Improving Tuberculosis Case Finding in Persons Living with Advanced HIV through New Diagnostic Algorithms

Epidemiology of Tuberculosis Among People Living With HIV in the African Cohort Study From 2013 to 2021

BACKGROUND

The prevalence and incidence of tuberculosis (TB) is high among people living with HIV (PLWH) but is often underdiagnosed in HIV programmatic settings.

SETTING

President's Emergency Plan for AIDS Relief (PEPFAR)-supported research sites in Uganda, Kenya, Tanzania, and Nigeria.

METHODS

All patients underwent molecular testing at entry into a longitudinal cohort of PLWH and annually thereafter. We assessed the prevalence and incidence of TB and identified clinical and demographic factors associated with prevalent and incident TB using logistic regression and Cox proportional hazard models.

RESULTS

From 21 January, 2013, to 1 December 2021, 3171 PLWH were enrolled with a TB prevalence of 3% (n = 93). Of the cases with prevalent TB, 66% (n = 61) were bacteriologically confirmed. The adjusted odds of prevalent TB were significantly higher among those with higher educational attainment, PLWH for 1-5 years since their HIV diagnosis, those who were underweight, and those with CD4 counts <200 cells/mm 3 . The overall TB incidence rate was 600 per 100,000 person-years (95% CI: 481-748). We found that shorter time since HIV diagnosis, being underweight, taking antiretroviral therapy <6 months, and having a CD4 count <200 cells/mm 3 were significantly associated with incident TB. PLWH on dolutegravir/lamivudine/tenofovir had a 78% lower risk of incident TB compared with those on tenofovir/lamivudine/efavirenz (hazard ratio: 0.22; 95% CI: 0.08-0.63).

CONCLUSION

The prevalence and incidence of TB was notably high in this cohort sourced from PEPFAR clinics. Aggressive efforts to enhance HIV diagnosis and optimize treatment in programmatic settings are warranted to reduce the risk of HIV-TB co-occurrence in this cohort.

Diagnosis and treatment of tuberculosis in adults with HIV

Mycobacterium tuberculosis, the causative agent of tuberculosis (TB), continues to pose a major public health problem and is the leading cause of mortality in people infected with human immunodeficiency virus (HIV). HIV infection greatly increases the risk of developing TB even before CD4+ T-cell counts decrease. Co-infection provides reciprocal advantages to both pathogens and leads to acceleration of both diseases. In HIV-coinfected persons, the diagnosis and treatment of tuberculosis are particularly challenging. Intensifying integration of HIV and tuberculosis control programmes has an impact on reducing diagnostic delays, increasing early case detection, providing prompt treatment onset, and ultimately reducing transmission. In this Review, we describe our current understanding of how these two pathogens interact with each other, new sensitive rapid assays for TB, several new prevention methods, new drugs and regimens.

Long Non-coding RNAs in Tuberculosis: From Immunity to Biomarkers

Tuberculosis (TB) caused by Mycobacterium tuberculosis (Mtb) is the leading lethal infectious disease with 1.3 million deaths in 2020. Despite significant advances have been made in detection techniques and therapeutic approaches for tuberculosis, no suitable diagnostic tools are available for early and precise screening. Many studies have reported that Long non-coding RNAs (lncRNAs) play a regulatory role in gene expression in the host immune response against Mtb. Dysregulation of lncRNAs expression patterns associated with immunoregulatory pathways arose in mycobacterial infection. Meanwhile, host-induced lncRNAs regulate antibacterial processes such as apoptosis and autophagy to limit bacterial proliferation. In this review, we try to summarize the latest reports on how dysregulated expressed lncRNAs influence host immune response in tuberculosis infection. We also discuss their potential clinical prospects for tuberculosis diagnosis and development as molecular biomarkers.

Novel Long Non-coding RNA and LASSO Prediction Model to Better Identify Pulmonary Tuberculosis: A Case-Control Study in China

Introduction

The insufficient understanding and misdiagnosis of clinically diagnosed pulmonary tuberculosis (PTB) without an aetiological evidence is a major problem in the diagnosis of tuberculosis (TB). This study aims to confirm the value of Long non-coding RNA (lncRNA) n344917 in the diagnosis of PTB and construct a rapid, accurate, and universal prediction model.

Methods

A total of 536 patients were prospectively and consecutively recruited, including clinically diagnosed PTB, PTB with an aetiological evidence and non-TB disease controls, who were admitted to West China hospital from Dec 2014 to Dec 2017. The expression levels of lncRNA n344917 of all patients were analyzed using reverse transcriptase quantitative real-time PCR. Then, the laboratory findings, electronic health record (EHR) information and expression levels of n344917 were used to construct a prediction model through the Least Absolute Shrinkage and Selection Operator algorithm and multivariate logistic regression.

Results

The factors of n344917, age, CT calcification, cough, TBIGRA, low-grade fever and weight loss were included in the prediction model. It had good discrimination (area under the curve = 0.88, cutoff = 0.657, sensitivity = 88.98%, specificity = 86.43%, positive predictive value = 85.61%, and negative predictive value = 89.63%), consistency and clinical availability. It also showed a good replicability in the validation cohort. Finally, it was encapsulated as an open-source and free web-based application for clinical use and is available online at https://ziruinptb.shinyapps.io/shiny/.

Conclusion

Combining the novel potential molecular biomarker n344917, laboratory and EHR variables, this web-based prediction model could serve as a user-friendly, accurate platform to improve the clinical diagnosis of PTB.

High Yield of Active Tuberculosis Case Finding Among HIV-Infected Patients Using Xpert MTB/RIF Testing

Objective

Conduct an active case finding study in Tbilisi, Georgia, for pulmonary tuberculosis (TB) among people living with HIV (PLWH).

Methods

Newly diagnosed HIV patients were assessed for symptoms and asked to submit sputum samples for smear microscopy, culture, and molecular diagnostic testing (Xpert MTB/RIF).

Results

Among 276 PLWH, 131 agreed to participate and 103 submitted sputum samples. Most participants were male (70%) and mean age of 43 years. There were high rates of a positive hepatitis C virus (HCV) antibody test (46%) and the median CD4 count was 122 cells/mm³. A total of 15 (11.5%) persons were diagnosed with pulmonary TB, including 1 each with multidrug-resistant and isoniazid-resistant disease. Twelve had a positive culture for Mycobacterium tuberculosis and Xpert TB/RIF assay, and 4 had positive smear microscopy. Patients with pulmonary TB were more likely to use injection drugs (67% vs 36%, P = .02) and have a positive HCV antibody (73% vs 42%, P = .02). The presence and absence of any TB symptom had a sensitivity and negative predictive value for TB of 93% and 98%, respectively.

Conclusion

Our findings highlight the high prevalence of TB among newly diagnosed HIV-infected patients in an area with high rates of drug-resistant TB and the utility of an active case finding strategy for TB diagnosis.