Opções de utilização sequencial de anti-retrovíricos em doentes com falência terapêutica em Angola

A infecção pelo VIH/SIDA constitui um dos principais problemas de saúde no Mundo e em África. A África Sub-sahariana detém actualmente 67% das infecções a nível global. Angola, localizada na sub-região central de África (OMS) tem uma prevalência actual média estimada em 2.4%, estando rodeada a Sul e Leste por países de prevalências mais elevadas. Em Angola, predomina o VIH-1. Os dados publicados sobre a epidemiologia molecular do VIH em Angola mostram uma grande diversidade de subtipos e formas recombinantes circulantes (CRF), recombinantes circulantes únicas (URF) e amostras não tipificadas. A motivação para o estudo presente foi o conhecimento ainda limitado sobre a infeção por VIH em Angola, desde a epidemiologia molecular às características clínicas, imunológicas, virológicas, resposta à terapêutica anti-retrovírica combinada (TARVc) e perfil de resistência do VIH à TARVc. Foi estudado um coorte de 300 doentes adultos, com infecção por VIH, de 15 de Junho de 2006 a 15 de Junho de 2010. Predomina o género feminino, 65% (194/300) e o grupo etário dos 25 aos 39 anos, 62% (186/300). A mediana de idades é 33 anos, residem em Luanda 98% (295/300), 94% são angolanos, sendo os estrangeiros de S. Tomé e RDC. A Classificação CDC de 1993 na linha de base mostrou um predomínio de doentes da categoria clínica C, 53% (160/300), com uma ou duas doenças definidoras; 34% (101/300) dos doentes eram da Categoria C3 do CDC e 49% (147/300) tinham linfócitos T CD4+ abaixo das 200 cel/l. A doença definidora mais frequente foi a Tuberculose, em 39% dos doentes (117/300). A mediana de linfócitos T CD4+ na linha de base foi de 195 cel/μl [1-1076]. Apenas 12,2% dos doentes (37/302) tinha T CD4+ de base superior a 500 células/l. Determinou-se a carga vírica na linha de base, em 213 dos doentes (71%), verificando-se que 46% destes doentes (97/213) tinham cargas virícas superiores a 100.000 cp/ml, 32% (69/213) entre 10001 e 100000, 21% (45/213) entre 400 e 10000, 0,9% (2/213) abaixo de 400 cp/ml. Iniciaram terapêutica anti-retrovírica no período de estudo 206 doentes (69%) com esquemas terapêuticos baseados em NNRTI, sendo 131 (64%) medicados com a associação d4t+3TC+ NVP. Ao fim de 4 anos, em Junho de 2010, havia 126 doentes monitorizados com contagem de linfócitos T CD4+ e CV, estando 62% dos doentes com CV indetectável (79/126). Os doentes em falência virológica corresponderam a 16% (20/126), 9% (11/126) tinham resultados discordantes (boa resposta imunológica mas carga viral detectável) e 13% (16/126) foram inconclusivos. Foi mudada a terapêutica para esquema de 2ª linha em 5 doentes, 4 dos 5 doentes com critérios de falência virológica e 1 sem critérios de falência virológica, por toxicidade ao EFV. Os doentes com critérios de falência imunológica ou virológica segundo a OMS e os doentes com dados inconclusivos foram seleccionados para testes genotípicos de resistência aos anti-retrovíricos (TR). Foram realizados TR e subtipagem em 37 doentes. Nos doentes que realizaram TR sob TARVc, as mutações de resistência mais frequentemente encontradas foram a M184V, em 16 doentes, a K103N em 12 doentes e a Y181C em 7 doentes. O subtipo C, foi o subtipo predominante em 30% (11/37) dos casos. Para avaliar a adesão à TARVc, foram estudados 63 doentes, faltosos a consultas ou demonstrado sinais de falência clínica, imunológica ou virológica. O método realizado foi o auto-relato por entrevista. Verificou-se uma adesão à TARVc de 100% em 33% (21/63), adesão entre 100% e 90% em 7% (4/63), de 50 a 90% em 7% (4/63) e inferior a 50% em 54% (34/63). Como factores de não-adesão, predominavam a mobilidade no emprego Opções de utilização sequencial de anti-retrovíricos em doentes com falência terapêutica em Angola X e factores familiares e sociais, apontados como razão para a falta às consultas que davam acesso aos medicamentos ARV. Fazendo corresponder os resultados dos testes de resistência realizados à adesão de todos os doentes entrevistados, verifica-se que o grupo de 34 doentes com menos de 50% de adesão, 19 realizaram TR e desses, 13 mostraram mutações de resistência, sendo 10 resistentes a 2 classes de ARV, NITR e NNITR, 2 a NNITR e 1 a NITR. Os restantes 6 doentes deste grupo eram aparentemente susceptíveis às 3 classes de ARV. Actualmente, estão em seguimento 58% dos doentes (176/300), 26 % (77/300) perderam-se no seguimento e 16% (47/300) faleceram. O estudo realizado salienta a fase tardia da chegada aos cuidados médicos; mostra a tuberculose como doença indicadora mais frequente e mostra que a maioria dos doentes foi medicada com D4T+3TC+NVP. Os critérios de sucesso terapêutico descem ao longo do estudo de 71% para 62%. Indica a necessidade de acções urgentes para acesso mais precoce aos cuidados de saúde e intervenção social para ultrapassar as limitações à adesão à TARVc e tornar esta mais eficaz. As opções de segunda linha já disponíveis são muito reduzidas (tenofovir, lopinavir potenciado com ritonavir e saquinavir), havendo necessidade de continuar estes estudos para uma avaliação mais profunda da eficácia destas terapêuticas.

A clinical, epidemological, laboratorial, histological and ultrasonographical evaluation of anti-HCV EIA-2 positive blood donors

Between 1992 and 1997, 790 blood donors with anti-HCV EIA-2 strongly reagent (relationship between the sample optical density/cut-off > 3) detected at the blood bank serological screening, were evaluated in ambulatory environment. They were all negative for Chagas disease, syphilis, hepatitis B (HBsAg) and AIDS. Blood samples were collected at the first ambulatorial evaluation, for hemogram, biochemical tests and new serological tests for HCV (anti-HCV EIA-2). In blood samples of 226 repeatedly reagent anti-HCV EIA-2 blood donors, supplementary "immunoblot" test for HCV (RIBA-2) was used. In 209 donors, the presence of HCV-RNA was investigated by the PCR test. The abdominal ultrasonography was realized in 366 donors. In 269 patients liver biopsy was performed for the histopathological study. The follow-up of blood donors showed that 95.6% were repeatedly EIA-2 reagent, 94% were symptomless and denied any hepatitis history, with only 2% mentioning previous jaundice. In 47% of this population at least one risk factor has been detected for the HCV transmission, the use of intravenous drugs being the main one (27.8%). Blood transfusion was the second factor for HCV transmission (27.2%). Hepatomegaly was detected in 54% of the cases. Splenomegaly and signs of portal hypertension have seldom been found in the physical examination, indicating a low degree of hepatic compromising in HCV. Abdominal ultrasound showed alterations in 65% of the subjects, being the steatosis the most frequent (50%). In 83.5% of the donors submitted to the liver biopsy, the histopathological exam showed the presence of chronic hepatitis, usually classified as active (89%) with mild or moderate grade in most of the cases (99.5%). The histopathological exam of the liver was normal in 1.5% of blood donors. The RIBA-2 test and the HCV-RNA investigation by PCR were positive in respectively 91.6 and 75% of the anti-HCV EIA-2 reagent donors. The HCV-RNA research was positive in 82% of the RIBA-2 positive subjects, in 37.5% of the indeterminate RIBA-2 donors and in 9% of the negative RIBA-2 donors. Chronic hepatitis has also been observed in 50% of the histopathological exams of the anti-HCV EIA-2 reagent donors which were indeterminate RIBA-2. Among 18 blood donors with minimal changes histopathological exam 11 (61%) were HCV-RNA positive. Our blood donors anti-HCV reagent generally had clinical, laboratorial and histopathological features observed in patients with chronic HCV hepatitis and a high proportion could be identified in interviews and medical evaluation realized in blood blanks. Generally, these HCV infected donors are identified and discharged only by the serological tests results.

Persistent infections in chronic Chagas' disease patients treated with anti-Trypanosoma cruzi nitroderivatives

We used a molecular method and demonstrated that treatment of the chronic human Trypanosoma cruzi infections with nitroderivatives did not lead to parasitological cure. Seventeen treated and 17 untreated chronic Chagas' disease patients, with at least two out of three positive serologic assays for the infection, and 17 control subjects formed the study groups. PCR assays with nested sets of T. cruzi DNA primers monitored the efficacy of treatment. The amplification products were hybridized to their complementary internal sequences. Untreated and treated Chagas' disease patients yielded PCR amplification products with T. cruzi nuclear DNA primers. Competitive PCR was conducted to determine the quantity of parasites in the blood and revealed < 1 to 75 T. cruzi/ml in untreated (means 25.83 ± 26.32) and < 1 to 36 T. cruzi/ml in treated (means 6.45 ± 9.28) Chagas' disease patients. The difference between the means was not statistically significant. These findings reveal a need for precise definition of the role of treatment of chronic Chagas' disease patients with nitrofuran and nitroimidazole compounds.

Detection of hepatitis A antibodies by ELISA using saliva as clinical samples

The possibility of detecting acute infection and immunity using body fluids that are easier to collect than blood, mainly in children, would facilitate the investigation and follow-up of outbreaks of hepatitis A (HAV). Our study was carried out to evaluate the detection of anti-HAV IgM, IgA and total antibodies in saliva using serum samples as reference. Forty three paired serum and saliva samples were analyzed. From this total, 24 samples were obtained from children and 1 from one adult during the course of acute hepatitis A; an additional 18 samples were obtained from health professionals from Adolfo Lutz Institute. The sensitivity to detect anti-HAV IgM was 100% (95%CI: 79.1 to 100.0%), employing saliva as clinical samples. In detecting anti-HAV IgA, the sensitivity was 80.8% (95%CI: 60.0 to 92.7%) and for the total antibodies was 82.1% (95%CI: 62.4 to 93.2%). The specificity was 100% for each. The rate of agreement was high comparing the results of serum and saliva samples for detecting HAV antibodies. We conclude that saliva is an acceptable alternative specimen for diagnosing acute hepatitis A infection, and for screening individuals to receive hepatitis A vaccine or immunoglobulin.

Caracterização do efeito anti-tumoral de complexos organometálicos contendo 1,10-fenantrolina-5,6-diona

Dissertação apresentada para a obtenção do Grau de Mestre em Genética Molecular e Biomedicina, pela Universidade Nova de Lisboa, Faculdade de Ciências e Tecnologia

Evaluation of anti-Schistosoma mansoni igG antibodies in patients with chronic schistosomiasis mansoni before and after specific treatment

The circumoval precipitin test (COPT), enzyme-linked immunosorbent assay (ELISA) and the immunoblotting anti-adult worm antigen (AWA) and soluble egg antigen (SEA) tests were applied to 17 chronically schistosome-infected patients for the detection of anti-Schistosoma mansoni antibodies before and on four occasions after oxamniquine administration over a period of six months. Compared to a control group, schistosomiasis patients showed high levels of IgG antibodies in AWA and SEA-ELISA. A decrease in IgG levels was observed six months after treatment, although negative reactions were not obtained. Significant decreases in IgG1, IgG3 and, mainly, IgG4, but not anti-SEA IgG2 levels were observed six months after treatment, again without negativity. Analysis of anti-AWA IgG antibodies by immunoblotting before treatment showed a 31 kDa strand in 14 patients (82%) which disappeared in three cases up to six months after treatment; furthermore, anti-SEA IgG antibodies showed the same band in nine patients (53%) before treatment, which disappeared in only four cases up to six months after treatment.

Estudo do efeito anti-angiogénico de novos alvos terapêuticos no tratamento do carcinoma mamário

Dissertação para obtenção do Grau de Mestre em Genética Molecular e Biomedicina

Human polyclonal anti-hepatitis B surface antigen immunoglobulin reduces the frequency of acute rejection after liver transplantation for chronic hepatitis B

BACKGROUND: Use of polyclonal anti-hepatitis B surface antigen immunoglobulin (HBIg) has been shown to reduce hepatitis B virus (HBV) recurrence after liver transplantation (LT) and to decrease the frequency of acute cellular rejection (ACR). However, the protective role of HBIg against ACR remains controversial, since HBV infection has been also associated with a lower incidence of ACR. AIM: To assess the relationship between HBIg immunoprophylaxis and the incidence of rejection after LT. METHODS: 260 patients (158 males, 43 ± 14 years old) submitted to LT were retrospectively evaluated and divided into three groups, according to the presence of HBsAg and the use of HBIg. Group I was comprised of HBsAg-positive patients (n = 12) that received HBIg for more than 6 months. Group II was comprised of HBsAg-positive patients that historically have not received HBIg or have been treated irregularly for less than 3 months (n = 10). Group III was composed of 238 HBsAg-negative subjects that have not received HBIg. RESULTS: HBIg-treated patients (group I) had significantly less ACR episodes, when compared to group II and III. No differences between groups II and III were observed. CONCLUSIONS: Long-term HBIg administration contributes independently to reduce the number of ACR episodes after LT.

Investigation of trypanothione synthetase of Leishmania infantum as a potential target for new anti-parasitic drugs

Dissertação para obtenção do Grau de Mestre em Biotecnologia

Frequency of serum anti-cysticercus antibodies in the population of a rural Brazilian community (Cássia dos Coqueiros, SP) determined by ELISA and immunoblotting using Taenia crassiceps antigens

Considering the impact of cysticercosis on public health, especially the neurologic form of the disease, neurocysticercosis (NC), we studied the frequency of positivity of anti-Taenia solium cysticercus antibodies in serum samples from 1,863 inhabitants of Cássia dos Coqueiros, SP, a municipal district located 80 km from Ribeirão Preto, an area considered endemic for cysticercosis. The 1,863 samples were tested by enzyme linked immunosorbent assay (ELISA) using an antigenic extract from Taenia crassiceps vesicular fluid (Tcra). The reactive and inconclusive ELISA samples were tested by immunoblotting. Of the 459 samples submitted to immunoblotting, 40 were strongly immunoreactive to the immunodominant 18 and 14 kD peptides. Considering the use of immunoblotting as confirmatory due to its high specificity, the anti-cysticercus serum prevalence in this population was 2.1%.

A rapid latex agglutination test for the detection of anti-cysticercus antibodies in cerebrospinal fluid (CSF)

Simple and rapid latex-based diagnostic tests have been used for detecting specific antigens or antibodies in several diseases. In this article, we present the preliminary results obtained with a latex agglutination test (LAT) for diagnosing neurocysticercosis by detection of antibodies in CSF. A total of 43 CSF samples were assayed by the LAT: 19 CSF samples from patients with neurocysticercosis and 24 CSF samples from patients with other neurologic disorders (neurosyphilis, n = 8; neurotoxoplasmosis, n = 3; viral meningitis, n = 4, chronic headache, n = 9). The LAT exhibited 89.5% sensitivity and 75% specificity. The use of LAT seems to be an additional approach for the screening of neurocysticercosis with advantage of simplicity and rapidity. Further studies could be performed using purified antigens and serum samples.

Anti-trypanosomal activity of pentacyclic triterpenes isolated from Austroplenckia populnea (Celastraceae)

Four pentacyclic triterpenes isolated from Austroplenckia populnea and four compounds of known anti T. cruzi or anti-malarial activity were tested. Of those triterpenes tested 20alpha-hydroxy-tingenone showed high activity, epikatonic acid was less active, while populnilic and populninic acids were inactive against the trypanosome of the subgenus Schizotrypanum tested. Benzonidazole, nifurtimox, ketoconazole and primaquine presented a remarkable dose-dependent inhibitory effect reaching practically to a total growth inhibition of the parasite at the end of incubation time. The trypanosome tested appear to be a suitable model for preliminary screen for anti T. (S.) cruzi compounds.

Anti-Taenia solium metacestodes antibodies in serum from blood donors from four cities of Triângulo Mineiro area, Minas Gerais, Brazil, 1995

Serological survey was performed to detect IgG antibodies anti-Taenia solium metacestodes in blood donors of Hemocentro Regional de Uberlândia, Minas Gerais, Brazil. A total of 1133 sera from blood donors coming from four cities of Triângulo Mineiro area were analyzed by the indirect fluorescence antibody test (IFAT) and the enzyme linked immunosorbent assay (ELISA). Specific IgG antibodies were found in 5.6% of the studied population, showing differences in the positive rates according to their origin: Araguari (13.5%), Tupaciguara (5.0%), Monte Alegre de Minas (4.8%) and Uberlândia (4.7%). The results indicate the probable endemicity of cysticercosis in this population.

Seasonal variation of hepatitis A virus infection in the city of Rio de Janeiro, Brazil

Hepatitis A virus (HAV) infection constitutes a major public health problem in Brazil. The transmission of HAV is primarily by fecal-oral route so the water is an important vehicle of HAV dissemination. There is a great incidence of acute cases of hepatitis A in some areas of Brazil however the seasonal variation of these cases was not documented. The aim of this study was to determine the seasonality of HAV infection in Rio de Janeiro. From January 1999 to December 2001, 1731 blood samples were collected at the National Reference Center for Hepatitis Viruses in Brazil (NRCHV). These samples were tested by a commercial enzyme-immunoassay to detect anti-HAV IgM antibodies. Yearly positive rates were 33.74% in 1999, 32.19% in 2000, and 30.63% in 2001. A seasonal variation was recognized with the highest incidence in spring and summer. Furthermore a seasonal increase in incidence of HAV infection was found during the rainy season (December to March) because the index of rains is very high. It is concluded that HAV infections occur all year round with a peak during hot seasons with great number of rains.

Seroprevalence of hepatitis B virus infection in individuals with clinical evidence of hepatitis in Goiânia, Goiás: detection of viral DNA and determination of subtypes

The presence of serological markers for hepatitis B virus (HBsAg, anti-HBc IgM and Anti-HBc total) was investigated in the serum of 1,396 individuals who had clinical suspect of hepatitis. It was observed that 50.7% of the individuals were positive and, from the total of the studied individuals, 14.5% were positive for HBsAg. From these, 8.5% were also positive for anti-HBc IgM. The analysis in relation to gender showed a higher seroprevalence index among male individuals (p < 0.0001). It was observed the occurrence of subtypes adw2 (62.7%), ayw3 (23.5%), ayw2 (9.8%) and adw4 (3.9%). The viral DNA was detected in 61 (33.9%) HBsAg positive samples and in one sample positive only for anti-HBc total. These results indicate an important incidence of the HBV infection in this population, and reinforce previous studies regarding this virus in the central west region of Brazil.