Immunopathogenesis of immune reconstitution disease in HIV patients responding to antiretroviral therapy

Non-infectious Uveitis as a Manifestation of the Immune Reconstitution Inflammatory Syndrome in Patients Infected by HIV

OBJECTIVE

To describe a retrospective review of HIV patients with noninfectious uveitis. Data collected included: demographics, anatomic classification and phenotypic diagnosis of the uveitis, systemic immune-mediated disorders (IMD), time from HIV diagnosis to uveitis, CD4 count, viral load, treatment and complications of treatment and time of follow-up.

RESULTS

Twenty patients (18 males) were included. The time lag between HIV diagnosis and the onset of uveitis was 9 ± 8.5 years. Mean CD4 count was 670 ± 294 cells/ml. Viral load was undetectable in 14 out of 18 cases. In 6 patients IMD was diagnosed prior to or concurring with the uveitis diagnosis. The use of immunosuppressive therapies was necessary in 6 patients (including biologics in 4 cases). The mean follow-up was 42.2 months.

CONCLUSIONS

noninfectious uveitis could be the first manifestation of IMD in patients with well-controlled HIV infection. Immunosuppression appeared to be a safe therapeutic option in our cohort of patients.

Clinical manifestations and risk factors for oral immune reconstitution inflammatory syndrome in Mexico

The immune reconstitution inflammatory syndrome (IRIS) is a rare acute complication presenting in people living with HIV (PLWH) within the first 6 months of starting combined antiretroviral therapy (cART). While there is relevant information about its pathogenesis and clinical spectrum, IRIS-oral lesions (IRIS-OLs) have been scarcely described. Thus, to establish the incidence and clinical characteristics of IRIS-OLs, data from a cohort of 158 HIV individuals starting cART, followed for 6 months, were obtained retrospectively. IRIS-OLs developed in 11.4% of the individuals, in a median time of 87.5 days, with oral candidiasis being the most frequent manifestation detected in eight individuals (5.1%). The study emphasizes the importance of the correct diagnosis and management of these lesions.

A surgical case of cerebellar tuberculoma caused by a paradoxical reaction while on therapy for tuberculosis spondylitis

Background:

A paradoxical reaction (PR) is a phenomenon in which the primary tuberculous lesion worsens or another de novo tuberculous lesion appears while on anti-tuberculosis therapy. Here, we report a rare case of cerebellar tuberculoma caused by a PR during therapy for lumbar tuberculous spondylitis (Pott’s disease).

Case Description:

A 47-year-old male with human immunodeficiency virus seronegative was diagnosed with lumber tuberculous spondylitis (Pott’s disease) and prescribed anti-tuberculous agents. His lower back pain and inflammatory condition recovered after initiation of anti-tuberculous therapy. Two months later, he complained of headache, nausea, and staggering. Magnetic resonance images revealed a ring-enhanced lesion located at the cerebellar hemisphere extending to the vermis, which caused perifocal edema and bilateral ventriculomegaly. These findings were consistent with his symptoms of hydrocephalus. He did not have preceding clinical findings of meningitis, and a PR was suggested to cause de novo aggregation of cerebellar tuberculoma. A lesionectomy was performed, and the surgical specimen was pathologically diagnosed as a tuberculoma. He recovered well from neurological disorders after the resection.

Conclusion:

De novo formation of intracranial tuberculoma alone caused by a PR without preceding meningitis is very rare. Lesionectomy is needed for intracranial tuberculoma, which manifests as a mass effect, as well as antituberculous therapy.

Immune Reconstitution Disorders: Spotlight on Interferons

Three decades of research in hematopoietic stem cell transplantation and HIV/AIDS fields have shaped a picture of immune restoration disorders. This manuscript overviews the molecular biology of interferon networks, the molecular pathogenesis of immune reconstitution inflammatory syndrome, and post-hematopoietic stem cell transplantation immune restoration disorders (IRD). It also summarizes the effects of thymic involution on T cell diversity, and the results of the assessment of diagnostic biomarkers of IRD, and tested targeted immunomodulatory treatments.

Does oxidative stress contribute to adverse outcomes in HIV-associated TB?

In HIV infection, oxidative stress is a pronounced phenomenon, with likely links to HIV-related pathologies and the progression of HIV infection per se. TB is an AIDS-defining condition. HIV-associated oxidative stress, like that associated with diabetes mellitus, might adversely impact the outcomes of TB, probably through increased propensity for generation of metabolically dormant mycobacterial persisters, alongside other mechanisms. This hypothesis might help in guiding the exploration of relevant research directions to improve the care of patients.

Hospital days attributable to immune reconstitution inflammatory syndrome in persons living with HIV before and after the 2012 DHHS HIV guidelines

Background

Immune reconstitution inflammatory syndrome (IRIS) can manifest with initiation or reintroduction of antiretroviral therapy (ART) in persons living with HIV (PLWH). In 2012, updated United States treatment guidelines recommended initiation of ART for all PLWH regardless of CD4 count. The objectives of this study were to quantify hospital usage attributable to IRIS and assess the reasons for hospitalization in PLWH before and after the guideline update.

Methods

Subjects were PLWH between 18–89 years of age who were hospitalized between November 1, 2009 and July 31, 2014. Equivalent time periods before and after updated treatment guidelines were considered, and designated as Time Period 1 and Time Period 2, respectively. IRIS-attributable hospitalizations were identified by ICD9 codes and electronic medical record searches with subsequent review and confirmation. For hospitalizations that were not confirmed as being IRIS-attributable, primary discharge diagnoses were reviewed.

Results

A total of 278 PLWH were hospitalized 521 times throughout the study period. Time Period 1 had 9 PLWH with 12 IRIS-attributable hospitalizations while Time Period 2 had 6 PLWH with 9 IRIS-attributable hospitalizations. A larger proportion of IRIS-attributable hospital days was observed in Time Period 1 compared to Time Period 2 (7.5 vs 4.2%; p < 0.001). Median length of stay for IRIS-attributable hospitalizations was longer than for other diagnoses, particularly during Time Period 1 (12.0 vs 4.0; p = 0.05). The most common causes for hospitalizations in PLWH were non AIDS-defining infection, AIDS-defining malignancy, and gastrointestinal. PLWH who had HIV viral suppression (<200 copies/mL) accounted for 34 and 24% of hospitalizations in Time Periods 1 and 2 respectively.

Conclusions

Hospitalizations for PLWH continue at high rates and IRIS is a significant contributing factor. In our single-center study, there was a lower number of IRIS-attributable hospitalizations and IRIS-attributable hospital days in Time Period 2 compared with Time Period 1. The hospital burden of IRIS may decrease over time as more PLWH are started on ART earlier in the course of infection. This study highlights the continued importance of early diagnosis and linkage to care of those infected with HIV, so that morbidity and costs associated with IRIS continue to decline.

The Epidemiology of IRIS in Southern India: An Observational Cohort Study

Immune reconstitution inflammatory syndrome (IRIS) is an uncommon but dynamic phenomenon seen among patients initiating antiretroviral therapy (ART). We aimed to describe incidence, risk factors, clinical spectrum, and outcomes among ART-naive patients experiencing IRIS in southern India. Among 599 eligible patients monitored prospectively between 2012 and 2014, there were 59.3% males, with mean age 36.6 ± 7.8 years. Immune reconstitution inflammatory syndrome incidence rate was 51.3 per 100 person-years (95% confidence interval: 44.5-59.2). One-third (31.4%) experienced at least 1 IRIS event, at a median of 27 days since ART initiation. Mucocutaneous infections and candidiasis were common IRIS events, followed by tuberculosis. Significant risk factors included age >40 years, body mass index <18.5 kg/m², CD4 count <100 cells/mm³, viral load >10 000 copies/mL, hemoglobin <11 g/dL, and erythrocyte sedimentation rate >50 mm/h. Immune reconstitution inflammatory syndrome-related morality was 1.3% (8 of 599); 3 patients died of complicated diarrhea. These findings highlight the current spectrum of IRIS in South India and underscore the importance of heightened vigilance for anemia and treatment of diarrhea and candidiasis during ART initiation.

Role of a NSAID in the apparent cure of a fungal mycetoma

We report the case of a fungal mycetoma due to Madurella mycetomatis that failed to respond to surgery and antifungal treatment but responded strongly to the addition of a non-steroidal anti-inflammatory drug (NSAID). This African patient was born in Mauritania in 1972. He was a herdsman, living close to the Senegal River. The first nodules appeared on the left foot at the age of 13years (1985). The patient suffered frequent flare-ups with the appearance of black grains and underwent surgery in 1988 and 1992 in Senegal. After remission for several months after surgery, new fistulae occurred. The patient emigrated to France in 1995 and underwent a third surgical intervention in 1996. M. mycetomatis was cultured from the black grains. The patient was otherwise in good health, with no diabetes, and HIV tests were negative. We saw the patient for the first time in 2005, at which time he had flare-ups every two to three months. Imaging disclosed an absence of bone involvement. The patient underwent a fourth operation in October, 2005, and voriconazole treatment was initiated. A new flare-up occurred in February, 2006. CT, MRI, and PET scans revealed calcaneus and tarsal involvement, and posaconazole then replaced voriconazole. Flucytosine was added four months later, due to an absence of improvement. New flares-ups occurred and a fifth surgical intervention was performed in September, 2006. The pain, which had been present for three years, worsened; the patient had to stop working and was no longer able to walk without crutches. Amputation of the foot was considered. Empiric treatment with a NSAID, diclofenac (Voltaren(®); 100mg/day), was added to the antifungal treatment in November 2006, to treat the patient's pain and inflammation. A major improvement was observed within one week. The patient was able to walk without crutches one month later. After two months, clinical examination was normal: no pain, inflammation, nodules or fistulae. Flucytosine was stopped after six months of treatment, in January 2007, diclofenac after 10months, in October 2007, and posaconazole after 18.5months, also in October 2007. No relapse has occurred during the eight years of follow-up since treatment ended. The patient seems to have been cured and has normal CT, MRI, and PET scans.

IN SUMMARY

This eumycetoma, which had progressed over 20years despite surgery and antifungal treatments, seems to have been cured by the addition of a NSAID. This observation suggests that inflammation plays a major role in the pathogenesis of fungal mycetoma. Clinical studies of treatments including an NSAID should be conducted to confirm this finding.

The immunopathogenesis of cryptococcal immune reconstitution inflammatory syndrome: understanding a conundrum

PURPOSE OF REVIEW

Cryptococcal meningitis causes significant mortality among HIV-infected patients, despite antifungal therapy and use of antiretroviral therapy (ART). In patients with cryptococcal meningitis, ART is often complicated by immune reconstitution inflammatory syndrome (IRIS), manifesting as unmasking of previously unrecognized subclinical infection (unmasking CM-IRIS) or paradoxical worsening of symptoms in the central nervous system after prior improvement with antifungal therapy (paradoxical CM-IRIS). We review our current understanding of the pathogenesis of this phenomenon, focusing on unifying innate and adaptive immune mechanisms leading to the development of this often fatal syndrome.

RECENT FINDINGS

We propose that HIV-associated CD4 T-cell depletion, chemokine-driven trafficking of monocytes into cerebrospinal fluid in response to cryptococcal meningitis, and poor localized innate cytokine responses lead to inadequate cryptococcal killing and clearance of the fungus. Subsequent ART-associated recovery of T-cell signaling and restored cytokine responses, characterized by IFN-γ production, triggers an inflammatory response. The inflammatory response triggered by ART is dysregulated because of impaired homeostatic and regulatory mechanisms, culminating in the development of CM-IRIS.

SUMMARY

Despite our incomplete understanding of the immunopathogenesis of CM-IRIS, emerging data exploring innate and adaptive immune responses could be exploited to predict, prevent and manage CM-IRIS and associated morbid consequences.

Lower Pre-Treatment T Cell Activation in Early- and Late-Onset Tuberculosis-Associated Immune Reconstitution Inflammatory Syndrome

Background

Tuberculosis-associated immune reconstitution inflammatory syndrome (TB-IRIS) is an inflammatory complication in HIV-TB co-infected patients receiving antiretroviral therapy (ART). The role of disturbed T cell reconstitution in TB-IRIS is not well understood. We investigated T cell activation and maturation profiles in patients who developed TB-IRIS at different intervals during ART.

Methods

Twenty-two HIV-TB patients who developed early-onset TB-IRIS and 10 who developed late-onset TB-IRIS were matched for age, sex and CD4 count to equal numbers of HIV-TB patients who did not develop TB-IRIS. Flow cytometry analysis was performed on fresh blood, drawn before and after ART initiation and during TB-IRIS events. T cell activation and maturation was measured on CD4+ and CD8+ T cells using CD45RO, CD38, HLA-DR, CCR7 and CD27 antibodies.

Results

CD8+ T cell activation before ART was decreased in both early-onset (77% vs. 82%, p = 0.014) and late-onset (71% vs. 83%, p = 0.012) TB-IRIS patients compared to non-IRIS controls. After ART initiation, the observed differences in T cell activation disappeared. During late-onset, but not early-onset TB-IRIS, we observed a skewing from memory to terminal effector CD4+ and CD8+ T cell populations (p≤0.028).

Conclusion

Our data provide evidence of reduced CD8+ T cell activation before ART as a common predisposing factor of early- and late-onset TB-IRIS. The occurrence of TB-IRIS itself was not marked by an over-activated CD8+ T cell compartment. Late- but not early-onset TB-IRIS was characterized by a more terminally differentiated T cell phenotype.

Opportunistic infections and immune reconstitution inflammatory syndrome in HIV-1-infected adults in the combined antiretroviral therapy era: a comprehensive review

Despite the availability of effective combined antiretroviral treatment, many patients still present with advanced HIV infection, often accompanied by an AIDS-defining disease. A subgroup of patients starting antiretroviral treatment under these clinical conditions may experience paradoxical worsening of their disease as a result of an exaggerated immune response towards an active (but also subclinical) infectious agent, despite an appropriate virological and immunological response to the treatment. This clinical condition, known as immune reconstitution inflammatory syndrome, may cause significant morbidity and even mortality if it is not promptly recognized and treated. This review updates current knowledge about the incidence, diagnostic criteria, risk factors, clinical manifestations, and management of opportunistic infections and immune reconstitution inflammatory syndrome in the combined antiretroviral treatment era.

Paradoxical Mycobacterium tuberculosis meningitis immune reconstitution inflammatory syndrome in an HIV-infected child

Immune reconstitution inflammatory syndrome occurs in a subset of HIV-infected individuals as the immune system recovers secondary to antiretroviral therapy. An exaggerated and uncontrolled inflammatory response to antigens of viable or nonviable organisms is characteristic, with clinical deterioration despite improvement in laboratory indicators. We describe a fatal case of Mycobacterium tuberculosis meningitis immune reconstitution inflammatory syndrome in an HIV-infected child and review the literature.

Paradoxical reactions during treatment of tuberculosis with extrapulmonary manifestations in HIV-negative patients

PURPOSE

Tuberculous paradoxical reactions (PR) have been seldom studied in non-immunocompromised patients. We conducted a study to describe the incidence, clinical and biological features, treatment and outcome of PR in human immunodeficiency virus (HIV)-negative patients treated for extrapulmonary tuberculosis (TB) and to identify predictive factors of PR.

METHODS

A single-center retrospective study was conducted in consecutive HIV-negative patients presenting with TB with at least one extrapulmonary manifestation who were hospitalized in an internal medicine department between 2000 and 2010.

RESULTS

Seventy-six patients were enrolled in the study. Lymphadenitis was the most common extrapulmonary manifestation of tuberculosis among this patient population (72 %). PR occurred in 19 (25 %) patients, mostly involving the lymph nodes (68 %) and lung (16 %), but also the pericardium, pleura, bone, muscle and brain. Median time to PR onset after initiation of anti-TB regimen was 86 days (interquartile range 36-125). Treatment of PR consisted mainly of corticosteroids (47 % of patients) and needle aspiration of PR lymph nodes (31 %). Peripheral lymph node involvement (p = 0.009), lymphopenia (p = 0.03) and anemia (p = 0.002) at presentation were associated with PR occurrence. Outcome was favorable in all patients with PR but one; the latter suffered residual paraplegia.

CONCLUSIONS

Paradoxical reactions are frequent in the course of extrapulmonary TB treatment in HIV-negative patients but their outcome is excellent, except in some cases with central nervous system involvement.

Acute poststreptococcal glomerulonephritis: a manifestation of immune reconstitution inflammatory syndrome

Immune reconstitution inflammatory syndrome (IRIS) is a well-described complication of initiation of highly active antiretroviral therapy in HIV-infected patients. As the immune system recovers, an inappropriate inflammatory response often occurs that causes significant disease. It is most commonly seen in patients naïve to therapy with CD4+ T-lymphocyte counts <100 cells/cmm and usually presents as a flare of mycobacterial, cytomegalovirus, or herpes zoster infections. Less commonly, this syndrome occurs in response to noninfectious triggers and results in autoimmune or malignant disease. Here we present the first case of acute poststreptococcal glomerulonephritis associated with varicella zoster virus and IRIS in an adolescent with perinatally acquired HIV and hepatitis C virus infections. Our patient was not naïve to therapy but was starting a new regimen of therapy because of virologic failure and had a relatively high CD4+ T-lymphocyte count. This case report indicates that IRIS remains a concern after initiation of a new highly active antiretroviral therapy regimen in HIV-infected patients with high viral loads, even in the presence of CD4+ T-lymphocyte counts >100 cells/cmm. It may present as infectious, malignant, or autoimmune conditions including poststreptococcal glomerulonephritis.

Immune reconstitution inflammatory syndrome and the influence of T regulatory cells: a cohort study in The Gambia

Objective

The factors associated with the development of immune reconstitution inflammatory syndrome in HIV patients commencing antiretroviral therapy have not been fully elucidated. Using a longitudinal study design, this study addressed whether alteration in the levels of T regulatory cells contributed to the development of IRIS in a West African cohort of HIV-1 and HIV-2 patients. Seventy-one HIV infected patients were prospectively recruited to the study and followed up for six months. The patients were categorized as IRIS or non-IRIS cases following published clinical guidelines. The levels of T regulatory cells were measured using flow cytometry at baseline and all follow-up visits. Baseline cytokine levels of IL-2, IL-6, IFN-γ, TNF-α, MIP-1β, IL-1, IL-12, IL-13, and IL-10 were measured in all patients.

Results

Twenty eight percent of patients (20/71) developed IRIS and were predominantly infected with HIV-1. Patients developing IRIS had lower nadir CD4 T cells at baseline (p = 0.03) and greater CD4 T cell reconstitution (p = 0.01) at six months post-ART. However, the development of IRIS was not influenced by the levels of T regulatory cells. Similarly, baseline cytokine levels did not predict the onset of IRIS.

Conclusion

The development of IRIS was not associated with differences in levels of T regulatory cells or baseline pro-inflammatory cytokines.

[Immune reconstitution syndrome]

The immune reconstitution inflammatory syndrome (IRIS) represents a heterogeneous group of conditions. Whilst they typically present in HIV-infected patients with advanced immunodeficiency, IRIS have also been described in HIV-negative patients with immune reconstitution due to other causes of immunosuppression. Frequently IRIS results from an immune response against underlying infection (pathogen-associated IRIS). However, IRIS might become evident during immune reconstitution without an underlying pathogen such as a sarcoid-like illness or an autoimmune thyropathy. Here we report on the epidemiology and risk factors of IRIS along with diagnosis and management of this clinically important inflammatory syndrome.

HIV and asthma, is there an association?

OBJECTIVE

To evaluate whether asthma and airway hyper-responsiveness are associated with HIV infection.

METHODS

We reviewed the literature on HIV-associated pulmonary diseases, pulmonary symptoms, and immune changes which may play a role in asthma. The information was analyzed comparing the pre-HAART era to the post-HAART era data.

RESULTS

HIV-seropositive individuals commonly experience respiratory complaints yet it is unclear if the frequency of these complaints have changed with the initiation of HAART. Changes in pulmonary function testing and serum IgE are seen with HIV infection even in the post-HAART era. An increased prevalence of asthma among HIV-seropositive children treated with HAART has been reported.

CONCLUSION

The spectrum of HIV-associated pulmonary disease has changed with the introduction of HAART. Current data is limited to determine if asthma and airway hyper-responsiveness are more common among HIV-seropositive individuals treated with HAART.

Pathogenesis and prevention of immune reconstitution disease during antiretroviral therapy

The risks of unmasking and paradoxical forms of immune reconstitution disease in HIV-infected patients starting antiretroviral therapy (ART) are fuelled by a combination of the late presentation of patients with advanced immunodeficiency, the associated high rates of opportunistic infections (OIs) and the need for rapid initiation of ART to minimize overall mortality risk. We review the risk factors and our current knowledge of the immunopathogenesis of immune reconstitution disease, leading to a discussion of strategies for prevention. Initiation of ART at higher CD4 counts, use of OI-preventive therapies prior to ART eligibility, intensified screening for OIs prior to ART initiation and optimum therapy for OIs are all needed. In addition, use of a range of pharmacological agents with immunosuppressive and immunomodulatory activity is being explored.

Immune Reconstitution Inflammatory Syndrome

Immune reconstitution inflammatory syndrome (IRIS) is a phenomenon observed in patients recovering from immunodeficiency. The clinical presentation of IRIS involves the unmasking of covert infections or the worsening of overt conditions. Several causes and pathways have been suggested, most recognizing an inflammatory flare component occurring in the context of rapid immune reconstitution. In HIV-infected patients, IRIS inadvertently occurs as the consequence of successful antiretroviral therapy, and it is affiliated with improvement of the immune function, complicating the course of the disease and presenting treatment challenges to clinicians. The pathogenesis of IRIS is poorly understood, but in recovering HIV patients, its initiation and progression seem to be primarily linked to an increase in CD4+ T-helper and CD8+ T-suppressor cell count and a reduction in T-regulatory cells, all endorsed by exaggerated cytokine release and activity. The clinical presentation of IRIS is usually atypical. The manifestations depend on the trigger antigen, which can be an infective agent (viable or nonviable), a host antigen, or a tumor antigen. Most IRIS cases are self-limiting, but a few cases can be overwhelming and life-threatening; hence, early recognition is important. In most cases, there is no need to discontinue the antiretroviral therapy, although in the more severe cases, other clinical intervention may be necessary.

Clinical Markers of Immunodeficiency and Mechanism of Immune Reconstitution Inflammatory Syndrome and Highly Active Antiretroviral Therapy on HIV

Antiretroviral therapy (ART) has improved survival and changed the disease pattern of HIV infection. However, ART may cause serious side effects, such as metabolic and cardiovascular complications. In addition, immune reconstitution inflammatory syndrome (IRIS) is being increasingly reported in relation to ART. The article presents the consensus of a workshop around 4 key issues: (1) the differences in the response of adults and children to highly active antiretroviral therapy, (2) the mechanism of the new HIV entry inhibitors and its effect on oral markers, (3) the pathogenesis of IRIS and the contradictory findings of the possible oral lesions related with IRIS, (4) and the benefits and barriers associated with using ART in the developing and developed world. The consensus of the workshop was that there is a need for future studies on the oral manifestations of HIV in individuals treated with new ARTs—especially, children. IRIS was considered a promising field for future research; as such, workshop attendees recommended formulating an IRIS–oral lesions case definition and following strict criteria for its diagnosis.

Clinical features and serum biomarkers in HIV immune reconstitution inflammatory syndrome after cryptococcal meningitis: a prospective cohort study

BACKGROUND

Although antiretroviral therapy (ART) improves survival in persons with cryptococcal meningitis (CM) and AIDS, ART frequently elicits HIV immune reconstitution inflammatory syndrome (IRIS), an exaggerated and frequently deadly inflammatory reaction that complicates recovery from immunodeficiency. The pathogenesis of IRIS is poorly understood and prediction of IRIS is not possible.

METHODS AND FINDINGS

We prospectively followed 101 ART-naïve Ugandans with AIDS and recent CM for one year after initiating ART, and used Luminex multiplex assays to compare serum cytokine levels in participants who did or did not develop IRIS. IRIS occurred in 45% of participants with recent CM on ART, including 30% with central nervous system (CNS) manifestations. The median time to CM-IRIS was 8.8 wk on ART. Overall mortality on ART was 36% with IRIS and 21% without IRIS. CM-IRIS was independently associated with death (HR = 2.3, 95% CI 1.1-5.1, p = 0.04). Patients experiencing subsequent CM-IRIS had 4-fold higher median serum cryptococcal antigen (CRAG) levels pre-ART (p = 0.006). Higher pre-ART levels of interleukin (IL)-4 and IL-17 as well as lower tumor necrosis factor (TNF)-α, granulocyte colony-stimulating factor (G-CSF), granulocyte-macrophage colony-stimulating factor (GM-CSF), and vascular endothelial growth factor (VEGF) predicted future IRIS in multivariate analyses (area under the curve [AUC] = 0.82). An algorithm based on seven pre-ART serum biomarkers was a robust tool for stratifying high (83%), moderate (48%), and low risk (23%) for IRIS in the cohort. After ART was initiated, increasing levels of C-reactive protein (CRP), D-dimer, IL-6, IL-7, IL-13, G-CSF, or IL-1RA were associated with increasing hazard of IRIS by time-to-event analysis (each p≤0.001). At the time of IRIS onset, multiple proinflammatory cytokine responses were present, including CRP and IL-6. Mortality was predicted by pre-ART increasing IL-17, decreasing GM-CSF, and CRP level >32 mg/l (highest quartile). Pre-ART CRP level >32 mg/l alone was associated with future death (OR = 8.3, 95% CI 2.7-25.6, p<0.001).

CONCLUSIONS

Pre-ART increases in Th(17) and Th(2) responses (e.g., IL-17, IL-4) and lack of proinflammatory cytokine responses (e.g., TNF-α, G-CSF, GM-CSF, VEGF) predispose individuals to subsequent IRIS, perhaps as biomarkers of immune dysfunction and poor initial clearance of CRAG. Although requiring validation, these biomarkers might be an objective tool to stratify the risk of CM-IRIS and death, and could be used clinically to guide when to start ART or use prophylactic interventions.

Severe multifocal form of buruli ulcer after streptomycin and rifampin treatment: comments on possible dissemination mechanisms

Buruli ulcer (BU), a disease caused by Mycobacterium ulcerans, leads to the destruction of skin and sometimes bone. Here, we report a case of severe multifocal BU with osteomyelitis in a 6-year-old human immunodeficiency virus (HIV)-negative boy. Such disseminated forms are poorly documented and generally occur in patients with HIV co-infection. The advent of antibiotic treatment with streptomycin (S) and rifampin (R) raised hope that these multifocal BU cases could be reduced. The present case raises two relevant points about multifocal BU: the mechanism of dissemination that leads to the development of multiple foci and the difficulties of treatment of multifocal forms of BU. Biochemical (hypoproteinemia), hematological (anemia), clinical (traditional treatment), and genetic factors are discussed as possible risk factors for dissemination.

Update on immune reconstitution inflammatory syndrome: progress and unanswered questions

The immune reconstitution inflammatory syndrome (IRIS) is characterized by clinical deterioration occurring after the initiation of effective antiretroviral therapy (ART) and results from a disordered and exuberant immune response. The syndrome may present as paradoxical IRIS or unmasking IRIS, depending on whether an opportunistic infection was recognized and treated before ART initiation. Numerous descriptions of IRIS caused by many pathogens were published in the years after the introduction of effective ART. In recent years, with enhanced rollout of ART in resource-limited settings, attention has again focused on IRIS because of the enormous burden of opportunistic infections. This review highlights recent findings elucidating risk factors for and the pathogenesis and treatment of IRIS.

Immune reconstitution inflammatory syndrome in patients starting antiretroviral therapy for HIV infection: a systematic review and meta-analysis

In patients with HIV-1 infection who are starting combination antiretroviral therapy (ART), the incidence of immune reconstitution inflammatory syndrome (IRIS) is not well defined. We did a meta-analysis to establish the incidence and lethality of the syndrome in patients with a range of previously diagnosed opportunistic infections, and examined the relation between occurrence and the degree of immunodeficiency. Systematic review identified 54 cohort studies of 13 103 patients starting ART, of whom 1699 developed IRIS. We calculated pooled cumulative incidences with 95% credibility intervals (CrI) by Bayesian methods and did a random-effects metaregression to analyse the relation between CD4 cell count and incidence of IRIS. In patients with previously diagnosed AIDS-defining illnesses, IRIS developed in 37.7% (95% CrI 26.6-49.4) of those with cytomegalovirus retinitis, 19.5% (6.7-44.8) of those with cryptococcal meningitis, 15.7% (9.7-24.5) of those with tuberculosis, 16.7% (2.3-50.7) of those with progressive multifocal leukoencephalopathy, and 6.4% (1.2-24.7) of those with Kaposi's sarcoma, and 12.2% (6.8-19.6) of those with herpes zoster. 16.1% (11.1-22.9) of unselected patients starting ART developed any type of IRIS. 4.5% (2.1-8.6) of patients with any type of IRIS died, 3.2% (0.7-9.2) of those with tuberculosis-associated IRIS died, and 20.8% (5.0-52.7) of those with cryptococcal meningitis died. Metaregression analyses showed that the risk of IRIS is associated with CD4 cell count at the start of ART, with a high risk in patients with fewer than 50 cells per microL. Occurrence of IRIS might therefore be reduced by initiation of ART before immunodeficiency becomes advanced.

Immune restoration diseases reflect diverse immunopathological mechanisms

Up to one in four patients infected with human immunodeficiency virus type 1 and given antiretroviral therapy (ART) experiences inflammatory or cellular proliferative disease associated with a preexisting opportunistic infection, which may be subclinical. These immune restoration diseases (IRD) appear to result from the restoration of immunocompetence. IRD associated with intracellular pathogens are characterized by cellular immune responses and/or granulomatous inflammation. Mycobacterial and cryptococcal IRD are attributed to a pathological overproduction of Th1 cytokines. Clinicopathological characteristics of IRD associated with viral infections suggest different pathogenic mechanisms. For example, IRD associated with varicella-zoster virus or JC polyomavirus infection correlate with a CD8 T-cell response in the central nervous system. Exacerbations or de novo presentations of hepatitis associated with hepatitis C virus (HCV) infection following ART may also reflect restoration of pathogen-specific immune responses as titers of HCV-reactive antibodies rise in parallel with liver enzymes and plasma markers of T-cell activation. Correlations between immunological parameters assessed in longitudinal sample sets and clinical presentations are required to illuminate the diverse immunological scenarios described collectively as IRD. Here we present salient clinical features and review progress toward understanding their pathogeneses.

Immune reconstitution disease associated with mycobacterial infections

PURPOSE OF REVIEW

We review immune reconstitution disease associated with mycobacterial infections in patients receiving antiretroviral treatment. We draw particular attention to data relevant to resource-limited settings and focus predominantly on publications over the past year.

RECENT FINDINGS

Worldwide mycobacteria are the most important group of pathogens associated with immune reconstitution disease. In cohorts of patients with tuberculosis in high-income countries, up to one-third develop immune reconstitution disease compared with only 8-13% in current reports from resource-limited settings. We speculate on potential explanations for this difference. While most cases of tuberculosis immune reconstitution disease are self-limiting, deaths have been reported in South African and Thai cohorts. We discuss how risk and outcomes of tuberculosis immune reconstitution disease represent key variables regarding the optimum time to initiate antiretroviral treatment in tuberculosis patients. A new conceptual framework has been proposed regarding 'unmasking' of tuberculosis during antiretroviral treatment. Increasing numbers of cases of leprosy immune reconstitution disease and Bacillus Calmette-Guérin immune reconstitution disease have also been reported, mainly from resource-limited settings. Immune reconstitution disease associated with a variety of mycobacteria (tuberculous and nontuberculous) was common in a cohort of Thai children.

SUMMARY

Immune reconstitution disease associated with a range of mycobacteria constitutes a challenge to delivery of antiretroviral treatment worldwide. Data concerning the pathogenesis and management of all forms of mycobacterial immune reconstitution disease are lacking.

Is vitamin D deficiency involved in the immune reconstitution inflammatory syndrome?

Background

About 20–30% of persons with HIV infection, especially those living in countries with limited resources, experience an immune reconstitution inflammatory syndrome (IRIS) after starting antiretroviral treatment. The active form of vitamin D, 1,25-dihydroxyvitamin D, is a key player in the clearance of pathogens and influences the level of inflammation and macrophage activation.

Presentation of the hypothesis

We hypothesize that low availability of 1,25-dihydroxyvitamin D, either due to vitamin D deficiency or due to polymorphisms in the vitamin D receptor or in its activating/inactivating enzymes, contributes to the appearance of IRIS. Furthermore, drug interactions with the enzymatic pathways of vitamin D could favour the development of IRIS.

Testing the hypothesis

Our hypothesis could be explored by a case-control study to assess the prevalence of vitamin D deficiency in HIV-infected patients on antiretroviral treatment who develop and do not develop IRIS.

Implications of the hypothesis

If the role of vitamin D in IRIS is confirmed, we would be able to screen patients at risk for IRIS by screening for vitamin D deficiency. After confirmation by means of a clinical trial, vitamin D supplementation could be a cheap and safe way to reduce the incidence of IRIS.

Biomarkers of HIV Immune Reconstitution Inflammatory Syndrome

Dysregulation of the immune system drives HIV pathogenesis. As we develop new ways to treat HIV and AIDS, we encounter new clinical ramifications of our treatment on regulatory components of the immune system. HIV-associated Immune Reconstitution Inflammatory Syndrome (IRIS) occurs after initiation of anti-retroviral therapy (ART) with inappropriate and dysbalanced restoration of the immune system resulting in pathologic inflammatory reactions with significant morbidity. IRIS is most commonly associated with latent, occult, or past infections, including tuberculosis, Cryptococcus neoformans, and Mycobacterium avium-complex. We discuss common clinical presentations, new diagnostic modalities, current hypotheses of IRIS pathogenesis, and future directions of IRIS-related research, focusing on the identification of biomarkers that can be used to predict and diagnose IRIS.