Serological confirmation of Chagas' disease by a recombinant and peptide antigen line immunoassay: INNO-LIA chagas.

Although screening for Trypanosoma cruzi antibodies is mandatory in most South American countries, current tests are insensitive and have poor specificity. A recently optimized line immunoassay (the INNO-LIA Chagas assay) for the serological confirmation of Chagas' disease was evaluated at a large blood bank in São Paulo, Brazil. Sera from blood donors who reacted in at least one of three serological screening assays (n = 1,604) and who returned for a follow-up were retested, and the donors were interviewed to assess their epidemiological risk. The results obtained by the confirmatory assay evaluated in this study were compared to those obtained by the three different screening assays. Upon consideration of the consensus results obtained by the three different screening assays as a "gold standard," the INNO-LIA Chagas assay showed a sensitivity of 99.4% (95% confidence interval [CI], 98.3 to 99.9) and a specificity of 98.1% (95% CI, 96.6 to 99.0) for positive (n = 503) and negative (n = 577) sera. The INNO-LIA Chagas assay confirmed the results for significantly larger numbers of positive samples of at-risk individuals independent of the number of positive screening tests (P = 0.017, Mantel-Haenszel test). In conclusion, the INNO-LIA Chagas assay reliably confirmed the presence of antibodies to T. cruzi and can be implemented as a confirmatory assay for Chagas' disease serology.

Chronic hepatitis C virus infections in brazilian patients: association with genotypes, clinical parameters and response to long term alpha interferon therapy

The present study assessed the clinical significance of hepatitis C virus (HCV) genotypes and their influence on response to long term recombinant-interferon-alpha (r-IFN-alpha) therapy in Brazilian patients. One hundred and thirty samples from patients previously genotyped for the HCV and with histologically confirmed chronic hepatitis C (CH-C) were evaluated for clinical and epidemiological parameters (sex, age, time of HCV infection and transmission routes). No difference in disease activity, sex, age or mode and time of transmission were seen among patients infected with HCV types 1, 2 or 3. One hundred and thirteen of them were treated with 3 million units of r-IFN-alpha, 3 times a week for 12 months. Initial response (IR) was significantly better in patients with genotype 2 (100%) and 3 (46%) infections than in patients with genotype 1 (29%) (p < 0. 005). Among subtypes, difference in IR was observed between 1b and 2 (p < 0.005), and between 1b and 3a (p < 0.05). Sustained response (SR) was observed in 12% for (sub)type 1a, 13% for 1b, 19% for 3a, and 40% for type 2; significant differences were found between 1b and 2 (p < 0.001), and between 1b and 3a (p < 0.05). Moreover, presence of cirrhosis was significantly associated with non response and response with relapse (p < 0.05). In conclusion, non-1 HCV genotype and lack of histological diagnosis of cirrhosis were the only baseline features associated with sustained response to treatment. These data indicate that HCV genotyping may have prognostic relevance in the responsiveness to r-IFN-alpha therapy in Brazilian patients with chronic HCV infection, as seen in other reports worldwide.

Human T-cell lymphotropic virus type 1 infection and ocular manifestations in São Paulo, Brazil.

OBJECTIVES: Although human T-cell lymphotropic virus type 1 (HTLV-1)-associated uveitis has been well recognized in Japan, related studies in Brazil are scarce. We performed a serologic survey for HTLV-1 infection among patients with uveitis and investigated the ocular findings in HTLV-1-asymptomatic carriers. METHODS: One hundred ninety serum samples from patients with uveitis of determined (n = 137) and undetermined origins (n = 53) being examined at the Uveitis Service, University of São Paulo, São Paulo, Brazil, underwent testing using HTLV enzyme-linked immunosorbent assay and discriminatory Western blots. One hundred five asymptomatic blood donors and/or their relatives who were seropositive for HTLV-1 (carrier group) and 105 age- and sex-paired blood donors who were seronegative for HTLV-1 (control group) underwent ocular evaluation. For the statistical analysis, chi2 test was used. RESULTS: Only 1 patient with uveitis was seropositive for HTLV- 1, and she belonged to the group with uveitis of undetermined origin. Results of tear films were evaluated in 52 carriers. The prevalence of a decreased tear break-up time was significantly higher in the carrier compared with the control group (P = .02). Two carriers had keratoconjunctivitis sicca. Three of the 105 carriers exhibited mild uveitis (cells in the vitreous, retinal and choroidal infiltrates, retinal vasculitis, and bilateral pars planitis). Retinal pigmentary changes were found in both groups (no statistical difference). CONCLUSIONS: Early tear abnormalities may be present in asymptomatic carriers, and mild uveitis may be found among them. The relatively low seroprevalence of HTLV-1 in the Brazilian population made it difficult to establish the real importance of HTLV-1-associated uveitis among our patients with uveitis.

Evaluation of the INNO-LIA HTLV I/II assay for confirmation of human T-cell leukemia virus-reactive sera in blood bank donations.

We have evaluated a new serological confirmatory test (INNO-LIA HTLV I/II Ab [INNO-LIA]) for human T-cell leukemia virus (HTLV) using a large collection of samples from Brazilian blood donors (São Paulo region) and compared the results with those obtained by Western blotting (WB) tests (WB2.3 and WB2.4). Blood donations were initially screened by enzyme-linked immunosorbent assays (ELISAs) based on viral lysates, and repeatedly reactive samples were further tested by WB2.3. When available, samples were also tested by PCR, two additional ELISAs based on recombinant antigens (recombinant ELISAs), a new-generation WB assay (WB2.4), and the INNO-LIA. Of the 18,169 samples tested, 292 (1.61%) were repeatedly reactive in the ELISAs (viral lysate based) and were further tested by WB2.3; 97 were positive (19 that were typed as HTLV type I [HTLV-I], 12 that were typed as HTLV type II [HTLV-II], and 66 that were nontypeable), 17 were negative, and 178 had indeterminate results. Of the samples with indeterminate results, 172 were tested by INNO-LIA, which could resolve 153 samples as negative. Regarding the positive samples, WB2. 3 and INNO-LIA produced concordant results for all HTLV-I-positive samples, whereas for HTLV-II they agreed for 10 of 12 samples; the 2 samples with discordant results were considered to be positive for HTLV-II by WB with WB2.3 but negative for HTLV-II by INNO-LIA and the two recombinant ELISAs. Furthermore, of the 66 nontypeable samples, 60 underwent testing by INNO-LIA; 54 turned out to be negative by the latter test as well as by recombinant ELISAs. In conclusion, the new serological confirmatory assay for HTLV (INNO-LIA HTLV I/II Ab) resolved the results for the majority of the indeterminate and positive-untypeable samples frequently observed by WB assays.

An improved, PCR-based strategy for the detection of Trypanosoma cruzi in human blood samples.

Attempts were made to improve the PCR-based detection of Trypanosoma cruzi in blood samples, primarily for screening blood donors. Samples were obtained from candidate donors who were reactive in one or two of three serological tests for Chagas disease (and therefore considered 'indeterminate') or in all three tests (3+). Each sample was then examined using three different, PCR-based techniques: 'PCR-I' (in which the target DNA is a nuclear repetitive sequence); 'PCR-II' [amplifying a conserved region of the T. cruzi kinetoplast DNA (kDNA)]; and 'PCR-III' (a new strategy in which the target kDNA is amplified by 'nested' PCR). Among the samples from 3+ individuals, PCR-I, PCR-II and PCR-III amplified two (3.8%) out of 52, four (4.5%) out of 88, and 27 (25.7%) out of 105 samples tested, respectively. Seven, 69 and 70 samples from 'indeterminate' subjects were tested by PCR-I, PCR-II and PCR-III, respectively; there was not a single positive result by PCR-I or PCR-II, but three (4.3%) of the samples tested by PCR-III were positive. In a reconstruction experiment, in conditions in which PCR-I and PCR-II could not detect 10,000 parasites/ml, PCR-III was able to detect one parasite/ml. Although all three PCR-based strategies examined had rather poor sensitivities, PCR-III was far more sensitive than PCR-I or PCR-II.

Evaluation of the performance of Brazilian blood banks in testing for Chagas' disease.

BACKGROUND AND OBJECTIVES: Due to the low sensitivity and reproducibility of available tests, in 1989 it became mandatory for all Brazilian blood donors to be screened for Chagas' disease by at least two serological techniques. In 1994 the Brazilian Ministry of health launched a program to systematically evaluate the quality of serological screening for the detection of blood-transmissible diseases as performed by public blood banks. METHODS: A blind panel containing positive samples for blood-transmissible disease was distributed to 57 major public blood banks in four sequential programs. RESULTS: The ELISA test was chosen by the majority of the blood banks. There were 64 (3.7%) false-negative results, 49 produced by banks using indirect hemagglutination. Since most blood banks screened with more than one test for Chagas, only 8 samples were actually missed, of which 3 were by banks using only one test. CONCLUSION: Our data show a clear improvement in performance of Brazilian blood banks testing for Chagas' disease.

[Control of blood transfusion malaria in an endemic and in a non-endemic region in Brazil]. / Controle da malária transfusional em região endêmica e não endêmica do Brasil.

The aim of the present work was to establish appropriate criteria for screening of donor blood from regions with distinct Malaria epidemiological characteristics. Three locations with different screening criteria were studied: São Paulo, SP (with no vectorial transmission), Belém, PA (with low active transmission) and Matupá and Peixoto de Azevedo, MT (with high active transmission). The Malaria parasite--Plasmodium sp--was searched for by "thick film", QBC Test and antigen Immunofluorescence test, and was not detected in any of the samples. There was, however, a great variation in the positivity of anti-plasmodial antibodies, as determined by IIF-IgG anti-P. vivax and -P. falciparum, between accepted donors in the 3 studied locations and between rejected and accepted donors in São Paulo (1.98% accepted, 22.3% rejected--p < 0.01) and Belém (17.2% accepted, 58.3% rejected--p < 0.01). These data endorse the use of the applied clinical and epidemiological screening. In Matupá and Peixoto de Azevedo, where there was no rejected donor, the serological positivity was 80.6%. We, therefore, consider that the Malaria screening in blood banks should follow clinical and epidemiological criteria suitable to each region. The laboratorial screening techniques should then detect either the parasites (thick film/QBC Test or the parasite antigens.

Hepatitis G virus: prevalence and sequence analysis in blood donors of São Paulo, Brazil.

BACKGROUND AND OBJECTIVES: Hepatitis G virus (HGV) is a recently discovered viral agent transmitted by blood, which was firstly identified in patients with acute or chronic liver disease. HGV prevalence in US blood donors was recently found to average 1-2%. We report a much higher HGV frequency among blood donors of São Paulo, Brazil. MATERIALS AND METHODS: 200 serum samples were submitted to RT-PCR using primers directed to the 5' untranslated region and nonstructural 5A (NS5A) region. PCR products were analyzed by gel electrophoresis and Southern blot hybridization. RESULTS: Of the 200 specimens, 18 (9%; 95% CI 5.4-13.8%) were positive by both sets of primers. Sequence analysis of the NS5A PCR products revealed a homology of 96.3%. Of the 18 HGV-positive samples, only one was positive for anti-HBc and all were anti-HCV- and HCV-RNA-negative. CONCLUSION: Such a high prevalence of HGV in a nonsymptomatic population suggests that this is a benign agent.

Controle da malária transfusional em região endêmica e não endêmica do Brasil / Control of blood transfusion malaria in an endemic and in a non-endemic region in Brazil

O presente trabalho teve como objetivo estabelecer critérios adequados à triagem de doadores de sangue de regiões com características epidemiológicas distintas, para malária. Foram estudados 3 locais com critérios de seleção diferentes: São Paulo, SP (sem transmissão vetorial), Belém (baixa transmissão ativa), Matupá, Belém, PA e Peixoto de Azevedo, MT (alta transmissão ativa). A pesquisa de plasmódios foi realizada por gota espessa, QBC Test® e imunofluorescência para pesquisa de antígenos, tendo sido todas as amostras negativas. Houve grande variação na positividade para anticorpos antiplasmodiais por IFI-IgG anti P. vivax e P. falciparum entre doadores aptos nos 3 locais de estudo e entre doadores aptos e inaptos em São Paulo (aptos 1,98%, inaptos 22,3%, p < 0.01) e Belém (aptos 17,2%, inaptos 58,3%, p < 0.01), o que atesta a validade da triagem clínico-epidemiológica realizada. Em Matupá e Peixoto de Azevedo não houve doadores inaptos e a positividade foi de 80,6%. Consideramos que em bancos de sangue a triagem deve seguir critérios clínico-epidemiológicos adequados à situação de cada região. Os métodos laboratoriais de triagem, devem ser para detecção de plasmódios (gota espessa/QBC Test® ou detecção de antígenos parasitários.

The aim of the present work was to establish appropriate criteria for screening of donor blood from regions with distinct Malaria epidemiological characteristics. Three locations with different screening criteria were studied: São Paulo, SP (with no vectorial transmission), Belém, PA (with low active transmission) and Matupá and Peixoto de Azevedo, MT (with high active transmission). The Malaria parasite--Plasmodium sp--was searched for by [quot ]thick film[quot ], QBC Test and antigen Immunofluorescence test, and was not detected in any of the samples. There was, however, a great variation in the positivity of anti-plasmodial antibodies, as determined by IIF-IgG anti-P. vivax and -P. falciparum, between accepted donors in the 3 studied locations and between rejected and accepted donors in São Paulo (1.98% accepted, 22.3% rejected--p < 0.01) and Belém (17.2% accepted, 58.3% rejected--p < 0.01). These data endorse the use of the applied clinical and epidemiological screening. In Matupá and Peixoto de Azevedo, where there was no rejected donor, the serological positivity was 80.6%. We, therefore, consider that the Malaria screening in blood banks should follow clinical and epidemiological criteria suitable to each region. The laboratorial screening techniques should then detect either the parasites (thick film/QBC Test or the parasite antigens.

Estimated Prevalence of Viral Hepatitis in the General Population of the Municipality of São Paulo, Measured by a Serologic Survey of a Stratified, Randomized and Residence-Based Population.

The present study was done to estimate the prevalence of Hepatitis A (HAV), B (HBV), C (HCV), and E (HEV) infection in the general population residing in the municipality of São Paulo, and to evaluate the level of knowledge related to the various modes of infection transmission by and protection against the different viruses. Blood samples and health questionnaires were collected from 1,059 individuals. The study design used an inductive method of predictive statistical inferences through randomized sampling stratified by Sex, age and residence region. The estimated prevalence rated found were: Hepatitis A = 66.59% (63.75%-69.44% CI); Hepatitis B = 5.94% (4.50%-7.35%); Hepatitis C = 1.42% (0,70%-2.12%); Hepatitis E = 1.68% (0.91%-2.46%). The frequency of hepatitis was similar in males and females. HAV showed an estimated prevalence of 56.16% in the population up to 17 years old, increasing to 65.30% in individuals between 18 and 29 years. The infection reached its peak of 90% in individuals 40 years of age or older. The study showed a greater tendency of dissemination of HBV among the population between 15 and 17 years. This specific age group showed an estimated prevalence of active infection of 1.04% (0.43%-1.65% CI), and also demonstrated an ascending level of acquired immunity with an estimated prevalence of 4.90% (3.60%-6.20% CI). HCV demonstrated an estimated prevalence of 1.42% (0.70%-2.12% CI). This specific infection occurred more frequently among adults 30 years of age or older, with the prevalence reaching a peak of 3.80% among the group aged 50 to 59 years. HEV showed zero prevalence among the age group between 2 and 9 years. This was followed by a slightly ascending rate starting from age 10, with an estimated prevalence of 1.05% (0.94%-3.04% CI) among those 10 to 14 years of age. This infection reached its peak of 3.00% (0.55%-6.74% CI) at the age of 60 years or older. Individuals with lower educational levels had a higher tendency of acquiring HAV and HCV, while there was no statistically significant difference for this parameter related to HBV and HEV. HBV occurred more frequently among inhabitants of the northern region of the city. All other hepatitis forms occurred at similar frequencies among the five regions of the city. Among the population, 1.90% (1.08%-2.72% CI) demonstrated an elevated hepatic enzyme with no serologic evidence indicating the cause was the viruses studied. This observation suggests the presence of other hepatic diseases, possibly including other viral diseases. It was also estimated that 75.12% of the city's population did not know the modes of transmission of hepatitis viruses and 76.70% did not know how to prevent them. This clearly suggests the need for a full-scale education program combined with public health measures regarding prevention of all forms of vial hepatitis.

Negligible prevalence of antibodies against Trypanosoma cruzi among blood donors in the southeastern United States.

Trypanosoma cruzi, a hemoflagellate, causes Chagas' disease and is endemic throughout Latin America. Increasing Latin American immigration to the United States has enhanced concern about transmission of Chagas' disease by infected donor blood. The insect vector and parasites also have been found in the southeastern United States. Autochthonous infection of several species of wild and domesticated mammals suggests that the general human population also may be at risk. To assess the prevalence of antibodies to T cruzi in humans, randomly selected donor blood was screened. Initial screening was performed by indirect hemagglutination (1:4 initial serum dilution) and at least one of three different enzyme immunoassays. All samples testing positive by at least one screening method were tested by radioimmunoprecipitation and indirect immunofluorescence supplemental methods, which were used for confirmation and calculation of specificity. Of the 6,013 serum samples evaluated, 85 tested positive by one screening method. Only 10 of the samples tested positive by more than one method. The percentages of positive screening tests are 0.05% by indirect hemagglutination and 0.06%, 0.91%, 3.97% by Abbott Laboratories (Abbott Park, Ill), Gull (Gull Laboratories, Salt Lake City, Utah), and Polychaco (Polychaco S.A.I.C., Buenos Aires, Argentina) enzyme immunoassays, respectively. All samples were negative by radioimmunoprecipitation and indirect immunofluorescence. These results suggest that although parasite and vector are found in the southeastern United States and both infect mammals, the risk of natural infection to humans in this region seems to be negligible. There was variation in positivity among different screening methods. The highest percentage of positive results was with the enzyme immunoassay, in which the binding of serum antibodies to antigens is amplified by enzymatic reactions.

Human T cell lymphotropic virus type-1-associated myelopathy/tropical spastic paraparesis in Sao Paulo, Brazil: association with blood transfusion.

Human T cell lymphotropic virus type-1 (HTLV-1) associated myelopathy/tropical spastic paraparesis (HAM/TSP) has been epidemiologically linked to prior blood transfusion. The prevalence of transfusion as a risk factor for infection varies among endemic areas. Here we report the relative frequency of reported history of blood transfusion among 52 patients evaluated in Sao Paulo, Brazil. A patient reported history of blood transfusion prior to the onset of symptoms, found in 15 (28.8%) of the patients, was the most important risk factor identified in this group of patients when compared with a history of sexually transmitted diseases, homo/bisexuality, sexual promiscuity (three or more sexual partners a year), and intravenous drug use. The mean time between reported transfusions and the onset of symptoms was longer than previously reported. There was no trend toward a more severe evolution to motor inability among the HAM/TSP patients with a history of previous transfusion.

Risk of exposure to Chagas' disease among seroreactive Brazilian blood donors.

BACKGROUND: Screening of blood donors for Chagas' disease by using currently available serologic tests is complicated by the lack of adequate sensitivity, discordant results between tests, and the absence of a gold standard. STUDY DESIGN AND METHODS: The study was designed to evaluate the serologic tests by using epidemiologic data relating to the risk of exposure to Trypanosoma cruzi in the urban centers of Brazil. The serologic results obtained from screening 411,617 voluntary blood donations in São Paulo during 1993 and 1994 were reviewed, as well as follow-up results on 1,267 donors who initially were repeatably reactive in at least one of three screening tests. Epidemiologic data were obtained from 321 individuals who on follow-up remained reactive in at least one test and who returned for medical counseling. Controls included 119 screen-negative blood donors and 45 blood donors who were repeatably reactive in at least one screening test but were negative on follow-up. RESULTS: Of the individuals who reacted in three screening tests, 94.6 percent remained reactive on follow-up. Of the individuals who were repeatably reactive in only one screening test, 70.8 percent were negative in all three tests on follow-up. Most individuals who reacted in two or three tests on follow-up had epidemiologic evidence of a risk of exposure to Chagas' disease. A significant proportion (29.1%) of those who were reactive in only one test on follow-up had epidemiologic evidence of exposure to the Chagas' disease vector as compared to 14.6 percent of controls (p = 0.007). This suggests that some of these individuals truly were infected. CONCLUSION: No single test for Chagas' disease is sufficiently sensitive to prevent transfusion transmission of the disease in the urban centers of Brazil.

Site of peptic ulcer. comparison of hydrochloric acid output, pepsinogen and gastrin serum levels.

BACKGROUND/AIMS: Basal (BAO) and maximum (PAO) hydrochloric acid output after Histalog stimulation, basal pepsinogen (SPL-B), at 60 (SPL-60) and at 90 minutes (SPL-90), and basal gastrin (BG) levels were measured and compared in different gastric (GU) and duodenal (DU) ulcer sites. MATERIAL AND METHODS: Fifty nine patients with peptic ulcer were grouped according to Johnson's classification for gastric ulcers: type I (15), type II (16) type III (12) GU and (16) DU. Fifteen normal subjects were studied as controls. RESULTS: The BAO was greater in the DU than in the control or GU groups. No significant difference was noted in the production of hydrochloric acid after stimulation with Histalog. The SPL-B, at 60 and at 90 minutes was higher in type II GU than in the DU group and controls. The SPL-60 was higher in type II GU patients than in type III GU. Basal gastrin was higher in group DU and types II and III GU compared to the type I GU patients and controls. CONCLUSION: The topographic criteria for differentiating peptic ulcers has low discrimination capacity based on comparison of mean values of HCl acid production, pepsinogen and gastrin serum levels both basal and after stimulation with Histalog due to heterogeneity of these variables in group studies. In these studies, peptic ulcers from different sites should not be grouped as distinct entities except for type II gastric ulcers.

Spontaneous hepatitis B surface antigen clearance in a long-term follow-up study of patients with chronic type B hepatitis. Lack of correlation with hepatitis C and D virus superinfection.

We investigated the frequency of HBsAg clearance and the possible role of viral superinfection in a long-term follow-up of 184 patients with chronic hepatitis B (CHB). Our subjects were 184 patients with chronic hepatitis B and the follow-up was 12-216 months (mean 66.2 +/- 53.7 months). The investigative methods used were: immunoenzymatic assays for HBV, HCV, HDV, and HIV markers; polymerase chain reaction (PCR) for HBV DNA; and liver biopsy and immunoperoxidase. During the follow-up, 20 of the 184 patients cleared serum HBsAg. A comparison of patients with persistent HBsAg(group I) and of those who cleared this marker (group II) showed a significant difference in mortality (P = 0.002) between the two groups and a tendency to a more severe exacerbation (flare) in group II (P = 0.07). Antibodies to hepatitis C and D virus as well as antibodies to HIV were equally distributed in both groups. Thirteen patients (7.9%) from group I, but none from group II, subsequently developed hepatocellular carcinoma. These results suggest that the frequency of spontaneous clearance of HBsAg during chronic HBV infection is low. No determinant factor for the clearance was found, including the presence of liver cirrhosis. Serum HBV DNA was undetectable by PCR after clearance in 16 out of 17 patients.

Prevalência de anticorpos anti-HTLVI/II em doadores de sangue da Fundaçäo Pró-Sangue Hemocentro de Säo Paulo / Prevalence of anti-HTLVI/II antibodies in blood donors of Fundaçäo Pró-Sangue Hemocentro de Säo Paulo

O teste ELISA ant-HTLVI/II foi introduzido na triagem sorlógica de doadores de sangue na Fundaçäo Pró-sangue Hemocentro de Säo Paulo (FPS/HSP) em julho de 1991. NO período compreendido entre julho de 1991 e julho de 1994 foram submetidos à triagem serológica 597.727 doadores. Destes, 7682 foram recusados por terem apresentado reatividade no teste ELISA anti-HTLVI/II. A positividade observada, para o referido teste, foi diminuindo com o correr do tempo: 2,12 por cento em 1991; 1,6 por cento em 1992; 0,8 por cento em 1993 e 1,0 por cento em 1994, sendo esse fato atribuido a melhora da especialidade e reprodutividade dos kits comerciais. Foi utilizado o teste suplementar de Western Blot para confirmar os resultados dos testes ELISA. Em 249 amostras de soros de doadores, com resultado repetidamente positivo (RRP) no teste ELISA (hemobio), o poder confirmatório do Western Blot (Cambridge Biotech) foi de 24.9 por cento (IC/90 por cento: 20,4 por cento-29,39 por cento). Baseados nesses dados, considera-se uma expectativa de prevalência de indivíduos infectados pelo HTLVI/II, na populaçäo de doadores de sangue da FPS/HSP de 0,142 por cento (IC/90 por cento; 0,116 por cento-0,167 por cento). Em 437 amostras de soro de doadores que retornaram ao Banco de Sangue, para confirmar o resultado inicial e apresentaram RRP no teste ELISA, o poder confirmatório do Western Blot foi de 34,55 por cento (IC/90 por cento: 30,82 por cento-38,28 por cento)...

Detection of hepatitis B virus DNA by the polymerase chain reaction in anti-HBE positive chronic hepatitis B patients

A deteccao do DNA do Virus da Hepatite B pela Reacao em cadeia Polimerase (PCR) foi comparada com os outros marcadores sorologicos virais (AgHBs, AgHBe e anti-HBe) numa serie de 49 pacientes com hepatite cronica B, incluindo 12 que apresentaram clareamento espontaneo do AgHBs. Nenhum caso AgHBs negativo foi PCR positivo, mas 33/37 (89,2 por cento) dos casos AgHBs positivos foram PCR positivos (p<0,0001). Entre as amostras AgHBs positivas, 9 foram AgHBe positivas e anti-HBe negativas, todas elas PCR positivas....