Adjunctive steroid therapy for managing pulmonary tuberculosis

Pulmonary tuberculosis in non-HIV adults: an evergreen old-fashioned disease in high-income countries. A narrative review

INTRODUCTION

Tuberculosis (TB), an infective air-borne disease with worldwide non-homogeneous distribution, remains a top cause of morbidity and mortality. TB control is linked to early diagnosis and proper treatment of contagious TB cases and infected subjects at high risk of developing TB.

AREAS COVERED

A narrative review of pulmonary TB in non-HIV adults with reference to high-income countries. Modern medicine offers several advancements in diagnostics and therapeutics of TB, but they often remain to be extensively implemented in real life. In high-income countries TB is now relatively uncommon, but it remains a health and socio-economic burden that should not be underestimated.

EXPERT OPINION

Pulmonologists should maintain expertise toward TB for several reasons. First, the lung is the most common and the infectious moiety of TB. Second, TB remains a global issue due to common travels of western people and migrations from areas with high incidence of TB. Third, as TB has heterogenous clinics, its prompt diagnosis may be difficult. Fourth, TB is a curable disease, but its management is complex and predisposes to poor adherence with failures/relapses and selection of drug-resistant strains.

Persistent Fever in Tuberculosis: Clinical Experience and Literature Review

Fever in tuberculosis has always been a challenge to clinicians treating the disease throughout history. There is a constant interplay between the host immune response and the bacillary load that results in high-grade fevers in patients with tuberculosis. In the setting of pulmonary tuberculosis, there is scant data regarding how long fevers last and the exact pathophysiology of its prolonged duration, especially once appropriate antituberculosis medication is initiated.  This case report elucidates our experience in treating a patient presenting with smear-positive pulmonary tuberculosis with significant bacillary load; despite responding microbiologically to antituberculosis therapy, he clinically continued to have persistent fever.

[DRESS syndrome induced by anti-TB drugs]

OBJETIVE

To describe the phenotype of DRESS syndrome induced by antituberculosis drugs.

METHODS

Descriptive study, withdrawn from the review of the records of patients with DRESS syndrome, identified in the interconsultation of the Department of Research in Immunogenetics and Allergy, of the Insti-tuto Nacional de Enfermedades Respiratorias (INER) Ismael Cosío Villegas, among 2014 and 2020. Frequency analysis was performed. The associations between biomarkers and latency are calculated with the χ2 test and log-rank, and the evaluation of the change in the biomarkers with the Wilcoxon test. The value of p < 0.05 is considered statistically significant. For data analysis, the SPSS v.21 program was obtained.

RESULTS

15 patients were identified; represented by 0.02% of total cases treated in the Department for so-meimmuno-allergic condition (15/7052); the main symptomatology were: rash (100%), eosinophilia (93%), fe-ver (80%), adenomegaly (60%), kidney damage (40%), liver damage (33%), and latency of 21 days. Liver damage was associated with prolonged latency (p = 0.02). After treatment, the total levels of eosinophils (p < 0.001) and liver and kidney biomarkers (p < 0.04) decreased. DRESS syndrome induced by antituberculosis drugs is not associated with the number of drugs prescribed or with the pattern of resistance of Mycobacterium tuberculosis.

CONCLUSIONS

DRESS syndrome induced by antituberculosis drugs is an atypical clinical reaction, similar to other types of DRESS syndrome that respond favorably to systemic corticosteroids.

Pulmonary tuberculosis associated acute fibrinous and organizing pneumonia: A case report and literature review

BACKGROUND

Acute fibrinous and organizing pneumonia (AFOP) is a rare histological interstitial pneumonia pattern characterized by patches of "fibrin balls" distributed within the alveoli and organizing pneumonia. Currently, there is no consensus on the diagnosis and treatment of this disease.

METHODS

We present the case of a 44-year-old male with AFOP secondary to Mycobacterium tuberculosis. We have further reviewed organizing pneumonia (OP) and AFOP caused by tuberculosis.

CONCLUSION

Tuberculosis secondary to OP or AFOP is rare and challenging to diagnose. We need to constantly adjust the treatment plan based on the patient's symptoms, test results, and response to treatment in order to arrive at an accurate diagnosis and maximize treatment efficacy.

Inflammation-mediated tissue damage in pulmonary tuberculosis and host-directed therapeutic strategies

Treatment of tuberculosis (TB) involves the administration of anti-mycobacterial drugs for several months. The emergence of drug-resistant strains of Mycobacterium tuberculosis (Mtb, the causative agent) together with increased disease severity in people with co-morbidities such as diabetes mellitus and HIV have hampered efforts to reduce case fatality. In severe disease, TB pathology is largely attributable to over-exuberant host immune responses targeted at controlling bacterial replication. Non-resolving inflammation driven by host pro-inflammatory mediators in response to high bacterial load leads to pulmonary pathology including cavitation and fibrosis. The need to improve clinical outcomes and reduce treatment times has led to a two-pronged approach involving the development of novel antimicrobials as well as host-directed therapies (HDT) that favourably modulate immune responses to Mtb. HDT strategies incorporate aspects of immune modulation aimed at downregulating non-productive inflammatory responses and augmenting antimicrobial effector mechanisms to minimise pulmonary pathology and accelerate symptom resolution. HDT in combination with existing antimycobacterial agents offers a potentially promising strategy to improve the long-term outcome for TB patients. In this review, we describe components of the host immune response that contribute to inflammation and tissue damage in pulmonary TB, including cytokines, matrix metalloproteinases, lipid mediators, and neutrophil extracellular traps. We then proceed to review HDT directed at these pathways.

Adjunctive corticosteroid therapy in patients with pulmonary tuberculosis

OBJECTIVES

In tuberculosis treatment, corticosteroids are used as adjuvants, especially in meningeal/pericardial tuberculosis. In other forms of the disease, especially in severe tuberculosis requiring mechanical ventilation, its use is controversial. The aim of the present study is to assess whether the use of corticosteroids in the treatment of pulmonary tuberculosis patients in mechanical ventilation is associated with in-hospital mortality.

METHODS

This is a retrospective cohort study. Tuberculosis patients >18 years requiring mechanical ventilation, admitted to the emergency department or intensive care unit, were included. Data on corticosteroid use and mortality were collected.

RESULTS

In total, 467 patients were included in the analysis; 399 used corticosteroids and 68 were noncorticosteroid users. The mortality rate was higher among corticosteroid users (59.9%) than in noncorticosteroid users (41.2%) (p=0.010). The total dose of corticosteroid in prednisone equivalents was not different between survivors and nonsurvivors (median [interquartile range]: 80 mg [5-56.6 mg] vs. 80 mg [50-135 mg]; p=0.881).

CONCLUSIONS

Tuberculosis patients in mechanical ventilation who used corticosteroids had a higher mortality rate than those who did not use corticosteroids. The role of corticosteroids in pulmonary tuberculosis, especially in critically ill patients, remains unclear and needs further evaluation in prospective studies.

HOMEOSTATIC ROLE OF GLUCOCORTICOIDS IN THE TREATMENT OF PULMONARY TUBERCULOSIS

OBJECTIVE

The aim: To establish the clinical and pathogenetic role of glucocorticoid imbalance as an important link of impairment of the adaptive system homeostasis and to determine ways of its correction as a way to increase the effectiveness of the pulmonary tuberculosis treatment.

PATIENTS AND METHODS

Materials and methods: The effectiveness of glucocorticoids in the pulmonary tuberculosis treatment was studied in 304 patients, of which 134 patients (group 1) received only antibacterial therapy, 67 patients (group 2) were supplemented with glucocorticoids (20-30 mg of prednisolone, daily, in 3 doses, with their cessation by gradual reduction of dose). 103 patients (group 3) also received antibacterial therapy in combination with glucocorticoids (20-30 mg of prednisolone, in the morning, in a daily dose every other day, cessation was carried out simultaneously without reducing the dose).

RESULTS

Results: The study found that the level of cortisol in patients with pulmonary tuberculosis was significantly higher than normal, did not have age and gender dependence, but showed a connection with the severity of clinical forms of tuberculosis, the duration of disease development and the presence of intoxication. It was established that the daily fluctuations of cortisol persist in tuberculosis patients, but its level significantly exceeds the norm, which indicates the functional stressing of the adaptive system.

CONCLUSION

Conclusions: The article substantiates the homeostatic role of glucocorticoids in the complex treatment of tuberculosis patients when administered in a double physiological dose every other day, taking into account the daily biorhythm of the hypothalamic-pituitary-adrenal axis function.

Review of the Effectiveness of Various Adjuvant Therapies in Treating Mycobacterium tuberculosis

Tuberculosis disease is caused by the bacterium Mycobacterium tuberculosis. It is estimated that 10 million people have developed tuberculosis disease globally, leading to 1.4 million deaths in 2019. Treatment of tuberculosis has been especially challenging due to the rise of multidrug-resistant (MDR-TB) and extensive drug-resistant (XDR-TB) tuberculosis. In addition to drug-resistant genotypes, the standard treatment of tuberculosis by first-line agents is also challenging due to toxicity and costs. In the last four decades, there have only been two new anti-tuberculosis agents—bedaquiline and delamanid. Therefore, shorter, safer, and more cost-effective therapies are needed to adequately treat tuberculosis. In this review, we explore various adjuvants such as glutathione, everolimus, vitamin D, steroid, aspirin, statin, and metformin and their usefulness in reducing the burden of tuberculosis. Glutathione, everolimus, aspirin, and metformin showed the most promise in alleviating the burden of tuberculosis. Despite their potential, more clinical trials are needed to unequivocally establish the effectiveness of these adjuvants as future clinical therapies. Methods: The journals for this review were selected by conducting a search via PubMed, Google Scholar, and The Lancet. Our first search included keywords such as “tuberculosis” and “adjuvant therapy.” From the search, we made a list of adjuvants associated with tuberculosis, and this helped guide us with our second online database search. Using the same three online databases, we searched “tuberculosis” and “respective therapy.” The adjuvants included in the paper were selected based on the availability of sufficient research and support between the therapy and tuberculosis. Adjuvants with minimal research support were excluded. There were no specific search criteria regarding the timing of publication, with our citations ranging between 1979 to 2021.

Glucocorticoid-Induced Exacerbation of Mycobacterial Infection Is Associated With a Reduced Phagocytic Capacity of Macrophages

Glucocorticoids are effective drugs for treating immune-related diseases, but prolonged therapy is associated with an increased risk of various infectious diseases, including tuberculosis. In this study, we have used a larval zebrafish model for tuberculosis, based on Mycobacterium marinum (Mm) infection, to study the effect of glucocorticoids. Our results show that the synthetic glucocorticoid beclomethasone increases the bacterial burden and the dissemination of a systemic Mm infection. The exacerbated Mm infection was associated with a decreased phagocytic activity of macrophages, higher percentages of extracellular bacteria, and a reduced rate of infected cell death, whereas the bactericidal capacity of the macrophages was not affected. The inhibited phagocytic capacity of macrophages was associated with suppression of the transcription of genes involved in phagocytosis in these cells. The decreased bacterial phagocytosis by macrophages was not specific for Mm, since it was also observed upon infection with Salmonella Typhimurium. In conclusion, our results show that glucocorticoids inhibit the phagocytic activity of macrophages, which may increase the severity of bacterial infections like tuberculosis.

Host-directed therapy to combat mycobacterial infections

Upon infection, mycobacteria, such as Mycobacterium tuberculosis (Mtb) and nontuberculous mycobacteria (NTM), are recognized by host innate immune cells, triggering a series of intracellular processes that promote mycobacterial killing. Mycobacteria, however, have developed multiple counter‐strategies to persist and survive inside host cells. By manipulating host effector mechanisms, including phagosome maturation, vacuolar escape, autophagy, antigen presentation, and metabolic pathways, pathogenic mycobacteria are able to establish long‐lasting infection. Counteracting these mycobacteria‐induced host modifying mechanisms can be accomplished by host‐directed therapeutic (HDT) strategies. HDTs offer several major advantages compared to conventional antibiotics: (a) HDTs can be effective against both drug‐resistant and drug‐susceptible bacteria, as well as potentially dormant mycobacteria; (b) HDTs are less likely to induce bacterial drug resistance; and (c) HDTs could synergize with, or shorten antibiotic treatment by targeting different pathways. In this review, we will explore host‐pathogen interactions that have been identified for Mtb for which potential HDTs impacting both innate and adaptive immunity are available, and outline those worthy of future research. We will also discuss possibilities to target NTM infection by HDT, although current knowledge regarding host‐pathogen interactions for NTM is limited compared to Mtb. Finally, we speculate that combinatorial HDT strategies can potentially synergize to achieve optimal mycobacterial host immune control.

Host-Directed Therapies and Anti-Virulence Compounds to Address Anti-Microbial Resistant Tuberculosis Infection

Despite global efforts to contain tuberculosis (TB), the disease remains a leading cause of morbidity and mortality worldwide, further exacerbated by the increased resistance to antibiotics displayed by the tubercle bacillus Mycobacterium tuberculosis. In order to treat drug-resistant TB, alternative or complementary approaches to standard anti-TB regimens are being explored. An area of active research is represented by host-directed therapies which aim to modulate the host immune response by mitigating inflammation and by promoting the antimicrobial activity of immune cells. Additionally, compounds that reduce the virulence of M. tuberculosis, for instance by targeting the major virulence factor ESX-1, are being given increased attention by the TB research community. This review article summarizes the current state of the art in the development of these emerging therapies against TB.

Corticosteroid as an Adjunct in the Treatment of Endobronchial Tuberculosis: A Systematic Review & Meta-analysis

BACKGROUND

Corticosteroid exerts anti-inflammatory action and can prevent tissue damage resulting from various causes. Studies have shown that corticosteroids may prevent the damaging effect of tuberculosis (TB) in various organs, but there is no published meta-analysis specifically looking for the effect of corticosteroid in endobronchial TB.

OBJECTIVE

To synthesize the evidence regarding the usefulness of corticosteroid in endo-bronchial TB.

METHODS

A comprehensive search was performed of the major electronic databases till 30th November 2018. Randomized trials comparing treatment with corticosteroid as an adjunct to antitubercular drugs (ATT) versus placebo/no treatment in endobronchial TB were included. Three authors independently applied eligibility criteria, assessed the studies for methodological quality, and extracted data. The review is registered at PROSPERO database [CRD42016047063].

RESULTS

Out of 525 search results, 4 trials including 205 patients (151 children) were eligible for inclusion. Oral prednisolone was used in various dose schedules. Rifampicin containing ATT regimen was used in 3 trials. The bronchoscopy findings showed no significant improvement at 1 month (effect size could not be calculated due to 0 event in the intervention group, p = 0.05), 2 months (RR 1.26, 95% CI 0.89 to 1.8), and at completion of ATT (RR 0.63, 95% CI 0.1 to 4.14) in steroid-treated group compared to the control group. The need for repeat bronchoscopy was significantly decreased in the steroid group (RR 0.13, 95% CI 0.02 to 0.9). Among the adverse events, the infection rate was significantly lesser in the steroid group (RR 0.53, 95% CI 0.29 to 0.97); but other adverse events (mortality, hypertension, and abdominal distension) showed no significant difference between the two groups. The GRADE evidence generated was of very low quality.

CONCLUSION

The present meta-analysis showed that oral steroid does not help patients with endobronchial tuberculosis. However, the quality of evidence was very low. Future trials with robust design and a larger sample size would be required to provide any firm recommendation regarding the use of oral prednisolone in endobronchial tuberculosis.

The Immune Mechanisms of Lung Parenchymal Damage in Tuberculosis and the Role of Host-Directed Therapy

Impaired lung function is common in people with a history of tuberculosis. Host-directed therapy added to tuberculosis treatment may reduce lung damage and result in improved lung function. An understanding of the pathogenesis of pulmonary damage in TB is fundamental to successfully predicting which interventions could be beneficial. In this review, we describe the different features of TB immunopathology that lead to impaired lung function, namely cavities, bronchiectasis, and fibrosis. We discuss the immunological processes that cause lung damage, focusing on studies performed in humans, and using chest radiograph abnormalities as a marker for pulmonary damage. We highlight the roles of matrix metalloproteinases, neutrophils, eicosanoids and cytokines, like tumor necrosis factor-α and interleukin 1β, as well as the role of HIV co-infection. Finally, we focus on various existing drugs that affect one or more of the immunological mediators of lung damage and could therefore play a role as host-directed therapy.

Corticosteroids as an adjunct to tuberculosis therapy

INTRODUCTION

Inflammation, or the prolonged resolution of inflammation, contributes to death from tuberculosis. Interest in inflammatory mechanisms and the prospect of beneficial immune modulation as an adjunct to antibacterial therapy has revived and the concept of host directed therapies has been advanced. Such renewed attention has however, overlooked the experience of such therapy with corticosteroids. Areas covered: The authors conducted literature searches and evaluated randomized clinical trials, systematic reviews and current guidelines and summarize these findings. They found evidence of benefit in meningeal and pericardial tuberculosis in HIV-1 uninfected persons, but less so in those HIV-1 coinfected and evidence of harm in the form of opportunist malignancy in those not prescribed antiretroviral therapy. Adjunctive corticosteroids are however of benefit in the treatment and prevention of paradoxical HIV-tuberculosis immune reconstitution inflammatory syndrome. Expert commentary: Further high-quality clinical trials and experimental medicine studies are warranted and analysis of materials arising from such studies could illuminate ways to improve corticosteroid efficacy or identify novel pathways for more specific intervention.

Medical treatment for urogenital tuberculosis (UGTB)

Urogenital tuberculosis (UGTB) should in general be treated as pulmonary TB with a four-drug regimen of Isoniazid, Rifampicin, Ethambutol and Pyrazinamide for a total of 6 months, Ethambutol and Pyrazinamide only the first two months. Some patients may need longer treatment (cavitary disease, kidney abscess/malfunction, HIV co-infection). Treatment of multi-drug resistant tuberculosis (MDR-TB) requires use of long-term intravenous treatment with aminoglycosides and other drugs with considerable toxicity for 18–24 months. Complications such as urinary tract obstruction may occur and should be treated with corticosteroids or surgery.

Corticosteroids for tuberculous pleurisy

BACKGROUND

Corticosteroids used in addition to antituberculous therapy have been reported to benefit people with tuberculous pleurisy. However, research findings are inconsistent and raise doubt as to whether such treatment is worthwhile. There is also concern regarding the potential adverse effects of corticosteroids, especially in HIV-positive people.

OBJECTIVES

To evaluate the effects of adding corticosteroids to drug regimens for tuberculous pleural effusion.

SEARCH METHODS

In April 2016, we searched the Cochrane Infectious Diseases Group Specialized Register, CENTRAL (the Cochrane Library), MEDLINE, Embase, LILACS, Current Controlled Trials, and the reference lists of articles identified by the literature search.

SELECTION CRITERIA

Randomized controlled trials (RCTs) and quasi-RCTs that compared any corticosteroid with no treatment, placebo, or other active treatment (both groups should have received the same antituberculous drug regimen) in people diagnosed with tuberculous pleurisy.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened the search results, extracted data from the included trials, and assessed trial methodological quality using the Cochrane 'Risk of bias' tool. We analysed the data using risk ratios (RR) with 95% confidence intervals (CIs). We applied the fixed-effect model in the absence of statistically significant heterogeneity.

MAIN RESULTS

Six trials with 590 participants met the inclusion criteria, which were conducted in Asia (three trials), Africa (two trials), and Europe (one trial). Two trials were in HIV-negative people, one trial was in HIV-positive people, and three trials did not report HIV status.Corticosteroids may reduce the time to resolution of pleural effusion. Risk of residual pleural effusion on chest X-ray was reduced by 45% at eight weeks (RR 0.54, 95% CI 0.37 to 0.78; 237 participants, 2 trials, low certainty evidence), and 65% at 24 weeks (RR 0.35, 95% CI 0.18 to 0.66; 237 participants, 2 trials, low certainty evidence).Compared with control, corticosteroids may reduce the risk of having pleural changes (such as pleural thickening or pleural adhesions), on chest X-ray at the end of follow-up by almost one third (RR 0.72, 95% CI 0.57 to 0.92; 393 participants, 5 trials,low certainty evidence), which translates to an absolute risk reduction of 16%.One trial reported deaths in people that were HIV-positive, with no obvious difference between the groups; the trial authors' analysis suggests that the deaths observed in this trial were related to HIV disease rather than pleural TB (RR 0.91, 95% CI 0.64 to 1.31; 197 participants, 1 trial).We found limited data on long-term functional respiratory impairment on 187 people in two trials, which reported that average percentage predicted forced vital capacity was similar in the group receiving prednisolone and in the control group (very low certainty evidence).The risk of adverse events that led to discontinuation of the trial drug was higher in people with pleural TB receiving corticosteroids (RR 2.78, 95% CI 1.11 to 6.94; 587 participants, 6 trials, low certainty evidence). The trial in HIV-positive people reported on six different HIV-related infections, with no obvious differences. However, cases of Kaposi's sarcoma were only seen in the corticosteroid group (with 6/99 cases in the steroid group compared to 0/98 in the control group) (very low certainty evidence).

AUTHORS' CONCLUSIONS

Long-term respiratory function is potentially the most important outcome for assessing the effects of adjunctive treatments for people with pleural TB. However, the information on the impact of pleural TB on long-term respiratory function is unknown and could be eclipsed by other risk factors, such as concurrent pulmonary TB, smoking, and HIV. This probably needs to be quantified to help decide whether further trials of corticosteroids for pleural TB would be worthwhile.

Imatinib Triggers Phagolysosome Acidification and Antimicrobial Activity against Mycobacterium bovis Bacille Calmette-Guérin in Glucocorticoid-Treated Human Macrophages

Glucocorticoids are extensively used to treat inflammatory diseases; however, their chronic intake increases the risk for mycobacterial infections. Meanwhile, the effects of glucocorticoids on innate host responses are incompletely understood. In this study, we investigated the direct effects of glucocorticoids on antimycobacterial host defense in primary human macrophages. We found that glucocorticoids triggered the expression of cathelicidin, an antimicrobial critical for antimycobacterial responses, independent of the intracellular vitamin D metabolism. Despite upregulating cathelicidin, glucocorticoids failed to promote macrophage antimycobacterial activity. Gene expression profiles of human macrophages treated with glucocorticoids and/or IFN-γ, which promotes induction of cathelicidin, as well as antimycobacterial activity, were investigated. Using weighted gene coexpression network analysis, we identified a module of highly connected genes that was strongly inversely correlated with glucocorticoid treatment and associated with IFN-γ stimulation. This module was linked to the biological functions autophagy, phagosome maturation, and lytic vacuole/lysosome, and contained the vacuolar H(+)-ATPase subunit a3, alias TCIRG1, a known antimycobacterial host defense gene, as a top hub gene. We next found that glucocorticoids, in contrast with IFN-γ, failed to trigger expression and phagolysosome recruitment of TCIRG1, as well as to promote lysosome acidification. Finally, we demonstrated that the tyrosine kinase inhibitor imatinib induces lysosome acidification and antimicrobial activity in glucocorticoid-treated macrophages without reversing the anti-inflammatory effects of glucocorticoids. Taken together, we provide evidence that the induction of cathelicidin by glucocorticoids is not sufficient for macrophage antimicrobial activity, and identify the vacuolar H(+)-ATPase as a potential target for host-directed therapy in the context of glucocorticoid therapy.