Lung Injury on Antiretroviral Therapy in Adults With Human Immunodeficiency Virus/Tuberculosis

Circulating Biomarkers, Fraction of Exhaled Nitric Oxide, and Lung Function in Patients With Human Immunodeficiency Virus and Tuberculosis

BACKGROUND

Identification of proinflammatory factors responding to Mycobacterium tuberculosis is important to reduce long-term sequelae of pulmonary tuberculosis (TB).

METHODS

We examined the association between plasma biomarkers, the fraction of exhaled nitric oxide (FeNO), and lung function among a prospective cohort of 105 adults newly diagnosed with TB/human immunodeficiency virus (HIV) in South Africa. Participants were followed for 48 weeks from antiretroviral therapy (ART) initiation with serial assessments of plasma biomarkers, FeNO, lung function, and respiratory symptoms. Linear regression and generalized estimating equations were used to examine the associations at baseline and over the course of TB treatment, respectively.

RESULTS

At baseline, higher FeNO levels were associated with preserved lung function, whereas greater respiratory symptoms and higher interleukin (IL)-6 plasma levels were associated with worse lung function. After ART and TB treatment initiation, improvements in lung function were associated with increases in FeNO (rate ratio [RR] = 86 mL, 95% confidence interval [CI] = 34-139) and decreases in IL-6 (RR = -118 mL, 95% CI = -193 to -43) and vascular endothelial growth factor ([VEGF] RR = -178 mL, 95% CI = -314 to -43).

CONCLUSIONS

Circulating IL-6, VEGF, and FeNO are associated with lung function in adults being treated for TB/HIV. These biomarkers may help identify individuals at higher risk for post-TB lung disease and elucidate targetable pathways to modify the risk of chronic lung impairment among TB survivors.

Same-day testing with initiation of antiretroviral therapy or tuberculosis treatment versus standard care for persons presenting with tuberculosis symptoms at HIV diagnosis: A randomized open-label trial from Haiti

BACKGROUND

Same-day HIV testing and antiretroviral therapy (ART) initiation is being widely implemented. However, the optimal timing of ART among patients with tuberculosis (TB) symptoms is unknown. We hypothesized that same-day treatment (TB treatment for those diagnosed with TB; ART for those not diagnosed with TB) would be superior to standard care in this population.

METHODS AND FINDINGS

We conducted an open-label trial among adults with TB symptoms at initial HIV diagnosis at GHESKIO in Haiti; participants were recruited and randomized on the same day. Participants were randomized in a 1:1 ratio to same-day treatment (same-day TB testing with same-day TB treatment if TB diagnosed; same-day ART if TB not diagnosed) versus standard care (initiating TB treatment within 7 days and delaying ART to day 7 if TB not diagnosed). In both groups, ART was initiated 2 weeks after TB treatment. The primary outcome was retention in care with 48-week HIV-1 RNA <200 copies/mL, with intention to treat (ITT) analysis. From November 6, 2017 to January 16, 2020, 500 participants were randomized (250/group); the final study visit occurred on March 1, 2021. Baseline TB was diagnosed in 40 (16.0%) in the standard and 48 (19.2%) in the same-day group; all initiated TB treatment. In the standard group, 245 (98.0%) initiated ART at median of 9 days; 6 (2.4%) died, 15 (6.0%) missed the 48-week visit, and 229 (91.6%) attended the 48-week visit. Among all who were randomized, 220 (88.0%) received 48-week HIV-1 RNA testing; 168 had <200 copies/mL (among randomized: 67.2%; among tested: 76.4%). In the same-day group, 249 (99.6%) initiated ART at median of 0 days; 9 (3.6%) died, 23 (9.2%) missed the 48-week visit, and 218 (87.2%) attended the 48-week visit. Among all who were randomized, 211 (84.4%) received 48-week HIV-1 RNA; 152 had <200 copies/mL (among randomized: 60.8%; among tested: 72.0%). There was no difference between groups in the primary outcome (60.8% versus 67.2%; risk difference: -0.06; 95% CI [-0.15, 0.02]; p = 0.14). Two new grade 3 or 4 events were reported per group; none were judged to be related to the intervention. The main limitation of this study is that it was conducted at a single urban clinic, and the generalizability to other settings is uncertain.

CONCLUSIONS

In patients with TB symptoms at HIV diagnosis, we found that same-day treatment was not associated with superior retention and viral suppression. In this study, a short delay in ART initiation did not appear to compromise outcomes.

TRIAL REGISTRATION

This study is registered with ClinicalTrials.gov NCT03154320.

Lung function and collagen 1a levels are associated with changes in 6 min walk test distance during treatment of TB among HIV-infected adults: a prospective cohort study

BACKGROUND

Patients with tuberculosis (TB) and HIV often present with impairments in lung function and exercise capacity after treatment. We evaluated clinical and immunologic variables associated with a minimum clinically important difference (MCID) in the change in the 6 min walk test distance during the first 24 weeks of antiretroviral (ART) and anti-tubercular therapy.

METHODS

Adults initiating ART and anti-TB treatment in the setting of newly-diagnosed HIV and pulmonary TB were enrolled in a prospective cohort study in South Africa. Patients underwent 6 min walk tests and spirometry at weeks 0, 4, 12, and 24 and biomarker level measurements early during treatment, at weeks 0, 4, and 12, when inflammation levels are typically elevated. Biomarkers included matrix metalloproteinases-1 (MMP-1), tissue inhibitor of MMP (TIMP)-1, collagen 1a, IL-6, IL-8, vascular cell adhesion molecule 1 (VCAM-1), C-X-C motif chemokine 10 (CXCL-10), CXCL-11, macrophage colony-stimulating factor (M-CSF), plasminogen activator, vascular endothelial growth factor, and chemokine (C-C) motif-2 (CCL-2). An MCID was derived statistically, and achievement of an MCID was modeled as the outcome using logistic regression model.

RESULTS

Eighty-nine patients walked an average of 393 (± standard deviation = 69) meters at baseline, which increased by an average of 9% (430 ± 70 m) at week 24. The MCID for change in walk distance was estimated as 41 m. Patients experiencing an MCID on treatment had worse lung function, lower 6 min walk test distance, higher levels of proinflammatory biomarkers including TIMP-1 and M-CSF, and lower levels of collagen 1a at baseline. Experiencing an MCID during treatment was associated with increases in forced expiratory volume in 1-s [odds ratio (OR) = 1.17, 95% confidence interval (CI) = 1.05-1.33] and increases in blood collagen 1a levels (OR = 1.31, 95%CI 1.06-1.62).

CONCLUSIONS

ART and TB treatment are associated with substantial improvements in 6 min walk test distance over time. Achievement of an MCID in the 6 min walk test in this study was associated with more severe disease at baseline and increases in collagen 1a levels and lung function during therapy.

Gene expression signatures identify biologically and clinically distinct tuberculosis endotypes

BACKGROUND

In vitro, animal model, and clinical evidence suggests that tuberculosis is not a monomorphic disease, and that host response to tuberculosis is protean with multiple distinct molecular pathways and pathologies (endotypes). We applied unbiased clustering to identify separate tuberculosis endotypes with classifiable gene expression patterns and clinical outcomes.

METHODS

A cohort comprised of microarray gene expression data from microbiologically confirmed tuberculosis patients were used to identify putative endotypes. One microarray cohort with longitudinal clinical outcomes was reserved for validation, as was two RNA-seq cohorts. Finally, a separate cohort of tuberculosis patients with functional immune responses was evaluated to clarify stimulated from unstimulated immune responses.

RESULTS

A discovery cohort, including 435 tuberculosis patients and 533 asymptomatic controls, identified two tuberculosis endotypes. Endotype A is characterised by increased expression of genes related to inflammation and immunity and decreased metabolism and proliferation; in contrast, endotype B has increased activity of metabolism and proliferation pathways. An independent RNA-seq validation cohort, including 118 tuberculosis patients and 179 controls, validated the discovery results. Gene expression signatures for treatment failure were elevated in endotype A in the discovery cohort, and a separate validation cohort confirmed that endotype A patients had slower time to culture conversion, and a reduced cure rate. These observations suggest that endotypes reflect functional immunity, supported by the observation that tuberculosis patients with a hyperinflammatory endotype have less responsive cytokine production upon stimulation.

CONCLUSION

These findings provide evidence that metabolic and immune profiling could inform optimisation of endotype-specific host-directed therapies for tuberculosis.

Respiratory symptoms and lung function in patients treated for pulmonary tuberculosis in Malawi: a prospective cohort study

Rationale

Pulmonary tuberculosis (PTB) can cause post-TB lung disease (PTLD) associated with respiratory symptoms, spirometric and radiological abnormalities. Understanding of the predictors and natural history of PTLD is limited.

Objectives

To describe the symptoms and lung function of Malawian adults up to 3 years following PTB-treatment completion, and to determine the evolution of PTLD over this period.

Methods

Adults successfully completing PTB treatment in Blantyre, Malawi were followed up for 3 years and assessed using questionnaires, post-bronchodilator spirometry, 6 min walk tests, chest X-ray and high-resolution CT. Predictors of lung function at 3 years were identified by mixed effects regression modelling.

Measurement and main results

We recruited 405 participants of whom 301 completed 3 years follow-up (mean (SD) age 35 years (10.2); 66.6% males; 60.4% HIV-positive). At 3 years, 59/301 (19.6%) reported respiratory symptoms and 76/272 (27.9%) had abnormal spirometry. The proportions with low FVC fell from 57/285 (20.0%) at TB treatment completion to 33/272 (12.1%), while obstruction increased from and 41/285 (14.4%) to 43/272 (15.8%) at 3 years. Absolute FEV₁ and FVC increased by mean 0.03 L and 0.1 L over this period, but FEV₁ decline of more than 0.1 L was seen in 73/246 (29.7%). Higher spirometry values at 3 years were associated with higher body mass index and HIV coinfection at TB-treatment completion.

Conclusion

Spirometric measures improved over the 3 years following treatment, mostly in the first year. However, a third of PTB survivors experienced ongoing respiratory symptoms and abnormal spirometry (with accelerated FEV₁ decline). Effective interventions are needed to improve the care of this group of patients.

Perspectives for systems biology in the management of tuberculosis

Standardised management of tuberculosis may soon be replaced by individualised, precision medicine-guided therapies informed with knowledge provided by the field of systems biology. Systems biology is a rapidly expanding field of computational and mathematical analysis and modelling of complex biological systems that can provide insights into mechanisms underlying tuberculosis, identify novel biomarkers, and help to optimise prevention, diagnosis and treatment of disease. These advances are critically important in the context of the evolving epidemic of drug-resistant tuberculosis. Here, we review the available evidence on the role of systems biology approaches - human and mycobacterial genomics and transcriptomics, proteomics, lipidomics/metabolomics, immunophenotyping, systems pharmacology and gut microbiomes - in the management of tuberculosis including prediction of risk for disease progression, severity of mycobacterial virulence and drug resistance, adverse events, comorbidities, response to therapy and treatment outcomes. Application of the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) approach demonstrated that at present most of the studies provide "very low" certainty of evidence for answering clinically relevant questions. Further studies in large prospective cohorts of patients, including randomised clinical trials, are necessary to assess the applicability of the findings in tuberculosis prevention and more efficient clinical management of patients.

Pulmonary restriction predicts long-term pulmonary impairment in people with HIV and tuberculosis

Background

While tuberculosis is considered a risk factor for chronic obstructive pulmonary disease, a restrictive pattern of pulmonary impairment may actually be more common among tuberculosis survivors. We aimed to determine the nature of pulmonary impairment before and after treatment among people with HIV and tuberculosis and identify risk factors for long-term impairment.

Methods

In this prospective cohort study conducted in South Africa, we enrolled adults newly diagnosed with HIV and tuberculosis who were initiating antiretroviral therapy and tuberculosis treatment. We measured lung function and symptoms at baseline, 6, and 12 months. We compared participants with and without pulmonary impairment and constructed logistic regression models to identify characteristics associated with pulmonary impairment.

Results

Among 134 participants with a median CD4 count of 110 cells/μl, 112 (83%) completed baseline spirometry at which time 32 (29%) had restriction, 13 (12%) had obstruction, and 9 (7%) had a mixed pattern. Lung function was dynamic over time and 30 (33%) participants had impaired lung function at 12 months. Baseline restriction was associated with greater symptoms and with long-term pulmonary impairment (adjusted odds ratio 5.44, 95% confidence interval 1.16–25.45), while baseline obstruction was not (adjusted odds ratio 1.95, 95% confidence interval 0.28–13.78).

Conclusions

In this cohort of people with HIV and tuberculosis, restriction was the most common, symptomatic, and persistent pattern of pulmonary impairment. These data can help to raise awareness among clinicians about the heterogeneity of post-tuberculosis pulmonary impairment, and highlight the need for further research into mediators of lung injury in this vulnerable population.

Declines in Lung Function After Antiretroviral Therapy Initiation in Adults With Human Immunodeficiency Virus and Tuberculosis: A Potential Manifestation of Respiratory Immune Reconstitution Inflammatory Syndrome

End-organ impairment has received relatively little research attention as a possible manifestation of tuberculosis immune reconstitution inflammatory syndrome (TB-IRIS). In this prospective cohort study, one-half of adults with human immunodeficiency virus and pulmonary tuberculosis experienced meaningful declines in lung function on antiretroviral therapy, suggesting a role for lung function in TB-IRIS definitions.

The effect of HIV-associated tuberculosis, tuberculosis-IRIS and prednisone on lung function

Residual pulmonary impairment is common after treatment for tuberculosis (TB). Lung function data in patients with HIV-associated TB are scarce, especially in the context of paradoxical TB-associated immune reconstitution inflammatory syndrome (TB-IRIS) and prophylactic prednisone. We aimed to determine the prevalence of lung function abnormalities in patients with HIV-associated TB and CD4 counts ≤100 cells·μL⁻¹ and assess the effect of prophylactic prednisone and the development of paradoxical TB-IRIS on pulmonary impairment.

We performed spirometry, 6-min walk test (6MWT) and chest radiography at baseline (week 0) and at weeks 4, 12 and 28 in participants of the PredART trial, which evaluated a 28-day course of prednisone to prevent TB-IRIS in patients with HIV-associated TB commencing antiretroviral therapy.

153 participants underwent spirometry and/or 6MWT at one or more time points. Abnormal spirometry measurements were present in 66% of participants at week 0 and 50% at week 28; low forced vital capacity was the commonest abnormality. Chest radiographs showed little or no abnormalities in the majority of participants. Prednisone use resulted in a 42 m greater 6-min walk distance and a 4.9% higher percentage of predicted forced expiratory volume in 1 s at week 4; these differences were no longer significantly different from week 12 onwards. TB-IRIS did not significantly impair lung function outcome.

Residual pulmonary impairment is common in HIV-associated TB. In patients with low CD4 counts, neither prophylactic prednisone as used in our study nor the development of TB-IRIS significantly affected week-28 pulmonary outcome.

Post-tuberculosis lung disease is common in patients with HIV-associated TB at high risk of TB-IRIS (CD4 count ≤100 cells·μL⁻¹). Neither TB-IRIS itself, nor prednisone treatment, affected long-term pulmonary outcomes in a South African clinical setting.http://bit.ly/2RjMl9c

Patient outcomes associated with post-tuberculosis lung damage in Malawi: a prospective cohort study

BACKGROUND

Post-tuberculosis lung damage (PTLD) is a recognised consequence of pulmonary TB (pTB). However, little is known about its prevalence, patterns and associated outcomes, especially in sub-Saharan Africa and HIV-positive adults.

METHODS

Adult (≥15 years) survivors of a first episode of pTB in Blantyre, Malawi, completed the St George's Respiratory Questionnaire, 6-minute walk test, spirometry and high-resolution CT (HRCT) chest imaging at TB treatment completion. Symptom, spirometry, health seeking, TB-retreatment and mortality data were collected prospectively to 1 year. Risk factors for persistent symptoms, pulmonary function decline and respiratory-related health-seeking were identified through multivariable regression modelling.

RESULTS

Between February 2016 and April 2017, 405 participants were recruited. Median age was 35 years (IQR: 28 to 41), 77.3% (313/405) had had microbiologically proven pTB, and 60.3% (244/403) were HIV-positive. At pTB treatment completion, 60.7% (246/405) reported respiratory symptoms, 34.2% (125/365) had abnormal spirometry, 44.2% (170/385) had bronchiectasis ≥1 lobe and 9.4% (36/385) had ≥1 destroyed lobe on HRCT imaging. At 1 year, 30.7% (113/368) reported respiratory symptoms, 19.3% (59/305) and 14.1% (43/305) of patients had experienced declines in FEV₁ or FVC of ≥100 mL, 16.3% (62/380) had reported ≥1 acute respiratory event and 12.2% (45/368) had symptoms affecting their ability to work.

CONCLUSIONS

PTLD is a common and under-recognised consequence of pTB that is disabling for patients and associated with adverse outcomes beyond pTB treatment completion. Increased efforts to prevent PTLD and guidelines for management of established disease are urgently needed. Low-cost clinical interventions to improve patient outcomes must be evaluated.