Prediction Models for Adverse Drug Reactions During Tuberculosis Treatment in Brazil

BACKGROUND

Tuberculosis (TB) treatment-related adverse drug reactions (TB-ADRs) can negatively affect adherence and treatment success rates.

METHODS

We developed prediction models for TB-ADRs, considering participants with drug-susceptible pulmonary TB who initiated standard TB therapy. TB-ADRs were determined by the physician attending the participant, assessing causality to TB drugs, the affected organ system, and grade. Potential baseline predictors of TB-ADR included concomitant medication (CM) use, human immunodeficiency virus (HIV) status, glycated hemoglobin (HbA1c), age, body mass index (BMI), sex, substance use, and TB drug metabolism variables (NAT2 acetylator profiles). The models were developed through bootstrapped backward selection. Cox regression was used to evaluate TB-ADR risk.

RESULTS

There were 156 TB-ADRs among 102 of the 945 (11%) participants included. Most TB-ADRs were hepatic (n = 82 [53%]), of moderate severity (grade 2; n = 121 [78%]), and occurred in NAT2 slow acetylators (n = 62 [61%]). The main prediction model included CM use, HbA1c, alcohol use, HIV seropositivity, BMI, and age, with robust performance (c-statistic = 0.79 [95% confidence interval {CI}, .74-.83) and fit (optimism-corrected slope and intercept of -0.09 and 0.94, respectively). An alternative model replacing BMI with NAT2 had similar performance. HIV seropositivity (hazard ratio [HR], 2.68 [95% CI, 1.75-4.09]) and CM use (HR, 5.26 [95% CI, 2.63-10.52]) increased TB-ADR risk.

CONCLUSIONS

The models, with clinical variables and with NAT2, were highly predictive of TB-ADRs.

Isoniazid Monoresistance and Antituberculosis Treatment Outcome in Persons With Pulmonary Tuberculosis in Brazil

Background

The high burden of drug-resistant tuberculosis (TB) is a problem to achieve the goals of the End TB Strategy by 2035. Whether isoniazid monoresistance (Hr) affects anti-TB treatment (ATT) outcomes remains unknown in high-burden countries.

Methods

We evaluated determinants of ATT outcome among pulmonary TB cases reported to the National Notifiable Disease Information System (SINAN) between June 2015 and June 2019, according to drug sensitivity testing (DST) results. Binomial logistic regression models were employed to evaluate whether Hr was associated with an unfavorable ATT outcome: death or failure, compared to cure or treatment completion.

Results

Among 60 804 TB cases reported in SINAN, 21 197 (34.9%) were included in the study. In this database, the frequency of unfavorable outcomes was significantly higher in those with Hr in contrast to isoniazid-sensitive persons with pulmonary TB (9.1% vs 3.05%; P < .001). Using a binomial logistic regression model, Hr was independently associated with unfavorable outcomes (odds ratio, 3.34 [95% confidence interval, 2.06-5.40]; P < .001).

Conclusions

Hr detected prior to ATT was predictive of unfavorable outcomes at the national level in Brazil. Our data reinforce the need for high-TB-burden countries to prioritize DST to detect Hr. Effective treatment regimens for Hr-TB are needed to improve outcomes.

Pharmacogenetics of tuberculosis treatment toxicity and effectiveness in a large Brazilian cohort

Background

Genetic polymorphisms have been associated with risk of anti-tuberculosis treatment toxicity. We characterized associations with adverse events and treatment failure/recurrence among adults treated for tuberculosis in Brazil.

Methods

Participants were followed in Regional Prospective Observational Research in Tuberculosis (RePORT)-Brazil. We included persons with culture-confirmed drug-susceptible pulmonary tuberculosis who started treatment between 2015-2019, and who were evaluable for pharmacogenetics. Treatment included 2 months of isoniazid, rifampin or rifabutin, pyrazinamide, and ethambutol, then 4 months of isoniazid and rifampin or rifabutin, with 24 month follow-up. Analyses included 43 polymorphisms in 20 genes related to anti-tuberculosis drug hepatotoxicity or pharmacokinetics. Whole exome sequencing was done in a case-control toxicity subset.

Results

Among 903 participants in multivariable genetic association analyses, NAT2 slow acetylator status was associated with increased risk of treatment-related grade 2 or greater adverse events, including hepatotoxicity. Treatment failure/recurrence was more likely among NAT2 rapid acetylators, but not statistically significant at the 5% level. A GSTM1 polymorphism (rs412543) was associated with increased risk of treatment-related adverse events, including hepatotoxicity. SLCO1B1 polymorphisms were associated with increased risk of treatment- related hepatoxicity and treatment failure/recurrence. Polymorphisms in NR1/2 were associated with decreased risk of adverse events and increased risk of failure/recurrence. In whole exome sequencing, hepatotoxicity was associated with a polymorphism in VTI1A , and the genes METTL17 and PRSS57 , but none achieved genome-wide significance.

Conclusions

In a clinical cohort representing three regions of Brazil, NAT2 acetylator status was associated with risk for treatment-related adverse events. Additional significant polymorphisms merit investigation in larger study populations.

Anemia and anti-tuberculosis treatment outcome in persons with pulmonary tuberculosis: A multi-center prospective cohort study

BACKGROUND

Tuberculosis (TB) remains a major plague of humanity. People with TB (PWTB) are commonly anemic. Here, we assessed whether the severity of anemia in PWTB prior to anti-TB treatment (ATT) was a risk factor for an unfavorable outcome.

METHODS

Patients ≥ 18 years old with culture-confirmed drug-susceptible pulmonary TB enrolled between 2015 and 2019 in a multi-center Brazilian cohort were followed for up to 24 months and classified according to anemia severity (mild, moderate, and severe), based on hemoglobin levels. A multinomial logistic regression model was employed to assess whether anemia was associated with unfavorable outcome (death, failure, loss to follow-up, regimen modification or relapse), compared to treatment success (cure or treatment completion).

RESULTS

Among 786 participants who met inclusion criteria, 441 (56 %) were anemic at baseline. Patients with moderate/severe anemia were more HIV-seropositive, as well as more symptomatic and had higher frequencies of unfavorable outcomes compared to the other groups. Moderate/severe anemia (adjusted OR [aOR]: 7.80, 95 %CI:1.34-45.4, p = 0.022) was associated with death independent of sex, age, BMI, HIV and glycemic status.

CONCLUSION

Moderate/severe anemia prior to ATT was a significant risk factor for death. Such patients should be closely monitored given the high risk of unfavorable ATT outcomes.

Tuberculosis treatment outcomes of diabetic and non-diabetic TB/HIV co-infected patients: A nationwide observational study in Brazil

Background

Tuberculosis (TB) is a worldwide public health problem, especially in countries that also report high numbers of people living with HIV (PLWH) and/or diabetes mellitus (DM). However, the unique features of persons with TB-HIV-DM are incompletely understood. This study compared anti-TB treatment (ATT) outcomes of diabetic and non-diabetic TB/HIV co-infected patients.

Methods

A nationwide retrospective observational investigation was performed with data from the Brazilian Tuberculosis Database System among patients reported to have TB-HIV co-infection between 2014 and 2019. This database includes all reported TB cases in Brazil. Exploratory and association analyses compared TB treatment outcomes in DM and non-DM patients. Unfavorable outcomes were defined as death, treatment failure, loss to follow-up or recurrence. Multivariable stepwise logistic regressions were used to identify the variables associated with unfavorable ATT outcomes in the TB-HIV population.

Results

Of the 31,070 TB-HIV patients analyzed, 999 (3.2%) reported having DM. However, in these TB-HIV patients, DM was not associated with any unfavorable treatment outcome [adjusted Odds Ratio (aOR): 0.97, 95% CI: 0.83-1.12, p = 0.781]. Furthermore, DM was also not associated with any specific type of unfavorable outcome in this study. In both the TB-HIV group and the TB-HIV-DM subpopulation, use of alcohol, illicit drugs and tobacco, as well as non-white ethnicity and prior TB were all characteristics more frequently observed in persons who experienced an unfavorable ATT outcome.

Conclusion

DM is not associated with unfavorable TB treatment outcomes in persons with TB-HIV, including death, treatment failure, recurrence and loss to follow up. However, consumption habits, non-white ethnicity and prior TB are all more frequently detected in those with unfavorable outcomes in both TB-HIV and TB-HIV-DM patients.

Possible sex difference in latent tuberculosis infection risk among close tuberculosis contacts

OBJECTIVES

More men than women develop and die of tuberculosis (TB). Fewer data exist on sex differences in latent TB infection (LTBI). We assessed for potential sex differences in LTBI acquisition among close TB contacts.

METHODS

Regional Prospective Observational Research for TB-Brazil is an observational multi-center cohort of individuals with culture-confirmed pulmonary TB and their close contacts. Participants were enrolled from five sites in Brazil from June 2015 - June 2019. Close contacts were followed for 24 months after enrollment, with LTBI defined as a positive interferon-γ release assay (IGRA; QuantiFERON 3^rd or 4^th generation) at baseline or 6 months. We performed univariate, bivariate, and multivariable logistic regression and propensity-score weighted models to assess odds ratios (OR) and 95% confidence intervals (CI) for LTBI acquisition by birth sex among close contacts.

RESULTS

Of 1093, 504 (46%) female close contacts were IGRA positive compared to 295 of 745 (40%) men. The unadjusted OR for IGRA positivity among women vs men was 1.31 (95% CI: 1.08-1.58). Bivariate adjustments yielded ORs in women vs men ranging from 1.19 to 1.33 (P-value range: <0.01-0.07). Multivariable regression and weighted models yielded similar ORs in women vs men, of 1.14 (95% CI: 0.92-1.41) and 1.15 (95% CI: 0.94-1.40), respectively.

CONCLUSION

The point estimate for LTBI among close TB contacts in Brazil was higher in women, though less pronounced in multivariable models. If the sex difference in LTBI is confirmed in additional settings, studies of possible underlying differences in socio-behavioral factors or TB pathogenesis are warranted.

Determinants of losses in the tuberculosis infection cascade of care among children and adolescent contacts of pulmonary tuberculosis cases: A Brazilian multi-centre longitudinal study

Background

Approximately 10% of the global tuberculosis (TB) burden is in children. Identification, diagnosis, and early treatment of Mycobacterium tuberculosis infection (TBI) is critical to prevent progression to TB in children. The risk of TB, including severe disease, is highest in children <5 years old. We evaluated the cascade of TBI care among child and adolescent TB contacts to identify factors associated with losses in the cascade.

Methods

Close contacts ≤ 18 years old of pulmonary TB patients enrolled between 2015 and 2019 in a multi-centre Brazilian cohort were followed for up to 24 months and classified according to age groups: <5 years, 5-9 years, 10-14 years and 15-18 years. Data on clinical investigation, radiographic examination, IGRA testing at baseline and 6 months, initiation and completion of TB preventive treatment (TPT) were collected. Multivariable regression analyses identified factors associated with TBI and losses in the cascade of care in children and adolescents.

Findings

Among 1795 TB contacts initially identified, 530 (29·5%) were ≤18 years old. Losses for all steps in the cascade were especially high in children <5 years old (88%) because at this age all contacts are recommended to initiate TPT. As a proportion of all children, completion of TPT was low (between 10% and 13%) in all age-groups. Furthermore, multivariable regression revealed that younger age of contacts and TB index cases who were female, had pulmonary cavities, and persistent cough were independently associated with losses in the cascade of care among persons ≤18 years old.

Interpretation

Losses in the TBI cascade were the highest among children <5 years, which was the group at highest risk for TB among the four age groups. The findings highlight the need to improve screening, initiation, and completion of TPT of young children who are close contacts of people with TB in Brazil.

Funding

National Institutes of Allergy and Infectious Diseases.

Effect of Dysglycemia on Urinary Lipid Mediator Profiles in Persons With Pulmonary Tuberculosis

Background

Oxidized lipid mediators such as eicosanoids play a central role in the inflammatory response associated with tuberculosis (TB) pathogenesis. Diabetes mellitus (DM) leads to marked changes in lipid mediators in persons with TB. However, the associations between diabetes-related changes in lipid mediators and clearance of M. tuberculosis (Mtb) among persons on anti-TB treatment (ATT) are unknown. Quantification of urinary eicosanoid metabolites can provide insights into the circulating lipid mediators involved in Mtb immune responses.

Methods

We conducted a multi-site prospective observational study among adults with drug-sensitive pulmonary TB and controls without active TB; both groups had sub-groups with or without dysglycemia at baseline. Participants were enrolled from RePORT-Brazil (Salvador site) and RePORT-South Africa (Durban site) and stratified according to TB status and baseline glycated hemoglobin levels: a) TB-dysglycemia (n=69); b) TB-normoglycemia (n=64); c) non-TB/dysglycemia (n=31); d) non-TB/non-dysglycemia (n=29). We evaluated the following urinary eicosanoid metabolites: 11α-hydroxy-9,15-dioxo-2,3,4,5-tetranor-prostane-1,20-dioic acid (major urinary metabolite of prostaglandin E2, PGE-M), tetranor-PGE₁ (metabolite of PGE2, TN-E), 9α-hydroxy-11,15-dioxo-2,3,4,5-tetranor-prostane-1,20-dioic acid (metabolite of PGD2, PGD-M), 11-dehydro-thromboxane B2 (11dTxB2), 2,3-dinor-6-keto-PGF₁α (prostaglandin I metabolite, PGI-M), and leukotriene E4 (LTE₄). Comparisons between the study groups were performed at three time points: before ATT and 2 and 6 months after initiating therapy.

Results

PGE-M and LTE₄ values were consistently higher at all three time-points in the TB-dysglycemia group compared to the other groups (p<0.001). In addition, there was a significant decrease in PGI-M and LTE₄ levels from baseline to month 6 in the TB-dysglycemia and TB-normoglycemia groups. Finally, TB-dysglycemia was independently associated with increased concentrations of PGD-M, PGI-M, and LTE₄ at baseline in a multivariable model adjusting for age, sex, BMI, and study site. These associations were not affected by HIV status.

Conclusion

The urinary eicosanoid metabolite profile was associated with TB-dysglycemia before and during ATT. These observations can help identify the mechanisms involved in the pathogenesis of TB-dysglycemia, and potential biomarkers of TB treatment outcomes, including among persons with dysglycemia.

Persistent dysglycemia is associated with unfavorable treatment outcomes in patients with pulmonary tuberculosis from Peru

BACKGROUND

Dysglycemia (i.e., prediabetes or diabetes) on patients with tuberculosis (PWTB) was associated with increased odds of mortality and treatment failure. Whether such association holds when dysglycemia is transient or persistent is unknown. Here we tested the association between persistent dysglycemia (PD) during anti-TB treatment and unfavorable treatment outcomes in PWTB from Lima, Peru.

METHODS

PWTB enrolled between February and November 2017 were followed for 24-months. Dysglycemia was measured by fasting glucose and HbA1c at baseline, 2^nd-and 6^th-month of TB treatment. PD was defined as dysglycemia detected in two different visits. The association between PD and unfavorable TB treatment outcome was evaluated by logistic regression.

RESULTS

Among 125 PWTB, PD prevalence was 29.6%. PD was associated with more lung lesion types, higher bacillary loads, low hemoglobin and high body mass index (BMI). Unfavorable TB treatment outcome was associated with older age, higher BMI, more lung lesion types and PD. After adjusting for age, hemoglobin levels, smoking and smear grade, PD was independently associated with unfavorable treatment (aOR: 6.1; 95%CI: 1.9-19.6).

CONCLUSION

Persistent dysglycemia is significantly associated with higher odds of unfavorable TB treatment outcomes. Dysglycemia control trough anti-TB treatment gives the opportunity to introduce appropriate interventions to TB management.

The Effect of Diabetes and Prediabetes on Mycobacterium tuberculosis Transmission to Close Contacts

BACKGROUND

It is unknown whether dysglycemia is associated with Mycobacterium tuberculosis transmission.

METHODS

We assessed epidemiological and clinical characteristics of patients with culture-confirmed pulmonary tuberculosis and their close contacts, enrolled in a multicenter prospective cohort in Brazil. Contacts were investigated at baseline and 6 months after enrollment. QuantiFERON positivity at baseline and conversion (from negative to positive at month 6) were compared between subgroups of contacts according to glycemic status of persons with tuberculosis (PWTB) as diabetes mellitus (DM) or prediabetes. Multivariable mixed-effects logistic regression models were performed to test independent associations with baseline QuantiFERON positive and QuantiFERON conversion.

RESULTS

There were 592 PWTB (153 DM, 141 prediabetes, 211 normoglycemic) and 1784 contacts, of whom 658 were QuantiFERON-positive at baseline and 106 converters. Multivariable analyses demonstrated that tuberculosis-prediabetes cases, acid-fast bacilli-positive, pulmonary cavities, and living with someone who smoked were independently associated with QuantiFERON positive in contacts at baseline. DM, persistent cough, acid-fast bacilli-positive, and pulmonary cavities in tuberculosis source cases were associated with QuantiFERON conversion.

CONCLUSIONS

Contacts of persons with pulmonary tuberculosis and dysglycemia were at increased risk of being QuantiFERON positive at baseline or month 6. Increased focus on such close contacts could improve tuberculosis control.

The Effect of Diabetes and Prediabetes on Anti-tuberculosis Treatment Outcomes: A Multi-center Prospective Cohort Study

BACKGROUND

It is unclear whether diabetes or prediabetes affect unfavorable treatment outcomes and death in people with tuberculosis (PWTB).

METHODS

Culture-confirmed drug-susceptible PWTB, enrolled in Regional Prospective Observational Research in Tuberculosis (RePORT)-Brazil between 2015-2019 (n=643) were stratified based on glycemic status according to baseline glycated hemoglobin. Unfavorable TB outcome was defined as treatment failure or modification, recurrence or death; favorable outcome was cure or treatment completion. We corroborated the findings using data from PWTB reported to the Brazilian National System of Diseases Notification (SINAN) during 2015-2019 (n=20,989). Logistic regression models evaluated associations between glycemic status and outcomes.

RESULTS

In both cohorts, in univariate analysis, unfavorable outcomes were more frequently associated with smoking, illicit drug use and HIV infection. Diabetes, but not prediabetes, was associated with unfavorable outcomes in the RePORT-Brazil (adjusted Relative Risk [aRR]: 2.45, p<0.001) and SINAN (aRR: 1.76, p<0.001) cohorts. Furthermore, diabetes was associated with high risk of death (during TB treatment) in both RePORT-Brazil (aRR:2.16, p=0.040) and SINAN (aRR:1.93, p= 0.001).

CONCLUSION

Diabetes was associated with an increased risk of unfavorable outcomes and mortality in Brazilian PWTB. Interventions to improve tuberculosis treatment outcomes in persons with diabetes are needed.

Determinants of losses in the latent tuberculosis infection cascade of care in Brazil

INTRODUCTION

Factors associated with losses in the latent tuberculosis infection (LTBI) cascade of care in contacts of patients with tuberculosis (TB) were investigated in a multicentre prospective cohort from highly endemic regions in Brazil.

METHODS

Close contacts of 1187 patients with culture-confirmed pulmonary TB were prospectively studied between 2015 and 2019, with follow-up of 6-24 months. Data on TB screening by clinical investigation, radiographic examination and interferon-gamma release assay (IGRA) were collected. Multivariable regressions were used to identify determinants of losses in the LTBI cascade.

RESULTS

Among 4145 TB contacts initially identified, 1901 were examined (54% loss). Among those examined, 933 were people living with HIV, ≤5 years old and/or had positive IGRA results, and therefore had a recommendation to start TB preventive treatment (TPT). Of those, 454 (23%) initiated treatment, and 247 (54% of those initiating; 26% of those in whom treatment was recommended) completed TPT. Multivariable regression analysis revealed that living with HIV, illiteracy and black/pardo (brown) race were independently associated with losses in the cascade.

CONCLUSION

There were losses at all LTBI cascade stages, but particularly at the initial screening and examination steps. Close contacts of low socioeconomic status and living with HIV were at heightened risk of not completing the LTBI cascade of care in Brazil.

Tuberculosis Burden and Determinants of Treatment Outcomes According to Age in Brazil: A Nationwide Study of 896,314 Cases Reported Between 2010 and 2019

Approximately 1.4 million people die annually worldwide from tuberculosis. Large epidemiologic studies can identify determinants of unfavorable clinical outcomes according to age, which can guide public health policy implementation and clinical management to improve outcomes. We obtained data from the national tuberculosis case registry; data were reported to the Brazilian National Program (SINAN) between 2010 and 2019. Clinical and epidemiologic variables were compared between age groups (child: <10 years, young: 10–24years, adult: 25–64years, and elderly: ≥65years). Univariate comparisons were performed together with second-generation p-values. We applied a backward stepwise multivariable logistic regression model to identify characteristics in each age group associated with unfavorable TB treatment outcomes. There were 896,314 tuberculosis cases reported during the period. Tuberculosis incidence was highest among adult males, but the young males presented the highest growth rate during the period. Directly observed therapy (DOT) was associated with protection against unfavorable outcomes in all age groups. The use of alcohol, illicit drugs, and smoking, as well as occurrence of comorbidities, were significantly different between age groups. Lack of DOT, previous tuberculosis, race, location of tuberculosis disease, and HIV infection were independent risk factors for unfavorable outcome depending on the age group. The clinical and epidemiological risk factors for unfavorable tuberculosis treatment outcomes varied according to age in Brazil. DOT was associated with improved outcomes in all age groups. Incidence according to age and sex identified adults and young males as the groups that need prevention efforts. This supports implementation of DOT in all populations to improve tuberculosis outcomes.

Pre-Treatment Neutrophil Count as a Predictor of Antituberculosis Therapy Outcomes: A Multicenter Prospective Cohort Study

Background

Neutrophils have been associated with lung tissue damage in many diseases, including tuberculosis (TB). Whether neutrophil count can serve as a predictor of adverse treatment outcomes is unknown.

Methods

We prospectively assessed 936 patients (172 HIV-seropositive) with culture-confirmed pulmonary TB, enrolled in a multicenter prospective cohort study from different regions in Brazil, from June 2015 to June 2019, and were followed up to two years. TB patients had a baseline visit before treatment (month 0) and visits at month 2 and 6 (or at the end of TB treatment). Smear microscopy, and culture for Mycobacterium tuberculosis (MTB) were performed at TB diagnosis and during follow-up. Complete blood counts were measured at baseline. Treatment outcome was defined as either unfavorable (death, treatment failure or TB recurrence) or favorable (cure or treatment completion). We performed multivariable logistic regression, with propensity score regression adjustment, to estimate the association between neutrophil count with MTB culture result at month 2 and unfavorable treatment outcome. We used a propensity score adjustment instead of a fully adjusted regression model due to the relatively low number of outcomes.

Results

Among 682 patients who had MTB culture results at month 2, 40 (5.9%) had a positive result. After regression with propensity score adjustment, no significant association between baseline neutrophil count (10³/mm³) and positive MTB culture at month 2 was found among either HIV-seronegative (OR = 1.06, 95% CI = [0.95;1.19] or HIV-seropositive patients (OR = 0.77, 95% CI = [0.51; 1.20]). Of 691 TB patients followed up for at least 18 months and up to 24 months, 635 (91.9%) were either cured or completed treatment, and 56 (8.1%) had an unfavorable treatment outcome. A multivariable regression with propensity score adjustment found an association between higher neutrophil count (10³/mm³) at baseline and unfavorable outcome among HIV-seronegative patients [OR= 1.17 (95% CI= [1.06;1.30]). In addition, adjusted Cox regression found that higher baseline neutrophil count (10³/mm³) was associated with unfavorable treatment outcomes overall and among HIV-seronegative patients (HR= 1.16 (95% CI = [1.05;1.27]).

Conclusion

Increased neutrophil count prior to anti-TB treatment initiation was associated with unfavorable treatment outcomes, particularly among HIV-seronegative patients. Further prospective studies evaluating neutrophil count in response to drug treatment and association with TB treatment outcomes are warranted.

Novel stepwise approach to assess representativeness of a large multicenter observational cohort of tuberculosis patients: The example of RePORT Brazil

BACKGROUND

A major goal of tuberculosis (TB) epidemiological studies is to obtain results that can be generalized to the larger population with TB. The ability to extrapolate findings on the determinants of TB treatment outcomes is also important.

METHODS

We compared baseline clinical and demographic characteristics and determinants of anti-TB treatment outcomes between persons enrolled in the Regional Prospective Observational Research in Tuberculosis (RePORT)-Brazil cohort between June 2015 and June 2019, and the registry of TB cases reported to the Brazilian National TB Program (Information System for Notifiable Diseases [SINAN]) during the same time period. Multivariable regression models adjusted for the study site were performed using second-generation p-values, a novel statistical approach. Associations with unfavorable treatment outcomes were tested for both RePORT-Brazil and SINAN cohorts.

FINDINGS

A total of 1,060 culture-confirmed TB patients were enrolled in RePORT-Brazil and 455,873 TB cases were reported to SINAN. Second-generation p-value analyses revealed that the cohorts were strikingly similar with regard to sex, age, use of antiretroviral therapy and positive initial smear sputum microscopy. However, diabetes, HIV infection, and smoking were more frequently documented in RePORT-Brazil. Illicit drug use, the presence of diabetes, and history of prior TB were associated with unfavorable TB treatment outcomes; illicit drug use was associated with such outcomes in both cohorts.

CONCLUSIONS

There were important similarities in demographic characteristics and determinants of clinical outcomes between the RePORT-Brazil cohort and the Brazilian National registry of TB cases.

Dysglycemia is associated with Mycobacterium tuberculosis lineages in tuberculosis patients of North Lima-Peru

This study was performed to investigate the role of dysglycemia on the genetic diversity of Mycobacterium tuberculosis (MTB) among pulmonary tuberculosis (TB) patients to build scientific evidence about the possible mechanisms of TB transmission. MTB isolates obtained of patients affected by pulmonary tuberculosis from health care facilities of North Lima-Peru, were analyzed using whole genome sequencing and 24-locus mycobacterial interspersed repetitive-unit -variable-number tandem repeats (MIRU-VNTR). Subsequently, clinical and epidemiological characteristics were associated with clustering, lineages and comorbid conditions. The analysis carried out 112 pulmonary TB patients from various health centers in North Lima, 17 (15%) had diabetes mellitus (DM) and 33 (29%) had pre-diabetes (PDM). Latin American-Mediterranean, Haarlem and Beijing were the most frequent MTB lineages found in those patients. Previous TB (adjusted odds ratio [aOR] = 3.65; 95%CI: 1.32-17.81), age (aOR = 1.12; 95%CI: 1.03-1.45) and Beijing lineage (aOR = 3.53; 95%CI: 1.08-13.2) were associated with TB-DM comorbidity. Alcoholism (aOR = 2.92; 95%CI: 1.10-8.28), age (aOR = 1.05; 95%CI: 1.03-1.12) and Haarlem lineage (aOR = 2.54; 95%CI: 1.04-6.51) were associated with TB-PDM comorbidity. Beijing and Haarlem lineages were independently associated with TB-DM and TB-PDM comorbidities, respectively. Although these findings may be surprising, we must be cautious to suggest that dysglycemia could be associated with a highly clustering and predisposition of MTB lineages related to a serious impact on the severity of TB disease, which requires further research.

Unfavorable Outcomes in Tuberculosis: Multidimensional Factors among Adolescents in Rio de Janeiro, Brazil

Since 2018, adolescents have been included as a target group for tuberculosis (TB) surveillance by the WHO. However, they are considered a neglected population, as there are considerable gaps in information about them. We aimed to analyze the risk factors for unfavorable TB treatment outcomes among adolescents in Rio de Janeiro, a Brazilian city with a high burden of TB. This is a retrospective study of adolescents (10-18 years) with TB notified in Rio de Janeiro, from four national database systems, covering 2014-2016. "Extreme vulnerability" was defined as adolescents who presented one of the following characteristics: homelessness, incarceration, tobacco use, illicit drug use, or alcohol abuse. Logistic regression analysis was used to identify factors associated with favorable (cure/completed treatment) and unfavorable outcomes (lost to follow-up, death, and treatment failure). A total of 725 adolescents with TB were included: 610 (84.1%) were cured, 94 (13%) were lost to follow-up, six (0.8%) died because of TB, 13 (1.8%) died because of other causes, and two (0.3%) failed treatment. Unfavorable outcomes were associated with retreatment (adjusted odds ratio [aOR]: 4.51; 95% CI: 2.23-9.17), TB-HIV coinfection (aOR: 10.15; 95% CI: 4.15-25.34), extreme vulnerability (aOR: 3.01; 95% CI: 1.70-5.33), and living in the two districts (3.1 and 3.3) with worst conditions: large population and rates of homicides and shantytowns (aOR: 4.11; 95% CI: 1.79-9.46 and aOR: 5.35; 95% CI: 2.20-13.03, respectively). Our findings underscore the need for strengthening early identification and interventions for adolescents at high risk of unfavorable outcomes, especially those living in shantytowns.

Polymorphisms in TLR4 and TNFA and Risk of Mycobacterium tuberculosis Infection and Development of Active Disease in Contacts of Tuberculosis Cases in Brazil: A Prospective Cohort Study

BACKGROUND

The role of genetic polymorphisms in latent tuberculosis (TB) infection and progression to active TB is not fully understood.

METHODS

We tested the single-nucleotide polymorphisms (SNPs) rs5743708 (TLR2), rs4986791 (TLR4), rs361525 (TNFA), rs2430561 (IFNG) rs1143627 (IL1B) as risk factors for tuberculin skin test (TST) conversion or development of active TB in contacts of active TB cases. Contacts of microbiologically confirmed pulmonary TB cases were initially screened for longitudinal evaluation up to 24 months, with clinical examination and serial TST, between 1998 and 2004 at a referral center in Brazil. Data and biospecimens were collected from 526 individuals who were contacts of 177 active TB index cases. TST conversion was defined as induration ≥5 mm after a negative TST result (0 mm) at baseline or month 4 visit. Independent associations were tested using logistic regression models.

RESULTS

Among the 526 contacts, 60 had TST conversion and 44 developed active TB during follow-up. Multivariable regression analysis demonstrated that male sex (odds ratio [OR]: 2.3, 95% confidence interval [CI]: 1.1-4.6), as well as SNPs in TLR4 genes (OR: 62.8, 95% CI: 7.5-525.3) and TNFA (OR: 4.2, 95% CI: 1.9-9.5) were independently associated with TST conversion. Moreover, a positive TST at baseline (OR: 4.7, 95% CI: 2.3-9.7) and SNPs in TLR4 (OR: 6.5, 95% CI: 1.1-36.7) and TNFA (OR: 12.4, 95% CI:5.1-30.1) were independently associated with incident TB.

CONCLUSIONS

SNPs in TLR4 and TNFA predicted both TST conversion and active TB among contacts of TB cases in Brazil.

Pediatric tuberculosis in the metropolitan area of Rio de Janeiro

AIM

To evaluate the clinical characteristics, diagnostic approach, and treatment outcomes of tuberculosis (TB) in children living in a high-burden metropolitan area.

METHODS

This was a retrospective study, based on a medical chart review, involving children under 15 years old treated for TB between 2007 and 2016, in four primary health units (PHU) and three reference centers (RC) in five cities of Rio de Janeiro metropolitan area. Factors associated with TB treatment setting, microbiological diagnosis, and treatment outcomes were evaluated.

RESULTS

A total of 544 children were enrolled; 71% were treated in PHU, 36% were under 5 years old, and 72% had pulmonary TB (PTB). The HIV prevalence was 10% (31/322). Fifty-three percent had at least one microbiological test for TB, 68% of them (196/287) had TB confirmed. Among 222 children with previous TB contact, information on LTBI was available for 78 (35%), and only 17% (13/78) were treated. Extrapulmonary TB (56% vs 32%), microbiologically confirmed TB (77% vs 60%), and HIV positivity (18.5% vs 4.0%) were significantly more frequent in RC. Treatment in RC (odds ratio (OR) 3.08, 95% confidence interval (CI) 1.74-5.44) and PTB (OR 2.47, 95% CI 1.34-4.56) were independently associated with a microbiological diagnosis of TB. The treatment success rate was 85%. In the logistic regression analysis, HIV-infected children had a 2.5-fold higher risk of an unfavorable outcome (OR 2.53, 95% CI 1.0-6.38; p = 0.05).

CONCLUSIONS

Opportunities for TB prevention and early TB treatment are missed due to suboptimal close contact screening. Microbiological diagnosis of TB and drug susceptibility testing in children should be made available through more sensitive and accessible tests.

Factors associated with non-completion of latent tuberculosis infection treatment in Rio de Janeiro, Brazil: A non-matched case control study

INTRODUCTION

There are scarce data on the routine latent tuberculosis infection treatment (LTBIT) and factors associated with a non-completion in high tuberculosis burden countries. Therefore, in this study we aimed to evaluate the factors associated with non-completion of LTBIT.

MATERIALS AND METHODS

This was a non-matched case control study conducted at a University Hospital in Rio de Janeiro, Brazil. A total of 114 cases and 404 controls were enrolled between January/1999 and December/2009. Cases were close contacts who did not complete the LTBIT and controls were the contacts that completed it. Multivariate analysis was used to investigate risk factors associated with non-completion of LTBIT among contacts in two different periods of recruitment.

RESULTS

Factors associated with non-completion LTBIT included: drug use (OR 23.33, 95% CI 1.83-296.1), TB treatment default by the index case (OR 16.97, 95% CI 3.63-79.24) and drug intolerance. TB disease rates after two years of follow up varied from 0.4% to 1.9%. The number necessary to treat to prevent one TB case among contacts was 116.

CONCLUSIONS

Non-completion treatment by the index case and illicit drug use were associated with not completing latent tuberculosis infection treatment and no tuberculosis disease was identified among those who completed latent tuberculosis infection treatment.

Contribution of Xpert MTB/RIF to clinical diagnosis in adolescents with tuberculosis in Rio de Janeiro, Brazil

SETTING: Rio de Janeiro, RJ, Brazil, a high tuberculosis (TB) burden city.OBJECTIVE: To compare the sociodemographics, clinical characteristics, care process indicators (CPIs) and treatment outcomes among adolescents with pulmonary TB (PTB) and those with PTB + extrapulmonary TB (EPTB), who underwent testing with Xpert^® and sputum culture.DESIGN: This was a retrospective study of data from three national databases from 2014 to 2016 of adolescents (aged 10-18 years) residing and notified in Rio de Janeiro City. Three groups were identified according to their Xpert and culture results: Group 1, Xpert- and culture-positive; Group 2, Xpert-positive and culture-negative; and Group 3, Xpert- and culture-negative. Study CPIs were as follows: the time between 'sample collection and Xpert result release', 'sample collection and treatment initiation' and 'notification and treatment outcome'.RESULTS: Of 258 adolescents included in the study, 223 (86.4%) were in Group 1, 20 (7.8%) in Group 2 and 15 (5.8%) in Group 3. Groups 1 and 2 had a similar profile. Compared to Group 1, Group 3 had a higher proportion of HIV-positive cases (21.4% vs. 3.0%, P = 0.016), adolescents with a hospital diagnosis (53.3% vs. 7.6%, P < 0.001), and PTB + EPTB cases (20% vs. 0.4%; P < 0.001). There were no statistically significant differences in CPIs or treatment outcomes.CONCLUSION: The clinical diagnosis was decisive in more critical or complex patients, despite Xpert-negative results.

Relationship of anti-tuberculosis drug-induced liver injury and genetic polymorphisms in CYP2E1 and GST

Setting

Treatment of tuberculosis (TB) can result in Drug-Induced Liver Injury (DILI) since hepatotoxic metabolites are formed during the biotransformation of isoniazid (INH).

DILI can be related to the genetic profile of the patient. Single nucleotide polymorphisms in the CYP2E1 gene and GSTM1 and GSTT1 deletion polymorphisms have been associated with adverse events caused by INH.

Objective

To characterize the genetic polymorphisms of CYP2E1, GSTT1 and GSTM1 in TB carriers.

Design

This is an observational prospective cohort study of 45 patients undergoing treatment of TB. PCR-RFLP and multiplex-PCR were used.

Results

The distribution of genotypic frequency in the promoter region (CYP2E1 gene) was: 98% wild genotype and 2% heterozygous. Intronic region: 78% wild genotype; 20% heterozygous and 2% homozygous variant. GST enzyme genes: 24% Null GSTM1 and 22% Null GSTT1. Patients with any variant allele of the CYP2E1 gene were grouped in the statistical analyses.

Conclusion

Patients with the CYP2E1 variant genotype or Null GSTT1 showed higher risk of presenting DILI (p = 0.09; OR: 4.57; 95% CI: 0.75–27.6). Individuals with both genotypes had no increased risk compared to individuals with one genotype.

Imbalance of NET and Alpha-1-Antitrypsin in Tuberculosis Patients Is Related With Hyper Inflammation and Severe Lung Tissue Damage

Background: Pulmonary tuberculosis (PTB) can lead to lung tissue damage (LTD) and compromise the pulmonary capacity of TB patients that evolve to severe PTB. The molecular mechanisms involved in LTD during anti-tuberculous treatment (ATT) remain poorly understood.

Methods and findings: We evaluated the role of neutrophil extracellular trap (NET) and the occurrence of LTD through chest radiographic images, the microbial load in sputum, and inflammatory serum profile (IL-12p40/p70, IL-8, IL-17A, IL-23, VEGF-A, MMP-1, and -8, galectin-3, citrunillated histone H3—cit-H3, alpha-1-antitrypsin—α1AT, C-reactive protein—CRP and albumin) in a cohort of 82 PTB patients before and after 60 days of ATT. Using univariate analysis, LTD was associated with neutrophilia and increase of several inflammatory proteins involved in the neutrophil-mediated response, being cit-H3 the more related to the event. In the multivariate analysis, neutrophilia and cit-H3 appear as directly related to LTD. The analysis of the ROC curve at day 60 presented AUC of 0.97 (95.0% CI 0.95–1). Interestingly, at day 0 of ATT, these biomarkers demonstrated fine relation with LTD showing an AUC 0.92 (95.0% CI 0.86–0.99). Despite of that, the same molecules have no impact in culture conversion during ATT.

Conclusions: Our data revealed that NETs may play a key role in the pathway responsible for non-specific inflammation and tissue destruction in PTB. High level of cit-H3 and low level of α1AT was observed in the serum of severe TB patients, suggesting a breakdown in the intrinsic control of NET-driven tissue damage. These data show a new insight to knowledge TB immunopathogenesis, the role of neutrophil and NET pathway. Likewise, we identified possible biomarkers to screening of PTB patients eligible to adjuvants therapies, as anti-inflammatories and alpha-1-antitrypsin.

Prevalence of depression among patients with presumptive pulmonary tuberculosis in Rio de Janeiro, Brazil

Objective:

To estimate the prevalence of major depressive episode (MDE) in patients with presumptive pulmonary tuberculosis (pre-PTB, defined by cough lasting ≥ 3 weeks) and compare it between patients with pulmonary tuberculosis (PTB) and without PTB.

Methods:

Patients with pre-PTB (n=260) were screened for depression using the Patient Health Questionnaire (PHQ-9). Those individuals with scores ≥ 10 were subsequently assessed with the depression module of the Mini International Neuropsychiatric Interview (MINI-Plus) to confirm diagnosis. Associations of categorical variables with PTB and MDE were calculated using the chi-square test and OR.

Results:

PTB was confirmed in 98 patients (37.7%). A high proportion of both groups (active PTB and no PTB) screened positive for depression (60.2 vs. 62.1%, respectively). Among 159 patients who screened positive for depression, a subset of 97 (61.0%) were further evaluated with the MINI-Plus; current MDE was confirmed in 54.6% (53/97). On univariate and multivariate analysis, female sex was the only factor associated with the diagnosis of current MDE (p = 0.04).

Conclusion:

The prevalence of MDE was high among individuals with prolonged respiratory symptoms, independent of PTB diagnosis. This is consistent with other studies of depression in primary care in Brazil.

Prevalence of pyrazinamide resistance and Wayne assay performance analysis in a tuberculosis cohort in Lima, Peru

BACKGROUND

Multidrug-resistant tuberculosis (MDR-TB) regimens often contain pyrazinamide (PZA) even if susceptibility to the drug has not been confirmed. This gap is due to the limited availability and reliability of PZA susceptibility testing.

OBJECTIVES

To estimate the prevalence of PZA resistance using the Wayne assay among TB patients in Lima, Peru, to describe characteristics associated with PZA resistance and to compare the performance of Wayne with that of BACTEC™ MGIT™ 960.

METHODS

PZA susceptibility using the Wayne assay was tested in patients diagnosed with culture-positive pulmonary TB from September 2009 to August 2012. Factors associated with PZA resistance were evaluated. We compared the performance of the Wayne assay to that of MGIT 960 in a convenience sample.

RESULTS

The prevalence of PZA resistance was 6.6% (95%CI 5.8-7.5) among 3277 patients, and 47.7% (95%CI 42.7-52.6) among a subset of 405 MDR-TB patients. In multivariable analysis, MDR-TB (OR 86.0, 95%CI 54.0-136.9) and Latin American-Mediterranean lineage (OR 3.40, 95%CI 2.33-4.96) were associated with PZA resistance. The Wayne assay was in agreement with MGIT 960 in 83.9% of samples (κ 0.66, 95%CI 0.56-0.76).

CONCLUSION

PZA resistance was detected using the Wayne assay in nearly half of MDR-TB patients in Lima. This test can inform the selection and composition of regimens, especially those dependent on additional resistance.

Outcomes from patients with presumed drug resistant tuberculosis in five reference centers in Brazil

Background

The implementation of rapid drug susceptibility testing (DST) is a current global priority for TB control. However, data are scarce on patient-relevant outcomes for presumptive diagnosis of drug-resistant tuberculosis (pDR-TB) evaluated under field conditions in high burden countries.

Methods

Observational study of pDR-TB patients referred by primary and secondary health units. TB reference centers addressing DR-TB in five cities in Brazil. Patients age 18 years and older were eligible if pDR-TB, culture positive results for Mycobacterium tuberculosis and, if no prior DST results from another laboratory were used by a physician to start anti-TB treatment. The outcome measures were median time from triage to initiating appropriate anti-TB treatment, empirical treatment and, the treatment outcomes.

Results

Between February,16th, 2011 and February, 15th, 2012, among 175 pDR TB cases, 110 (63.0%) confirmed TB cases with DST results were enrolled. Among study participants, 72 (65.5%) were male and 62 (56.4%) aged 26 to 45 years. At triage, empirical treatment was given to 106 (96.0%) subjects. Among those, 85 were treated with first line drugs and 21 with second line. Median time for DST results was 69.5 [interquartile - IQR: 35.7–111.0] days and, for initiating appropriate anti-TB treatment, the median time was 1.0 (IQR: 0–41.2) days. Among 95 patients that were followed-up during the first 6 month period, 24 (25.3%; IC: 17.5%–34.9%) changed or initiated the treatment after DST results: 16/29 MDRTB, 5/21 DR-TB and 3/45 DS-TB cases. Comparing the treatment outcome to DS-TB cases, MDRTB had higher proportions changing or initiating treatment after DST results (p = 0.01) and favorable outcomes (p = 0.07).

Conclusions

This study shows a high rate of empirical treatment and long delay for DST results. Strategies to speed up the detection and early treatment of drug resistant TB should be prioritized.

Evaluation of the Mean Cost and Activity Based Cost in the Diagnosis of Pulmonary Tuberculosis in the Laboratory Routine of a High-Complexity Hospital in Brazil

At a global level, with the increase in healthcare costs, there is a need to assess the economic impact of the incorporation of new technologies in different health disorders in different countries. There is scarce information regarding costs incurred with the use of current or new diagnostic tests for tuberculosis or from the vantage point of their incorporation within the healthcare systems of high-burden countries. The present study aimed to assess the mean cost and the activity based cost of the laboratory diagnosis for tuberculosis by means of conventional techniques and from the Detect TB^®LabTest molecular test kit in a general high-complexity hospital of the public health system in Brazil. Cost analysis was performed by means of primary data, collected in the Mycobacteria and Molecular Biology Laboratory in 2013. The mean cost and activity based cost were, respectively, U$10.06/U$5.61 for centrifuged bacilloscopy by Ziehl Neelsen (ZN) and Auramine (AU); U$7.42/U$4.15 for direct bacilloscopy by ZN; U$27.38/U$16.50 for culture in a Loweinstein-Jensen solid medium; and U$115.74/U$73.46 for the Detect TB^®LabTest Kit. The calculation of the ABC should be used in making decisions by administrators to be the best method of assessing the costs of conventional techniques and molecular method for providing the real value of the tests. So it is need to calculate the ABC, and not of the mean cost, in various scenarios before incorporating new technologies in health institutions.

Transcriptomic Biomarkers for Tuberculosis: Evaluation of DOCK9. EPHA4, and NPC2 mRNA Expression in Peripheral Blood

Lately, much effort has been made to find mRNA biomarkers for tuberculosis (TB) disease/infection with microarray-based approaches. In a pilot investigation, through RNA sequencing technology, we observed a prominent modulation of DOCK9, EPHA4, and NPC2 mRNA abundance in the blood of TB patients. To corroborate these findings, independent validations were performed in cohorts from different areas. Gene expression levels in blood were evaluated by quantitative real-time PCR (Brazil, n = 129) or reanalysis of public microarray data (UK: n = 96; South Africa: n = 51; Germany: n = 26; and UK/France: n = 63). In the Brazilian cohort, significant modulation of all target-genes was observed comparing TB vs. healthy recent close TB contacts (rCt). With a 92% specificity, NPC2 mRNA high expression (NPC2^high) showed the highest sensitivity (85%, 95% CI 65%–96%; area under the ROC curve [AUROC] = 0.88), followed by EPHA4 (53%, 95% CI 33%–73%, AUROC = 0.73) and DOCK9 (19%, 95% CI 7%–40%; AUROC = 0.66). All the other reanalyzed cohorts corroborated the potential of NPC2^high as a biomarker for TB (sensitivity: 82–100%; specificity: 94–97%). An NPC2^high profile was also observed in 60% (29/48) of the tuberculin skin test positive rCt, and additional follow-up evaluation revealed changes in the expression levels of NPC2 during the different stages of Mycobacterium tuberculosis infection, suggesting that further studies are needed to evaluate modulation of this gene during latent TB and/or progression to active disease. Considering its high specificity, our data indicate, for the first time, that NPC2^high might serve as an accurate single-gene biomarker for TB.

Development of two artificial neural network models to support the diagnosis of pulmonary tuberculosis in hospitalized patients in Rio de Janeiro, Brazil

Pulmonary tuberculosis (PTB) remains a worldwide public health problem. Diagnostic algorithms to identify the best combination of diagnostic tests for PTB in each setting are needed for resource optimization. We developed one artificial neural network model for classification (multilayer perceptron-MLP) and another risk group assignment (self-organizing map-SOM) for PTB in hospitalized patients in a high complexity hospital in Rio de Janeiro City, using clinical and radiologic data collected from 315 presumed PTB cases admitted to isolation rooms from March 2003 to December 2004 (TB prevalence = 21.5 %). The MLP model included 7 variables-radiologic classification, age, gender, cough, night sweats, weight loss and anorexia. The sensitivity of the MLP model was 96.0 % (95 % CI ±2.0), the specificity was 89.0 % (95 % CI ±2.0), the positive predictive value was 72.5 % (95 % CI ±3.5) and the negative predictive value was 98.5 % (95 % CI ±0.5). The variable with the highest discriminative power was the radiologic classification. The high negative predictive value found in the MLP model suggests that the use of this model at the moment of hospital admission is safe. SOM model was able to correctly assign high-, medium- and low-risk groups to patients. If prospective validation in other series is confirmed, these models can become a tool for decision-making in tertiary health facilities in countries with limited resources.

Safety and effectiveness of HAART in tuberculosis-HIV co-infected patients in Brazil

BACKGROUND

Antiretroviral therapy (ART) significantly reduces tuberculosis (TB) incidence among persons with human immunodeficiency virus (HIV), but the safety and effectiveness of concomitant treatment for both diseases remain unclear.

OBJECTIVE

To evaluate the impact of ART and anti-tuberculosis treatment on survival and risk of adverse events (AE) among co-infected individuals.

METHODS

In a retrospective cohort study, clinical data were collected from 618 TB-HIV patients treated with rifampin, isoniazid and pyrazinamide ± ethambutol between 1 January 1995 and 31 December 2003. Patients were categorized into two groups: highly active ART (HAART) or no ART. Different HAART regimens were evaluated. Bivariate analysis, multivariate logistic regression and survival analysis using Cox proportional hazards regression were used.

RESULTS

One-year mortality was lower for patients receiving HAART (adjusted hazard ratio [aHR] 0.17, 95%CI 0.09-0.31) compared to no ART. HAART increased the risk of AE (aHR 2.08, 95%CI 1.29-3.36). The odds of AE when receiving a ritonavir + saquinavir HAART regimen was eight-fold higher compared to no ART (OR 8.31, 95%CI 3.04-22.69), while efavirenz-based HAART was not associated with a significantly increased risk of AE (OR 1.42, 95%CI 0.76-2.65).

CONCLUSION

HIV patients with TB have significantly better survival if they receive HAART during anti-tuberculosis treatment. Efavirenz-based HAART is associated with fewer AEs than protease inhibitor-based HAART.

Tuberculosis caused by RDRio Mycobacterium tuberculosis is not associated with differential clinical features

BACKGROUND

We recently described the Mycobacterium tuberculosis RD(Rio) genotype, a clonally derived sublineage within the Latin American-Mediterranean (LAM) family. Genetic diversity of M. tuberculosis likely affects the clinical aspects of tuberculosis (TB). Prospective studies that address this issue are scarce and remain controversial.

OBJECTIVE

To determine the association of differential clinical features of pulmonary TB with the RD(Rio) M. tuberculosis etiology.

METHODS

Culture-proven pulmonary TB patients (n = 272) were clinically evaluated, including history, physical examination, chest X-ray and anti-human immunodeficiency virus serology. Isolates were classified as RD(Rio) or non-RD(Rio) M. tuberculosis by multiplex polymerase chain reaction and further spoligotyped. Clinical and M. tuberculosis genotype data were analyzed.

RESULTS

RD(Rio) M. tuberculosis caused disease in 26.5% (72/270) of all TB cases. The LAM genotype, of which RD(Rio) strains are members, was responsible for 46.0% of the TB cases. Demographic data, major signs and symptoms, radiographic presentation, microbiological features and clinical outcomes were not significantly different among patients with TB caused by RD(Rio) and non-RD(Rio) strains.

CONCLUSIONS

Disease caused by M. tuberculosis RD(Rio) strains was not clinically distinctive or more severe than disease caused by non-RD(Rio) strains in this series of TB patients. Larger prospective studies specifically designed to disclose differential clinical characteristics of TB caused by specific M. tuberculosis lineages are needed.

Interleukin-10 and interferon-gamma patterns during tuberculosis treatment: possible association with recurrence

Interleukin (IL) 10 and interferon-gamma (IFN-) levels in induced sputum supernatants of 21 tuberculosis (TB) patients at diagnosis and during chemotherapy were correlated to recurrence rates. IL-10 decreased until day 60 of treatment (T60), and between T60 and T180 it increased again in 7 cases (Pattern 1) and further decreased in 14 cases (Pattern 2). Follow-up of 69 months was performed in 20/21 cases; 6 had recurrence of TB, of which 5/7 (71%) had Pattern 1 and 1/13 (7.7%) Pattern 2 (OR 30.0, 95%CI 2.19411.3, P 0.0072). This was not observed for IFN-. High IL-10 levels at the end of treatment may function as a risk factor for TB recurrence.

Challenges and perspectives for improved management of HIV/Mycobacterium tuberculosis co-infection

HIV and Mycobacterium tuberculosis (MTB) are two widespread and highly successful microbes whose synergy in pathogenesis has created a significant threat for human health globally. In acknowledgement of this fact, the European Union (EU) has funded a multinational support action, the European Network for global cooperation in the field of AIDS and TB (EUCO-Net), that brings together experts from Europe and those regions that bear the highest burden of HIV/MTB co-infection. Here, we summarise the main outcome of the EUCO-Net project derived from an expert group meeting that took place in Stellenbosch (South Africa) (AIDS/TB Workshop on Research Challenges and Opportunities for Future Collaboration) and the subsequent discussions, and propose priority areas for research and concerted actions that will have impact on future EU calls.

Comparison of two laboratory-developed PCR methods for the diagnosis of pulmonary tuberculosis in Brazilian patients with and without HIV infection

BACKGROUND

Direct smear examination with Ziehl-Neelsen (ZN) staining for the diagnosis of pulmonary tuberculosis (PTB) is cheap and easy to use, but its low sensitivity is a major drawback, particularly in HIV seropositive patients. As such, new tools for laboratory diagnosis are urgently needed to improve the case detection rate, especially in regions with a high prevalence of TB and HIV.

OBJECTIVE

To evaluate the performance of two in house PCR (Polymerase Chain Reaction): PCR dot-blot methodology (PCR dot-blot) and PCR agarose gel electrophoresis (PCR-AG) for the diagnosis of Pulmonary Tuberculosis (PTB) in HIV seropositive and HIV seronegative patients.

METHODS

A prospective study was conducted (from May 2003 to May 2004) in a TB/HIV reference hospital. Sputum specimens from 277 PTB suspects were tested by Acid Fast Bacilli (AFB) smear, Culture and in house PCR assays (PCR dot-blot and PCR-AG) and their performances evaluated. Positive cultures combined with the definition of clinical pulmonary TB were employed as the gold standard.

RESULTS

The overall prevalence of PTB was 46% (128/277); in HIV+, prevalence was 54.0% (40/74). The sensitivity and specificity of PCR dot-blot were 74% (CI 95%; 66.1%-81.2%) and 85% (CI 95%; 78.8%-90.3%); and of PCR-AG were 43% (CI 95%; 34.5%-51.6%) and 76% (CI 95%; 69.2%-82.8%), respectively. For HIV seropositive and HIV seronegative samples, sensitivities of PCR dot-blot (72% vs 75%; p=0.46) and PCR-AG (42% vs 43%; p=0.54) were similar. Among HIV seronegative patients and PTB suspects, ROC analysis presented the following values for the AFB smear (0.837), Culture (0.926), PCR dot-blot (0.801) and PCR-AG (0.599). In HIV seropositive patients, these area values were (0.713), (0.900), (0.789) and (0.595), respectively.

CONCLUSION

Results of this study demonstrate that the in house PCR dot blot may be an improvement for ruling out PTB diagnosis in PTB suspects assisted at hospitals with a high prevalence of TB/HIV.

Usefulness of the polymerase chain reaction dot-blot assay, used with Ziehl-Neelsen staining, for the rapid and convenient diagnosis of pulmonary tuberculosis in human immunodeficiency virus-seropositive and -seronegative individuals

There are scarce data regarding the value of molecular tests, when used in parallel with classical tools, for the diagnosis of tuberculosis (TB) under field conditions, especially in regions with a high burden of TB-human immunodeficiency virus (HIV) co-infection. We evaluated the usefulness of the polymerase chain reaction dot-blot assay (PCR) used in parallel with Ziehl-Neelsen staining (ZN) for pulmonary tuberculosis (PTB) diagnosis, in a TB-HIV reference hospital. All sputum samples from 277 patients were tested by ZN, culture, and PCR. Performances were assessed individually, in parallel, for HIV status, history of anti-TB treatment, and in different simulated TB prevalence rates. Overall, the PTB prevalence was 46% (128/277); in HIV-seropositive (HIV⁺) individuals, PTB prevalence was 54% (40/74); the ZN technique had a lower sensitivity (SE) in the HIV⁺ group than in the HIV-seronegative (HIV⁻) group (43% vs. 68%; Fisher test, P<0.05); and the SE of PCR was not affected by HIV status (Fisher test; P=0.46). ZN, in parallel with PCR, presented the following results: i) among all PTB suspects, SE of 90%, specificity (SP) of 84%, likelihood ratio (LR)⁺ of 5.65 and LR⁻ of 0.12; ii) in HIV⁻ subjects: SE of 92%, LR⁻ of 0.10; iii) in not previously treated cases: SE of 90%, LR⁻ of 0.11; iv) in TB, prevalence rates of 5–20%; negative predictive values (NPV) of 98–99%. ZN used in parallel with PCR showed an improvement in SE, LR⁻, and NPV, and may offer a novel approach in ruling out PTB cases, especially in not previously treated HIV⁻ individuals, attended in hospitals in developing nations.

Sequence analysis of NAT2 gene in Brazilians: identification of undescribed single nucleotide polymorphisms and molecular modeling of the N-acetyltransferase 2 protein structure

N-Acetyltransferase 2 (NAT2) metabolizes a variety of xenobiotics that includes many drugs, chemicals and carcinogens. This enzyme is genetically variable in human populations and polymorphisms in the NAT2 gene have been associated with drug toxicity and efficacy as well as cancer susceptibility. Here, we have focused on the identification of NAT2 variants in Brazilian individuals from two different regions, Rio de Janeiro and Goiás, by direct sequencing, and on the characterization of new haplotypes after cloning and re-sequencing. Upon analysis of DNA samples from 404 individuals, six new SNPs (c.29T>C, c.152G>T, c.203G>A, c.228C>T, c.458C>T and c.600A>G) and seven new NAT2 alleles were identified with different frequencies in Rio de Janeiro and Goiás. All new SNPs were found as singletons (observed only once in 808 genes) and were confirmed by three independent technical replicates. Molecular modeling and structural analysis suggested that p.Gly51Val variant may have an important effect on substrate recognition by NAT2. We also observed that amino acid change p.Cys68Tyr would affect acetylating activity due to the resulting geometric restrictions and incompatibility of the functional group in the Tyr side chain with the admitted chemical mechanism for catalysis by NATs. Moreover, other variants, such like p.Thr153Ile, p.Thr193Met, p.Pro228Leu and p.Val280Met, may lead to the presence of hydrophobic residues on NAT2 surface involved in protein aggregation and/or targeted degradation. Finally, the new alleles NAT2*6H and NAT2*5N, which showed the highest frequency in the Brazilian populations considered in this study, may code for a slow activity. Functional studies are needed to clarify the mechanisms by which new SNPs interfere with acetylation.

Drug-resistant tuberculosis in six hospitals in Rio de Janeiro, Brazil

SETTING

Tuberculosis (TB) drug resistance survey in six hospitals in Rio de Janeiro, Brazil.

OBJECTIVE

To estimate resistance to at least one drug (DR) and multidrug resistance (MDR) and identify associated factors.

DESIGN

One-year cross-sectional survey. Hospitals were included as a convenience sample.

RESULTS

Of 595 patients investigated, 156 (26.2%) had previously undergone anti-tuberculosis treatment, 433 (72.8%) were not previously treated and information on the remaining 6 was not available. Overall, DR and MDR rates were high, at respectively 102 (17.1%, 95%CI 14.3-20.5) and 44 (7.4%, 95%CI 5.5-9.9) cases. Among individuals not previously treated, 17 had MDR (3.9%, 95%CI 2.4-6.3) and diagnosis in a TB reference hospital was independently associated with MDR (prevalence ratio [PR] 3.3, 95%CI 1.2-8.7) after multivariate analysis. Among previously treated individuals, 27 had MDR (17.3%, 95%CI 11.7-24.2). MDR-TB was independently associated with diagnosis in a TB reference hospital (PR 3.6, 95%CI 1.5-8.7), male sex (PR 2.3, 95%CI 1.2-4.4) and dyspnoea (PR 0.3, 95%CI 0.1-0.7).

CONCLUSION

We found high levels of DR- and MDR-TB. Our study design did not permit us to determine the contribution of community versus nosocomial transmission. Further studies are needed to establish this. Nevertheless, hospitals should be recognised as a potential source of transmission of resistant TB strains and urgent measures to avoid nosocomial TB transmission should be taken.

Cost-effectiveness analysis of PCR for the rapid diagnosis of pulmonary tuberculosis

Background

Tuberculosis is one of the most prominent health problems in the world, causing 1.75 million deaths each year. Rapid clinical diagnosis is important in patients who have co-morbidities such as Human Immunodeficiency Virus (HIV) infection. Direct microscopy has low sensitivity and culture takes 3 to 6 weeks [1-3]. Therefore, new tools for TB diagnosis are necessary, especially in health settings with a high prevalence of HIV/TB co-infection.

Methods

In a public reference TB/HIV hospital in Brazil, we compared the cost-effectiveness of diagnostic strategies for diagnosis of pulmonary TB: Acid fast bacilli smear microscopy by Ziehl-Neelsen staining (AFB smear) plus culture and AFB smear plus colorimetric test (PCR dot-blot).

From May 2003 to May 2004, sputum was collected consecutively from PTB suspects attending the Parthenon Reference Hospital. Sputum samples were examined by AFB smear, culture, and PCR dot-blot. The gold standard was a positive culture combined with the definition of clinical PTB. Cost analysis included health services and patient costs.

Results

The AFB smear plus PCR dot-blot require the lowest laboratory investment for equipment (US$ 20,000). The total screening costs are 3.8 times for AFB smear plus culture versus for AFB smear plus PCR dot blot costs (US$ 5,635,760 versus US$ 1,498, 660). Costs per correctly diagnosed case were US$ 50,773 and US$ 13,749 for AFB smear plus culture and AFB smear plus PCR dot-blot, respectively. AFB smear plus PCR dot-blot was more cost-effective than AFB smear plus culture, when the cost of treating all correctly diagnosed cases was considered. The cost of returning patients, which are not treated due to a negative result, to the health service, was higher in AFB smear plus culture than for AFB smear plus PCR dot-blot, US$ 374,778,045 and US$ 110,849,055, respectively.

Conclusion

AFB smear associated with PCR dot-blot associated has the potential to be a cost-effective tool in the fight against PTB for patients attended in the TB/HIV reference hospital.

Access to tuberculosis diagnosis in Itaboraí City, Rio de Janeiro, Brazil: the patient's point of view

SETTING

Itaboraí Municipality in Rio de Janeiro, Brazil.

OBJECTIVE

To evaluate access to tuberculosis (TB) diagnosis for users of the Family Health Program (FHP) and Reference Ambulatory Units (RAUs).

DESIGN

A cross-sectional study was conducted in Itaboraí City, Rio de Janeiro, Brazil. Between July and October 2007, a sample of 100 TB patients registered consecutively with the TB Control Program was interviewed using the primary care assessment tool. The two highest scores, describing 'almost always' and 'always', or 'good' and 'very good', were used as a cut-off point to define high quality access to diagnosis.

RESULTS

FHP patients were older and had less education than RAU interviewees. Sex and overcrowding did not differ in the two groups. Patient groups did not differ with regard to the number of times care was sought at a unit, transport problems, cost of attending units and availability of consultation within 24 h. Adequate access to diagnosis was identified by 62% of the FHP patients and 53% of the RAU patients (P = 0.01).

CONCLUSION

In Itaboraí, Rio de Janeiro, TB patients believe that the FHP units provide greater access to TB diagnosis than RAUs. These findings will be used by the Department of Health to improve access to diagnosis in Itaboraí.

Pleural fluid ADA, IgA‐ELISA and PCR sensitivities for the diagnosis of pleural tuberculosis

The diagnosis of pleural tuberculosis (pTB) is difficult, and more sensitive and specific techniques are needed. In the period August 1998 to November 2002, we evaluated 132 patients with a pleural effusion submitted to a thoracentesis and pleural biopsy in a tertiary care hospital in Rio de Janeiro, Brazil. Three tests were performed and compared in the pleural fluid: ADA activity measurement, IgA-ELISA for two combined specific Mycobacterium tuberculosis antigens, and polymerase chain reaction (PCR) for detection of M. tuberculosis DNA. Ninety-five patients (72%) were given a final diagnosis of pTB. Overall histopathologic sensitivity was 77%. The sensitivities of pleural fluid culture and AFB smear were 42% and 1%, respectively. Twenty-one (22%) additional patients had a clinical diagnosis of pTB. Median follow-up time of all TB patients after the completion of antituberculous treatment was 13 months. Sensitivities of ADA, IgA-ELISA and PCR were 91%, 78% and 82%, while specificities were 93%, 96% and 85%, respectively. Only ADA sensitivity was significantly higher than the histopathologic examination (McNemar chi2 test; p = 0.002) and also significantly higher than ELISA (p = 0.049), but not higher than PCR (p = 0.143). We conclude that the routine use of ADA activity measurement in pleural fluid can obviate the need for a pleural biopsy in the initial diagnostic approach to pleural effusions, while IgA-ELISA and PCR techniques, potentially more specific tests, need further refinement to improve their accuracy.

Correlations of mutations in katG, oxyR-ahpC and inhA genes and in vitro susceptibility in Mycobacterium tuberculosis clinical strains segregated by spoligotype families from tuberculosis prevalent countries in South America

Background

Mutations associated with resistance to rifampin or streptomycin have been reported for W/Beijing and Latin American Mediterranean (LAM) strain families of Mycobacterium tuberculosis. A few studies with limited sample sizes have separately evaluated mutations in katG, ahpC and inhA genes that are associated with isoniazid (INH) resistance. Increasing prevalence of INH resistance, especially in high tuberculosis (TB) prevalent countries is worsening the burden of TB control programs, since similar transmission rates are noted for INH susceptible and resistant M. tuberculosis strains.

Results

We, therefore, conducted a comprehensive evaluation of INH resistant M. tuberculosis strains (n = 224) from three South American countries with high burden of drug resistant TB to characterize mutations in katG, ahpC and inhA gene loci and correlate with minimal inhibitory concentrations (MIC) levels and spoligotype strain family. Mutations in katG were observed in 181 (80.8%) of the isolates of which 178 (98.3%) was contributed by the katG S315T mutation. Additional mutations seen included oxyR-ahpC; inhA regulatory region and inhA structural gene. The S315T katG mutation was significantly more likely to be associated with MIC for INH ≥2 μg/mL. The S315T katG mutation was also more frequent in Haarlem family strains than LAM (n = 81) and T strain families.

Conclusion

Our data suggests that genetic screening for the S315T katG mutation may provide rapid information for anti-TB regimen selection, epidemiological monitoring of INH resistance and, possibly, to track transmission of INH resistant strains.

Typing of Mycobacterium tuberculosis strains isolated in Community Health Centers of Rio de Janeiro City, Brazil

Fingerprinting of Mycobacterium tuberculosis strains from tuberculosis (TB) patients attended in Community Health Centers (CHCs) of Rio de Janeiro was performed to verify possible risk factors for TB transmission. A prospective community-based study was performed during the period of July 1996 to December 1996 by collecting sputum samples of 489 patients in 11 different CHCs in four different planning areas (APs) of the city. Bacteriological, clinical, and epidemiological information was collected and M. tuberculosis genotypes defined after restriction fragment length polymorphism (IS6110-RFLP) and double repetitive element (DRE) fingerprinting of RFLP-clustered cases. Risk factors for TB transmission were looked for using three levels of cluster stringency. Among 349 (71%) positive cultures obtained, IS6110-RFLP typing could be performed on strains from 153 different patients. When using identity of RFLP patterns as cluster definition, 49 (32%) of the strains belonged to a cluster and none of the clinical or epidemiologic characteristics was associated with higher clustering levels. However, higher clustering level was observed in the AP including the central region of the city when compared to others. This strongly suggests that more recent transmission occurs in that area and this may be related with higher incidence of TB and HIV in this region.

PCR colorimetric dot-blot assay and clinical pretest probability for diagnosis of Pulmonary Tuberculosis in smear-negative patients

BACKGROUND

Smear-negative pulmonary tuberculosis (SNPTB) accounts for 30% of Pulmonary Tuberculosis (PTB) cases reported annually in developing nations. Polymerase chain reaction (PCR) may provide an alternative for the rapid detection of Mycobacterium tuberculosis (MTB); however little data are available regarding the clinical utility of PCR in SNPTB, in a setting with a high burden of TB/HIV co-infection.

METHODS

To evaluate the performance of the PCR dot-blot in parallel with pretest probability (Clinical Suspicion) in patients suspected of having SNPTB, a prospective study of 213 individuals with clinical and radiological suspicion of SNPTB was carried out from May 2003 to May 2004, in a TB/HIV reference hospital. Respiratory specialists estimated the pretest probability of active disease into high, intermediate, low categories. Expectorated sputum was examined by direct microscopy (Ziehl-Neelsen staining), culture (Lowenstein Jensen) and PCR dot-blot. Gold standard was based on culture positivity combined with the clinical definition of PTB.

RESULTS

In smear-negative and HIV subjects, active PTB was diagnosed in 28.4% (43/151) and 42.2% (19/45), respectively. In the high, intermediate and low pretest probability categories active PTB was diagnosed in 67.4% (31/46), 24% (6/25), 7.5% (6/80), respectively. PCR had sensitivity of 65% (CI 95%: 50%-78%) and specificity of 83% (CI 95%: 75%-89%). There was no difference in the sensitivity of PCR in relation to HIV status. PCR sensitivity and specificity among non-previously TB treated and those treated in the past were, respectively: 69%, 43%, 85% and 80%. The high pretest probability, when used as a diagnostic test, had sensitivity of 72% (CI 95%:57%-84%) and specificity of 86% (CI 95%:78%-92%). Using the PCR dot-blot in parallel with high pretest probability as a diagnostic test, sensitivity, specificity, positive and negative predictive values were: 90%, 71%, 75%, and 88%, respectively. Among non-previously TB treated and HIV subjects, this approach had sensitivity, specificity, positive and negative predictive values of 91%, 79%, 81%, 90%, and 90%, 65%, 72%, 88%, respectively.

CONCLUSION

PCR dot-blot associated with a high clinical suspicion may provide an important contribution to the diagnosis of SNPTB mainly in patients that have not been previously treated attended at a TB/HIV reference hospital.

Genetic profile of the arylamine N-acetyltransferase 2 coding gene among individuals from two different regions of Brazil

Arylamine N-acetyltranferase 2 is the main enzyme responsible for the isoniazid metabolization into hepatotoxic intermediates and the degree of hepatotoxicity severity has been attributed to genetic variability in the NAT2 gene. The main goal of this study was to describe the genetic profile of the NAT2 gene in individuals from two different regions of Brazil: Rio de Janeiro and Goiás States. Therefore, after preparation of DNA samples from 404 individuals, genotyping of the coding region of NAT2 was performed by direct PCR sequencing. Thirteen previously described SNPs were detected in these Brazilian populations, from which seven: 191 G>A; 282 C>T; 341 T>C; 481 C>T; 590 G>A; 803 A>G and 857 G>A are the most frequent in other populations. The presence of so-called ethnic-specific SNPs in our population is in accordance with the Brazilians' multiple ancestry. Upon allele and genotype analysis, the most frequent NAT2 alleles were respectively NAT2*5B (33%), NAT2*6A (26%) and NAT2*4 (20%) being NAT2*5/*5 the more prevalent genotype (31.7%). These results clearly demonstrate the predominance in the studied Brazilian groups of NAT2 alleles associated with slow over the fast and intermediate acetylator genotypes. Additionally, in Rio de Janeiro, a significantly higher frequency of intermediate acetylation status was found when compared to Goiás (42.5% versus 25%) (p=0.05), demonstrating that different regions of a country with a population characterized by a multi-ethnic ancestry may present a large degree of variability in NAT2 allelic frequencies. This finding has implications in the determination of nationwide policies for use of appropriate anti-TB drugs.

Low expression of antigen-presenting and costimulatory molecules by lung cells from tuberculosis patients

Costimulatory and antigen-presenting molecules are essential to the initiation of T cell immunity to mycobacteria. The present study analyzed by immunocytochemistry, using monoclonal antibodies and alkaline phosphatase-anti-alkaline phosphatase method, the frequency of costimulatory (CD86, CD40, CD40L, CD28, and CD152) and antigen-presenting (MHC class II and CD1) molecules expression on human lung cells recovered by sputum induction from tuberculosis (TB) patients (N = 22) and non-TB controls (N = 17). TB cases showed a statistically significant lower percentage of HLA-DR+ cells than control subjects (21.9 +/- 4.2 vs 50.0 +/- 7.2%, P < 0.001), even though similar proportions of TB cases (18/22) and control subjects (16/17, P = 0.36) had HLA-DR-positive-stained cells. In addition, fewer TB cases (10/22) compared to control subjects (16/17) possessed CD86-expressing cells (P = 0.04; OR: 0.05; 95%CI = 0.00-0.51), and TB cases expressed a lower percentage of CD86+ cells (P = 0.04). Moreover, TB patients with clinically limited disease ( pound1 lobe) on chest X-ray exhibited a lower percentage of CD86-bearing cells compared to patients with more extensive lung disease (>1 lobe) (P = 0.02). The lower expression by lung cells from TB patients of HLA-DR and CD86, molecules involved in antigen presentation and activation of T cells, may minimize T cell recognition of Mycobacterium tuberculosis, fostering an immune dysfunctional state and active TB.