Treatment of HIV-related tuberculosis in the era of effective antiretroviral therapy

Clinical considerations and pharmacokinetic interactions between HIV and tuberculosis therapeutics

INTRODUCTION

Tuberculosis (TB) is a leading infectious disease cause of mortality worldwide, especially for people living with human immunodeficiency virus (PLWH). Treating TB in PLWH can be challenging due to numerous drug interactions.

AREAS COVERED

This review discusses drug interactions between antitubercular and antiretroviral drugs. Due to its clinical importance, initiation of antiretroviral therapy in patients requiring TB treatment is discussed. Special focus is placed on the rifamycin class, as it accounts for the majority of interactions. Clinically relevant guidance is provided on how to manage these interactions. An additional section on utilizing therapeutic drug monitoring (TDM) to optimize drug exposure and minimize toxicities is included.

EXPERT OPINION

Antitubercular and antiretroviral coadministration can be successfully managed. TDM can be used to optimize drug exposure and minimize toxicity risk. As new TB and HIV drugs are discovered, additional research will be needed to assess for clinically relevant drug interactions.

Synthesis, antimycobacterial screening, molecular docking, ADMET prediction and pharmacological evaluation on novel pyran-4-one bearing hydrazone, triazole and isoxazole moieties: Potential inhibitors of SARS CoV-2

The respiratory infection tuberculosis is caused by the bacteria Mycobacterium tuberculosis and its unrelenting spread caused millions of deaths around the world. Hence, it is needed to explore potential and less toxic anti-tubercular drugs. In the present work, we report the synthesis and antitubercular activity of four different (hydrazones 7-12, O-ethynyl oximes 19-24, triazoles 25-30, and isoxazoles 31-36) hybrids. Among these hybrids 9, 10, 33, and 34, displayed high antitubercular activity at 3.12 g/mL with >90% of inhibitions. The hybrids also showed good docking energies between -6.8 and -7.8 kcal/mol. Further, most active molecules were assayed for their DNA gyrase reduction ability towards M. tuberculosis and E.coli DNA gyrase by the DNA supercoiling and ATPase gyrase assay methods. All four hybrids showed good IC50 values comparable to that of the reference drug. In addition, the targets were also predicted as a potential binder for papain-like protease (SARS CoV-2 PLpro) by molecular docking and a good interaction result was observed. Besides, all targets were predicted for their absorption, distribution, metabolism, and excretion - toxicity (ADMET) profile and found a significant amount of ADMET and bioavailability.

Paradoxical Reaction to Antitubercular Treatment in a Case of Tuberculous Meningitis

Tuberculous meningitis (TBM) is a challenging disease to treat, as Mycobacterium tuberculosis infects the meninges, which are the outer membranes of the brain and the spinal cord. The majority of patients diagnosed with TBM acquire various other central nervous system complications, and as a result, treating the disease becomes a challenging task. A paradoxical reaction to the treatment may occur in the course of managing TBM. This case study describes a 20-year-old Southeast Asian female who was diagnosed and treated for TBM and subsequently developed a resurgence of the disease due to a paradoxical reaction.

Diagnostic Accuracy of Therapeutic Drug Monitoring During Tuberculosis Treatment

Tuberculosis (TB) patients co-infected with human immunodeficiency virus (HIV) are more likely to have low blood concentrations of the first-line anti-TB drugs (associated with poor outcomes). Therapeutic drug monitoring (TDM) is recommended for certain TB patient populations at increased risk for a poor outcome. Our objective was to estimate the diagnostic accuracy of a 2-hour TDM serum sample for the first-line anti-TB drugs among HIV/TB patients, and evaluate the information gained by an additional 6-hour sample. We created a virtual (n = 1,000) HIV/TB patient population and performed pharmacokinetic (PK) simulations using published population models for isoniazid, rifampin, pyrazinamide, and ethambutol. We performed receiver-operating-characteristic (ROC) analysis to compare the diagnostic performance of a single 2-hour serum sample with samples obtained at 2- and 6-hours post-dosing. The sensitivity of a single 2-hour serum concentration to identify HIV/TB patients with adequate serum exposures was lowest for rifampin (54.9%, 95% CI 50.79-59.41%) and highest for ethambutol (70.8%, 95% CI 66.06-72.61%) for C_max targets. Diagnostic accuracy of a single 2-hour serum sample for the AUC_0-24 target was highest for isoniazid (93%, 95% CI 90.9-94.1%) and lowest for pyrazinamide (66.3%, 95% CI 62.6-70.0%). In summary, the diagnostic performance of TDM for C_max and AUC_0-24 targets demonstrated variability across the first-line anti-TB drugs. The addition of a 6-hour serum sample lead to the highest statistically significant improvement (p < 0.001) and highest increase in diagnostic accuracy (area under the ROC curve) for rifampin for C_max and AUC. The other first-line drugs had modest/negligible increases in diagnostic accuracy. This article is protected by copyright. All rights reserved.

Risk factors for TB in Australia and their association with delayed treatment completion

BACKGROUND: Australia has a low incidence of TB and has committed to eliminating the disease. Identification of risk factors associated with TB is critical to achieving this goal.METHODS: We undertook a prospective cohort study involving persons receiving TB treatment in four Australian jurisdictions. Risk factors and their association with delayed treatment completion (treatment delayed by at least 1 month) were analysed using univariate analyses and multivariate logistic regression.RESULTS: Baseline surveys were completed for 402 persons with TB. Most (86.1%) were born overseas. Exposure to a person with TB was reported by 19.4%. Diabetes mellitus (10.2%), homelessness (9.2%), cigarette smoking (8.7%), excess alcohol consumption (6.0%) and mental illness (6.2%) were other common risk factors. At follow-up, 24.8% of patients had delayed treatment completion, which was associated with adverse events (34.1%, aOR 6.67, 95% CI 3.36-13.27), excess alcohol consumption (6.0%, aOR 21.94, 95% CI 6.03-79.85) and HIV co-infection (2.7%, aOR 8.10, 95% CI 1.16-56.60).CONCLUSIONS: We identified risk factors for TB and their association with delayed treatment completion, not all of which are routinely collected for surveillance purposes. Recognition of these risk factors should facilitate patient-centred care and assist Australia in reaching TB elimination.

Discovery of a novel class of small-molecule antibacterial agents against Staphylococcus aureus

Background: With constantly increasing resistance against the known antibiotics, the search for novel antibacterial compounds is a challenge. The number of synthetic antibacterial agents is limited. Materials & methods: We discovered novel small-molecule antibacterial agents that are accessible via a simple two-step procedure. The evaluation against Staphylococcus aureus showed antibacterial effects depending on the substituent positioning at the residues of the molecular scaffold. Additionally, we investigated the potential of the compounds to increase the antibacterial activity of tetracycline. Results: The most effective antibacterial compounds possessed a 3-methoxy function at an aromatic residue. In combination with tetracycline, we found a strong effect for a few compounds in boosting the antibacterial activity, so the first promising lead compounds with dual activities could be identified.

Development of New Therapeutics to Meet the Current Challenge of Drug Resistant Tuberculosis

Tuberculosis (TB) is a prominent infective disease and a major reason of mortality/ morbidity globally. Mycobacterium tuberculosis causes a long-lasting latent infection in a significant proportion of human population. The increasing burden of tuberculosis is mainly caused due to multi drug-resistance. The failure of conventional treatment has been observed in large number of cases. Drugs that are used to treat extensively drug-resistant tuberculosis are expensive, have limited efficacy, and have more side effects for a longer duration of time and are often associated with poor prognosis. To regulate the emergence of multidrug resistant tuberculosis, extensively drug-resistant tuberculosis and totally drug resistant tuberculosis, efforts are being made to understand the genetic/molecular basis of target drug delivery and mechanisms of drug resistance. Understanding the molecular approaches and pathology of Mycobacterium tuberculosis through whole genome sequencing may further help in the improvement of new therapeutics to meet the current challenge of global health. Understanding cellular mechanisms that trigger resistance to Mycobacterium tuberculosis infection may expose immune associates of protection, which could be an important way for vaccine development, diagnostics, and novel host-directed therapeutic strategies. The recent development of new drugs and combinational therapies for drug-resistant tuberculosis through major collaboration between industry, donors, and academia gives an improved hope to overcome the challenges in tuberculosis treatment. In this review article, an attempt was made to highlight the new developments of drug resistance to the conventional drugs and the recent progress in the development of new therapeutics for the treatment of drugresistant and non-resistant cases.

HIV TB coinfection - perspectives from India

Introduction: HIV and tuberculosis (TB) are two of the most challenging infections faced by humanity and place immense burden on health care systems worldwide. Both HIV and TB impact one another's progression.Areas covered: HIV is the most important risk factor for progression of latent TB to active disease. TB is the most common cause of death among People Living with HIV (PLHIV). Timely detection of TB among PLHIV and screening for HIV among TB patients, early initiation of ART and ATT among coinfected persons, provision of CPT and TB Preventive therapy along with control of air-borne infection are some of the key activities to reduce morbidity and mortality among coinfected persons. Despite many challenges, the collaboration between two programs has yielded good results and globally more than 7.3 million lives of PLHIV have been saved globally through scale-up of collaborative TB/HIV activities since 2005. The review looked into key features of both programs that are the collaboration strategies and challenges that still need to be addressed.Expert opinion: The overarching principle for effective implementation of collaborative activities is integration of the TB and HIV national programs right from policy making to service delivery and monitoring.

Pathogenesis of Human Immunodeficiency Virus-Mycobacterium tuberculosis Co-Infection

Given that infection with Mycobacterium tuberculosis (Mtb) is the leading cause of death amongst individuals living with HIV, understanding the complex mechanisms by which Mtb exacerbates HIV infection may lead to improved treatment options or adjuvant therapies. While it is well-understood how HIV compromises the immune system and leaves the host vulnerable to opportunistic infections such as Mtb, less is known about the interplay of disease once active Mtb is established. This review explores how glutathione (GSH) depletion, T cell exhaustion, granuloma formation, and TNF-α upregulation, as a result of Mtb infection, leads to an increase in HIV disease severity. This review also examines the difficulties of treating coinfected patients and suggests further research on the clinical use of GSH supplementation.

Predictors of Adverse TB Treatment Outcome among TB/HIV Patients Compared with Non-HIV Patients in the Greater Accra Regional Hospital from 2008 to 2016

Introduction

The convergence of TB and HIV dual epidemics is a major public health challenge in Ghana as well as many developing countries. Treatment outcome monitoring is a vital part of the surveillance needed to successfully eliminate TB. The impact of HIV status and demographic and treatment-related factors on adverse TB treatment outcome has not been studied in the Greater Accra Regional Hospital. This study determined factors associated with TB treatment outcome in patients with TB-HIV coinfection and TB-only infection in the hospital.

Method

A cross-sectional study was carried out in the Greater Accra Regional Hospital. We reviewed TB treatment cards of patients who received treatment for tuberculosis in the hospital from 2008 to 2016. Data on treatment outcome and sociodemographic and clinical characteristics were extracted on TB-only-infected and TB/HIV-coinfected patients. The chi-squared test and binary and multiple logistic regression models were used to assess factors associated with adverse treatment outcome.

Results

Out of the 758 patient records analyzed, 174 (22.9%) were TB-HIV-coinfected patients. Overall treatment success for all TB patients was 88.1% (668/758). About 11.9% (90/758) of the patients had an adverse treatment outcome, including treatment failure 0.9% (7/758), defaulting 0.9% (7/758), and death 10.0% (76/758). TB-HIV-coinfected patients' treatment success was 78.1% (136/174). TB-only patients' treatment success was 91.4% (532/582). Independent predictors of adverse treatment outcome were found to be as follows: being HIV positive (aOR: 3.85, 95% CI: 2.19-6.75; p < 0.01); aged 65 and above (aOR: 1.76, 95% CI: 1.44-1.54; p = 0.01); and previously failed TB treatment (aOR: 5.02, 95% CI: 2.09-28.87; p < 0.01).

Conclusion

Treatment outcome for TB-HIV-coinfected patients is below the WHO target. HIV status, age, and category of patient of the TB patients were associated with adverse treatment outcome. Strengthening the TB/HIV collaborative efforts by stakeholders is required for good treatment outcomes.

Prognostic Factors for Outcome after Vitrectomy for Retinal Detachment Secondary to Cytomegalovirus Retinitis in Patients with AIDS: A Retrospective Single-center Analysis

Purpose: To analyze the clinical characteristics and relevant prognostic factors of vitrectomy for retinal detachment (RD) secondary to cytomegalovirus retinitis (CMVR) in patients with acquired immune deficiency syndrome (AIDS).Methods: This study involved 39 eyes that underwent vitrectomy. Best-corrected visual acuity (BCVA), CD4⁺ cell counts, retinal attachment rate, and prognostic factors were assessed 1, 3, and 6 months postoperatively.Results: The rate of retinal attachment at 1 month (87.2%) was higher than at 3 (82.1%) and 6 (71.8%) months. Factors significantly related with recurrent RD at 6 months were CD4⁺ cell count <50 cell/µL (p = .000) and relaxed retinotomy (p = .002). Factors significantly related with the visual (≤logMAR1.0) prognosis at 6 months include band keratopathy (p = .015) and macular involvement by the RD (p = .012).Conclusion: CD4⁺ cell counts <50 cell/µL and relaxed retinotomy are associated with worse prognosis, while band keratopathy and macular involvement by the RD are related to poorer vision.

Pharmacokinetic Parameters of HIV-1 Protease Inhibitors

Since the beginning of the HIV epidemic, research has been carried out to control the virus. Understanding the mechanisms of replication has given access to the various classes of drugs that over time have transformed AIDS into a manageable chronic disease. The class of protease inhibitors (PIs) gained notice in anti-retroviral therapy, once it was found that peptidomimetic molecules act by blocking the active catalytic center of the aspartic protease, which is directly related to HIV maturation. However, mutations in enzymatic internal residues are the biggest issue for these drugs, because a small change in biochemical interaction can generate resistance. Low plasma concentrations of PIs favor viral natural selection; high concentrations can inhibit even partially resistant enzymes. Food-drug/drug-drug interactions can decrease the bioavailability of PIs and are related to many side effects. Therefore, this review summarizes the pharmacokinetic properties of current PIs, the changes when pharmacological boosters are used and also lists the major mutations to help understanding of how long the continuous treatment can ensure a low viral load in patients.

Bis-(imidazole/benzimidazole)-pyridine derivatives: synthesis, structure and antimycobacterial activity

Aim:

Over the last decades, few significant achievements have been made in tuberculosis (TB) therapy. As a result, there is an urgent need for new anti-TB drugs.

Results:

Two new classes of bis-(imidazole/benzimidazole)-pyridine derivatives were designed, synthesized and evaluated for their antimycobacterial activity.

Conclusion:

The synthesis is efficient and straightforward, involving only two successive N-alkylations. The anti-TB assay reveal that our compounds have an excellent anti-TB activity against both replicating and nonreplicating Mtb, are not cytotoxic, exhibited a very good intracellular activity and are active against drug-resistant Mtb strains, some compounds have a bactericidal mechanism. The absorption, distribution, metabolism, excretion and toxicity studies performed for one compound are promising, indicating that it is a good candidate for a future drug.

Ground-glass opacity as a paradoxical reaction in miliary tuberculosis: A case report and review of the literature

A paradoxical reaction (PR) is an excessive immune response occurring during antitubercular therapy (ATT), but is rare in patients with miliary tuberculosis. A 78-year-old woman complained of general malaise, loss of appetite, and fever for 10 days. Chest computed tomography (CT) showed diffuse, bilateral, discrete miliary nodules. The patient was treated with ATT for miliary tuberculosis. Nine days after starting the treatment, she developed a spiking fever and worsening malaise. Repeat CT showed new localized ground-glass opacity (GGO) in the right upper lobe. After excluding possible etiologies, she was diagnosed with PR due to ATT. She was successfully managed with oral prednisolone while continuing ATT. The GGO diminished and did not recur after discontinuation of the steroids. We reviewed 28 reported cases of miliary tuberculosis with a PR in patients not infected with human immunodeficiency virus. Those not on immunosuppressive therapy were likely to develop a PR early. This case illustrates that a PR may present as localized GGO in miliary tuberculosis in the lung of patients treated with ATT. In cases of a PR with marked symptoms, steroid therapy may be valuable.

Reflecting on tuberculosis case notification and treatment outcomes in the Volta region of Ghana: a retrospective pool analysis of a multicentre cohort from 2013 to 2017

BACKGROUND

Tuberculosis (TB) remains a petrified condition with a huge economic and health impact on families and health systems in Ghana. Monitoring of TB programme performance indicators can provide reliable data for direct measurement of TB incidence and mortality. This study reflects on the trends of TB case notification and treatment outcomes and makes comparison among 10 districts of the Volta region of Ghana.

METHODS

This was a retrospective analysis of surveillance data of a cohort of TB cases from 2013 to 2017. Trends of case notification and treatment outcomes were examined and compared. Logistic regression was used to determine the independent relationship between patients and disease characteristics and unsuccessful treatment outcomes. Odds ratios, 95% confidence intervals and p-values were estimated.

RESULTS

A gradual declining trend of case notification of all forms of TB was noticed, with an overall case notification rate (CNR) of 65 cases per 100,000 population during the period. A wide variation of case notification of TB was observed among the districts, ranging from 32 to 124 cases per 100,000 population. Similarly, treatment success rate decreased slightly from 83.1% during the first year to 80.2% in 2017, with an overall treatment success rate of 82.5% (95% CI: 81.3-83.8%). Treatment failure, death, and lost to follow up rates were 0.8% (range 0.5-1.2%), 13.5% (range 12.4-14.7%), and 3.1% (range 2.6-3.8%) respectively. The treatment success rate among districts ranged from 70.5% in South Tongu to 90.8% in Krachi West district. Returned after treatment interruption (Adjusted odds ratio [AOR]: 3.62; 95% CI: 1.66-7.91; P < 0.001) and TB/HIV co-infection (AOR: 1.94; 95% CI: 1.57-2.40; P < 0.001) predicts poor treatment outcomes.

CONCLUSION

Over the past five years, TB case notification and successful treatment outcomes did not significantly improve. Wide district variations in CNR was observed. The overall treatment success rate observed in this study is below the target of > 90% set by the World Health Organization's (WHO) end TB strategy. Additionally, patients who returned to continue treatment after interruption and those who were co-infected with HIV strongly predict unsuccessful treatment outcomes. Sustained interventions to prevent treatment interruptions and improved management of co-morbidities can enhance treatment outcomes, as required to achieve the elimination goal.

Paradoxical Reaction of Tuberculosis in a Heart Transplant Recipient During Antituberculosis Therapy: A Case Report

INTRODUCTION

Tuberculous paradoxical reactions (PRs) are excessive immune reactions occurring after antituberculosis (TB) treatment and are commonly observed in immunocompromised hosts such as patients infected with the human immunodeficiency virus.

CASE REPORT

We recently encountered a 63-year-old male heart transplant recipient who developed tuberculous PR after treatment for miliary TB. The patient had been receiving immunosuppressive therapy with cyclosporine and mycophenolate mofetil for over 15 years. The diagnosis of miliary TB was made based on the presence of intermittent fever and fatigue; thus, anti-TB treatments (isoniazid, levofloxacin, ethambutol, and pyrazinamide) were started, which led to rapid defervescence and regression of the granular shadow and pleural effusion. However, a new persistent fever and confused state developed 1 month after the anti-TB therapy was started. After excluding possible etiologies of the patient's symptom, a PR was suspected, and anti-TB drugs were continued; corticosteroids were added as anti-inflammatory agents. After that, he has shown a favorable course with long-term anti-TB chemotherapy.

CONCLUSION

A PR should always be considered when the patients' symptoms of tuberculosis re-exacerbate after an appropriate anti-TB therapy. A PR commonly occurs in patients with various immunologic conditions including heart transplant recipients.

The burden of HIV on Tuberculosis patients in the Volta region of Ghana from 2012 to 2015: implication for Tuberculosis control

Background

The impact of HIV on TB, and the implications for TB control, has been acknowledged as a public health challenge. It is imperative therefore to assess the burden of HIV on TB patients as an indicator for monitoring the control efforts of the two diseases in this part of the world. This study aimed at determining the burden of HIV infection in TB patients.

Methods

We conducted a retrospective review of TB registers in five districts of the Volta Region of Ghana. Prevalence of TB/HIV co-infection was determined. Bivariate and multivariate logistic regression were used to identify the predictors of HIV infection among TB patients and statistical significance was set at p-value <0.05.

Results

Of the 1772 TB patients, 1633 (92.2%) were tested for HIV. The overall prevalence of TB/HIV co-infection was (18.2%; 95% CI: 16.4–20.1). The prevalence was significantly higher among females (24.1%; 95%CI: 20.8–27.7), compared to males (15.1%; 95% CI: 13.1–17.4) (p < 0.001) and among children <15 years of age (27.0%; 95% CI: 18.2–38.1), compared to the elderly ≥70 years (3.5%; 95% CI: 1.6–7.4) (p < 0.001). Treatment success rate was higher among patients with only TB (90%; 95% CI: 88.1–91.5) than among TB/HIV co-infected patients (77.0%; 95% CI: 71.7–81.7) (p < 0.001). Independent predictors of HIV infection were found to be: being female (AOR: 1.79; 95% CI: 1.38–2.13; p < 0.001); smear negative pulmonary TB (AOR: 1.84; 95% CI: 1.37–2.47; p < 0.001); and patients registered in Hohoe, Kadjebi, and Kpando districts with adjusted odds ratios of 1.69 (95% CI: 1.13–2.54; p = 0.011), 2.29 (95% CI: 1.46–3.57; p < 0.001), and 2.15 (95% CI: 1.44–3.21; p < 0.001) respectively. Patients ≥70 years of age and those registered in Keta Municipal were less likely to be HIV positive with odds ratios of 0.09 (95% CI: 0.04–0.26; p < 0.001) and 0.62 (95% CI: 0.38–0.99; p = 0.047) respectively.

Conclusion

TB/HIV co-infection rate in five study districts of the Volta region is quite high, occurs more frequently in female patients than males; among smear negative pulmonary TB patients, and children <15 years of age. Findings also demonstrate that HIV co-infection affects TB treatment outcomes adversely. Strengthening the TB/HIV collaborative efforts is required in order to reduce the burden of co-infection in patients.

Paradoxical Reactions and the Immune Reconstitution Inflammatory Syndrome

In HIV-infected individuals, paradoxical reactions after the initiation of antiretroviral therapy (ART) are associated with a variety of underlying infections and have been called the immune reconstitution inflammatory syndrome (IRIS). In cases of IRIS associated with tuberculosis (TB), two distinct patterns of disease are recognized: (i) the progression of subclinical TB to clinical disease after the initiation of ART, referred to as unmasking, and (ii) the progression or appearance of new clinical and/or radiographic disease in patients with previously recognized TB after the initiation of ART, the classic or "paradoxical" TB-IRIS. IRIS can potentially occur in all granulomatous diseases, not just infectious ones. All granulomatous diseases are thought to result from interplay of inflammatory cells and mediators. One of the inflammatory cells thought to be integral to the development of the granuloma is the CD4 T lymphocyte. Therefore, HIV-infected patients with noninfectious granulomatous diseases such as sarcoidosis may also develop IRIS reactions. Here, we describe IRIS in HIV-infected patients with TB and sarcoidosis and review the basic clinical and immunological aspects of these phenomena.

Prisoners co-infected with tuberculosis and HIV: a systematic review

INTRODUCTION

Almost from the beginning of the HIV epidemic in 1981, an association with tuberculosis (TB) was recognized. This association between HIV and TB co-infection has been particularly evident amongst prisoners. However, despite this, few studies of TB in prisons have stratified results by HIV status. Given the high prevalence of HIV-positive persons and TB-infected persons in prisons and the documented risk of TB in those infected with HIV, it is of interest to determine how co-infection varies amongst prison populations worldwide. For this reason we have undertaken a systematic review of studies of co-infected prisoners to determine the incidence and/or prevalence of HIV/TB co-infection in prisons, as well as outcomes in this group, measured as treatment success or death.

METHODS

A literature search was undertaken using the online databases PubMed, Embase, IBSS, Scopus, Web of Science, Global Health and CINAHL Plus. No restrictions were set on language or publication date for article retrieval, with articles included if indexed up to 18 October 2015. A total of 1975 non-duplicate papers were identified. For treatment and outcome data all eligible papers were appraised for inclusion; for incidence/prevalence estimates papers published prior to 2000 were excluded from full text review. After full text appraisal, 46 papers were selected for inclusion in the review, 41 for incidence/prevalence estimates and nine for outcomes data, with four papers providing evidence for both outcomes and prevalence/incidence.

RESULTS

Very few studies estimated the incidence of TB in HIV positive prisoners, with most simply reporting prevalence of co-infection. Co-infection is rarely explicitly measured, with studies simply reporting HIV status in prisoners with TB, or a cross-sectional survey of TB prevalence amongst prisoners with HIV. Estimates of co-infection prevalence ranged from 2.4 to 73.1% and relative risks for one, given the other, ranged from 2.0 to 10.75, although some studies reported no significant association between HIV and TB. Few studies provided a comparison with the risk of co-infection in the general population.

CONCLUSIONS

Prisoners infected with HIV are at high risk of developing TB. However, the magnitude of risk varies between different prisons and countries. There is little evidence on treatment outcomes in co-infected prisoners, and the existing evidence is conflicting in regards to HIV status influence on prisoner treatment outcomes.PROSPERO Number: CRD42016034068.

Current trends and intricacies in the management of HIV-associated pulmonary tuberculosis

Human immunodeficiency virus (HIV) epidemic has undoubtedly increased the incidence of tuberculosis (TB) globally, posing a formidable global health challenge affecting 1.2 million cases. Pulmonary TB assumes utmost significance in the programmatic perspective as it is readily transmissible as well as easily diagnosable. HIV complicates every aspect of pulmonary tuberculosis from diagnosis to treatment, demanding a different approach to effectively tackle both the diseases. In order to control these converging epidemics, it is important to diagnose early, initiate appropriate therapy for both infections, prevent transmission and administer preventive therapy. Liquid culture methods and nucleic acid amplification tests for TB confirmation have replaced conventional solid media, enabling quicker and simultaneous detection of mycobacterium and its drug sensitivity profile Unique problems posed by the syndemic include Acquired rifampicin resistance, drug-drug interactions, malabsorption of drugs and immune reconstitution inflammatory syndrome or paradoxical reaction that complicate dual and concomitant therapy. While the antiretroviral therapy armamentarium is constantly reinforced by discovery of newer and safer drugs every year, only a few drugs for anti tuberculosis treatment have successfully emerged. These include bedaquiline, delamanid and pretomanid which have entered phase III B trials and are also available through conditional access national programmes. The current guidelines by WHO to start Antiretroviral therapy irrespective of CD4+ cell count based on benefits cited by recent trials could go a long way in preventing various complications caused by the deadly duo. This review provides a consolidated gist of the advancements, concepts and updates that have emerged in the management of HIV-associated pulmonary TB for maximizing efficacy, offering latest solutions for tackling drug-drug interactions and remedial measures for immune reconstitution inflammatory syndrome.

Life-Threatening Complications of HIV Infection

Few modern diseases have experienced as rapid and dramatic change in prognosis and treatment as HIV infection. The introduction of active antiretroviral therapy (ART) and effective prophylaxis of opportunistic infections ushered in a new era in the treatment of HIV infection and changed dramatically the natural history of this disease. The rates of admission to the intensive care unit (ICU) and intensive care mortality in patients with HIV infection have shifted repeatedly during the AIDS epidemic, influenced by attitudes of patients and providers toward utility of care. In the ART era, patients with HIV infection admitted to the ICU fall into 3 general categories: those with AIDS-related opportunistic infections, those who are experiencing complications related to ART, and those with medical problems unrelated to HIV infection. In this article, the authors provide a review of the most common life-threatening complications in patients with HIV infection.

Impact of HIV infection on treatment outcome of tuberculosis in Europe

BACKGROUND

The effect of HIV on tuberculosis (TB) treatment outcomes has not been well established. We aimed to assess the impact of HIV infection on TB treatment outcomes by using data from notifiable disease surveillance in Europe.

METHODS

We analyzed the treatment outcomes of TB cases reported from nine European countries during 2010-2012. We investigate the effect of HIV on TB treatment outcomes using a multilevel and a multinomial logistic model, and considering the interaction between HIV and multidrug-resistant (MDR) TB.

RESULTS

A total of 61,138 TB cases including 5.5% HIV-positive were eligible for our analysis. In the multilevel model adjusted for age and an interaction with MDR TB, HIV was significantly associated with lower treatment success in all MDR strata [non-MDR TB: odds ratio (OR) 0.24 CI (confidence interval) 0.20-0.29; unknown MDR TB status: OR 0.26 CI 0.23-0.30; MDR TB: OR 0.57 CI 0.35-0.91]. In the multinomial regression model, HIV-positive cases had significantly higher relative risk ratio (RRR) for death (non-MDR TB: RRR 4.30 CI 2.31-7.99; unknown MDR TB status: 5.55 CI 3.10-9.92; MDR TB: 3.59 CI 1.56-8.28) and being 'still on treatment' (non-MDR TB: RRR 7.27 CI 3.00-17.6; unknown MDR TB status: 5.36 CI 2.44-11.8; MDR TB: 3.76 CI 2.48-5.71). We did not find any significant association between HIV and TB treatment failure (non-MDR TB: RRR 0.50 CI 0.15-1.67; unknown MDR TB status: 1.51 CI 0.86-2.64; MDR TB: 0.51 CI 0.13-1.87).

CONCLUSION

This large study confirms that HIV is a strong risk factor for an adverse TB treatment outcome, which is mainly manifested by an increased risk of death and still being on TB treatment.

Clinical Outcomes of Retinal Detachment Surgery following Cytomegalovirus Retinitis in Patients on Highly Active Anti-retroviral Therapy for Acquired Immune Deficiency Syndrome

AIM

The objective of this study is to describe the surgical outcomes of patients of HIV on HAART who underwent surgery for CMV retinitis related retinal detachment.

METHOD AND MATERIALS

A retrospective analysis of the medical records of 40 eyes of 35 consecutive HIV positive patients who underwent surgical repair for CMV retinitis associated rhegmatogenous retinal detachment between January 2000 to August 2010 was done. All patients had an adequate follow up of atleast 6 months.

RESULTS

Favourable anatomical outcome was achieved in 78 % of eyes with the eyes having a attached retina, clear media and controlled intraocular pressure.Favourable functional outcome (vision >3/60) was achieved in 56%.

CONCLUSION

Though anatomical outcomes have not changed from the pre HAART era but there has been an increase in favorable functional outcomes possibly due to effects of antiretroviral therapy.

Pharmacological interactions between rifampicin and antiretroviral drugs: challenges and research priorities for resource-limited settings

Coadministration of antituberculosis and antiretroviral therapy is often inevitable in high-burden countries where tuberculosis (TB) is the most common opportunistic infection associated with HIV/AIDS. Concurrent use of rifampicin and many antiretroviral drugs is complicated by pharmacokinetic drug-drug interactions. Rifampicin is a very potent enzyme inducer, which can result in subtherapeutic antiretroviral drug concentrations. In addition, TB drugs and antiretroviral drugs have additive (pharmacodynamic) interactions as reflected in overlapping adverse effect profiles. This review provides an overview of the pharmacological interactions between rifampicin-based TB treatment and antiretroviral drugs in adults living in resource-limited settings. Major progress has been made to evaluate the interactions between TB drugs and antiretroviral therapy; however, burning questions remain concerning nevirapine and efavirenz effectiveness during rifampicin-based TB treatment, treatment options for TB-HIV-coinfected patients with nonnucleoside reverse transcriptase inhibitor resistance or intolerance, and exact treatment or dosing schedules for vulnerable patients including children and pregnant women. The current research priorities can be addressed by maximizing the use of already existing data, creating new data by conducting clinical trials and prospective observational studies and to engage a lobby to make currently unavailable drugs available to those most in need.

Radiological Follow-up of a Cerebral Tuberculoma with a Paradoxical Response Mimicking a Brain Tumor

We report a case of a paradoxical response of a tuberculoma in the brain mimicking a brain tumor. A 76-year-old woman presented with a 2 week history of headache, dysarthia, and orthopnea. Brain magnetic resonance images (MRI) revealed two rim-enhancing lesions on the pons and occipital lobe, and chest computed tomography showed randomly distributed miliary nodules. The tentative diagnosis was tuberculosis (TB) of the brain and lung. She complained of right hemiparesis and worsening general weakness after taking the anti-TB medication. On the monthly follow-up images, the enhanced lesions were enlarged with increased perfusion and choline/creatinine ratio, suggesting a high grade glioma. A surgical resection was completed to diagnose the occipital lesion, and the tuberculoma was pathologically confirmed by a positive TB-polymerase chain reaction. The anti-TB medication was continued for 13 months. A follow-up MRI showed decreased size of the brain lesions associated with perilesional edema, and the clinical symptoms had improved. Brain tuberculoma could be aggravated mimicking brain malignancy during administration of anti-TB medication. This paradoxical response can be effectively managed by continuing the anti-TB drugs.

[Treatment of tuberculosis]

The aim of this article is to give practicing physicians a practical approach to the treatment of latent and active tuberculosis. Most patients follow TB standard treatment recommended by WHO that depend on category of patient. It is a combination of four essential tuberculosis drugs of the first group: isoniazid, rifampicin, pyrazinamid and ethambutol; in some cases streptomycin can replace ethambutol. This initial phase of intensive treatment is followed by a consolidation phase. Drugs should be administered in the morning on an empty stomach one hour before meals. Treatment of latent tuberculosis (TB) infection is an important component of TB control programs. Preventive treatment can reduce the risk of developing active TB.

Drug Resistance Mechanisms in Mycobacterium tuberculosis

Tuberculosis (TB) is a serious public health problem worldwide. Its situation is worsened by the presence of multidrug resistant (MDR) strains of Mycobacterium tuberculosis, the causative agent of the disease. In recent years, even more serious forms of drug resistance have been reported. A better knowledge of the mechanisms of drug resistance of M. tuberculosis and the relevant molecular mechanisms involved will improve the available techniques for rapid drug resistance detection and will help to explore new targets for drug activity and development. This review article discusses the mechanisms of action of anti-tuberculosis drugs and the molecular basis of drug resistance in M. tuberculosis.

Aetiology of pulmonary symptoms in HIV-infected smear negative recurrent PTB suspects in Kampala, Uganda: a cross-sectional study

Introduction

Previously treated TB patients with pulmonary symptoms are often considered recurrent TB suspects in the resource-limited settings, where investigations are limited to microscopy and chest x-ray. Category II anti-TB drugs may be inappropriate and may expose patients to pill burden, drug toxicities and drug-drug interactions.

Objective

To determine the causes of pulmonary symptoms in HIV-infected smear negative recurrent pulmonary tuberculosis suspects at Mulago Hospital, Kampala.

Methods

Between March 2008 and December 2011, induced sputum samples of 178 consented HIV-infected smear negative recurrent TB suspects in Kampala were subjected to MGIT and LJ cultures for mycobacteria at TB Reference Laboratory, Kampala. Processed sputum samples were also tested by PCR to detect 18S rRNA gene of P.jirovecii and cultured for other bacteria.

Results

Bacteria, M. tuberculosis and Pneumocystis jirovecii were detected in 27%, 18% and 6.7% of patients respectively and 53.4% of the specimens had no microorganisms. S. pneumoniae, M. catarrhalis and H. influenzae were 100% susceptible to chloramphenicol and erythromycin but co-trimoxazole resistant.

Conclusion

At least 81.5% of participants had no microbiologically-confirmed TB. However our findings call for thorough investigation of HIV-infected smear negative recurrent TB suspects to guide cost effective treatment.

Improved synthesis of capuramycin and its analogues

Capuramycin and its congeners are considered to be important lead molecules for the development of a new drug for multidrug-resistant (MDR) Mycobacterium tuberculosis infections. Extensive structure-activity relationship studies of capuramycin to improve the efficacy have been limited because of difficulties in selectively chemically modifying the desired position(s) of the natural product with biologically interesting functional groups. We have developed efficient syntheses of capuramycin and its analogues by using new protecting groups, derived from the chiral (chloro-4-methoxyphenyl)(chlorophenyl)methanols, for the uridine ureido nitrogen and primary alcohol. The chiral nonracemic (2,6-dichloro-4-methoxyphenyl)(2,4-dichlorophenyl)methanol derivative is a useful reagent to resolve rac-3-amino-1,3-dihydro-5-phenyl-2H-1,4-benzodiazepin-2-one, the (S)-configuration isomer of which plays a significant role in improving the mycobactericidal activity of capuramycin.

Therapy and prophylaxis of opportunistic infections in HIV-infected patients: a guideline by the German and Austrian AIDS societies (DAIG/ÖAG) (AWMF 055/066)

INTRODUCTION

There was a growing need for practical guidelines for the most common OIs in Germany and Austria under consideration of the local epidemiological conditions.

MATERIALS AND METHODS

The German and Austrian AIDS societies developed these guidelines between March 2010 and November 2011. A structured Medline research was performed for 12 diseases, namely Immune reconstitution inflammatory syndrome, Pneumocystis jiroveci pneumonia, cerebral toxoplasmosis, cytomegalovirus manifestations, candidiasis, herpes simplex virus infections, varizella zoster virus infections, progressive multifocal leucencephalopathy, cryptosporidiosis, cryptococcosis, nontuberculosis mycobacteria infections and tuberculosis. Due to the lack of evidence by randomized controlled trials, part of the guidelines reflects expert opinions. The German version was accepted by the German and Austrian AIDS Societies and was previously published by the Arbeitsgemeinschaft der Wissenschaftlichen Medizinischen Fachgesellschaften (AWMF; German Association of the Scientific Medical Societies).

CONCLUSION

The review presented here is a translation of a short version of the German-Austrian Guidelines of opportunistic infections in HIV patients. These guidelines are well-accepted in a clinical setting in both Germany and Austria. They lead to a similar treatment of a heterogeneous group of patients in these countries.

Impact of tuberculosis on mortality among HIV-infected patients receiving antiretroviral therapy in Uganda: a prospective cohort analysis

Background

Tuberculosis (TB) disease affects survival among HIV co-infected patients on antiretroviral therapy (ART). Yet, the magnitude of TB disease on mortality is poorly understood.

Methods

Using a prospective cohort of 22,477 adult patients who initiated ART between August 2000 and June 2009 in Uganda, we assessed the effect of active pulmonary TB disease at the initiation of ART on all-cause mortality using a Cox proportional hazards model. Propensity score (PS) matching was used to control for potential confounding. Stratification and covariate adjustment for PS and not PS-based multivariable Cox models were also performed.

Results

A total of 1,609 (7.52%) patients had active pulmonary TB at the start of ART. TB patients had higher proportions of being male, suffering from AIDS-defining illnesses, having World Health Organization (WHO) disease stage III or IV, and having lower CD4 cell counts at baseline (p < 0.001). The percentages of death during follow-up were 10.47% and 6.38% for patients with and without TB, respectively. The hazard ratio (HR) for mortality comparing TB to non-TB patients using 1,686 PS-matched pairs was 1.37 (95% confidence interval [CI]: 1.08 – 1.75), less marked than the crude estimate (HR = 1.74, 95% CI: 1.49 – 2.04). The other PS-based methods and not PS-based multivariable Cox model produced similar results.

Conclusions

After controlling for important confounding variables, HIV patients who had TB at the initiation of ART in Uganda had an approximate 37% increased hazard of overall mortality relative to non-TB patients.

Drug therapy in spinal tuberculosis

Although the discovery of effective anti-tuberculosis drugs has made uncomplicated spinal tuberculosis a medical disease, the advent of multi-drug-resistant Mycobacterium tuberculosis and the co-infection of HIV with tuberculosis have led to a resurgence of the disease recently. The principles of drug treatment of spinal tuberculosis are derived from our experience in treating pulmonary tuberculosis. Spinal tuberculosis is classified to be a severe form of extrapulmonary tuberculosis and hence is included in Category I of the WHO classification. The tuberculosis bacilli isolated from patients are of four different types with different growth kinetics and metabolic characteristics. Hence multiple drugs, which act on the different groups of the mycobacteria, are included in each anti-tuberculosis drug regimen. Prolonged and uninterrupted chemotherapy (which may be 'short course' and 'intermittent' but preferably 'directly observed') is effective in controlling the infection. Spinal Multi-drug-resistant TB and spinal TB in HIV-positive patients present unique problems in management and have much poorer prognosis. Failure of chemotherapy and emergence of drug resistance are frequent due to the failure of compliance hence all efforts must be made to improve patient compliance to the prescribed drug regimen.

Cerebral tuberculoma as a manifestation of paradoxical reaction in patients with pulmonary and extrapulmonary tuberculosis

Expansion of cerebral tuberculomas or their new appearance as a manifestation of paradoxical reaction in patients under antituberculous chemotherapy is well documented. Distinguishing paradoxical reaction from disease progression or treatment failure is an important issue in tuberculosis management. Five cases of cerebral tuberculomas are reported here as manifestations of paradoxical reaction in patients with pulmonary and extrapulmonary tuberculosis on antituberculous treatment. Case 1 and 2 had tuberculous meningitis, Case 3 had miliary tuberculosis, Case 4 had miliary tuberculosis and destructive vertebral lesions, and Case 5 had pulmonary tuberculosis. Continuation of antituberculous drugs and addition of steroids led to full recovery of all patients.

Modelling HIV and MTB co-infection including combined treatment strategies

A new host-pathogen model is described that simulates HIV-MTB co-infection and treatment, with the objective of testing treatment strategies. The model includes CD4+ and CD8+ T cells, resting and activated macrophages, HIV and Mycobacterium tuberculosis (MTB). For TB presentation at various stages of HIV disease in a co-infected individual, combined treatment strategies were tested with different relative timings of treatment for each infection. The stages were early HIV disease, late HIV disease and AIDS. The main strategies were TB treatment followed by anti-retroviral therapy (ART) after delays of 15 days, 2 months and 6 months. ART followed by TB treatment was an additional strategy that was tested. Treatment was simulated with and without drug interaction. Simulation results were that TB treatment first followed by ART after a stage-dependent delay has the best outcome. During early HIV disease a 6 month delay is acceptable. During late HIV disease, a 2 month delay is best. During AIDS it is better to start ART after 15 days. However, drug interaction works against the benefits of early ART. These results agree with expert reviews and clinical trials.

Hepatotoxicity induced by antituberculosis drugs among patients coinfected with HIV and tuberculosis

Hepatotoxicity due to antituberculosis drugs limits treatment in patients coinfected with HIV and tuberculosis. We conducted a case-control study to identify risk factors for hepatotoxicity among patients coinfected with tuberculosis and HIV in two hospitals in Recife, Pernambuco State, Brazil. The sample consisted of 57 patients (36.5% of the total) who developed hepatotoxicity and a control group of 99 patients (63.5% of the total), who did not present this effect. Hepatotoxicity consisted of jaundice or a high concentration of AST/ALT or total bilirubinemia. Multivariate logistic regression showed that a T CD4+ count of < 200 cells/mm(3) increased the risk of hepatotoxicity by a factor of 1.233 (p < 0.001) and that coinfection with hepatitis B or C virus increased this risk by a factor of 18.187 (p = 0.029). Discharge occurred among 66.1% of the case group (p = 0.026). The absence of hepatotoxicity was a protective factor against death (OR = 0.42; 95%CI: 0.20-0.91). Coinfection with the B and C hepatitis virus and a T CD4+ cell count below 200 cells/mm(3) were independent risk factors for hepatotoxicity in these patients.

Central nervous system immune reconstitution inflammatory syndrome in AIDS: experience of a Mexican neurological centre

BACKGROUND

Highly active antiretroviral therapy (HAART) restores the inflammatory immune response in AIDS patients and it may unmask previous subclinical infections or paradoxically exacerbate symptoms of opportunistic infections. Up to 25% of patients receiving HAART develop immune reconstitution inflammatory syndrome (IRIS). We describe six patients with IRIS central nervous system (CNSIRIS) manifestations emphasizing the relevance of CSF cultures and neuroimaging in early diagnosis and management.

METHODS

Patients with CNSIRIS were identified among hospitalized HIV-infected patients that started HAART from January 2002 through December 2007 at a referral neurological center in Mexico.

RESULTS

One-hundred and forty-two HIV-infected patients with neurological signs were hospitalized, 64 of which had received HAART, and six (9.3%) developed CNSIRIS. Five patients were male. Two cases of tuberculosis, two of cryptococcosis, one of brain toxoplasmosis, and one possible PML case were found. IRIS onset occurred within 12 weeks of HAART in five patients. Anti-infective therapy was continued. In one case, HAART was temporarily suspended. In long-term follow-up the clinical condition improved in all patients.

CONCLUSIONS

CNSIRIS associated to opportunistic infections appeared in 9% of patients receiving HAART. Interestingly, no cases of malignancy or neoplasm IRIS-related were found. Frequent clinical assessment and neuroimaging studies supported diagnosis and treatment. Risk factors were similar to those found in other series.

Efficacy and safety of once-daily nevirapine- or efavirenz-based antiretroviral therapy in HIV-associated tuberculosis: a randomized clinical trial

BACKGROUND

Nevirapine (NVP) can be safely and effectively administered once-daily but has not been assessed in human immunodeficiency virus (HIV)-infected patients with tuberculosis (TB). We studied the safety and efficacy of once-daily NVP, compared with efavirenz (EFV; standard therapy); both drugs were administered in combination with 2 nucleoside reverse-transcriptase inhibitors.

METHODS

An open-label, noninferiority, randomized controlled clinical trial was conducted at 3 sites in southern India. HIV-infected patients with TB were treated with a standard short-course anti-TB regimen (2EHRZ(3)/4RH(3); [2 months of Ethambutol, Isoniazid, Rifampicin, Pyrazinamide / 4 months of Isoniazid and Rifampicin] thrice weekly) and randomized to receive once-daily EFV at a dose of 600 mg or NVP at a dose of 400 mg (after 14 days of 200 mg administered once daily) with didanosine 250/400 mg and lamivudine 300 mg after 2 months. Sputum smears and mycobacterial cultures were performed every month. CD4+ cell count, viral load, and liver function test results were monitored periodically. Primary outcome was a composite of death, virological failure, default, or serious adverse event (SAE) at 24 weeks. Both intent-to-treat and per protocol analyses were done, and planned interim analyses were performed.

RESULTS

A total of 116 patients (75% [87 patients] of whom had pulmonary TB), with a mean age of 36 years, a median CD4+ cell count of 84 cells/mm(3), and a median viral load of 310 000 copies/mL, were randomized. At 24 weeks, 50 of 59 patients in the EFV group and 37 of 57 patients in the NVP group had virological suppression (P = .024). There were no deaths, 1 SAE, and 5 treatment failures in the EFV arm, compared with 5 deaths, 2 SAEs, and 10 treatment failures in the NVP arm. The trial was halted by the data and safety monitoring board at the second interim analysis. Favorable TB treatment outcomes were observed in 93% of the patients in the EFV arm and 84% of the patients in the NVP arm (P = .058).

CONCLUSIONS

Compared with a regimen of didanosine, lamivudine, and EFV, a regimen of once-daily didanosine, lamivudine, and NVP was inferior and was associated with more frequent virologic failure and death. Clinical Trials Registration. NCT00332306.

Pharmacophore insights into rpoB gene mutations in Mycobacterium tuberculosis rifampicin resistant isolates

This paper reports the susceptibility profile to rifabutin (RFB) 1 and six recently synthesized RFB analogs 3-8, of either rifampicin (RFP) susceptible Mycobacterium tuberculosis and resistant clinical isolates from two sources: Mexico and Brazil. Taking into account that about 95% of M. tuberculosis strains resistant to RFP present mutations in the rpoB gene, with some of these mutations being determinant also to RFB resistance, the RFB analogs were screened for activity against a set of known RFP susceptible and resistant strains. N'-Acetyl-RFB 5 and N'-(undec-10″-enoyl)-RFB 8 showed the best results, in particular with mutations in the codon 516, 522 and 531 of the rpoB gene, and were therefore selected for in vivo assessment of their efficacy. Studies conducted with tuberculous Balb/C mice previously infected with Ser531Leu mutated clinical isolate, evidenced both 5 and 8 as promoters of a significant decrease on tubercle bacilli burden in lungs associated with lower tissue damage, thus confirming them as good leads for drug discovery. The SAR of the acylated compounds 5 and 8 envisaging the identification of pharmacophore features, highlights the importance of profiling more clearly the chemistry within the molecular aspects for elucidation of the mode of action of RFB and analogs, in relation to mutations in Multidrug-Resistant (MDR) strains.

The antiretroviral efficacy of highly active antiretroviral therapy and plasma nevirapine concentrations in HIV-TB co-infected Indian patients receiving rifampicin based antituberculosis treatment

Background

Rifampicin reduces the plasma concentrations of nevirapine in human immunodeficiency virus (HIV) and tuberculosis (TB) co-infected patients, who are administered these drugs concomitantly. We conducted a prospective interventional study to assess the efficacy of nevirapine-containing highly active antiretroviral treatment (HAART) when co-administered with rifampicin-containing antituberculosis treatment (ATT) and also measured plasma nevirapine concentrations in patients receiving such a nevirapine-containing HAART regimen.

Methods

63 cases included antiretroviral treatment naïve HIV-TB co-infected patients with CD4 counts less than 200 cells/mm³ started on rifampicin-containing ATT followed by nevirapine-containing HAART. In control group we included 51 HIV patients without tuberculosis and on nevirapine-containing HAART. They were assessed for clinical and immunological response at the end of 24 and 48 weeks. Plasma nevirapine concentrations were measured at days 14, 28, 42 and 180 of starting HAART.

Results

97 out of 114 (85.1%) patients were alive at the end of 48 weeks. The CD4 cell count showed a mean increase of 108 vs.113 cells/mm3 (p=0.83) at 24 weeks of HAART in cases and controls respectively. Overall, 58.73% patients in cases had viral loads of less than 400 copies/ml at the end of 48 weeks. The mean (± SD) Nevirapine concentrations of cases and control at 14, 28, 42 and 180 days were 2.19 ± 1.49 vs. 3.27 ± 4.95 (p = 0.10), 2.78 ± 1.60 vs. 3.67 ± 3.59 (p = 0.08), 3.06 ± 3.32 vs. 4.04 ± 2.55 (p = 0.10) respectively and 3.04 μg/ml (in cases).

Conclusions

Good immunological and clinical response can be obtained in HIV-TB co-infected patients receiving rifampicin and nevirapine concomitantly despite somewhat lower nevirapine trough concentrations. This suggests that rifampicin-containing ATT may be co administered in resource limited setting with nevirapine-containing HAART regimen without substantial reduction in antiretroviral effectiveness. Larger sample sized studies and longer follow-up are required to identify populations of individuals where the reduction in nevirapine concentration may result in lower ART response or shorter response duration.

Molecular basis and mechanisms of drug resistance in Mycobacterium tuberculosis: classical and new drugs

Tuberculosis (TB) remains one of the leading public health problems worldwide. Declared as a global emergency in 1993 by the WHO, its control is hampered by the emergence of multidrug resistance (MDR), defined as resistance to at least rifampicin and isoniazid, two key drugs in the treatment of the disease. More recently, severe forms of drug resistance such as extensively drug-resistant (XDR) TB have been described. After the discovery of several drugs with anti-TB activity, multidrug therapy became fundamental for control of the disease. Major advances in molecular biology and the availability of new information generated after sequencing the genome of Mycobacterium tuberculosis increased our knowledge of the mechanisms of resistance to the main anti-TB drugs. Better knowledge of the mechanisms of drug resistance in TB and the molecular mechanisms involved will help us to improve current techniques for rapid detection and will also stimulate the exploration of new targets for drug activity and drug development. This article presents an updated review of the mechanisms and molecular basis of drug resistance in M. tuberculosis. It also comments on the several gaps in our current knowledge of the molecular mechanisms of drug resistance to the main classical and new anti-TB drugs and briefly discusses some implications of the development of drug resistance and fitness, transmission and pathogenicity of M. tuberculosis.

Timing of antiretroviral therapy for HIV in the setting of TB treatment

The convergent human immunodeficiency virus (HIV) and tuberculosis (TB) pandemics continue to collectively exact significant morbidity and mortality worldwide. Highly active antiretroviral therapy (HAART) has been a critical component in combating the scourge of these two conditions as both a preemptive and therapeutic modality. However, concomitant administration of antiretroviral and antituberculous therapies poses significant challenges, including cumulative drug toxicities, drug-drug interactions, high pill burden, and the immune reconstitution inflammatory syndrome (IRIS), thus complicating the management of coinfected individuals. This paper will review data from recent studies regarding the optimal timing of HAART initiation relative to TB treatment, with the ultimate goal of improving coinfection-related morbidity and mortality while mitigating toxicity resulting from concurrent treatment of both infections.