Retrospective comparison of levofloxacin and moxifloxacin on multidrug-resistant tuberculosis treatment outcomes

9 months of delamanid, linezolid, levofloxacin, and pyrazinamide versus conventional therapy for treatment of fluoroquinolone-sensitive multidrug-resistant tuberculosis (MDR-END): a multicentre, randomised, open-label phase 2/3 non-inferiority trial in South Korea

BACKGROUND

With the introduction of new anti-tuberculosis drugs, all-oral regimens with shorter treatment durations for multidrug-resistant tuberculosis have been anticipated. We aimed to investigate whether a new all-oral regimen was non-inferior to the conventional regimen including second-line anti-tuberculosis drugs for 20-24 months in the treatment of fluoroquinolone-sensitive multidrug-resistant tuberculosis.

METHODS

In this multicentre, randomised, open-label phase 2/3 non-inferiority trial, we enrolled men and women aged 19-85 years with multidrug-resistant tuberculosis confirmed by phenotypic or genotypic drug susceptibility tests or rifampicin-resistant tuberculosis by genotypic tests at 12 participating hospitals throughout South Korea. Participants with fluoroquinolone-resistant multidrug-resistant tuberculosis were excluded. Participants were randomly assigned (1:1) to two groups using a block randomisation, stratified by the presence of diabetes and cavitation on baseline chest radiographs. The investigational group received delamanid, linezolid, levofloxacin, and pyrazinamide for 9 months, and the control group received a conventional 20-24-month regimen, according to the 2014 WHO guidelines. The primary outcome was the treatment success rate at 24 months after treatment initiation in the modified intention-to-treat population and the per-protocol population. Participants who were "cured" and "treatment completed" were defined as treatment success following the 2014 WHO guidelines. Non-inferiority was confirmed if the lower limit of a 97·5% one-sided CI of the difference between the groups was greater than -10%. Safety data were collected for 24 months in participants who received a predefined regimen at least once. This study is registered with ClinicalTrials.gov, NCT02619994.

FINDINGS

Between March 4, 2016, and Sept 14, 2019, 214 participants were enrolled, 168 (78·5%) of whom were included in the modified intention-to-treat population. At 24 months after treatment initiation, 60 (70·6%) of 85 participants in the control group had treatment success, as did 54 (75·0%) of 72 participants in the shorter-regimen group (between-group difference 4·4% [97·5% one-sided CI -9·5% to ∞]), satisfying the predefined non-inferiority margin. No difference in safety outcomes was identified between the control group and the shorter-regimen group.

INTERPRETATION

9-month treatment with oral delamanid, linezolid, levofloxacin, and pyrazinamide could represent a new treatment option for participants with fluoroquinolone-sensitive multidrug-resistant tuberculosis.

FUNDING

Korea Disease Control and Prevention Agency, South Korea.

Temporal trends of pharmacologic treatments for tuberculosis and multidrug resistant tuberculosis following dissemination of treatment guidelines in South Korea

BACKGROUND/PURPOSE(S)

The World Health Organization (WHO) released treatment guidelines for multidrug resistant tuberculosis (MDR-TB) in 2008, with subsequent revisions in 2011; Korea disseminated corresponding guidelines in 2011 and 2014, respectively. Thus, we aimed to investigate the temporal trends of and the updated guideline's impact on the prescription patterns of anti-TB drugs.

METHODS

We conducted a time-series study using Korea's nationwide healthcare database (2007-2015), where patients with TB or MDR-TB were included. Only anti-TB drugs prescribed during the intensive phase of treatment for TB (two months) or MDR-TB (eight months) were assessed. We estimated the annual utilization of TB treatment regimens and the relative difference (RD) in the proportion of MDR-TB treatment medications between the following periods: before the first Korean guideline (June 2008 to March 2011); between the first and revised guidelines (April 2011 to July 2014); after the revised guideline (August 2014 to December 2015).

RESULTS

Of 3523 TB (mean age 54.1 years; male 56.8%) patients, treatment regimens for TB complied with guideline recommendations as >80% of patients received either quadruple (mean 66.8%) or triple (14.5%) therapy of first-line anti-TB drugs. Following the WHO's guideline update, prescription patterns changed accordingly among 111 MDR-TB (mean age 46.0 years; male 67.6%) patients, as use of pyrazinamide (RD +20.3%) and prothionamide (+11.5%) increased (recommended to be compulsory), and streptomycin (-43.1%) decreased (ototoxicity risks).

CONCLUSIONS

Anti-TB drug prescription patterns for both TB and MDR-TB well reflected WHO's treatment guideline as well as corresponding domestic guidelines of South Korea.

The treatment effect of Levofloxacin, Moxifloxacin, and Gatifloxacin contained in the conventional therapy regimen for pulmonary tuberculosis: Systematic review and network meta-analysis

BACKGROUND

Tuberculosis (TB) is one of the serious epidemics that highly threaten the global public health. To explore the treatment effect of Levofloxacin, Moxifloxacin, and Gatifloxacin contained in the conventional therapy regimen for pulmonary tuberculosis.

METHODS

Medline, PubMed, Embase, and Cochrane Library were searched with the keyword such as "Levofloxacin," "Moxifloxacin," "Gatifloxacin," and "tuberculosis", through June 1992 to 2017. According to the inclusion and exclusion criteria, 2 researchers independently screened the literature, extracted the data, and evaluated the quality of the included studies. The Cochrane system was evaluated by RevMan5.2 and the network meta-analysis was performed by Stata 15.

RESULTS

A total of 891 studies were included, with a total of 6565 patients. The results of network meta-analysis showed that Moxifloxacin + conventional therapy (CT) regimen was superior to CT regimen only on the spectrum culture negative. Both Levofloxacin + CT and Moxifloxacin + CT were superior to the CT regimen in treatment success rate. For the adverse events, the Levofloxacin + CT showed much safer results than CT group, while Moxifloxacin + CT had more adverse events than CT group.

CONCLUSION

Levofloxacin, Moxifloxacin, and Gatifloxacin have different superiority, comparing to CT regimen in spectrum culture negative, treatment success rate, and adverse events. Hence, combined utilization of these quinolone is important on the clinical treatment for tuberculosis.

Meta-analysis on Effectiveness and Safety of Moxifloxacin in Treatment of Multidrug Resistant Tuberculosis in Adults

BACKGROUND

Moxifloxacin, a fourth generation fluoroquinolone, which has good antibacterial activity against both Gram-positive cocci and Gram-negative bacteria. To date, there are no meta-analysis to evaluate the efficacy and safety of moxifloxacin for multi-drug resistant tuberculosis (MDR-TB) treatment. This meta-analysis to explore the efficacy and safety of the moxifloxacin in treatment of MDR-TB in adults.

METHODS

Databases of PubMed, Embase, Embase, Ovid, and Google Scholar databases were investigated for eligible literatures from their establishments to August, 2019. Included studies were selected according to precise eligibility criteria: MDR-TB confirmed by the clinical diagnostic criteria (at least 2 or more first-line drugs resistant to isoniazid and rifampicin). Study design was limited to retrospective studies, randomized controlled trials, or prospective cohort studies; the control group was treated with other drugs or no moxifloxacin. Statistical analysis was performed by RevMan 5.3 software.

RESULTS

Eight studies with a total of 1447 patients were finally eligible for the final systematic review and meta-analysis. Moxifloxacin regimen was related to a significantly elevated treatment success rate compared with levofloxacin or conventional therapy regimen (OR = 1.94; 95% CI = 1.16-3.25, P = .01). No significant difference of sputum culture conversion rate (OR = 1.15; 95% CI = 0.82-1.60; P = 0.43) was found between 2 groups. In addition, there was no significant difference in the increased risks of gastrointestinal trouble (OR = 1.28; 95% CI = 0.98-1.68; P = .05), hepatotoxicity (OR = 0.91; 95% CI = 0.64-1.30; P = .6), dermatologic abnormalities (OR = 1.11; 95% CI = 0.74-1.67; P = .62), and vision change (OR = 1.47; 95% CI = 0.74-2.89; P = .27) between the moxifloxacin-containing regimens and control group.

CONCLUSIONS

This meta-analysis revealed that the addition of moxifloxacin to the recommended regimen significantly improved the rate of treatment success in the treatment of MDR-TB, with no additional adverse moxifloxacin events.

Fluoroquinolones in Drug-Resistant Tuberculosis: Culture Conversion and Pharmacokinetic/Pharmacodynamic Target Attainment To Guide Dose Selection

Fluoroquinolones are group A drugs in tuberculosis guidelines. We aim to compare the culture conversion between new-generation (levofloxacin and moxifloxacin) and old-generation (ciprofloxacin and ofloxacin) fluoroquinolones, develop pharmacokinetic models, and calculate target attainment for levofloxacin and moxifloxacin. We included three U.S. tuberculosis centers.

Fluoroquinolones are group A drugs in tuberculosis guidelines. We aim to compare the culture conversion between new-generation (levofloxacin and moxifloxacin) and old-generation (ciprofloxacin and ofloxacin) fluoroquinolones, develop pharmacokinetic models, and calculate target attainment for levofloxacin and moxifloxacin. We included three U.S. tuberculosis centers. Patients admitted between 1984 and 2015, infected with drug-resistant tuberculosis, and who had received fluoroquinolones for ≥28 days were included. Demographics, sputum cultures and susceptibility, treatment regimens, and serum concentrations were collected. A time-to-event analysis was conducted, and Cox proportional hazards model was used to compare the time to culture conversion. Using additional data from ongoing studies, pharmacokinetic modelling and Monte Carlo simulations were performed to assess target attainment for different doses. Overall, 124 patients received fluoroquinolones. The median age was 40 years, and the median weight was 60 kg. Fifty-six patients (45%) received old-generation fluoroquinolones. New-generation fluoroquinolones showed a faster time to culture conversion (median 16 versus 40 weeks, P = 0.012). After adjusting for isoniazid and clofazimine treatment, patients treated with new-generation fluoroquinolones were more likely to have culture conversion (adjusted hazards ratio, 2.16 [95% confidence interval, 1.28 to 3.64]). We included 178 patients in the pharmacokinetic models. Levofloxacin and moxifloxacin were best described by a one-compartment model with first-order absorption and elimination. At least 1,500 to 1,750 mg levofloxacin and 800 mg moxifloxacin may be needed for maximum kill at the current epidemiologic cutoff values. In summary, new-generation fluoroquinolones showed faster time to culture conversion compared to the old generation. For optimal target attainment at the current MIC values, higher doses of levofloxacin and moxifloxacin may be needed.

Molecular dynamics simulation and binding free energy studies of novel leads belonging to the benzofuran class inhibitors of Mycobacterium tuberculosis Polyketide Synthase 13

In this work, the binding mechanism of new Polyketide Synthase 13 (Pks13) inhibitors has been studied through molecular dynamics simulation and free energy calculations. The drug Tam1 and its analogs, belonging to the benzofuran class, were submitted to 100 ns simulations, and according to the results obtained for root mean square deviation, all the simulations converged from approximately 30 ns. For the analysis of backbone flotation, the root mean square fluctuations were plotted for the Cα atoms; analysis revealed that the greatest fluctuation occurred in the residues that are part of the protein lid domain. The binding free energy value (ΔG_bind) obtained for the Tam16 lead molecule was of -51.43 kcal/mol. When comparing this result with the ΔG_bind values for the remaining analogs, the drug Tam16 was found to be the highest ranked: this result is in agreement with the experimental results obtained by Aggarwal and collaborators, where it was verified that the IC₅₀ for Tam16 is the smallest necessary to inhibit the Pks13 (IC₅₀ = 0.19 μM). The energy decomposition analysis suggested that the residues which most interact with inhibitors are: Ser1636, Tyr1637, Asn1640, Ala1667, Phe1670, and Tyr1674, from which the greatest energy contribution to Phe1670 was particularly notable. For the lead molecule Tam16, a hydrogen bond with the hydroxyl of the phenol not observed in the other analogs induced a more stable molecular structure. Aggarwal and colleagues reported this hydrogen bonding as being responsible for the stability of the molecule, optimizing its physic-chemical, toxicological, and pharmacokinetic properties.

Comparing efficacies of moxifloxacin, levofloxacin and gatifloxacin in tuberculosis granulomas using a multi-scale systems pharmacology approach

Granulomas are complex lung lesions that are the hallmark of tuberculosis (TB). Understanding antibiotic dynamics within lung granulomas will be vital to improving and shortening the long course of TB treatment. Three fluoroquinolones (FQs) are commonly prescribed as part of multi-drug resistant TB therapy: moxifloxacin (MXF), levofloxacin (LVX) or gatifloxacin (GFX). To date, insufficient data are available to support selection of one FQ over another, or to show that these drugs are clinically equivalent. To predict the efficacy of MXF, LVX and GFX at a single granuloma level, we integrate computational modeling with experimental datasets into a single mechanistic framework, GranSim. GranSim is a hybrid agent-based computational model that simulates granuloma formation and function, FQ plasma and tissue pharmacokinetics and pharmacodynamics and is based on extensive in vitro and in vivo data. We treat in silico granulomas with recommended daily doses of each FQ and compare efficacy by multiple metrics: bacterial load, sterilization rates, early bactericidal activity and efficacy under non-compliance and treatment interruption. GranSim reproduces in vivo plasma pharmacokinetics, spatial and temporal tissue pharmacokinetics and in vitro pharmacodynamics of these FQs. We predict that MXF kills intracellular bacteria more quickly than LVX and GFX due in part to a higher cellular accumulation ratio. We also show that all three FQs struggle to sterilize non-replicating bacteria residing in caseum. This is due to modest drug concentrations inside caseum and high inhibitory concentrations for this bacterial subpopulation. MXF and LVX have higher granuloma sterilization rates compared to GFX; and MXF performs better in a simulated non-compliance or treatment interruption scenario. We conclude that MXF has a small but potentially clinically significant advantage over LVX, as well as LVX over GFX. We illustrate how a systems pharmacology approach combining experimental and computational methods can guide antibiotic selection for TB.

Tuberculosis (TB) is caused by infection with the bacterium Mycobacterium tuberculosis (Mtb) and kills 1.5 million people each year. TB requires at least 6 months of treatment with up to four drugs, and is characterized by formation of granulomas in patient lungs. Granulomas are spherical collections of host cells and bacteria. Fluoroquinolones (FQs) are a class of drug that could help shorten TB treatment. Three FQs that are used to treat TB are: moxifloxacin (MXF), levofloxacin (LVX) or gatifloxacin (GFX). To date, it is unclear if one FQ is better than the others at treating TB, in part because little is known about how these drugs distribute and work inside the lung granulomas. We use computer simulations of Mtb infection and FQ treatment within granulomas to predict which FQ is better and why. Our computer model is calibrated to multiple experimental data sets. We compare the three FQs by multiple metrics, and predict that MXF is better than LVX and GFX because it kills bacteria more quickly, and it works better when patients miss doses. However, all three FQs are unable to kill a part of the bacterial population living in the center of granulomas. Our results can now inform future experimental studies.

An updated systematic review and meta-analysis for treatment of multidrug-resistant tuberculosis

This systematic review aimed to update the current evidence for multidrug-resistant tuberculosis (MDR-TB) treatment.We searched for studies that reported treatment information and clinical characteristics for at least 25 patients with microbiologically confirmed pulmonary MDR-TB and either end of treatment outcomes, 6-month culture conversion or severe adverse events (SAEs). We assessed the association of these outcomes with patients' characteristics or treatment parameters. We identified 74 studies, including 17 494 participants.The pooled treatment success was 26% in extensively drug-resistant TB (XDR-TB) patients and 60% in MDR-TB patients. Treatment parameters such as number or duration and individual drugs were not associated with improved 6-month sputum culture conversion or end of treatment outcomes. However, MDR-TB patients that received individualised regimens had higher success than patients who received standardised regimens (64% versus 52%; p<0.0.01). When reports from 20 cohorts were pooled, proportions of SAE ranged from 0.5% attributed to ethambutol to 12.2% attributed to para-aminosalicylic acid. The lack of significant associations of treatment outcomes with specific drugs or regimens may reflect the limitations of pooling the data rather than a true lack of differences in efficacy of regimens or individual drugs.This analysis highlights the need for stronger evidence for treatment of MDR-TB from better-designed and reported studies.

Impact of Fluoroquinolone Exposure Prior to Tuberculosis Diagnosis on Clinical Outcomes in Immunocompromised Patients

There have been concerns about an association of fluoroquinolone (FQ) use prior to tuberculosis (TB) diagnosis with adverse outcomes. However, FQ use might prevent clinical deterioration in missed TB patients, especially in those who are immunocompromised, until they receive definitive anti-TB treatment. All adult immunocompromised patients with smear-negative and culture-positive TB at a tertiary care hospital in Korea over a 2-year period were included in this study. Long-term FQ (≥7 days) use was defined as exposure to FQ for at least 7 days prior to TB diagnosis. A total of 194 patients were identified: 33 (17%) in the long-term FQ group and 161 (83%) in the comparator, including a short-term FQ group (n = 23), non-FQ group (n = 78), and a group receiving no antibiotics (n = 60). Patients in the long-term FQ group presented with atypical chest radiologic pattern more frequently than those in the comparator (77% [24/31] versus 46% [63/138]; P = 0.001). The median time from mycobacterial test to positive mycobacterial culture appeared to be longer in the long-term FQ group (8.1 weeks versus 7.7 weeks; P = 0.09), although the difference was not statistically significant. Patients in the long-term FQ group were less likely to receive empirical anti-TB treatment (55% versus 74%; P = 0.03). The median time from mycobacterial test to anti-TB therapy was longer in the long-term FQ group (4.6 weeks versus 2.2 weeks; P < 0.001), but there was no significant difference in FQ resistance (0% versus 3%; P > 0.99) or in the 30-day (6% versus 6%; P > 0.99) or 90-day (12% versus 12%; P > 0.99) mortality rate between the two groups. FQ exposure (≥7 days) prior to TB diagnosis in immunocompromised patients appears not to be associated with adverse outcomes.

Specific gyrA gene mutations predict poor treatment outcome in MDR-TB

OBJECTIVES

Mutations in the gyrase genes cause fluoroquinolone resistance in Mycobacterium tuberculosis. However, the predictive value of these markers for clinical outcomes in patients with MDR-TB is unknown to date. The objective of this study was to determine molecular markers and breakpoints predicting second-line treatment outcomes in M. tuberculosis patients treated with fourth-generation fluoroquinolones.

METHODS

We analysed treatment outcome data in relation to the gyrA and gyrB sequences and MICs of ofloxacin, gatifloxacin and moxifloxacin for pretreatment M. tuberculosis isolates from 181 MDR-TB patients in Bangladesh whose isolates were susceptible to injectable drugs.

RESULTS

The gyrA 90Val, 94Gly and 94Ala mutations were most frequent, with the highest resistance levels for 94Gly mutants. Increased pretreatment resistance levels (>2 mg/L), related to specific mutations, were associated with lower cure percentages, with no cure in patients whose isolates were resistant to gatifloxacin at 4 mg/L. Any gyrA 94 mutation, except 94Ala, predicted a significantly lower proportion of cure compared with all other gyrA mutations taken together (all non-94 mutants + 94Ala) [OR = 4.3 (95% CI 1.4-13.0)]. The difference in treatment outcome was not explained by resistance to the other drugs.

CONCLUSIONS

Our study suggests that gyrA mutations at position 94, other than Ala, predict high-level resistance to gatifloxacin and moxifloxacin, as well as poor treatment outcome, in MDR-TB patients in whom an injectable agent is still effective.

Comparative efficacy and acceptability of five anti-tubercular drugs in treatment of multidrug resistant tuberculosis: a network meta-analysis

Multidrug resistant tuberculosis (MDR-TB) is a serious form of tuberculosis (TB). There is no recognized effective treatment for MDR-TB, although there are a number of publications that have reported positive results for MDR-TB. We performed a network meta-analysis to assess the efficacy and acceptability of potential antitubercular drugs. We conducted a network meta-analysis of randomized controlled clinical trials to compare the efficacy and acceptability of five antitubercular drugs, bedaquiline, delamanid, levofloxacin, metronidazole and moxifloxacin in the treatment of MDR-TB. We included eleven suitable trials from nine journal articles and six clinical trials from ClinicalTrials.gov, with data for 1472 participants. Bedaquiline (odds ratio [OR] 2.69, 95% CI 1.02-7.43), delamanid (OR 2.45, 95% CI 1.36-4.89) and moxifloxacin (OR 2.47, 95% CI 1.01, 7.31) were significantly more effective than placebo. For efficacy, the results indicated no statistical significance between each antitubercular drug. For acceptability, the results indicated no statistically significant difference between each compared intervention. There is insufficient evidence to suggest that any one of the five antitubercular drugs (bedaquiline, delamanid, levofloxacin, metronidazole and moxifloxacin) has superior efficacy compared to the others.

Risk factors for poor treatment outcomes in patients with MDR-TB and XDR-TB in China: retrospective multi-center investigation

BACKGROUND

The treatment of patients with MDR- and XDR-TB is usually more complex, toxic and costly and less effective than treatment of other forms of TB. However, there is little information available on risk factors for poor outcomes in patients with MDR- and XDR-TB in China.

METHODOLOGY/PRINCIPAL FINDINGS

We retrospectively analyzed the clinical records of HIV-negative TB Patients with culture-proven MDR- or XDR-TB who were registered from July 2006 to June 2011 at five large-scale Tuberculosis Specialized Hospitals in China. Among 1662 HIV-seronegative TB cases which were culture-positive for M. tuberculosis complex and had positive sputum-smear microscopy results, 965 cases (58.1%) were DR-TB, and 586 cases (35.3%) were classified as having MDR-TB, accounting for 60.7% of DR-TB. 169 cases (10.2%) were XDR-TB, accounting for 17.5% of DR-TB, 28.8% of MDR-TB. The MDR-TB patients were divided into XDR-TB group (n=169) and other MDR-TB group (non-XDR MDR-TB) (n=417). In total, 240 patients (40.95%) had treatment success, and 346 (59.05%) had poor treatment outcomes. The treatment success rate in other MDR-TB group was 52.2%, significantly higher than that in the XDR-TB group (13%, P<0.001). In multivariate logistic regression analysis, poor outcomes were associated with duration of previous anti-TB treatment of more than one year (OR, 0.077; 95% CI, 0.011-0.499, P<0.001), a BMI less than 18.5 kg/m(2) (OR, 2.185; 95% CI, 1.372-3.478, P<0.001), XDR (OR, 13.368; 95% CI, 6.745-26.497, P<0.001), retreatment (OR, 0.171; 95% CI, 0.093-0.314, P<0.001), diabetes (OR, 0.305; 95% CI, 0.140-0.663, P=0.003), tumor (OR, 0.095; 95% CI, 0.011-0.795, P=0.03), decreased albumin (OR, 0.181; 95% CI, 0.118-0.295, P<0.001), cavitation (OR, 0.175; 95% CI, 0.108-0.286, P<0.001).

CONCLUSIONS/SIGNIFICANCE

The patients with MDR-TB and XDR-TB have poor treatment outcomes in China.The presence of extensive drug resistance, low BMI, hypoalbuminemia, comorbidity, cavitary disease and previous anti-TB treatment are independent prognostic factors for poor outcome in patients with MDR-TB.

Medical treatment of pulmonary multidrug-resistant tuberculosis

Treatment of multidrug-resistant tuberculosis (MDR-TB) is challenging because of the high toxicity of second-line drugs and the longer treatment duration required compared with drug-susceptible TB. The efficacy of treatment for MDR-TB is poorer than that for drug-susceptible TB. The selection of drugs in MDR-TB is based on previous treatment history, drug susceptibility results, and TB drug resistance patterns in the each region. Recent World Health Organization guidelines recommend the use of least 4 second-line drugs (a newer fluoroquinolone, an injectable agent, prothionamide, and cycloserine or para-aminosalicylic acid) in addition to pyrazinamide. The kanamycin is the initial choice of injectable durgs, and newer fluoroquinolones include levofloxacin and moxifloxacin. For MDR-TB, especially cases that are extensively drug-resistant, group 5 drugs such as linezolid, clofazimine, and amoxicillin/clavulanate need to be included. New agents with novel mechanisms of action that can be given for shorter durations (9-12 months) for MDR-TB are under investigation.

Interferon-gamma release assays versus tuberculin skin testing in patients with rheumatoid arthritis

OBJECTIVE

The aim of this study was to analyze the results of interferon-gamma release assays (IGRAs) and tuberculin skin tests (TST) performed to detect latent tuberculosis infection (LTBI) in patients with rheumatoid arthritis (RA).

METHODS

Interferon-γ release assays and TST test results were summarized and systematically reviewed.

RESULTS

Four hundred and five RA patients and 339 controls that underwent IGRA and/or TST were identified in seven studies. Five studies were case-control studies and two were cross-sectional studies. Among RA patients, the IGRA positivity rate was 31.6% (89/282; range 11.4%-44.6%), and the TST positivity rate was 23.0% (78/339; range from 14.60% to 45%). Concordance rates ranged from 40% to 76% and discordance rates from 24% to 29.7%. Agreement between IGRAs and TST in RA was poor (69.6%, k = 0.33, 95% CI 0.188-0.478). The IGRA positivity rate was 31.0% in RA and 40.0% in controls, which was not significant (relative risk [RR] 0.802, 95% CI 0.629-1.023, P = 0.075). The TST positivity rate was 24.7% in RA and 50.5% in controls, and this difference was not significant (RR 0.680, 95% CI 0.331-1.339, P = 0.295).

CONCLUSIONS

Positivity rates of IGRA and TST were 31.6 and 23.0%, respectively, in RA patients. Agreement between IGRA and TST results in RA was poor. Our data suggest that both IGRA and TST are needed to detect LTBI in RA.

Fluoroquinolones for treating tuberculosis (presumed drug-sensitive)

BACKGROUND

Currently the World Health Organization only recommend fluoroquinolones for people with presumed drug-sensitive tuberculosis (TB) who cannot take standard first-line drugs. However, use of fluoroquinolones could shorten the length of treatment and improve other outcomes in these people. This review summarises the effects of fluoroquinolones in first-line regimens in people with presumed drug-sensitive TB.

OBJECTIVES

To assess fluoroquinolones as substitute or additional components in antituberculous drug regimens for drug-sensitive TB.

SEARCH METHODS

We searched the Cochrane Infectious Diseases Group Specialized Register; CENTRAL (The Cochrane Library 2013, Issue 1); MEDLINE; EMBASE; LILACS; Science Citation Index; Databases of Russian Publications; and metaRegister of Controlled Trials up to 6 March 2013.

SELECTION CRITERIA

Randomized controlled trials (RCTs) of antituberculous regimens based on rifampicin and pyrazinamide and containing fluoroquinolones in people with presumed drug-sensitive pulmonary TB.

DATA COLLECTION AND ANALYSIS

Two authors independently applied inclusion criteria, assessed the risk of bias in the trials, and extracted data. We used the risk ratio (RR) for dichotomous data and the fixed-effect model when it was appropriate to combine data and no heterogeneity was present. We assessed the quality of evidence using the GRADE approach.

MAIN RESULTS

We identified five RCTs (1330 participants) that met the inclusion criteria. None of the included trials examined regimens of less than six months duration. Fluoroquinolones added to standard regimensA single trial (174 participants) added levofloxacin to the standard first-line regimen. Relapse and treatment failure were not reported. For death, sputum conversion, and adverse events we are uncertain if there is an effect (one trial, 174 participants, very low quality evidence for all three outcomes). Fluoroquinolones substituted for ethambutol in standard regimens Three trials (723 participants) substituted ethambutol with moxifloxacin, gatifloxacin, and ofloxacin into the standard first-line regimen. For relapse, we are uncertain if there is an effect (one trial, 170 participants, very low quality evidence). No trials reported on treatment failure. For death, sputum culture conversion at eight weeks, or serious adverse events we do not know if there was an effect (three trials, 723 participants, very low quality evidence for all three outcomes). Fluoroquinolones substituted for isoniazid in standard regimens A single trial (433 participants) substituted moxifloxacin for isoniazid. Treatment failure and relapse were not reported. For death, sputum culture conversion, or serious adverse events the substitution may have little or no difference (one trial, 433 participants, low quality evidence for all three outcomes). Fluoroquinolines in four month regimensSix trials are currently in progress testing shorter regimens with fluoroquinolones.

AUTHORS' CONCLUSIONS

Ofloxacin, levofloxacin, moxifloxacin, and gatifloxacin have been tested in RCTs of standard first-line regimens based on rifampicin and pyrazinamide for treating drug-sensitive TB. There is insufficient evidence to be clear whether addition or substitution of fluoroquinolones for ethambutol or isoniazid in the first-line regimen reduces death or relapse, or increases culture conversion at eight weeks. Much larger trials with fluoroquinolones in short course regimens of four months are currently in progress.

Treatment of refractory Mycobacterium avium complex lung disease with a moxifloxacin-containing regimen

Moxifloxacin (MXF) has in vitro and in vivo activity against Mycobacterium avium complex (MAC) in experimental models. However, no data are available concerning its treatment effect in patients with MAC lung disease. The aim of this study was to evaluate the clinical efficacy of an MXF-containing regimen for the treatment of refractory MAC lung disease. Patients with MAC lung disease who were diagnosed between January 2002 and December 2011 were identified from our hospital database. We identified 41 patients who received MXF for ≥ 4 weeks for the treatment of refractory MAC lung disease. A total of 41 patients were treated with an MXF-containing regimen because of a persistent positive culture after at least 6 months of clarithromycin-based standardized antibiotic therapy. The median duration of antibiotic therapy before MXF administration was 410 days (interquartile range [IQR], 324 to 683 days). All patients had culture-positive sputum when MXF treatment was initiated. The median duration of MXF administration was 332 days (IQR, 146 to 547 days). The overall treatment success rate was 29% (12/41), and the median time to sputum conversion was 91 days (IQR, 45 to 190 days). A positive sputum acid-fast-bacillus smear at the start of treatment with MXF-containing regimens was an independent predictor of an unfavorable microbiological response. Our results indicate that MXF may improve treatment outcomes in about one-third of patients with persistently culture-positive MAC lung disease who fail to respond to clarithromycin-based standardized antibiotic treatment. Prospective studies are required to assess the clinical efficacy of MXF treatment for refractory MAC lung disease.

New treatment options for multidrug-resistant tuberculosis

Despite the development of effective treatments, tuberculosis (TB) remains a major health problem. TB continues to infect new victims and kills nearly 2 million people annually. The problem is much greater in resource-limited countries but is present worldwide. Inadequate public health resources, cost, the obligatory long treatment period, and adverse drug effects contribute to treatment failures and relapses. Drug-resistant Mycobacterium tuberculosis (MTB) strains arise spontaneously and are propagated by inadequate treatment. According to World Health Organization global data, 17% of MTB strains in new, previously untreated cases are resistant to at least one drug. Approximately, 3.3% of new MTB cases are resistant to both isoniazid and rifampin, also called multidrug resistant (MDR), and rates of MDR-TB are greater than 60% in previously treated patients in some countries. Approximately 5% of cases of MDR-TB are also resistant to fluoroquinolones and to injectable drugs, and are called extensively drug resistant (XDR). Recently, XDR strains have been isolated that are also resistant to all standard second-line anti-TB medications. Successful drug treatment of TB with complex resistance profiles is virtually impossible with currently available drugs. There is a desperate need for new compounds that cure strains resistant to currently available drugs and for drugs that are better tolerated and will shorten treatment regimens. In the short term, new strategies for the management of drug-resistant TB with currently available drugs are being explored. These include the use of high-dose isoniazid, substitution of rifabutin in a small proportion of rifampin-resistant cases, linezolid, fluoroquinolones, and phenothiazines. A number of novel drugs are undergoing clinical testing and will hopefully be available in the near future. These include the newer oxazolidinones, diarylquinolines, nitroimidazopyrans, ethenylenediamines, pyrroles, and benzothiazinones.