CD4+ cell count stratification to guide tuberculosis preventive therapy for people living with HIV

Sex differences in tuberculosis infection and disease among people with HIV

OBJECTIVES

Worldwide, adult men experience an excess burden of tuberculosis (TB) disease compared with women, but few studies have examined sex differences in TB among people with HIV. In this study, we aimed to investigate sex differences in TB infection and disease among people with HIV in Rio de Janeiro, Brazil.

DESIGN

Analysis of data from a randomized controlled trial and retrospective cohort study.

METHODS

We analyzed data from two studies conducted between 2005 and 2017. The THRio Study (2005-2012) evaluated increasing tuberculin skin testing (TST) and TB preventive therapy (TPT), and Universal ART in Rio study (UnivART; 2010-2017) was a virtual cohort study of people with HIV and TB with data from four national electronic registries.

RESULTS

Among 4606 people with HIV in THRio, 2992 (65.0%) had a TST placed and read, of whom 312 of 1865 (17%) males and 203 of 1127 (18%) females ( P  = 0.37) had prevalent TB infection. TB disease incidence was higher among males compared with females overall [IRR 1.33, 95% confidence interval (95% CI) 1.04-1.69], among males compared with females who did not receive TPT [incidence rate ratios (IRR) 1.30, 95% CI 1.01-1.67], and among males compared with females on ART (IRR 1.64, 95% CI 1.17-2.29). Among 54 957 people with HIV in UnivART, TB disease incidence rates were higher among males than females overall (IRR 1.28, 95% CI 1.18-1.39), among males compared with females on ART (IRR 1.58, 95% CI 1.40-1.77), and among males compared with females not on ART (IRR 1.11, 95% CI 0.99-1.25).

CONCLUSION

In this medium TB and HIV burden setting, TB disease incidence was higher among males than females with HIV, despite similar prevalence of TB infection.

Impact of Latent M. tuberculosis Infection Treatment on Time to CD4/CD8 Recovery in Acute, Recent, and Chronic HIV Infection

INTRODUCTION

In people living with HIV, active and latent tuberculosis (TB) coinfections are associated with immune activation that correlate with HIV progression and mortality. We investigated the effect of initiating antiretroviral therapy (ART) during acute (AHI), recent (RHI), or chronic HIV infection (CHI) on CD4/CD8 ratio normalization and associated factors, the impact of latent TB infection treatment, and prior/concomitant TB diagnosis at the time of ART initiation.

METHODS

We included sex with men and transgender women individuals initiating ART with AHI, RHI and CHI between 2013 and 2019, from a prospective cohort in Brazil. We compared time from ART initiation to the first normal CD4/CD8 ratio (CD4/CD8 ≥1) using Kaplan-Meier curves and multivariable Cox proportional hazards models. Sociodemographic and clinical variables were explored. Variables with P -values <0.20 in univariable analyses were included in multivariable analyses.

RESULTS

Five hundred fifty participants were included, 11.8% classified as AHI and 6.4% as RHI, 46.7% with CHI-CD4 cell counts ≥350 cells/mm 3 and 35.1% with CHI-CD4 cell counts <350 cells/mm 3 . Time to normalization was shortest among AHI patients, followed by RHI and CHI individuals with higher baseline CD4. In the multivariable model, AHI was associated with a six-fold increased likelihood of achieving a CD4/CD8 ratio ≥1 (hazard ratio [HR]: 6.03; 95% confidence interval [CI]: 3.70 to 9.82; P < 0.001), RHI with HR: 4.47 (95% CI: 2.57 to 7.76; P < 0.001), and CHI CD4 ≥350 cells/mm 3 with HR: 1.87 (95% CI: 1.24 to 2.84; P = 0.003). Latent TB infection treatment was significantly associated with a higher likelihood of the outcome (HR: 1.79; 95% CI: 1.22 to 2.62; P = 0.003). Previous history or concomitant active TB at ART initiation was associated with a lower likelihood of the outcome (HR: 0.41; 95% CI: 0.16 to 1.02; P = 0.054).

CONCLUSIONS

Initiating ART early during AHI may offer an opportunity to mitigate immune damage. Efforts to implement HIV diagnosis and ART initiation during AHI are critical to amplify ART benefits.

Incidence of active tuberculosis among people living with HIV receiving long-term antiretroviral therapy in high TB/HIV burden settings in Thailand: implication for tuberculosis preventive therapy

Introduction

Among high tuberculosis (TB) and HIV burden countries in Asia, tuberculosis preventive therapy (TPT) in people living with HIV (PLWH) has been underutilized despite its proven benefits independent of antiretroviral therapy (ART). Therefore, we determined the incidence of active TB and mortality among 9179 adult PLWH who attended and received ART from 15 tertiary care hospitals across Thailand.

Methods

A retrospective study was conducted in 2018 using follow‐up data from 1999 to 2018. The primary endpoint was incident TB disease after ART initiation. Factors associated with TB incidence were analysed using competing risk regression. The Kaplan–Meier method was used to estimate mortality after ART initiation.

Results

During a median of 5.1 years of ART (IQR 2.2–9.5 years), 442 (4.8%) PLWH developed TB (TB/HIV), giving an overall incidence of 750 (95% CI 683–823) per 100,000 persons‐year of follow up (PYFU). In multivariate analysis, lower CD4 at ART initiation (≤100 cells/mm³, adjusted sub‐distribution hazard ratio [aSHR]: 2.08, 95% CI, 1.47–2.92; 101–200 cells/mm³, aSHR: 2.21, 95% CI, 1.54–3.16; 201–350 cells/mm³, aSHR: 1.59, 95% CI, 1.11–2.28 vs. >350 cells/mm³), male sex (aSHR: 1.40, 95% CI, 1.11–1.78), lower body weight (<50 kg, aSHR: 1.52, 95% CI, 1.17–1.95) and prior TB event (aSHR: 3.50, 95% CI, 2.72–4.52) were associated with TB incidence. PLWH with HIV RNA ≥50 copies/ml had 5–9 times higher risk of active TB disease higher than those with HIV RNA <50 copies/ml at the same CD4 level. The risk for developing TB was remarkably high during the initial period of ART (175,511 per 100,000 PYFU at<3 months) and was comparable to the general population after 10 years of ART (151 per 100,000 PYFU). TB/HIV had higher mortality (10% vs. 5%) and poorer HIV treatment outcomes: HIV RNA <50 copies/ml (63.8% vs. 82.8%), CD4 cells count (317 vs. 508 cells/mm³) at the most recent visit.

Conclusions

In this high TB burden country, TB incidence was remarkably high during the first few years after ART initiation and thereafter decreased significantly. Rapid ART initiation and appropriate TPT can be potential key interventions to tackle the TB epidemic and reduce mortality among PLWH in TB/HIV high burden settings.

Changes of lymphocyte subsets in smear-negative pulmonary tuberculosis

Background and Aims

The host immune system plays an important role in the pathogenesis and defense mechanism of Mycobacterium tuberculosis (Mtb). This study aimed to explore the different changes in the immune system between smear-negative pulmonary tuberculosis (PTB) and smear-positive PTB patients.

Materials and Methods

A total of 85 active PTB patients and 50 healthy adults were enrolled. The participants were divided into smear-negative PTB, smear-positive PTB, and control groups. Chest computed tomography (CT) and lymphocyte subgroup counts in peripheral blood were measured in all participants.

Results

There were higher numbers of CD4 + T-cells, NK cells, and pulmonary cavities in the smear-positive PTB group, whereas the numbers of B-ells were significantly increased in the smear-negative PTB group.

Conclusions

Smear-negative PTB showed fewer pulmonary cavities, mild inflammatory response, lower numbers of immune cells, and higher numbers of B- cells.

Brief Report: Yield of Repeat Tuberculin Skin Testing for People Living With HIV in Brazil

OBJECTIVES

In Brazil, annual tuberculin skin tests (TSTs) are recommended for people living with HIV (PLWH) with CD4 >350, with tuberculosis preventive therapy provided on test conversion. We aimed to determine the yield of repeat TSTs for PLWH.

DESIGN

Secondary analysis of the stepped-wedge, cluster-randomized THRio trial for isoniazid preventive therapy (IPT) to prevent tuberculosis (TB).

METHODS

We analyzed data from newly registered PLWH with negative baseline TST results. We calculated the number of TST conversions after 1 and/or 2 years among patients eligible for follow-up TSTs, the proportion of converters initiating IPT, and incidence of TB/death.

RESULTS

Among 1770 PLWH with a negative baseline TST, 679 (38%) were female and median age was 36 years (IQR 29-43). Eighty-six (5%) developed TB or died within 1 year. Among 1684 eligible for a follow-up 1-year TST, 582 (35%) were tested and 53 (9%) were positive. Forty-nine converters (92%) started IPT. Of 529 patients with a negative 1-year TST, 7 (1%) developed TB or died over the following year. Of 522 patients eligible for a 2-year TST, 158 (30%) were tested and 13 (8%) were positive. Ten converters (77%) started IPT. Of 1102 patients who did not receive a 1-year TST, 33 (3%) developed TB or died. Of the 1069 patients eligible for a 2-year TST, 259 (24%) were tested and 34 (13%) were positive. Thirty converters (88%) started IPT.

CONCLUSIONS

In this cohort of PLWH in Brazil, TST conversion was high among those retested, but only 48% received a follow-up TST within 2 years.

Cost-effectiveness of newer technologies for the diagnosis of Mycobacterium tuberculosis infection in Brazilian people living with HIV

Tuberculosis is the leading cause of death among people living with HIV (PLH). Preventive tuberculosis therapy reduces mortality in PLH, especially in those with a positive tuberculin skin test (TST). New, more specific technologies for detecting latent tuberculosis infection (LTBI) are now commercially available. We sought to analyse the cost-effectiveness of four different strategies for the diagnosis of LTBI in PLH in Brazil, from the Brazilian public health care system perspective. We developed a Markov state-transition model comparing four strategies for the diagnosis of LTBI over 20 years. The strategies consisted of TST with the currently used protein purified derivative (PPD RT 23), two novel skin tests using recombinant allergens (Diaskintest [Generium Pharmaceutical, Moscow, Russia] and EC [Zhifei Longcom Biologic Pharmacy Co., Anhui, China]), and the QuantiFERON-TB-Gold-Plus (Qiagen, Hilden, Germany). The main outcome was cost (in 2020 US dollars) per quality-adjusted life years (QALY). For the base case scenario, the Diaskintest was dominant over all other examined strategies. The cost saving estimate per QALY was US $1375. In sensitivity analyses, the Diaskintest and other newer tests remained cost-saving compared to TST. For PLH, TST could be replaced by more specific tests in Brazil, considering the current national recommendations.