Latent Tuberculosis and HIV Infection

Physiologically based pharmacokinetic modeling of drug-drug interactions between ritonavir-boosted atazanavir and rifampicin in pregnancy

Ritonavir-boosted atazanavir (ATV/r) and rifampicin are mainstays of second-line antiretroviral and multiple anti-TB regimens, respectively. Rifampicin induces CYP3A4, a major enzyme involved in atazanavir metabolism, causing a drug-drug interaction (DDI) which might be exaggerated in pregnancy. Having demonstrated that increasing the dose of ATV/r from once daily (OD) to twice daily (BD) in non-pregnant adults can safely overcome this DDI, we developed a pregnancy physiologically based pharmacokinetic (PBPK) model to explore the impact of pregnancy. Predicted pharmacokinetic parameters were validated with separate clinical datasets of ATV/r alone (NCT03923231) and rifampicin alone in pregnant women. The pregnancy model was considered validated when the absolute average fold error (AAFE) for Ctrough and AUC0-24 of both drugs were <2 when comparing predicted vs. observed data. Thereafter, predicted atazanavir Ctrough was compared against its protein-adjusted IC90 (14 ng/mL) when simulating the co-administration of ATV/r 300/100 mg OD and rifampicin 600 mg OD. Pregnancy was predicted to increase the rifampicin DDI effect on atazanavir. For the dosing regimens of ATV/r 300/100 mg OD, ATV/r 300/200 mg OD, and ATV/r 300/100 mg BD (all with rifampicin 600 mg OD), predicted atazanavir Ctrough was above 14 ng/mL in 29%, 71%, and 100%; and 32%, 73% and 100% of the population in second and third trimesters, respectively. Thus, PBPK modeling suggests ATV/r 300/100 mg BD could maintain antiviral efficacy when co-administered with rifampicin 600 mg OD in pregnancy. Clinical studies are warranted to confirm safety and efficacy in pregnancy.

Cystatin F Depletion in Mycobacterium tuberculosis-Infected Macrophages Improves Cathepsin C/Granzyme B-Driven Cytotoxic Effects on HIV-Infected Cells during Coinfection

Cystatin F (CstF) is a protease inhibitor of cysteine cathepsins, including those involved in activating the perforin/granzyme cytotoxic pathways. It is targeted at the endolysosomal pathway but can also be secreted to the extracellular milieu or endocytosed by bystander cells. CstF was shown to be significantly increased in tuberculous pleurisy, and during HIV coinfection, pleural fluids display high viral loads. In human macrophages, our previous results revealed a strong upregulation of CstF in phagocytes activated by interferon γ or after infection with Mycobacterium tuberculosis (Mtb). CstF manipulation using RNA silencing led to increased proteolytic activity of lysosomal cathepsins, improving Mtb intracellular killing. In the present work, we investigate the impact of CstF depletion in macrophages during the coinfection of Mtb-infected phagocytes with lymphocytes infected with HIV. The results indicate that decreasing the CstF released by phagocytes increases the major pro-granzyme convertase cathepsin C of cytotoxic immune cells from peripheral blood-derived lymphocytes. Consequently, an observed augmentation of the granzyme B cytolytic activity leads to a significant reduction in viral replication in HIV-infected CD4+ T-lymphocytes. Ultimately, this knowledge can be crucial for developing new therapeutic approaches to control both pathogens based on manipulating CstF.

Factors Associated with Absence of Active Pulmonary Tuberculosis in HIV Patients with Latent Tuberculosis, Beyond Isoniazid Preventive Therapy

BACKGROUND

Tuberculosis (TB) is a leading cause of death in patients with human immunodeficiency virus (HIV)/AIDS. About 60% of HIV-positive individuals with latent TB infection (LTBI) develop active TB. Isoniazid preventive therapy (IPT) is recommended by the World Health Organization to prevent the progression of active TB in people living with HIV/AIDS (PLWHA). However, IPT implementation has been limited in some countries like Indonesia. The objective of this study was to assess the effect of IPT administration on the incidence of active TB in HIV patients with latent TB.

METHODS

This was a quasi-experimental prospective cohort study conducted in an academic hospital in Indonesia. Interferon-gamma release assay-positive HIV-TB patients were randomly divided into an IPT group (received 6 months of IPT) and a non-IPT group. The incidence of active pulmonary TB was compared between the two groups after 6 months of follow-up.

RESULTS

Of the 23 eligible patients, 22 were enrolled (10 in the IPT group, 12 in the non-IPT group). The incidence of active pulmonary TB was 0% in both groups. Factors associated with the absence of TB in both groups were the use of antiretroviral therapy for >4 years and a CD4+ T lymphocyte count >200 cells/μL. IPT was found to be safe with minimal adverse effects.

CONCLUSIONS

In this setting, the use of long-term antiretroviral therapy and higher CD4+ counts, rather than just IPT, were the key factors associated with preventing active TB in latent HIV-TB patients. These findings suggest that comprehensive HIV management may be more important than IPT alone for TB control in PLWHA. Further research is needed to optimize TB prevention strategies in this high-risk population.

Integrated management of cryptococcal meningitis and concurrent opportunistic infections to improve outcomes in advanced HIV disease: a randomised strategy trial

Background

Mortality associated with HIV-associated cryptococcal meningitis remains high even in the context of clinical trials (24-45% at 10 weeks); mortality at 12-months is up to 78% in resource limited settings. Co-prevalent tuberculosis (TB) is common and preventable, and likely contributes to poor patient outcomes. Innovative strategies to increase TB preventative therapy (TPT) provision and uptake within this high-risk group are needed.

Protocol

The IMPROVE trial (Integrated management of cryptococcal meningitis and concurrent opportunistic infections to improve outcomes in advanced HIV disease) is a nested open label, two arm, randomised controlled strategy trial to evaluate the safety (adverse events) and feasibility (adherence and tolerability) of two ultra-short course TPT strategies, in the context of recent diagnosis and treatment for cryptococcal meningitis. We will enrol 205 adults with HIV-associated cryptococcal meningitis from three hospitals in Uganda. Participants will be randomised to either inpatient initiation (early) or outpatient initiation (standard, week 6) of 1HP (one month of isoniazid and rifapentine). Participant follow-up is to include TB screening, 1HP pill counts and tolerability reviews on alternate weeks until week-18. The trial primary endpoint is TB-disease free 1HP treatment completion at 18-weeks, secondary endpoints: 1HP treatment completion, 1HP discontinuation, grade ≥3 adverse events and serious adverse events, drug-induced liver injury, incident active TB, 18-week survival; rifapentine, fluconazole and dolutegravir concentrations will be measured with intensive sampling in a pharmacokinetic sub-study of 15 eligible participants.

Discussion

The IMPROVE trial will provide preliminary safety and feasibility data to inform 1HP TPT strategies for adults with advanced HIV disease and cryptococcal meningitis. The potential impact of demonstrating that inpatient initiation of 1HP TPT is safe and feasible amongst this high-risk subpopulation with advanced HIV disease, would be to expand the range of clinical encounters in which clinicians can feasibly provide 1HP, and therefore increase the reach of TPT as a preventative intervention.

ISRCTN registration

ISRCTN18437550 (05/11/2021).

Tuberculosis preventive treatment uptake among people living with HIV during COVID-19 period in Addis Ababa, Ethiopia: a retrospective data review

BACKGROUND

Screening for tuberculosis (TB) and providing TB preventive treatment (TPT) along with antiretroviral therapy is key components of human immune deficiency virus (HIV) care. The uptake of TPT during the coronavirus disease 2019 (COVID-19) period has not been adequately assessed in Addis Ababa City Administration. This study aimed at assessing TPT uptake status among People living with HIV (PLHIV) newly initiated on antiretroviral therapy during the COVID-19 period at all public hospitals of Addis Ababa City Administration, Ethiopia.

METHODS

A retrospective data review was conducted from April-July 2022. Routine District Health Information System 2 database was reviewed for the period from April 2020-March 2022. Proportion and mean with standard deviation were computed. Logistic regression analysis was conducted to assess factors associated with TPT completion. A p-value of < 0.05 was considered statistically significant.

RESULTS

A total of 1,069 PLHIV, aged 18 years and above were newly initiated on antiretroviral therapy, and of these 1,059 (99.1%) underwent screening for TB symptoms. Nine hundred twelve (86.1%) were negative for TB symptoms. Overall, 78.8% (719) of cases who were negative for TB symptoms were initiated on TPT, and of these 70.5% and 22.8% were completed and discontinued TPT, respectively. Of 719 cases who were initiated on TPT, 334 (46.5%) and 385 (53.5%) were initiated on isoniazid plus rifapentine weekly for three months and Isoniazid preventive therapy daily for six months, respectively. PLHIV who were initiated on isoniazid plus rifapentine weekly for three months were more likely to complete TPT (adjusted odds ratio [AOR],1.68; 95% confidence interval [CI], 1.01, 2.79) compared to those who were initiated on Isoniazid preventive therapy daily for six months.

CONCLUSION

While the proportion of PLHIV screened for TB was high, TPT uptake was low and far below the national target of achieving 90% TPT coverage. Overall a considerable proportion of cases discontinued TPT in this study. Further strengthening of the programmatic management of latent TB infection among PLHIV is needed. Therefore, efforts should be made by the Addis Ababa City Administration Health Bureau authorities and program managers to strengthen the initiation and completion of TPT among PLHIV in public hospitals.

Imaging of infra-thoracic tuberculosis

Tuberculosis (TB) is a potentially curable disease that is a leading cause of death globally. While it typically affects the lungs, this disease may involve many extra-pulmonary sites, particularly in patients with risk factors. Extra-pulmonary TB often mimics a variety of different diseases, posing a diagnostic dilemma. Imaging aids in early diagnosis of TB, especially in patients with non-specific or atypical symptoms found at extra-pulmonary infra-thoracic locations. Imaging also helps guide appropriate laboratory investigation, monitor disease progress, and response to treatment. This review aims to highlight the imaging spectrum of TB affecting the infra-thoracic region, that is, gastrointestinal tract, abdominal lymph nodes, peritoneal cavity, intra-abdominal solid organs, and urogenital system.

HIV-TB Coinfection: Current Therapeutic Approaches and Drug Interactions

The co-occurrence of human immunodeficiency virus (HIV) and tuberculosis (TB) infection poses a significant global health challenge. Treatment of HIV and TB co-infection often necessitates combination therapy involving antiretroviral therapy (ART) for HIV and anti-TB medications, which introduces the potential for drug-drug interactions (DDIs). These interactions can significantly impact treatment outcomes, the efficacy of treatment, safety, and overall patient well-being. This review aims to provide a comprehensive analysis of the DDIs between anti-HIV and anti-TB drugs as well as potential adverse effects resulting from the concomitant use of these medications. Furthermore, such findings may be used to develop personalized therapeutic strategies, dose adjustments, or alternative drug choices to minimize the risk of adverse outcomes and ensure the effective management of HIV and TB co-infection.

Imaging of musculoskeletal tuberculosis

Extra-pulmonary tuberculosis (TB) of the musculoskeletal system usually manifests with non-specific clinical features, mimicking a variety of diseases. Diagnosis and treatment of spinal and extra-spinal musculoskeletal TB are often challenging. Imaging has an important role in detecting this disease, aiding diagnosis, identifying complications, and monitoring disease progression. Radiographs and magnetic resonance imaging are the key imaging modalities utilized. Radiologists should aim to be familiar with the spectrum of imaging features of TB affecting spinal and extra-spinal locations in the musculoskeletal system.

Isoniazid preventive therapy completion between July-September 2019: A comparison across HIV differentiated service delivery models in Uganda

BACKGROUND

Tuberculosis (TB) remains the leading cause of death among people living with HIV (PLHIV). To prevent TB among PLHIV, the Ugandan national guidelines recommend Isoniazid Preventive Therapy (IPT) across differentiated service delivery (DSD) models, an effective way of delivering ART. DSD models include Community Drug Distribution Point (CDDP), Community Client-led ART Delivery (CCLAD), Facility-Based Individual Management (FBIM), Facility-Based Group (FBG), and Fast Track Drug Refill (FTDR). Little is known about the impact of delivering IPT through DSD.

METHODS

We reviewed medical records of PLHIV who initiated IPT between June-September 2019 at TASO Soroti (TS), Katakwi Hospital (KH) and Soroti Regional Referral Hospital (SRRH). We defined IPT completion as completing a course of isoniazid within 6-9 months. We utilized a modified Poisson regression to compare IPT completion across DSD models and determine factors associated with IPT completion in each DSD model.

RESULTS

Data from 2968 PLHIV were reviewed (SRRH: 50.2%, TS: 25.8%, KH: 24.0%); females: 60.7%; first-line ART: 91.7%; and Integrase Strand Transfer Inhibitor (INSTI)-based regimen: 61.9%. At IPT initiation, the median age and duration on ART were 41.5 (interquartile range [IQR]; 32.3-50.2) and 6.0 (IQR: 3.7-8.6) years, respectively. IPT completion overall was 92.8% (95%CI: 91.8-93.7%); highest in CDDP (98.1%, 95%CI: 95.0-99.3%) and lowest in FBG (85.8%, 95%CI: 79.0-90.7%). Compared to FBIM, IPT completion was significantly higher in CDDP (adjusted rate ratio [aRR] = 1.15, 95%CI: 1.09-1.22) and CCLAD (aRR = 1.09, 95% CI 1.02-1.16). In facility-based models, IPT completion differed between sites (p<0.001). IPT completion increased with age for FBIM and CCLAD and was lower among female participants in the CCLAD (aRR = 0.82, 95%CI 0.67-0.97).

CONCLUSION

IPT completion was high overall but highest in community-based models. Our findings provide evidence that supports integration of IPT within DSD models for ART delivery in Uganda and similar settings.

Antibody response to mycobacterial Rpf B protein and its immunodominant peptides in HIV-TB co-infected individuals

Diagnosis of TB at early stages of HIV infection may lead to timely intervention for improving patient outcome. Antibodies to Mycobacterium tuberculosis recombinant RpfB protein and two immunodominant peptides of Rpf B protein were evaluated in the sera of HIV +TB+, HIV+ and HIV- pulmonary TB patients by ELISA. Serum antibodies from 90 % and 65 % of HIV+TB+ patients reacted to recombinant RpfB protein and synthetic peptide RpfP1 respectively. Overall, this study shows that resuscitation promoting factor B elicits humoral antibody response in HIV+TB+ co-infected individuals and be proposed as a potential biomarker for diagnosis of HIV+TB+ patients, however further longitudinal follow up studies are warranted.

Adverse Events of Latent Tuberculosis Treatment With Isoniazid in People Living With HIV: A Case-Control Study in a Resource-Rich Setting

Introduction Multiple risk factors, such as human immunodeficiency virus (HIV) infection and immunosuppressive therapies, increase the odds of latent tuberculosis infection (LTBI) reactivation and progression to active tuberculosis. A six-to-nine-month preventive treatment with isoniazid (INH) decreases the risk of LTBI reactivation, but its effectiveness can be limited by its long duration and adverse events (AEs), including liver toxicity. Due to comorbidities and polypharmacy, people living with HIV (PLHIV) may be at increased risk of INH-associated AEs. Our study aimed to assess the prevalence of AEs among patients receiving INH treatment for LTBI, to identify risk factors for their occurrence, and to evaluate whether PLHIV have higher odds of developing INH-associated AEs. Methods We conducted a single-center retrospective case-control study, including 130 outpatients with LTBI treated with INH between July 2019 and March 2022. Participants who developed AE (cases) were compared to controls, and a subgroup of PLHIV was compared to HIV-negative participants. Demographics, socioeconomic variables, comorbidities, and clinical variables were compared between study groups. Patient data were obtained from institutional electronic medical records, and outcomes were measured at regularly scheduled appointments. Results We included 130 participants, of which 54 were PLHIV. The PLHIV subgroup was significantly younger (p = 0.01) and demonstrated significantly higher prevalences of chronic liver disease, previous viral hepatitis, daily alcohol consumption, and intravenous drug use (IDU). One-third of the participants had an AE (45 cases, 34.6%), with liver toxicity being the most common (22.3%). Participants who developed AEs were significantly older (p = 0.030) and had a higher prevalence of economic hardship (p = 0.037), as well as higher scores of the Charlson comorbidity index (p = 0.002) than the controls. INH withdrawal occurred in 17 participants (13.1%) and was mainly associated with liver toxicity (p < 0.01) and gastrointestinal symptoms (p = 0.022). In the adjusted effect model, an age ≥ 65 years, economic hardship, and excessive alcohol consumption were significantly associated with higher odds of AEs, while HIV infection decreased the odds by 68.4% (p = 0.033). Conclusions In our study, INH-associated AEs were common, with liver toxicity being the most frequent. Older age, economic hardship, and excessive alcohol consumption increased the odds of INH-associated AEs, while PLHIV had lower odds of developing INH-associated AEs, even when adjusting for other variables in the multivariate analysis. Further studies should be conducted to assess if these results are replicable in a larger population and in different settings.

Clinical-Epidemiological Characteristics and Outcomes of Latent Tuberculosis Treatment at a Tertiary Center in Central-West Brazil from 2017 to 2019

Detailed information concerning latent tuberculosis infection (LTBI) and treatment outcomes is scarce in Brazil. This retrospective cross-sectional study aimed to describe LTB treatment (LTBT) at a tertiary center in Central-West Brazil from 2017 to 2019. We recommended the use of LTBTs before the implementation of a rifapentine-isoniazid (3HP) regimen in Brazil. We conducted a descriptive analysis using chi-square or t-tests to assess differences in the proportions and means. Of 79 notified adult patients (males, 68%; median age, 40 (interquartile range, 30-51) years), most people were living with human immunodeficiency virus (PLHIV) (82%) or receiving immunosuppressant medication (15%), and 92% were receiving their first treatment. Isoniazid (INH) for 6-9 months had previously been proposed for 95% of the patients, with only 35% completeness. Four patients treated with rifampicin (4RMP) completed the regimen (p = 0.009). Adverse events occurred in 19% of the patients. In this Brazilian tertiary center, the target population for LTBT were young PLHIV patients under immunosuppression with low education levels. However, the INH monotherapy dropout rate was 65%. Therefore, shorter courses, such as 3HP and 4RMP, are promising alternatives. Behavioral aspects, education level, and regimen length can influence the course completion, and further studies are required to evaluate the 3HP regime in Brazil.

Different diets and their effect on tuberculosis prevention in HIV patients

Introduction:

The relationship between nutrition and human immunodeficiency virus (HIV) infection, tuberculosis, and other infectious diseases is logically proven. Nutrition affects the immune system and the health of the organs. Inadequate dietary intake endangers the immune system, which itself increases susceptibility to disease and often culminates in active disease. The disease then reduces the body’s appetite and ability to absorb nutrients, and the cycle continues. Considering the importance of the role of nutrition in the health of acquired immune deficiency syndrome (AIDS) patients, this current review aimed to discuss the different diets and their effects on tuberculosis (TB) prevention in HIV patients.

Method and Materials:

The present study evaluates the important points related to AIDS and the prevention and treatment of this disease by considering the diet and known scientific cases during the last 10 years, in simple terms, the prevalence of this disease.

Result:

Articles were searched by valid databases in May 2021. The findings showed that in addition to malnutrition, the high prevalence of infectious diseases can have serious consequences for public health. Many people will be safe from getting infections if there are safe and effective interventions for many of these infectious diseases.

Conclusion:

Based on the information presented herein, it is clear that TB affects the nutritional status. Many patients with active TB experience severe weight loss, and many people with the symptoms show a lack of vitamins and minerals.

Recent Advances in the Development of Protein- and Peptide-Based Subunit Vaccines against Tuberculosis

The World Health Organization (WHO) herald of the “End TB Strategy” has defined goals and targets for tuberculosis prevention, care, and control to end the global tuberculosis endemic. The emergence of drug resistance and the relative dreadful consequences in treatment outcome has led to increased awareness on immunization against Mycobacterium tuberculosis (Mtb). However, the proven limited efficacy of Bacillus Calmette-Guérin (BCG), the only licensed vaccine against Mtb, has highlighted the need for alternative vaccines. In this review, we seek to give an overview of Mtb infection and failure of BCG to control it. Afterward, we focus on the protein- and peptide-based subunit vaccine subtype, examining the advantages and drawbacks of using this design approach. Finally, we explore the features of subunit vaccine candidates currently in pre-clinical and clinical evaluation, including the antigen repertoire, the exploited adjuvanted delivery systems, as well as the spawned immune response.