RESUMO

Clinical improvement has been described in AIDS patients submitted to zinc therapy, but the mechanisms involved are not well understood. In order to evaluate the effect of the zinc ions in the enhancement of the immune response, we tested its role in the lymphoproliferative response to a mitogen, as well as in the prevention of apoptosis. The mitogenic effect of zinc (10(-4)M ZnCl2) on the lymphocyte proliferative response was observed in healthy controls as well as in HIV-1+ asymptomatic individuals. Very low stimulation index could be observed in AIDS patients (CD4+<200/mm3). However, zinc treatment of phytohaemagglutinin (PHA; 5 microg/ml)-stimulated PBMC cultures significantly enhanced 3H-thymidine incorporation in both asymptomatic and symptomatic groups. A decreased percentage of apoptotic cells could be identified in cell cultures from HIV-1+ individuals submitted to zinc treatment compared with cells treated only with PHA, as detected by both flow cytometry and agarose gel electrophoresis. Further studies with zinc supplementation associated to anti-retroviral therapy would be of great interest to evaluate the in vivo role of this oligoelement in the improvement of the immunological functions of HIV-1-infected individuals and AIDS patients.

Assuntos

RESUMO

Recent reports have indicated the possibility that HIV-2 has been introduced into groups at risk for AIDS in Brazil. We studied sera collected in 1987 and 1988 from 1,821 at-risk individuals from diverse regions in Brazil. Of the 1,821 sera, 367 (20%) were confirmed as being positive for HIV-1 antibodies by enzyme-linked immunosorbent assay (ELISA), immunofluorescence (IF), and Western blot. An additional 33 (2%) sera displayed some reactivity to HIV-2-infected cells by IF. All 33 sera were subsequently tested in HIV-1 and HIV-2 Western blots as well as an ELISA using HIV-1- or HIV-2-specific peptides. All sera were confirmed as positive for HIV-1 and negative for HIV-2 antibodies in both assays. We conclude that caution should be used in the interpretation of serologic cross-reactivity between HIV-1 and HIV-2 and that there is no evidence that HIV-2 has entered groups at risk for HIV infection in Brazil.

Assuntos

RESUMO

Os soros de 472 brasileiros, confirmados como sendo positivos ou negativos em relacao a presenca de anticorpos anti-HIV e compreendendo todo o espectro clinico da infeccao, foram utilizados na avaliaco de seis ensaios imunoenzimaticos comerciais (ELISA), bem como de quatro testes alternativos tais como imunofluorescencia indireta (IFI), hemaglutinacao passiva (HP), dot blot e Karpas AIDS cell test. As sensibilidades variaram de 100 por cento (ELISA Abbott e Roche) a 84,2 por cento (HP) e as especificidades variaram de 99,3 por cento (IFI) a 80,2 por cento (HP). A sensibilidade e especificidade da HP e a sensibilidade do Karpas AIDS cell test foram significativamente menores que os outros ensaios. Embora a IFI e o dot blot tivessem apresentado uma boa sensibilidade e especificidade, os ensaios imunoenzimaticos (ELISA) foram mais adequados para serem utilizados em triagem quando outros parametros tais como facilidade de leitura e interpretacao dos resultados e duracao dos ensaios foram considerados

Assuntos

RESUMO

Sera from 472 Brazilian subjects, confirmed to be either positive or negative for HIV antibodies and comprising the total clinical spectrum of HIV infection, were utilized in the evaluation of six commercially available enzyme-linked immunosorbent assays (ELISA), as well as of four alternative assays, namely indirect immunofluorescence (IIF), passive hemagglutination (PHA), dot blot and Karpas AIDS cell test. The sensitivities ranged from 100% (Abbott and Roche ELISA) to 84.2% (PHA) and the specificities ranged from 99.3% (IIF) to 80.2% (PHA). The sensitivity and specificity of the PHA and the sensitivity of the Karpas cell test were significantly lower than those of the other tests. Although the IFF and dot blot had good sensitivities and specificities, the six ELISA were more attractive than those tests when other parameters such as ease of reading and duration of assay were considered.

PIP: 6 commercially available ELISA kits and 4 new Brazilian made methods for detecting HIV were compared on 2 panels of sera, 292 from AIDS patients, HIV-positives and negatives, and 180 sera from asymptomatic blood donors, including 90 HIV-positives. The kits tested were 5 ELISAs: Roche Diagnostica (Basel), Hoechst Enzygnostic (Sao Paulo), Virgo Electronuclionics (Columbia MD), Organon Teknika (Boxtel, Netherlands), Salck Industria e Comercio de Produtos Biologicos (Sao Paulo), and a passive hemagglutination test, (Salck Ind), and indirect immunofluorescence IIF (Virgo electronucleonics, Columbia), a dot blot (Embrabio, Empressa Brasiliera de Biotecnologia Ltda, Sao Paolo) and Karpas AIDS cell test, Fujichemical Industries Ltd (Chokeiji, Takaoka, Japan). The sensitivities ranged from 84.2% to 100% with no significant differences in sera from panel A. In panel B, the sensitivity of the PHA test was significantly lower than that of the ELISA and the AIDS cell tests. The specificities of the PHA and the AIDS cell tests were also lower than that of the ELISA. The costs of all the tests were similar, but the equipment needs varied. The simplest tests to perform were the dot blot assay, PHA and Karpas AIDS cell test. The Hoechst ELISA is simpler because it does not require dilution of the serum. The dot takes too long for use in a blood bank, 16-18 hours. Immunofluorescence tests would be practical in countries already screening blood for malaria or Changes disease. Brazil is not doing so on a large scale due to lack of political will. In countries with high incidence of malaria, Chagas disease, leishmania, hepatitis and leprosy, HIV test need to be tested on local sera because of possible B cell activation.

Assuntos