Pulmonary manifestations of the immune reconstitution inflammatory syndrome

A Case of Steroid-Responsive, COVID-19 Immune Reconstitution Inflammatory Syndrome Following the Use of Granulocyte Colony-Stimulating Factor

We present a case report of a 54-year-old male with metastasized nasopharyngeal carcinoma presenting to the hospital with dyspnea, anorexia and fever. Examination revealed chemotherapy-induced pancytopenia. The patient tested positive for SARSCoV-2, but respiratory complications were mild. The patient was treated with granulocyte-colony stimulating factor (G-CSF) leading to amelioration of the neutropenia. However, severe acute respiratory distress syndrome (ARDS) occurred, prompting the diagnosis of immune reconstitution inflammatory syndrome (IRIS). GCSF is currently investigated as additional therapy in ARDS, but this case report emphasizes that risks and benefits must be carefully assessed. To our knowledge, this is the first case report of IRIS-induced ARDS in a COVID-19 patient.

Pulmonary cryptococcal immune reconstitution syndrome in a person living with HIV: a case report

Cryptococcal immune reconstitution inflammatory syndrome (C-IRIS) in human immunodeficiency virus (HIV)-1 infection manifests as a clinical worsening or new presentation of cryptococcal disease after initiating antiretroviral therapy (ART). C-IRIS involving the respiratory system has been scarcely reported. Here, we report a case of pulmonary C-IRIS in a person living with HIV after initiating ART, characterized by an exacerbation of a pulmonary nodule and new occurrence of pleural effusions, which responded well to corticosteroid treatment.

Clinical Aspects of Immune Damage in Cryptococcosis

Purpose of review

To perform an extensive review of recent literature and provide an update on the current epidemiology, clinical features and management of cryptococcal disease with a focus on the differences between patients depending on their immune status.

Recent findings

Emerging literature has highlighted the inflammatory pathophysiology and varied manifestations of cryptococcal infections in patients who are apparently healthy but paradoxically have a more critical clinical course compared to their immunosuppressed counterparts.

Summary

Non-HIV cryptococcal meningitis has greater mortality compared to that seen in HIV patients. Basic science experiments closely analyzing the underlying pathophysiological response to this infection have demonstrated the predominant role of T cell-mediated inflammatory injury in causing worse clinical outcomes. Further studies are needed to define the need for immunosuppressive agents in the treatment of this illness.

HIV Suppression Restores the Lung Mucosal CD4+ T-Cell Viral Immune Response and Resolves CD8+ T-Cell Alveolitis in Patients at Risk for HIV-Associated Chronic Obstructive Pulmonary Disease

BACKGROUND

Lung CD4⁺ T-cell depletion and dysfunction, CD8⁺ T-cell alveolitis, smoking, and poor control of human immunodeficiency virus (HIV) are features of HIV-associated chronic obstructive pulmonary disease (COPD), but these changes have not been evaluated in smokers at risk for COPD. We evaluated the impact of viral suppression following initiation of antiretroviral therapy (ART) on HIV-specific immunity and the balance of the CD4⁺ T-cell to CD8⁺ T-cell ratio in the lung.

METHODS

Using flow cytometry, we assessed the T-cell immune response in lung and blood specimens obtained from 12 actively smoking HIV-positive patients before ART initiation and after ART-associated viral suppression.

RESULTS

HIV suppression resulted in enhanced lung and systemic HIV-specific CD4⁺ T-cell immune responses without significant changes in CD8⁺ T-cell responses. We observed an increase in lung ratios of CD4⁺ T cells to CD8⁺ T cells and CD4⁺ T-cell frequencies, decreased CD8⁺ T-cell numbers, and resolution of CD8⁺ T-cell alveolitis after ART in 9 of 12 individuals. Viral suppression reduced Fas receptor and programmed death 1 expression in lung CD4⁺ T cells, correlating with enhanced effector function and reduced susceptibility to apoptosis. HIV suppression rescued peripheral but not lung HIV-specific CD4⁺ T-cell proliferation, resulting in augmented effector multifunction.

DISCUSSION

Together, our results demonstrate that HIV suppression restores lung mucosal HIV-specific CD4⁺ T-cell multifunctional immunity and balance in the ratio of CD4⁺ T cells to CD8⁺ T cells, often resolving CD8⁺ T-cell alveolitis in active smokers. Peripheral expansion and redistribution of CD4⁺ T cells and increased resistance to apoptosis are 2 mechanisms contributing to immunologic improvement following viral suppression in patients at risk for HIV-associated COPD.

Thoracic diseases associated with HIV infection in the era of antiretroviral therapy: clinical and imaging findings

The human immunodeficiency virus (HIV) and acquired immunodeficiency syndrome (AIDS) pandemic has entered its 4th decade. Since the introduction of combination antiretroviral therapy (ART) in 1996, the number of AIDS-related deaths has plateaued worldwide. Today, owing to the effectiveness of ART, the HIV-infected population is aging and HIV infection has become a chronic illness. Non-AIDS comorbidities are increasing, and the spectrum of HIV-related thoracic diseases is evolving. In developed countries, bacterial pneumonia has become more common than Pneumocystis pneumonia. Its imaging appearance depends on the responsible organism, most commonly Streptococcus pneumoniae. Mycobacterium tuberculosis continues to be a major threat. Its imaging patterns vary depending on CD4 count. Primary lung cancer and Hodgkin lymphoma are two important non-AIDS-defining malignancies that are increasingly encountered at chest imaging. Human herpesvirus 8, also known as Kaposi sarcoma-associated herpesvirus (KSHV), is strongly linked to HIV-related diseases, including Kaposi sarcoma, multicentric Castleman disease, KSHV inflammatory cytokine syndrome, and primary effusion lymphoma. Immune reconstitution inflammatory syndrome is a direct complication of ART whose manifestations vary with the underlying disease. Given the high rate of smoking among HIV-infected patients, chronic obstructive pulmonary disease is another important cause of morbidity and mortality. A high degree of suspicion is required for the early diagnosis of pulmonary arterial hypertension and lymphocytic interstitial pneumonia, given their nonspecific manifestations. Finally, multilocular thymic cyst manifests as a cystic anterior mediastinal mass. Recognition of the clinical and radiologic manifestations of these less traditional HIV-related diseases can expedite diagnosis and treatment in the ART era.

Immune reconstitution inflammatory syndrome in HIV-infected patients

Access to antiretroviral therapy (ART) is improving worldwide. Immune reconstitution inflammatory syndrome (IRIS) is a common complication of ART initiation. In this review, we provide an overview of clinical and epidemiological features of HIV-associated IRIS, current understanding of pathophysiological mechanisms, available therapy, and preventive strategies. The spectrum of HIV-associated IRIS is described, with a particular focus on three important pathogen-associated forms: tuberculosis-associated IRIS, cryptococcal IRIS, and Kaposi's sarcoma IRIS. While the clinical features and epidemiology are well described, there are major gaps in our understanding of pathophysiology and as a result therapeutic and preventative strategies are suboptimal. Timing of ART initiation is critical to reduce IRIS-associated morbidity. Improved understanding of the pathophysiology of IRIS will hopefully enable improved diagnostic modalities and better targeted treatments to be developed.

Lung function abnormalities in HIV-infected adults and children

Despite the advent of antiretroviral therapy (ART), the human immunodeficiency virus (HIV) epidemic remains a global health crisis with a high burden of respiratory disease among infected persons. While the early complications of the epidemic were dominated by opportunistic infections, improved survival has led to the emergence of non-infectious conditions that are associated with chronic respiratory symptoms and pulmonary disability. Obstructive ventilatory defects and reduced diffusing capacity are common findings in adults, and the association between HIV and chronic obstructive pulmonary disease is increasingly recognized. There is synergism between viral factors, opportunistic infections, conventional influences like tobacco smoke and biomass fuel exposure, and potentially, the immunological effects of ART on the development of HIV-associated chronic obstructive lung disease. Pulmonary function data for HIV-infected infants and children are scarce, but shows that bronchiectasis and obliterative bronchiolitis with severe airflow limitation are major problems, particularly in the developing world. However, studies from these regions are sorely lacking. There is thus a major unmet need to understand the influences of chronic HIV infection on the lung in both adults and children, and to devise strategies to manage and prevent these diseases in HIV-infected individuals. It is important for clinicians working with HIV-infected individuals to have an appreciation of their effects on measurements of lung function. This review therefore summarizes the lung function abnormalities described in HIV-positive adults and children, with an emphasis on obstructive lung disease, and examines potential pathogenic links between HIV and the development of chronic pulmonary disability.

The complexity of HIV persistence and pathogenesis in the lung under antiretroviral therapy: challenges beyond AIDS

Antiretroviral therapy (ART) represents a significant milestone in the battle against AIDS. However, we continue learning about HIV and confronting challenges 30 years after its discovery. HIV has cleverly tricked both the host immune system and ART. First, the many HIV subtypes and recombinant forms have different susceptibilities to antiretroviral drugs, which may represent an issue in countries where ART is just being introduced. Second, even under the suppressive pressures of ART, HIV still increases inflammatory mediators, deregulates apoptosis and proliferation, and induces oxidative stress in the host. Third, the preference of HIV for CXCR4 as a co-receptor may also have noxious outcomes, including potential malignancies. Furthermore, HIV still replicates cryptically in anatomical reservoirs, including the lung. HIV impairs bronchoalveolar T-lymphocyte and macrophage immune responses, rendering the lung susceptible to comorbidities. In addition, HIV-infected individuals are significantly more susceptible to long-term HIV-associated complications. This review focuses on chronic obstructive pulmonary disease (COPD), pulmonary arterial hypertension, and lung cancer. Almost two decades after the advent of highly active ART, we now know that HIV-infected individuals on ART live as long as the uninfected population. Fortunately, its availability is rapidly increasing in low- and middle-income countries. Nevertheless, ART is not risk-free: the developed world is facing issues with antiretroviral drug toxicity, resistance, and drug-drug interactions, while developing countries are confronting issues with immune reconstitution inflammatory syndrome. Several aspects of the complexity of HIV persistence and challenges with ART are discussed, as well as suggestions for new avenues of research.

Tuberculosis Immune Reconstitution Inflammatory Syndrome in children initiating Antiretroviral Therapy for HIV infection: A systematic literature review

BACKGROUND

People with HIV initiating combination antiretroviral therapy are at risk for tuberculosis-associated immune reconstitution inflammatory syndrome (TB-IRIS). While this syndrome has been well researched in adults, little is known about the incidence, case fatality, underlying immunopathology and treatment approaches in children.

METHODS

Major databases were searched for articles related to TB-IRIS in children. Data were abstracted using standardized forms.

RESULTS

Thirteen studies were identified: 6 retrospective and 2 prospective cohort studies, 1 cross-sectional study, 3 case reports and 1 case series. In total, 303 cases of TB-IRIS were described, of which 270 were unmasking TB-IRIS, 12 paradoxical TB-IRIS and 21 were not classifiable due to lack of key information. None of the cohort studies had investigation of TB-IRIS as its primary aim. Nine studies were from Africa, 3 from Asia and 1 from Latin America. Age at cART initiation (reported by 12 studies) ranged from 1 month to 16 years. Median time from start of cART to IRIS diagnosis (reported by 8 studies) ranged from 8 days to 16 weeks. Few deaths attributable to TB-IRIS were recorded. Treatment was only discussed in 2 case studies, both of which reported children receiving corticosteroids. No studies evaluated risk factors for, or immunopathogenesis of, pediatric TB-IRIS.

CONCLUSIONS

There is a paucity of information available on TB-IRIS in children. Future research assessing incidence, risk factors, case fatality and optimal treatment or prevention strategies of TB-IRIS is needed.

Cryptococcal immune reconstitution inflammatory syndrome

PURPOSE OF REVIEW

The epidemiology and pathogenesis of, and risk factors for, cryptococcal immune reconstitution inflammatory syndrome (CM-IRIS) are reviewed with an emphasis on how new insights inform a rational management approach and prevention strategies.

RECENT FINDINGS

Risk factors for paradoxical CM-IRIS are a low inflammatory response and CD4 cell count at baseline, rapid immune restoration from this low baseline, and a high organism or antigen load at baseline and at antiretroviral therapy (ART) initiation. Detailed immune mechanisms are still unclear. Rapidly fungicidal induction therapy, allowing prompt initiation of ART (from around 3 weeks in resource-limited settings in the context of amphotericin B induction) at a time when organism and antigen loads are low, may reduce overall mortality without exacerbating paradoxical CM-IRIS, compared with initiation of ART at later time points. Recent cohorts suggest early recognition and management can reduce the mortality associated with paradoxical CM-IRIS. Unmasking CM-IRIS is preventable through screening for cryptococcal antigen prior to ART and preemptive antifungal treatment for those testing positive, although prospective studies are needed.

SUMMARY

Optimal antifungal induction and judicious ART timing, together with early recognition and management of developing cases, with thorough exclusion of alternative diagnoses, should help reduce paradoxical CM-IRIS-related mortality. Unmasking CM-IRIS cases should be preventable.

Evaluation of respiratory disease

The spectrum of HIV-associated pulmonary diseases is broad. Opportunistic infections, neoplasms, and noninfectious complications are all major considerations. Clinicians caring for persons infected with HIV must have a systematic approach. The approach begins with a thorough history and physical examination and often involves selected laboratory tests and a chest radiograph. Frequently, the clinical, laboratory, and chest radiographic presentation suggests a specific diagnosis or a few diagnoses, which then prompts specific diagnostic testing and treatment. This article presents an overview of the evaluation of respiratory disease in persons with HIV/AIDS.

The immune reconstitution inflammatory syndrome after antiretroviral therapy initiation in patients with tuberculosis: findings from the SAPiT trial

BACKGROUND

Concerns about the immune reconstitution inflammatory syndrome (IRIS) remain a barrier to antiretroviral therapy (ART) initiation during antituberculosis treatment in co-infected patients.

OBJECTIVE

To assess IRIS incidence, severity, and outcomes relative to the timing of ART initiation in patients with HIV-related tuberculosis.

DESIGN

Randomized, open-label clinical trial. (ClinicalTrials.gov registration number: NCT00398996)

SETTING

An outpatient clinic in Durban, South Africa.

PATIENTS

642 patients co-infected with HIV and tuberculosis.

MEASUREMENTS

In a secondary analysis of the SAPiT (Starting Antiretroviral Therapy at Three Points in Tuberculosis) trial, IRIS was assessed in patients randomly assigned to initiate ART within 4 weeks of tuberculosis treatment initiation (early integrated treatment group), within 4 weeks of completion of the intensive phase of tuberculosis treatment (late integrated treatment group), or within 4 weeks after tuberculosis therapy completion (sequential treatment group). The syndrome was defined as new-onset or worsening symptoms, signs, or radiographic manifestations temporally related to treatment initiation, accompanied by a treatment response. Severity of IRIS, hospitalization, and time to resolution were monitored.

RESULTS

Incidence of IRIS was 19.5 (n = 43), 7.5 (n = 18), and 8.1 (n = 19) per 100 person-years in the early integrated, late integrated, and sequential treatment groups, respectively. Among patients with a baseline CD4+ count less than 0.050 × 109 cells/L, IRIS incidence was 45.5, 9.7, and 19.7 per 100 person-years in the early integrated, late integrated, and sequential treatment groups, respectively. Incidence of IRIS was higher in the early integrated treatment group than in the late integrated (incidence rate ratio, 2.6 [95% CI, 1.5 to 4.8]; P < 0.001) or sequential (incidence rate ratio, 2.4 [CI, 1.4 to 4.4]; P < 0.001) treatment groups. More severe IRIS cases occurred in the early integrated treatment group than in the other 2 groups (35% vs. 19%; P = 0.179), and patients in the early integrated treatment group had significantly higher hospitalization rates (42% vs. 14%; P = 0.007) and longer time to resolution (70.5 vs. 29.0 days; P = 0.001) than patients in the other 2 groups.

LIMITATIONS

It was not possible to assess IRIS in more patients in the sequential treatment group (n = 74) than in the late integrated (n = 50) and early integrated (n = 32) treatment groups because of loss to follow-up, withdrawal, or death within 6 months of scheduled ART initiation. This study did not assess IRIS risk in nonambulatory patients or in those with extrapulmonary and smear-negative tuberculosis.

CONCLUSION

Initiation of ART in early stages of tuberculosis treatment resulted in significantly higher IRIS rates, longer time to resolution, and more severe cases of IRIS requiring hospitalization. These findings are particularly relevant to patients initiating ART with a CD4+ count less than 0.050 × 109 cells/L, given the increased survival benefit of early ART initiation in this group.

PRIMARY FUNDING SOURCE

Comprehensive International Program of Research on AIDS.

Paradoxical Immune Reconstitution Syndrome Presenting as Acute Respiratory Distress Syndrome in a Leukemia Patient during Neutrophil Recovery

Immune reconstitution inflammatory syndrome (IRIS) in the setting of antiretroviral therapy is well described, but it is not as common in non-HIV patients; here, we present a case of immune reconstitution inflammatory syndrome presenting as acute respiratory distress syndrome in a leukemia patient who had neutropenic fever and septic shock after high-dose cytarabine. During neutropenia recovery, his chest X-ray showed progressive worsening despite being on adequate therapy, we started him on steroids which resulted in significant clinical improvement.

Dynamics of adrenal steroids are related to variations in Th1 and Treg populations during Mycobacterium tuberculosis infection in HIV positive persons

Tuberculosis (TB) remains the most frequent cause of illness and death from an infectious agent, and its interaction with HIV has devastating effects. We determined plasma levels of dehydroepiandrosterone (DHEA), its circulating form DHEA-suphate (DHEA-s) and cortisol in different stages of M. tuberculosis infection, and explored their role on the Th1 and Treg populations during different scenarios of HIV-TB coinfection, including the immune reconstitution inflammatory syndrome (IRIS), a condition related to antiretroviral treatment. DHEA levels were diminished in HIV-TB and HIV-TB IRIS patients compared to healthy donors (HD), HIV+ individuals and HIV+ individuals with latent TB (HIV-LTB), whereas dehydroepiandrosterone sulfate (DHEA-s) levels were markedly diminished in HIV-TB IRIS individuals. HIV-TB and IRIS patients presented a cortisol/DHEA ratio significantly higher than HIV+, HIV-LTB and HD individuals. A positive correlation was observed between DHEA-s and CD4 count among HIV-TB individuals. Conversely, cortisol plasma level inversely correlated with CD4 count within HIV-TB individuals. M. tuberculosis-specific Th1 lymphocyte count was increased after culturing PBMC from HIV-TB individuals in presence of DHEA. We observed an inverse correlation between DHEA-s plasma level and Treg frequency in co-infected individuals, and CD4+FoxP3+ Treg frequency was increased in HIV-TB and IRIS patients compared to other groups. Strikingly, we observed a prominent CD4+CD25-FoxP3+ population across HIV-TB and HIV-TB IRIS patients, which frequency correlated with DHEA plasma level. Finally, DHEA treatment negatively regulated FoxP3 expression without altering Treg frequency in co-infected patients. These data suggest an enhancing role for DHEA in the immune response against M. tuberculosis during HIV-TB coinfection and IRIS.