A Paradoxical Treatment for a Paradoxical Condition: Infliximab Use in Three Cases of Mycobacterial IRIS

(Re-)introduction of TNF antagonists and JAK inhibitors in patients with previous tuberculosis: a systematic review

BACKGROUND

Tuberculosis (TB) is a common complication associated with treatment with tumour necrosis factor (TNF) antagonists and Janus kinase (JAK) inhibitors. However, there is uncertainty about the risk of TB relapse in patients with TB and comorbidities requiring treatment with these agents.

OBJECTIVES

To assess the risk of TB relapse in patients (re-)started on TNF antagonists or JAK inhibitors.

METHODS

Systematic review.

DATA SOURCES

PubMed and Cochrane Library databases until 11 December 2023.

STUDY ELIGIBILITY CRITERIA

Randomized control trials, prospective and retrospective cohort studies, case reports and case series.

PARTICIPANTS

Patients with current or previous TB who were (re-)started on TNF antagonists or JAK inhibitors.

INTERVENTIONS

(Re-)introduction of TNF antagonists and JAK inhibitors.

ASSESSMENT OF RISK OF BIAS

All studies meeting entry criteria were included regardless of quality.

METHODS OF DATA SYNTHESIS

Categorical data are presented as frequencies and percentages. For non-normally distributed aggregated data, we calculated the pooled weighted median with 95% CI. For individual patient data, the median and interquartile range (IQR) were calculated.

RESULTS

Of 5018 articles screened for eligibility, 67 publications reporting on 368 TB patients who (re-)initiated treatment with TNF antagonists for underlying diseases were included. The median age was 42.5 years (95% CI: 40.4-42.5) and the proportion of female patients was 36.6% (n = 74) of patients whose sex was reported. A total of 14 patients (3.8%, 95% CI: 2.1-6.3%) developed TB relapse after a median of 8.5 months (interquartile range, 6.8-14.8 months) following (re-)initiation of anti-TNF treatment. Furthermore, among 251 articles screened for eligibility, 11 reports on TB patients who were (re-)started on JAK inhibitors for underlying diseases were identified. The median age was 62 years (interquartile range, 48.5-68.5 years) and 45.5% (n = 5) were female. Only one patient (9.1%; 95% CI: 0.2-41.3%) had TB reactivation 10 months after starting treatment with ruxolitinib. In addition, 94 patients who were treated with TNF antagonists and two patients temporarily treated with JAK inhibitors for the prevention or treatment of paradoxical reactions were analysed. None of the publications reported microbiological failure or worsening of TB-related symptoms.

CONCLUSIONS

(Re-)initiation of TNF antagonists and JAK inhibitors may be relatively safe in patients with current or previous TB and the need for further treatment of underlying diseases.

[Paradoxical tuberculosis reaction]

Paradoxical tuberculosis reaction is defined as the aggravation of lesions present at diagnosis or the development of new lesions under anti-tuberculosis treatment, after exclusion of other alternate causes. It affects 5 to 30% of tuberculosis patients, with a variable prevalence depending on the site of infection and the clinical background. The diagnosis of paradoxical reaction is one of elimination, and requires having ruled out therapeutic failure, notably linked to poor compliance and/or to the presence of mycobacterial antibiotic resistance. The severity of paradoxical tuberculosis reaction lies in its neurological impairment. Despite its clinical importance, the mechanisms involved remain poorly understood and its management is not consensual. Corticosteroids are the cornerstone in the medical management. The role of anti-TNF agents, currently proposed in cases of corticodependence or corticoresistance, remains to be properly defined.

Successful rescue TNF-α blocking for Mycobacterium genavense - Related immune reconstitution inflammatory syndrome: A case report

Immune reconstitution inflammatory syndrome (IRIS) has been reported in immunocompromised patients with disseminated Mycobacterium genavense. Management relies on high-dose corticosteroids. We describe two cases of late-onset corticosteroid-refractory IRIS related to disseminated infection in a HIV-positive patient and a renal transplant patient who had a favorable outcome with a monoclonal TNF-α blocker.

Current knowledge of the immune reconstitution inflammatory syndrome in Whipple disease: a review

Immune reconstitution inflammatory syndrome (IRIS) is characterized by exaggerated and dysregulated inflammatory responses that occur as a result of reconstitution of adaptive or innate immunity. A wide range of microorganisms have been found to be associated with IRIS, such as human immunodeficiency virus (HIV), Mycobacterium and actinobacteria. Whipple disease (WD) is an infectious disorder caused by the Gram-positive bacterium Tropheryma whipplei (T. whipplei) and IRIS also serves as a complication during its treament. Although many of these pathological mechanisms are shared with related inflammatory disorders, IRIS in WD exhibits distinct features and is poorly described in the medical literature. Novel investigations of the intestinal mucosal immune system have provided new insights into the pathogenesis of IRIS, elucidating the interplay between systemic and local immune responses. These insights may be used to identify monitoring tools for disease prevention and to develop treatment strategies. Therefore, this review synthesizes these new concepts in WD IRIS to approach the feasibility of manipulating host immunity and immune reconstitution of inflammatory syndromes from a newer, more comprehensive perspective and study hypothetical options for the management of WD IRIS.

The use of TNF-α antagonists in tuberculosis to control severe paradoxical reaction or immune reconstitution inflammatory syndrome: a case series and literature review

Paradoxical reaction (PR) and immune reconstitution inflammatory syndrome (IRIS) are common complications of tuberculosis treatment. Corticosteroids are first-line treatment for severe PR or IRIS, particularly neurological. We report four cases of severe PR or IRIS during tuberculosis treatment who required TNF-α antagonists, and identified 20 additional cases through literature review. They were 14 women and 10 men, with a median age of 36 years (interquartile range, 28-52). Twelve were immunocompromised before tuberculosis: untreated HIV infection (n=6), or immunosuppressive treatment (TNF-α antagonists, n=5; tacrolimus, n=1). Tuberculosis was mostly neuromeningeal (n=15), pulmonary (n=10), lymph node (n=6), and miliary (n=6), multi-susceptible in 23 cases. PR or IRIS started after a median time of 6 weeks (IQR, 4-9) following anti-tuberculosis treatment start, and consisted primarily of tuberculomas (n=11), cerebral vasculitis (n=8), and lymphadenitis (n=6). First-line treatment of PR or IRIS was high-dose corticosteroids in 23 cases. TNF-α antagonists were used as salvage treatment in all cases, with infliximab (n=17), thalidomide (n=6), and adalimumab (n=3). All patients improved, but 6 had neurological sequelae, and 4 had TNF-α antagonist-related severe adverse events. TNF-α antagonists are safe and effective as salvage or corticosteroid-sparing therapeutic for severe PR or IRIS during tuberculosis treatment.

Association between severe anaemia and inflammation, risk of IRIS and death in persons with HIV: A multinational cohort study

BACKGROUND

After initiating antiretroviral therapy (ART), approximately 25% of people with HIV (PWH) may develop Immune Reconstitution Inflammatory Syndrome (IRIS), which is associated with increased morbidity and mortality. Several reports have demonstrated that low haemoglobin (Hb) levels are a risk factor for IRIS. To what extent the severity of anaemia contributes to the risk of IRIS and/or death is still insufficiently explored.

METHODS

We investigated both the presence and severity of anaemia in PWH in a multinational cohort of ART-naïve patients. A large panel of plasma biomarkers was measured pre-ART and patients were followed up for 6 months. IRIS or deaths during this period were considered as outcomes. We performed multidimensional analyses, logistic regression, and survival curves to delineate associations.

FINDINGS

Patients with severe anaemia (SA) presented a distinct systemic inflammatory profile, characterized by higher TNF, IL-6, and IL-27 levels. SA was independently associated with IRIS, with a higher risk of both early IRIS onset and death. Among IRIS patients, those with SA had a higher risk of mycobacterial IRIS.

INTERPRETATION

PWH with SA display a more pronounced inflammatory profile, with an elevated risk of developing IRIS earlier and a statistically significant higher risk of death.

FUNDING

Intramural Research Program of National Institute of Allergy and Infectious Diseases/National Institutes of Health (NIAID/NIH). Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (Finance code: 001) and the Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq), Brazil.

Consensus guidelines for the diagnosis and management of cryptococcosis and rare yeast infections in the haematology/oncology setting, 2021

Cryptococcosis caused by the Cryptococcus neoformans-Cryptococcus gattii complex is an important opportunistic infection in people with immunodeficiency, including in the haematology/oncology setting. This may manifest clinically as cryptococcal meningitis or pulmonary cryptococcosis, or be detected incidentally by cryptococcal antigenemia, a positive sputum culture or radiological imaging. Non-Candida, non-Cryptococcus spp. rare yeast fungaemia are increasingly common in this population. These consensus guidelines aim to provide clinicians working in the Australian and New Zealand haematology/oncology setting with clear guiding principles and practical recommendations for the management of cryptococcosis, while also highlighting important and emerging rare yeast infections and their recommended management.

The use of thalidomide to treat children with tuberculosis meningitis: A review

Much of the morbidity and mortality caused by tuberculous meningitis (TBM) is mediated by a dysregulated immune response. Effective host-directed therapy is therefore critical to improve survival and clinical outcomes. Currently only one host-directed therapy (HDT), corticosteroids, is proven to improve mortality. However, there is no evidence that corticosteroids reduce morbidity and the mechanism of action for mortality reduction is uncertain. Further, it has no proven benefit in HIV co-infected individuals. One promising host-directed therapy approach is to restrict the immunopathology arising from tumour necrosis factor (TNF)-α excess is via TNF-α inhibitors. There are accumulating data on the role of thalidomide, anti-TNF-α monoclonal antibodies (infliximab, adalimumab) and the soluble TNF-α receptor (etanercept) in TBM treatment. Thalidomide was developed nearly seventy years ago and has been a highly controversial drug. Birth defects and toxic adverse effects have limited its use but an improved understanding of its immunological mechanism of action suggest that it may have a crucial role in regulating the destructive host response seen in inflammatory conditions such as TBM. Observational studies at our institution found low dosage adjunctive thalidomide safe in treating tuberculous mass lesions and blindness related to optochiasmatic arachnoiditis, with good clinical and radiological response. In this review, we discuss possible mechanisms of action for thalidomide, based on our clinico-radiologic experience and post-mortem histopathological work. We also propose a rationale for its use in the treatment of certain TBM-related complications.

Potential disease trigger as a therapeutic option: infliximab for paradoxical reaction in tuberculosis of the central nervous system

A 36-year-old man of central Asian origin was diagnosed with subacute disseminated tuberculosis. Initially, central nervous system involvement was suggested by an encephalopathic condition and MRI showing extensive basal and spinal meningitis. After initiation of anti-tuberculosis drugs and corticosteroid therapy, clinical and radiological deterioration of spinal damage was noted. We interpreted this in the context of a paradoxical reaction, which is suggested to be an overshooting inflammatory response after reconstitution of the immune system. Despite increased dosage of corticosteroids, a gradual worsening of gait ataxia over several weeks was noted. After administration of infliximab, the patient's condition progressively improved.

Plasma Metabolomics Reveals Dysregulated Metabolic Signatures in HIV-Associated Immune Reconstitution Inflammatory Syndrome

Immune reconstitution inflammatory syndrome (IRIS) is an inflammatory complication associated with an underlying opportunistic infection that can be observed in HIV-infected individuals shortly after the initiation of antiretroviral therapy, despite successful suppression of HIV viral load and CD4⁺ T cell recovery. Better understanding of IRIS pathogenesis would allow for targeted prevention and therapeutic approaches. In this study, we sought to evaluate the metabolic perturbations in IRIS across longitudinal time points using an unbiased plasma metabolomics approach as well as integrated analyses to include plasma inflammatory biomarker profile and whole blood transcriptome. We found that many lipid and amino acid metabolites differentiated IRIS from non-IRIS conditions prior to antiretroviral therapy and during the IRIS event, implicating the association between oxidative stress, tryptophan pathway, and lipid mediated signaling and the development of IRIS. Lipid and amino acid metabolic pathways also significantly correlated with inflammatory biomarkers such as IL-12p70 and IL-8 at the IRIS event, indicating the role of cellular metabolism on cell type specific immune activation during the IRIS episode and in turn the impact of immune activation on cellular metabolism. In conclusion, we defined the metabolic profile of IRIS and revealed that perturbations in metabolism may predispose HIV-infected individuals to IRIS development and contribute to the inflammatory manifestations during the IRIS event. Furthermore, our findings expanded our current understanding IRIS pathogenesis and highlighted the significance of lipid and amino acid metabolism in inflammatory complications.

To Induce Immune Reconstitution Inflammatory Syndrome or Suppress It: The Spectrum of Mycobacterium genavense in the Antiretroviral Era

Mycobacterium  genavense is a challenging opportunistic pathogen to diagnose and manage in patients with human immunodeficiency virus (HIV). Persistent immunosuppression or protracted immune reconstitution inflammatory syndrome can lead to complicated clinical courses. We describe 3 cases of M. genavense in patients with HIV representing the spectrum between disease burden and strength of immune response.

Mycobacterial Infections Potentiated by Biologics

Biologic therapies have revolutionized the treatment of immune-mediated inflammatory diseases but are associated with an increased risk of serious and opportunistic infections, including tuberculosis and nontuberculous mycobacterial disease. Despite this increased risk, the overall risk-benefit ratio remains favorable with appropriate screening and risk assessment. Further population-based studies are needed to establish the risk of tuberculosis and nontuberculous mycobacterial disease with the new biologics. This article highlights the incidence and drug-specific risk of tuberculous and nontuberculous mycobacterial infection in the setting of biologics, screening and prevention, and treatment of latent tuberculosis in this setting.

Targeting immunometabolism in host defence against Mycobacterium tuberculosis

In the face of ineffective vaccines, increasing antibiotic resistance and the decline in new antibacterial drugs in the pipeline, tuberculosis (TB) still remains pandemic. Exposure to Mycobacterium tuberculosis (Mtb), which causes TB, results in either direct elimination of the pathogen, most likely by the innate immune system, or infection and containment that requires both innate and adaptive immunity to form the granuloma. Host defence strategies against infectious diseases are comprised of both host resistance, which is the ability of the host to prevent invasion or to eliminate the pathogen, and disease tolerance, which is defined by limiting the collateral tissue damage. In this review, we aim to examine the metabolic demands of the immune cells involved in both host resistance and disease tolerance, chiefly the macrophage and T-lymphocyte. We will further discuss how baseline metabolic heterogeneity and inflammation-driven metabolic reprogramming during infection are linked to their key immune functions containing mycobacterial growth and instructing protective immunity. Targeting key players in immune cellular metabolism may provide a novel opportunity for treatments at different stages of TB disease.

Systemic Inflammation Associated with Immune Reconstitution Inflammatory Syndrome in Persons Living with HIV

Antiretroviral therapy (ART) has represented a major advancement in the care of people living with HIV (PLWHH), resulting in significant reductions in morbidity and mortality through immune reconstitution and attenuation of homeostatic disruption. Importantly, restoration of immune function in PLWH with opportunistic infections occasionally leads to an intense and uncontrolled cytokine storm following ART initiation known as immune reconstitution inflammatory syndrome (IRIS). IRIS occurrence is associated with the severe and rapid clinical deterioration that results in significant morbidity and mortality. Here, we detail the determinants underlying IRIS development in PLWH, compiling the available knowledge in the field to highlight details of the inflammatory responses in IRIS associated with the most commonly reported opportunistic pathogens. This review also highlights gaps in the understanding of IRIS pathogenesis and summarizes therapeutic strategies that have been used for IRIS.

Use of Infliximab to Treat Paradoxical Tuberculous Meningitis Reactions

We documented dramatic responses to infliximab in 4 tuberculous meningitis cases with severe paradoxical reactions after effective antibacterial treatment, despite high-dose steroids. In every instance, infliximab was used as a last resort after all other options were exhausted, resulting in delayed initiation that may have adversely affected patient outcomes.

Tuberculosis and Biologic Therapies: Anti-Tumor Necrosis Factor-α and Beyond

Biologic drugs have revolutionized the treatment of certain hematologic, autoimmune, and malignant diseases, but they may place patients at risk for reactivation or acquisition of tuberculosis. This risk is highest with the tumor necrosis factor-alpha (TNF-α) inhibitors. Amongst this class of drugs, the monoclonal antibodies (infliximab, adalimumab, golimumab) and antibody fragment (certolizumab) carry an increased risk compared to the soluble receptor fusion molecule, etanercept. Treatment of latent TB is critical to decrease the risk of reactivation. Data continues to emerge regarding tuberculosis risk associated with novel biologics targeting cytokines involved in tuberculosis control.

Successful Treatment of a Severe Vision-Threatening Paradoxical Tuberculous Reaction with Infliximab: First Pediatric Use

A 7-year-old girl with tuberculous (TB) meningitis developed optochiasmatic arachnoiditis, a vision-threatening paradoxical reaction, after starting TB treatment including adjunctive steroid therapy. She was treated with infliximab with complete recovery. This is the first report of the use of a tissue necrosis factor α inhibitor for the treatment of a severe paradoxical TB reaction in a child.

Immune reconstruction inflammatory syndrome in HIV infection: beyond what meets the eye

A high proportion of individuals with HIV infection currently are diagnosed at an advanced stage of disease (late presenters), increasing their risk for immune reconstitution inflammatory syndrome (IRIS). IRIS typically occurs within 6 months of initiation of antiretroviral therapy (ART) in patients with low CD4+ cell counts and can occur before any marked elevation in CD4+ count is achieved on ART. In addition to low CD4+ count at ART initiation, 2 other major clinical predictors of IRIS are preexisting opportunistic infection (including subclinical infection) and shorter treatment period for opportunistic infection prior to starting ART. Mycobacterial infection-associated IRIS, including tuberculosis (TB)-associated IRIS, and cryptococcal infection-associated IRIS are the most common forms of the syndrome. Corticosteroid prophylaxis and early treatment can be effective in reducing incidence of TB-IRIS and severity of symptoms in select patients. Sterilization of the cerebrospinal fluid should be achieved prior to starting ART in patients with TB meningitis and cryptococcal meningitis. This article summarizes a presentation by Irini Sereti, MD, MHS, at the International Antiviral Society-USA (IAS-USA) continuing education program held in Washington, DC, in April 2019.

Neurotuberculosis: Control of Steroid-Refractory Paradoxical Inflammatory Reaction With Ruxolitinib

Paradoxical inflammatory reactions associated with treatment of neurotuberculosis can lead to severe morbidity and mortality and may not be controlled by steroids alone. We report the use of the Janus kinase inhibitor ruxolitinib to treat a steroid-refractory neurotuberculosis paradoxical reaction.

Two cases of immune reconstitution inflammatory syndrome in HIV patients treated with thalidomide

Immune reconstitution inflammatory syndrome (IRIS) is a clinical manifestation that accompanies paradoxical deterioration of symptoms in human immunodeficiency virus (HIV)-infected patients after commencement of antiretroviral treatment. This disease is caused by immune dysregulation, resulting in a cytokine storm and limited effector T-cell function. IRIS treatment involves supportive care and corticosteroid therapy to regulate the immune response. However, prolonged steroid therapy may increase the risk of opportunistic infections. Previous studies have highlighted the use of thalidomide to shorten the duration of steroid use. Herein, we report two cases of IRIS in HIV-infected patients whose symptoms were successfully controlled with thalidomide therapy. Both patients had opportunistic infections involving the central nervous system; one patient had cryptococcal meningitis and the other had progressive multifocal leukoencephalopathy.

The tuberculosis-associated immune reconstitution inflammatory syndrome: recent advances in clinical and pathogenesis research

Purpose of review

Antiretroviral therapy (ART) is an essential, life-saving intervention for HIV infection. However, ART initiation is frequently complicated by the tuberculosis-associated immune reconstitution inflammatory syndrome (TB-IRIS) in TB endemic settings. Here, we summarize the current understanding highlighting the recent evidence.

Recent findings

The incidence of paradoxical TB-IRIS is estimated at 18% (95% CI 16–21%), higher than previously reported and may be over 50% in high-risk groups. Early ART initiation in TB patients increases TB-IRIS risk by greater than two-fold, but is critical in TB patients with CD4 counts less than 50 cells/μl because it improves survival. There remains no validated diagnostic test for TB-IRIS, and biomarkers recently proposed are not routinely used. Prednisone initiated alongside ART in selected patients with CD4 less than 100 cells/μl reduced the risk of paradoxical TB-IRIS by 30% in a recent randomized-controlled trial (RCT) and was not associated with significant adverse effects. Effective also for treating paradoxical TB-IRIS, corticosteroids remain the only therapeutic intervention for TB-IRIS supported by RCT trial data. TB-IRIS pathogenesis studies implicate high antigen burden, innate immune cell cytotoxicity, inflammasome activation and dysregulated matrix metalloproteinases in the development of the condition.

Summary

Specific biomarkers would aid in identifying high-risk patients for interventions and a diagnostic test is needed. Clinicians should consider prednisone for TB-IRIS prevention in selected patients. Future research should focus on improving diagnosis and investigating novel therapeutic interventions, especially for patients in whom corticosteroid therapy is contraindicated.

Adjuvant immunosuppression for paradoxical deterioration in tuberculous meningitis including one case responsive to cyclosporine. A tertiary referral hospital experience

BACKGROUND

Tuberculous meningitis (TBM) accounts for 1-4% of all tuberculosis (TB) presentations. Paradoxical deterioration in non-HIV patients is a common manifestation of anti-tuberculosis therapy, characterised by clinico-radiological deterioration. We report a case series of TBM admissions to our institution including one case with paradoxical deterioration refractory to corticosteroids who responded to adjuvant cyclosporine.

METHODS

Retrospective review of 12 HIV-negative patients admitted to Liverpool Hospital, Sydney (2005-2016) with laboratory and/or radiologically confirmed TBM.

RESULTS

Median patient age was 40 (range 22-81 years), M:F = 7:5. Eleven patients (92%) were of Asia-Pacific origin. Eleven initially presented with central nervous system manifestations and one had preceding miliary TB. Nine patients had extra-cranial TB involvement including eight with past or current pulmonary disease. Cerebrospinal fluid (CSF) TB PCR/culture was positive in 10 patients. Paradoxical deterioration developed in three patients despite concomitant corticosteroids in two. One patient with paradoxical deterioration was refractory to corticosteroids: A 22-year-old Vietnamese male with TBM developed worsening headaches and altered mentation after seven weeks concomitant anti-TB and corticosteroid treatment. Interval MRI brain demonstrated increased size and number of tuberculomas as well as hydrocephalus. Cyclosporine was added with gradual improvement and ultimately good outcome.

CONCLUSION

Our case series highlights the seriousness of paradoxical deterioration in TBM and the potential role of adjuvant cyclosporine in patients refractory to corticosteroids.

Identification of rare HIV-1-infected patients with extreme CD4+ T cell decline despite ART-mediated viral suppression

BACKGROUND

The goal of antiretroviral therapy (ART) is to suppress HIV-1 replication and reconstitute CD4+ T cells. Here, we report on HIV-infected individuals who had a paradoxical decline in CD4+ T cells despite ART-mediated suppression of plasma HIV-1 load (pVL). We defined such an immunological outcome as extreme immune decline (EXID).

METHODS

EXID's clinical and immunological characteristics were compared to immunological responders (IRs), immunological nonresponders (INRs), healthy controls (HCs), and idiopathic CD4+ lymphopenia (ICL) patients. T cell immunophenotyping and assembly/activation of inflammasomes were evaluated by flow cytometry. PBMC transcriptome analysis and genetic screening for pathogenic variants were performed. Levels of cytokines/chemokines were measured by electrochemiluminescence. Luciferase immunoprecipitation system and NK-mediated antibody-dependent cellular cytotoxicity (ADCC) assays were used to identify anti-lymphocyte autoantibodies.

RESULTS

EXIDs were infected with non-B HIV-1 subtypes and after 192 weeks of consistent ART-mediated pVL suppression had a median CD4+ decrease of 157 cells/μl, compared with CD4+ increases of 193 cells/μl and 427 cells/μl in INR and IR, respectively. EXID had reduced naive CD4+ T cells, but similar proportions of cycling CD4+ T cells and HLA-DR+CD38+CD8+ T cells compared with IR and INR. Levels of inflammatory cytokines were also similar in EXID and INR, but the IL-7 axis was profoundly perturbed compared with HC, IR, INR, and ICL. Genes involved in T cell and monocyte/macrophage function, autophagy, and cell migration were differentially expressed in EXID. Two of the 5 EXIDs had autoantibodies causing ADCC, while 2 different EXIDs had an increased inflammasome/caspase-1 activation despite consistently ART-suppressed pVL.

CONCLUSIONS

EXID is a distinct immunological outcome compared with previously described INR. Anti-CD4+ T cell autoantibodies and aberrant inflammasome/caspase-1 activation despite suppressed HIV-1 viremia are among the mechanisms responsible for EXID.

Current Medical Management of Pulmonary Tuberculosis

Tuberculosis (TB) remains a common cause of infection and disease in much of the world. The majority of disease occurs from reactivation months or years after initial infection and most often involves the lungs. Sputum smears for acid-fast bacilli remain the initial diagnostic test but have limited sensitivity and specificity. Nucleic acid amplification tests are more sensitive and specific and can detect some mutations that cause drug resistance. Treatment of TB resistant to rifamycins alone or in combination with isoniazid and other drugs remains difficult and should be done in consultation with an expert in treating drug-resistant disease.

Immune reconstitution inflammatory syndrome associated with disseminated histoplasmosis and TNF-alpha inhibition

Endemic fungal infections are a significant problem for patients on TNF-alpha inhibitors. Immune reconstitution inflammatory syndrome, IRIS, can present in patients with waning TNF-alpha inhibition and an endemic fungal infection. There may be a potential role that TNF-alpha inhibitors can play in mitigating IRIS related to disseminated endemic fungal infections.

Understanding Pathogenesis and Care Challenges of Immune Reconstitution Inflammatory Syndrome in Fungal Infections

Immune deficiency of diverse etiology, including human immunodeficiency virus (HIV), antineoplastic agents, immunosuppressive agents used in solid organ recipients, immunomodulatory therapy, and other biologics, all promote invasive fungal infections. Subsequent voluntary or unintended immune recovery may induce an exaggerated inflammatory response defining immune reconstitution inflammatory syndrome (IRIS), which causes significant mortality and morbidity. Fungal-associated IRIS raises several diagnostic and management issues. Mostly studied with Cryptococcus, it has also been described with other major fungi implicated in human invasive fungal infections, such as Pneumocystis, Aspergillus, Candida, and Histoplasma. Furthermore, the understanding of IRIS pathogenesis remains in its infancy. This review summarizes current knowledge regarding the clinical characteristics of IRIS depending on fungal species and existing strategies to predict, prevent, and treat IRIS in this patient population, and tries to propose a common immunological background to fungal IRIS.

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.

Adalimumab for Corticosteroid and Infliximab-Resistant Immune Reconstitution Inflammatory Syndrome in the Setting of TB/HIV Coinfection

Corticosteroids are the mainstay of therapy for immune reconstitution inflammatory syndrome (IRIS). However, little is known about how to treat IRIS unresponsive to steroids. We report a patient with HIV-TB coinfection who was unresponsive to first prednisolone and then infliximab but whose IRIS resolved with adalimumab.

Infliximab Biosimilars: A Promising but Unusual Treatment for Mycobacterial Immune Reconstitution Inflammatory Syndrome in Human Immunodeficiency Virus-Infected Patients

Immune reconstitution inflammatory syndrome can present as a paradoxical reaction after initiation of antiretroviral treatment in patients with severe immunosuppression and underlying infections. Immune reconstitution inflammatory syndrome has often been associated with mycobacteria, and the clinical response to traditional treatment with corticosteroids is not always satisfactory. Consequently, administration of an infliximab biosimilar could lead to an improvement in the clinical status of these patients.

Immunosenescence and hurdles in the clinical management of older HIV-patients

People living with HIV (PLWH) who are treated with effective highly active antiretroviral therapy (HAART) have a similar life expectancy to the general population. Moreover, an increasing proportion of new HIV diagnoses are made in people older than 50 y. The number of older HIV-infected patients is thus constantly growing and it is expected that by 2030 around 70% of PLWH will be more than 50 y old. On the other hand, HIV infection itself is responsible for accelerated immunosenescence, a progressive decline of immune system function in both the adaptive and the innate arm, which impairs the ability of an individual to respond to infections and to give rise to long-term immunity; furthermore, older patients tend to have a worse immunological response to HAART. In this review we focus on the pathogenesis of HIV-induced immunosenescence and on the clinical management of older HIV-infected patients.

Immune reconstitution inflammatory syndrome in HIV infection: taking the bad with the good

In this review, we will describe the immunopathogies of immune reconstitution inflammatory syndrome, IRIS. IRIS occurs in a small subset of HIV patient, initiating combination antiretroviral therapy (ART), where immune reconstitution becomes dysregulated, resulting in an overly robust antigen-specific inflammatory reaction. We will discuss IRIS in terms of the associated coinfections: mycobacteria, cryptococci, and viruses.

HIV infection and immune activation: the role of coinfections

PURPOSE OF REVIEW

This article explores new data from recent studies addressing the role of coinfections in immune activation in HIV-1-infected patients, with a focus on immune reconstitution inflammatory syndrome (IRIS), an aberrant inflammatory response occurring shortly after antiretroviral therapy (ART) initiation.

RECENT FINDINGS

Chronic HIV infection is associated with several coinfections that contribute to immune activation in various settings including early after ART initiation in the most noticeable form of IRIS and also in chronic-treated infection, with chronic viral infections like cytomegalovirus and hepatitis C or hepatitis B virus contributing to immune activation and also morbidity and mortality. Expanding on older studies, the role of T cells in IRIS has been further elucidated with evidence of more pronounced effector activity in patients with IRIS that may be leading to excessive tissue disorder. Newer studies are also continuing to shed light on the role of myeloid cells as well as the contribution of antigen load in IRIS. In addition, preliminary data are beginning to suggest a possible role of inflammasome formation in IRIS. In cryptococcal IRIS, the role of activated immune cells (T cell and myeloid) and biomarkers were evaluated in more detail at the site of infection (cerebrospinal fluid). Finally, important differences of patients developing IRIS versus those who die from tuberculosis despite ART initiation were reported, a distinction that may have important implications for participant selection in studies aiming to prevent IRIS with immunosuppressive agents.

SUMMARY

Better understanding of the role of opportunistic infections at ART initiation and IRIS pathogenesis will assist in improved strategies for prevention and treatment. The long-term consequences of IRIS remain unclear. Chronic viral coinfections with herpesviruses and hepatitis C virus are important factors in persistent immune activation in chronic-treated HIV.

Mycobacterium kansasii Infection in a Patient Receiving Biologic Therapy-Not All Reactive Interferon Gamma Release Assays Are Tuberculosis

Mycobacterium kansasii, a nontuberculous mycobacterium, can lead to lung disease similar to tuberculosis. Immunotherapeutic biologic agents predispose to infections with mycobacteria, including M kansasii. T-cell-mediated interferon gamma release assays like QuantiFERON-TB Gold Test (QFT) are widely used by clinicians for the diagnosis of infections with Mycobacterium tuberculosis; however, QFT may also show positive result with certain nontuberculous mycobacterial infections. We report a case of M kansasii pulmonary infection, with a positive QFT, in an immunocompromised patient receiving prednisone, leflunomide and tocilizumab, a humanized anti-interleukin-6 receptor monoclonal antibody. This case highlights the risk of mycobacterial infections with the use of various biologic agents and the need for caution when interpreting the results of interferon gamma release assays.

Robust Reconstitution of Tuberculosis-Specific Polyfunctional CD4+ T-Cell Responses and Rising Systemic Interleukin 6 in Paradoxical Tuberculosis-Associated Immune Reconstitution Inflammatory Syndrome

BACKGROUND

The immunopathogenesis of paradoxical tuberculosis-associated immune reconstitution inflammatory syndrome (TB-IRIS) remains unclear. We determined the association between pathogen-specific T-cell responses and development of paradoxical TB-IRIS on antiretroviral therapy (ART).

METHODS

This study was nested within a prospective cohort study of HIV-infected patients with active pulmonary tuberculosis and baseline CD4 counts ≤125 cells/µL initiating ART. T-cell immune activation (CD38, HLA-DR, and PD-1 expression), phenotype, and polyfunctional pathogen-specific cellular immune responses prior to and 4 weeks after ART initiation were determined by flow cytometry. Patients with TB-IRIS were compared to non-IRIS controls using χ(2) and rank-sum tests and logistic regression.

RESULTS

TB-IRIS patients and controls had similar CD4 counts, levels of T-cell-associated immune activation, frequencies of T-cell memory subsets, and frequencies of interferon gamma (IFN-γ(+))/interleukin 2 (IL-2(+))/tumor necrosis factor alpha (TNF-α(+)) CD4(+) T-cells prior to ART initiation. After ART initiation, cellular immune activation and T-cell subsets also were similar in TB-IRIS patients and controls. In contrast, TB-IRIS patients had significantly greater early increases in the frequency of tuberculosis-specific polyfunctional IFN-γ(+)/IL-2(+)/TNF-α(+) CD4(+) T-cells on ART (P = .02); each quartile increase in the percentage of these cells was independently associated with a 2.8-fold increased risk of TB-IRIS (95% confidence interval, 1.1 to 7.5-fold). In a secondary analysis, patients with TB-IRIS had rapid, concomitant increases in tuberculosis-specific adaptive immune responses and interleukin 6 (IL-6) levels, whereas controls with similarly rapid increases in cellular immune function had IL-6 levels that tended to decrease on ART.

CONCLUSIONS

Rapid expansion of tuberculosis-specific polyfunctional CD4(+) T-cell responses, likely linked to increases in IL-6, is associated with development of paradoxical TB-IRIS.