Clinical Impact of the Line Probe Assay and Xpert® MTB/RIF Assay in the Presumptive Diagnosis of Drug-Resistant Tuberculosis in Brazil: A Pragmatic Clinical Trial

ABSTRACT Background: Rapid molecular methods such as the line probe assay (LPA) and Xpert® MTB/RIF assay (Xpert) have been recommended by the World Health Organization for drug-resistant tuberculosis (DR-TB) diagnosis. We conducted an interventional trial in DR-TB reference centers in Brazil to evaluate the impact of the use of LPA and Xpert. Methods: Patients with DR-TB were eligible if their drug susceptibility testing results were available to the treating physician at the time of consultation. The standard reference MGITTM 960 was compared with Xpert (arm 1) and LPA (arm 2). Effectiveness was considered as the start of the appropriate TB regimen that matched drug susceptibility testing (DST) and the proportions of culture conversion and favorable treatment outcomes after 6 months. Results: A higher rate of empirical treatment was observed with MGIT alone than with the Xpert assay (97.0% vs. 45.0%) and LPA (98.2% vs. 67.5%). Patients started appropriate TB treatment more quickly than those in the MGIT group (median 15.0 vs. 40.5 days; p<0.01) in arm 1. Compared to the MGIT group, culture conversion after 6 months was higher for Xpert in arm 1 (90.9% vs. 79.3%, p=0.39) and LPA in arm 2 (80.0% vs. 83.0%, p=0.81). Conclusions: In the Xpert arm, there was a significant reduction in days to the start of appropriate anti-TB treatment and a trend towards greater culture conversion in the sixth month.

Cost-effectiveness of Xpert®MTB/RIF in the diagnosis of tuberculosis: pragmatic study

Abstract INTRODUCTION: The intensification of research and innovation with the creation of networks of rapid and effective molecular tests as strategies for the end of tuberculosis are essential to avoid late diagnosis and for the eradication of the disease. We aimed to evaluate the cost-effectiveness of Xpert®MTB/RIF (Xpert) in the diagnosis of drug-resistant tuberculosis in reference units, in scenarios with and without subsidies, and the respective cost adjustment for today. METHODS: The analyses were performed considering as criterion of effectiveness, negative culture or clinical improvement in the sixth month of follow-up. The comparison was performed using two diagnostic strategies for the drug susceptibility test (DST), BactecTMMGITTM960 System, versus Xpert. The cost effectiveness and incremental cost-effectiveness ratio (ICER) were calculated and dollar-corrected for American inflation (US$ 1.00 = R$ 5,29). RESULTS: Subsidized Xpert had the lowest cost of US$ 33.48 (R$67,52) and the highest incremental average efficiency (13.57), thus being a dominated analysis. After the inflation was calculated, the mean cost was DST-MGIT=US$ 74.85 (R$ 396,73) and Xpert = US$ 37.33 (R$197,86) with subsidies. CONCLUSIONS: The Xpert in the diagnosis of TB-DR in these reference units was cost-effective with subsidies. In the absence of a subsidy, Xpert in TB-DR is not characterized as cost effective. This factor reveals the vulnerability of countries dependent on international organizations' subsidy policies.

Detection of tuberculosis drug resistance: a comparison by Mycobacterium tuberculosis MLPA assay versus Genotype®MTBDRplus

BACKGROUND To cope with the emergence of multidrug-resistant tuberculosis (MDR-TB), new molecular methods that can routinely be used to screen for a wide range of drug resistance related genetic markers in the Mycobacterium tuberculosis genome are urgently needed. OBJECTIVE To evaluate the performance of multiplex ligaton-dependent probe amplification (MLPA) against Genotype® MTBDRplus to detect resistance to isoniazid (INHr) and rifampicin (RIFr). METHOD 96 culture isolates characterised for identification, drug susceptibility testing (DST) and sequencing of rpoB, katG, and inhA genes were evaluated by the MLPA and Genotype®MTBDRplus assays. RESULTS With sequencing as a reference standard, sensitivity (SE) to detect INHr was 92.8% and 85.7%, and specificity (SP) was 100% and 97.5%, for MLPA and Genotype®MTBDRplus, respectively. In relation to RIFr, SE was 87.5% and 100%, and SP was 100% and 98.8%, respectively. Kappa value was identical between Genotype®MTBDRplus and MLPA compared with the standard DST and sequencing for detection of INHr [0.83 (0.75-0.91)] and RIFr [0.93 (0.88-0.98)]. CONCLUSION Compared to Genotype®MTBDRplus, MLPA showed similar sensitivity to detect INH and RIF resistance. The results obtained by the MLPA and Genotype®MTBDRplus assays indicate that both molecular tests can be used for the rapid detection of drug-resistant TB with high accuracy. MLPA has the added value of providing information on the circulating M. tuberculosis lineages.

Association between serum selenium level and conversion of bacteriological tests during antituberculosis treatment / Associações entre níveis de selênio sérico e conversão de testes bacteriológicos durante o tratamento antituberculose

Objective: To determine whether serum selenium levels are associated with the conversion of bacteriological tests in patients diagnosed with active pulmonary tuberculosis after eight weeks of standard treatment. Methods: We evaluated 35 healthy male controls and 35 male patients with pulmonary tuberculosis, the latter being evaluated at baseline, as well as at 30 and 60 days of antituberculosis treatment. For all participants, we measured anthropometric indices, as well as determining serum levels of albumin, C-reactive protein (CRP) and selenium. Because there are no reference values for the Brazilian population, we used the median of the serum selenium level of the controls as the cut-off point. At 30 and 60 days of antituberculosis treatment, we repeated the biochemical tests, as well as collecting sputum for smear microscopy and culture from the patients. Results: The mean age of the patients was 38.4 ± 11.4 years. Of the 35 patients, 25 (71%) described themselves as alcoholic; 20 (57.0%) were smokers; and 21 (60.0%) and 32 (91.4%) presented with muscle mass depletion as determined by measuring the triceps skinfold thickness and arm muscle area, respectively. Of 24 patients, 12 (39.2%) were classified as moderately or severely emaciated, and 15 (62.5%) had lost > 10% of their body weight by six months before diagnosis. At baseline, the tuberculosis group had lower serum selenium levels than did the control group. The conversion of bacteriological tests was associated with the CRP/albumin ratio and serum selenium levels 60 days after treatment initiation. Conclusions: Higher serum selenium levels after 60 days of treatment were associated with the conversion of bacteriological tests in pulmonary tuberculosis patients. .

Objetivo: Determinar se os níveis séricos de selênio estão associados à conversão dos testes bacteriológicos em pacientes diagnosticados com tuberculose pulmonar ativa após oito semanas de tratamento-padrão. Métodos: No início do estudo, avaliamos 35 controles saudáveis, do sexo masculino, e 35 pacientes do sexo masculino com tuberculose pulmonar. Estes foram também avaliados após 30 e 60 dias de tratamento antituberculose. Todos os participantes submeteram-se a medições antropométricas e quantificação dos níveis séricos de albumina, proteína C reativa (PCR) e selênio. Como não há valores de referência para a população brasileira, usamos a mediana dos resultados de selênio sérico dos controles como ponto de corte. Aos 30 e 60 dias do tratamento antituberculose, todos os testes bioquímicos foram repetidos, e foram coletadas amostras de escarro para baciloscopia e cultura. Resultados: A média de idade dos pacientes foi de 38,4 ± 11.4 anos. Dos 35 pacientes, 25 (71,0%) referiram alcoolismo, 20 (57,0%) eram fumantes, e 21 (60,0%) e 32 (91,4%) apresentavam depleção muscular pela medição da dobra cutânea tricipital e da área muscular do braço, respectivamente. De 24 pacientes, 12 (39,2%) foram classificados em moderadamente ou gravemente magros, e 15 (62,5%) apresentaram perda de peso > 10% em até seis meses antes do diagnóstico. No início do estudo, o grupo com tuberculose apresentou menores níveis de selênio sérico que os controles. A conversão dos testes bacteriológicos associou-se à relação PCR/albumina e aos níveis de selênio sérico 60 dias após o início do tratamento. Conclusões: Níveis maiores de selênio sérico após 60 ...

Inflammatory and immunogenetic markers in correlation with pulmonary tuberculosis / Marcadores inflamatorios e imunogeneticos e sua relacao com tuberculose pulmonar

OBJECTIVE: To describe serum levels of the cytokines IL-10, TNF-α, and IFN-γ, as well as polymorphisms in the genes involved in their transcription, and their association with markers of the acute inflammatory response in patients with pulmonary tuberculosis. METHODS: This was a descriptive, longitudinal study involving 81 patients with pulmonary tuberculosis treated at two referral hospitals. We collected data on sociodemographic variables and evaluated bacteriological conversion at the eighth week of antituberculosis treatment, gene polymorphisms related to the cytokines studied, and serum levels of those cytokines, as well as those of C-reactive protein (CRP). We also determined the ESR and CD4+ counts. RESULTS: The median age of the patients was 43 years; 67 patients (82.7%) were male; and 8 patients (9.9%) were infected with HIV. The ESR was highest in the patients with high IFN-γ levels and low IL-10 levels. IFN-γ and TNF-α gene polymorphisms at positions +874 and −238, respectively, showed no correlations with the corresponding cytokine serum levels. Low IL-10 levels were associated with IL-10 gene polymorphisms at positions −592 and −819 (but not −1082). There was a negative association between bacteriological conversion at the eighth week of treatment and CRP levels. CONCLUSIONS: Our results suggest that genetic markers and markers of acute inflammatory response are useful in predicting the response to antituberculosis treatment. .

OBJETIVO: Descrever os níveis séricos das citocinas IL-10, TNF-α e IFN-γ, assim como polimorfismos presentes em genes envolvidos na sua transcrição, e sua associação com marcadores de resposta inflamatória aguda em pacientes com tuberculose. MÉTODOS: Estudo descritivo e longitudinal realizado em 81 pacientes com tuberculose pulmonar atendidos em dois hospitais de referência. Foram coletadas informações sociodemográficas, conversão bacteriológica na oitava semana de tratamento antituberculose, polimorfismos relacionados às citocinas estudadas, níveis séricos dessas citocinas, assim como de proteína C reativa (PCR). Também foram avaliados VHS e contagem de CD4+. RESULTADOS: A mediana de idade dos pacientes era de 43 anos, sendo 67 (82,7%) do sexo masculino e 8 (9,9%) infectados por HIV. Os pacientes com níveis elevados de IFN-γ e baixos níveis de IL-10 apresentaram valores mais elevados de VHS. Não houve associação dos polimorfismos do gene IFN-γ na posição +874 e do gene TNF-α na posição −238 com os níveis das citocinas correspondentes. Houve uma associação entre polimorfismos do gene IL-10 nas posições −592 e −819 (mas não −1082) e baixos níveis de IL-10. Houve uma associação negativa entre a taxa de conversão bacteriológica na oitava semana de tratamento e níveis de PCR. CONCLUSÕES: Nossos resultados sugerem que marcadores genéticos e de resposta inflamatória aguda podem ser úteis na predição da resposta ao tratamento antituberculose. .

Avaliação da autopercepção do tratamento restaurador atraumático pelo paciente infantil / Perception assessment of atraumatic restorative treatment by child patient

Objetivo: O objetivo deste trabalho foi a avaliar a percepção do tratamento restaurador atraumático (ART) pelo paciente infantil. Método: Para esta avaliação foi utilizada como instrumento uma escala visual analógica de face (EVAF) adaptada. Assim, 142 crianças com idade entre 5 e 11 anos, estudantes de escolas públicas, com indicação para o ART, foram tratadas e orientadas pelo cirurgião-dentista sobre a utilização da EVAF adaptada logo após o término do procedimento odontológico. As crianças foram classificadas em dois grupos. Grupo 1: crianças de 5-7 anos: 74 (52%) e Grupo 2: crianças de 8-11 anos: 68 (48%). Resultados: A escolha da figura representativa de "satisfeito" (85%) na EVAF adaptada pelas crianças foi predominante sobre as figuras representativas de "surpreso" (12%) e "preocupado" (3%). Segundo análise estatística qui-quadrado, não houve diferença estatisticamente significante de percepção do tratamento restaurador atraumático entre crianças segundo as faixas etárias (p = 0,055). Conclusão: A escala analógica de face adaptada mostrou que a maioria das crianças apresentou percepção positiva do tratamento segundo a técnica do ART.

Termo de consentimento e análise de material biológico armazenado / Consent procedures and research on stored biological samples

OBJETIVO: Relatar uma experiência envolvendo a obtenção de termo de consentimento livre e esclarecido (TCLE) para estudo retrospectivo realizado no Instituto Nacional de Câncer (INCA). O mesmo envolvia a revisão de prontuários e a análise de blocos de parafina de pacientes com câncer de cólon operados entre 2000 e 2004. Respeitando a resolução 196/96 do Conselho Nacional de Saúde e a determinação do Comitê de Ética em Pesquisa (CEP) do INCA, buscou-se obter o consentimento informado. MÉTODOS: Nas consultas agendadas, conseguiu-se aplicar o termo a apenas quatro pacientes, durante três meses. Foram enviadas então pelo correio duas cópias do TCLE, juntamente com um sumário e um envelope selado para o re-envio aos pesquisadores. Antes da postagem, tentou-se contato telefônico. RESULTADOS: Obteve-se retorno de 115 dos 155 TCLE enviados (74 por cento). Dentre as respostas recebidas, 111 consentiram participar do estudo, houve uma recusa e foi informado que três pacientes haviam falecido. O tempo entre o envio da correspondência e o recebimento da resposta variou entre 2 e 89 dias (mediana: 10 dias). Houve sucesso no contato telefônico com 60 dos 160 pacientes (37,5 por cento). Para os que já haviam falecido e para os que não retornaram o TCLE, o CEP aprovou a dispensa do mesmo. O custo final do envio dos envelopes foi de R$1.004,40. CONCLUSÃO: A busca de comunicação telefônica e postal com pacientes para a obtenção de TCLE de estudo clínico retrospectivo é factível. A maioria respondeu ao contato e consentiu participar. Há, porém, custos e riscos agregados que não podem ser desprezados.

OBJECTIVE: To present practical experience in obtaining consent form (CF) for a study performed at the "Instituto Nacional de Câncer" involving research on stored biologic samples from patients operated for colon cancer from 2000 to 2004. According to the Brazilian National Health Council resolution nº196/96, researchers must make every effort to obtain consent from patients participating in clinical studies, which is reinforced by the Research Ethics Committee (REC). METHODS: After attempting phone contact, two copies and a synopsis of the CF were posted to each patient, with a stampedreturn envelope. RESULTS: 160 patients were included in the study. The attempt of phone contact was successful with 60 of them (37.5 percent). The consent form was mailed to 155 patients: 115 posted it back (74 percent) Three patients had already passed away, 111 accepted and one refused to participate. The median time between posting and receiving the CF back was 10 days (interval: 2-89). The REC waived the requirement of CF for those who died and for the ones who did not reply. The final cost for sending the CF was R$1,004.40. CONCLUSION: Obtaining consent by postal and phone communication for retrospective genetic research with stored tissue samples is feasible. Most responded to contact and consented to participate, but there were costs and risks that cannot be neglected.