Multidrug- and extensively drug-resistant TB in persons living with HIV

Dibenzofuran, dibenzothiophene and N-methyl carbazole tethered 2-aminothiazoles and their cinnamamides as potent inhibitors of Mycobacterium tuberculosis

Herein described the design, synthesis and antitubercular evaluation of novel series of dibenzofuran, dibenzothiophene and N-methyl carbazole tethered 2-aminothiazoles and their cinnamamide analogs. One pot condensation of N-methyl carbazole, dibenzofuran and dibenzothiophene methyl ketones with thiourea in the presence of Iodine and CuO gave respective 2-aminothiazoles 4-6 in very good yields. Aminothiazoles were further coupled with substituted cinnamic acids using acid-amine coupling conditions to give desired cinnamamide analogs 8a-e, 9a-e and 10a-e. All the newly synthesized compounds were fully characterized by their NMR and mass spectral analysis. In vitro screening of new derivatives against Mycobacterium tuberculosis H37Rv (Mtb) resulted 8c, 10d and 10e (MIC: 0.78 µg/mL) and 2-aminothiazoles 5 and 6 (MIC: 1.56 µg/mL) as potent compounds with lower cytotoxicity profile.

Treatment optimization in patients co-infected with HIV and Mycobacterium tuberculosis infections: focus on drug-drug interactions with rifamycins

Tuberculosis (TB) and HIV continue to be two of the major causes of morbidity and mortality in the world, and together are responsible for the death of millions of people every year. There is overwhelming evidence to recommend that patients with TB and HIV co-infection should receive concomitant therapy of both conditions regardless of the CD4 cell count level. The principles for treatment of active TB disease in HIV-infected patients are the same as in HIV-uninfected patients. However, concomitant treatment of both conditions is complex, mainly due to significant drug-drug interactions between TB and HIV drugs. Rifamycins are potent inducers of the cytochrome P450 (CYP) pathway, leading to reduced (frequently sub-therapeutic) plasma concentrations of some classes of antiretrovirals. Rifampicin is also an inducer of the uridine diphosphate glucuronosyltransferase (UGT) 1A1 enzymes and interferes with drugs, such as integrase inhibitors, that are metabolized by this metabolic pathway. Rifampicin is also an inducer of the adenosine triphosphate (ATP) binding cassette transporter P-glycoprotein, which may also lead to decreased bioavailability of concomitantly administered antiretrovirals. On the other side, rifabutin concentrations are affected by the antiretrovirals that induce or inhibit CYP enzymes. In this review, the pharmacokinetic interactions, and the relevant clinical consequences, of the rifamycins-rifampicin, rifabutin, and rifapentine-with antiretroviral drugs are reviewed and discussed. A rifampicin-based antitubercular regimen and an efavirenz-based antiretroviral regimen is the first choice for treatment of TB/HIV co-infected patients. Rifabutin is the preferred rifamycin to use in HIV-infected patients on a protease inhibitor-based regimen; however, the dose of rifabutin needs to be reduced to 150 mg daily. More information is required to select optimal treatment regimens for TB/HIV co-infected patients whenever efavirenz cannot be used and rifabutin is not available. Despite significant pharmacokinetic interactions between antiretrovirals and antitubercular drugs, adequate clinical response of both infections can be achieved with an acceptable safety profile when the pharmacological characteristics of drugs are known, and appropriate combination regimens, dosing, and timing of initiation are used. However, more clinical research is needed for newer drugs, such as rifapentine and the recently introduced integrase inhibitor antiretrovirals, and for specific population groups, such as children, pregnant women, and patients affected by multidrug-resistant TB.

Management of patients with multidrug-resistant/extensively drug-resistant tuberculosis in Europe: a TBNET consensus statement

The emergence of multidrug-resistant (MDR) and extensively drug-resistant (XDR) tuberculosis (TB) substantially challenges TB control, especially in the European Region of the World Health Organization, where the highest prevalence of MDR/XDR cases is reported. The current management of patients with MDR/XDR-TB is extremely complex for medical, social and public health systems. The treatment with currently available anti-TB therapies to achieve relapse-free cure is long and undermined by a high frequency of adverse drug events, suboptimal treatment adherence, high costs and low treatment success rates. Availability of optimal management for patients with MDR/XDR-TB is limited even in the European Region. In the absence of a preventive vaccine, more effective diagnostic tools and novel therapeutic interventions the control of MDR/XDR-TB will be extremely difficult. Despite recent scientific advances in MDR/XDR-TB care, decisions for the management of patients with MDR/XDR-TB and their contacts often rely on expert opinions, rather than on clinical evidence.

This document summarises the current knowledge on the prevention, diagnosis and treatment of adults and children with MDR/XDR-TB and their contacts, and provides expert consensus recommendations on questions where scientific evidence is still lacking.

TBNET consensus statement on the management of patients with MDR/XDR-TB has been released in theEur Respir Jhttp://ow.ly/uizRD

Global Impact of Multidrug-Resistant Pulmonary Tuberculosis Among HIV-Infected and Other Immunocompromised Hosts: Epidemiology, Diagnosis, and Strategies for Management

Multidrug-resistant (MDR) tuberculosis (TB), or TB caused by strains of Mycobacterium tuberculosis resistant to at least isoniazid and rifampicin, represents a major threat to global TB control. Comprising more than 5% of all TB cases annually worldwide, these cases require treatment duration of 2 years on average with expensive and toxic second-line anti-TB drugs. Cure rates are far lower and mortality far higher than for drug-susceptible TB, particularly if patients are coinfected with HIV. Use of rapid diagnostic tools and assessment of risk factors for MDR TB, as well as rapid initiation of MDR TB treatment as recommended by the World Health Organization, including use of appropriate empiric regimens as necessary, is essential to achieving good outcomes from treatment. Rapid initiation of antiretroviral therapy (ART) for those with HIV coinfection, as well as strategic management of overlapping side effects from ART and first and second-line drugs for treating MDR TB to maintain patients on treatment are critical to patient survival and achieving good treatment outcomes. Employing sensible infection control practices in the context of diagnosis and treatment is essential to reducing transmission of MDR TB strains among patient populations and healthcare personnel.

Lethal tuberculosis in a previously healthy adult with IL-12 receptor deficiency

A 33-year-old man was admitted in hospital due to fever, generalized lymphadenopathy, and hepatosplenomegaly. He had a history of anti-tuberculosis treatment in the previous 3 years. Despite normal chest radiograph, a sputum sample was smear-positive for acid-fast bacilli, and polymerase chain reaction was positive for Mycobacterium tuberculosis complex. Drug susceptibility test revealed resistance to isoniazid and rifampin. Evaluation of the patient's immune system revealed IL-12Rβ1 deficiency. The patient died of disseminated tuberculosis (TB), despite appropriate antibiotic treatment. This is the first IL-12 receptor-deficient patient presenting with disseminated TB in adulthood, without any previous relevant medical history. This diagnosis should be considered in selected adult patients with unexplained, overwhelming TB. IL-12Rβ1 deficiency is a genetic etiology of severe TB in adults and should be considered in adult patients with disseminated TB.