia , Microscopia/métodos , Reação em Cadeia da Polimerase , Prevalência , Plasmodium falciparum/genética , Plasmodium falciparum/imunologia , Plasmodium vivax/genética , Plasmodium vivax/imunologia , Sensibilidade e Especificidade , Venezuela/epidemiologiaRESUMO
Malaria antibody detection is valuable in providing retrospective confirmation of an attack of malaria. Blood bank screening is another area were malaria serology is potentially useful. In the present study, we tested the presence of antibodies to Plasmodium falciparum in sera from blood bank donors of non-endemic and malaria-endemic areas of Venezuela. Sera from 1,000 blood donors were tested by an indirect immunofluorescent antibody (IFA) assay and an IgG-ELISA for the presence of malaria antibodies using a synchronized in vitro-cultured Venezuelan isolate of P. falciparum as the antigen source. A selected group of positive and negative sera (n = 100) was also tested by a dot-IgG-ELISA. Positive results (reciprocal titer > or = 40) were found in 0.8% and 3.8% of blood donors when tested by the IFA assay and in 0.8% and 2% (optical density > or = 0.2) when tested by the IgG-ELISA in Caracas (non-endemic area) and Bolivar City (endemic area), respectively. The presence of anti-malarial antibodies in some sera from non-endemic areas such as Caracas reflects the increased potential risk of post-transfusional malaria in those areas due to the mobility of the blood donors. The data obtained indicate the need to implement new blood donor policy in blood banks in developing areas. Our results also indicate that the IFA assay is the most reliable test to use in malaria serodiagnosis.
Assuntos
Anticorpos Antiprotozoários/sangue , Doadores de Sangue , Portador Sadio/imunologia , Malária Falciparum/imunologia , Plasmodium falciparum/imunologia , Adolescente , Adulto , Animais , Antígenos de Protozoários/biossíntese , Bancos de Sangue , Western Blotting , Portador Sadio/epidemiologia , Ensaio de Imunoadsorção Enzimática , Reações Falso-Positivas , Feminino , Técnica Indireta de Fluorescência para Anticorpo , Humanos , Malária Falciparum/epidemiologia , Masculino , Pessoa de Meia-Idade , Plasmodium falciparum/isolamento & purificação , Curva ROC , Sensibilidade e Especificidade , Estatísticas não Paramétricas , Venezuela/epidemiologiaRESUMO
RESA-IFA assays were conducted using 63 adult sera from 7 different malarious areas against 7 different strains of Plasmodium falciparum, and 28 children's sera against 3 different parasite strains. Generally, where immunity to malaria was high, there was little or no antigenic diversity among the different strains examined. However, where sera were collected from semi-immunes, or from children, some variation in the RESA-IFA endpoint titers was discernible. Correlation between antibody titers determined by RESA-IFA and in vitro parasite invasion inhibition was not complete. Sera having high RESA-IFA titers were predictably inhibitory; however, many sera having low RESA-IFA titers were as inhibitory as sera having high titers, indicating that antibodies with specificities different from the RESA may be as important, or more important, to clinical immunity to blood-stage infections.
Assuntos
Anticorpos Antiprotozoários/análise , Antígenos de Protozoários/imunologia , Antígenos de Superfície/imunologia , Malária/imunologia , Plasmodium falciparum/imunologia , Proteínas de Protozoários , Adolescente , Adulto , Animais , Variação Antigênica , Burkina Faso , Criança , Pré-Escolar , Equador , Imunofluorescência , Humanos , Indonésia , Nigéria , SudãoRESUMO
Cryoprecipitates from systemic lupus erythematosus (SLE) patients with high levels of anti DNA antibodies show a sharply migrating large circulating DNA species of about 17-20 kb (M. Rieber et al., Clin. exp. Immunol. (1986) 66, 61). We have now used Southern blot analysis of circulating DNA from different individuals to analyse the relative cross-hybridization of circulating DNA from different individuals, as well as their homology with genomic DNA from different species. Molecular hybridization showed significant homology of the various circulating DNA examined, only with human genomic DNA, but limited cross-reactivity among circulating DNA from different individuals. This suggests that the circulating DNA is composed of sequences repeated in human genomic DNA and by specific sequences unique to circulating DNA from some individuals. Our data suggests the possibility of using probes derived from the specific sequences now reported in the circulating DNA, in gene typing and in the analysis of susceptibility to disease.
Assuntos
DNA/sangue , Lúpus Eritematoso Sistêmico/sangue , Sequência de Bases , Precipitação Química , Temperatura Baixa , Enzimas de Restrição do DNA/farmacologia , Desoxirribonuclease EcoRI , Desoxirribonuclease I/farmacologia , Eletroforese em Gel de Ágar , Humanos , Peso Molecular , Hibridização de Ácido Nucleico , Sequências Repetitivas de Ácido NucleicoRESUMO
Se estudio la respuesta inmunologica del compartimiento humoral en el suero sanguineo y humor acuoso en tres grupos de pacientes: Grupo I: pacientes con uveitis; Grupo II con enfermedad sistemica autoinmune sin uveitis, y Grupo III: control.Los resultados senalan alteraciones locales en este sentido encontrandose elevacion de la IgG e IgA en los pacientes del Grupo I asi como la presencia del factor B y C3, los cuales se reportan en forma original; los complejos inmunologicos fueron detectados por dos metodos, siendo significativos los resultados en el Grupo I