Compartmentalization of the immune response in varicella zoster virus immune restoration disease causing transverse myelitis

A Case of Varicella-Zoster Virus Meningomyelitis in an HIV-1-Infected Patient: Facing the Challenges Related to Its Management and Prognosis

Varicella-zoster virus (VZV) myelitis is a rare complication of herpes zoster. Diagnosing and treating this entity may be challenging. Clinical outcomes vary and neurological sequelae may be seen despite treatment. We report a case of a 43-year-old woman with human immunodeficiency virus type 1 (HIV-1) infection (CD4 cell count 191 cells/µL - 14%; undetectable viral load) who was started on antiretroviral treatment eight months before. She presented with VZV meningitis and transverse myelitis and concomitant thoracic vesicular rash at the dermatomal level T6. Neurological examination revealed neck stiffness, paraplegia, sensory level below T4, and autonomic dysfunction. Magnetic resonance imaging (MRI) revealed signs of myelitis from C4 to T10 and VZV DNA by polymerase chain reaction (PCR) was positive (20,00,000 cp/mL) in the cerebrospinal fluid (CSF). The patient completed four weeks of intravenous acyclovir and systemic corticosteroids. Repeat lumbar puncture returned negative for VZV PCR and MRI showed spinal cord improvement. However, only partial neurological improvement was observed after six months. Some features of the present case may be associated with an unfavorable outcome, including high VZV viral load in the CSF and rapid progression of neurological deficits to paraplegia and sphincter dysfunction. Moreover, the recovery of CD4+ cells from 4% to 14% after starting antiretroviral treatment might also have contributed to the extension of myelopathy. Further studies are needed to improve the understanding of VZV myelitis course and optimize its treatment.

Transverse myelitis caused by varicella-zoster

Transverse myelitis is a rare neurological complication seen with varicella-zoster virus (VZV) infection, which is common among immunocompromised hosts. It can occur during the primary VZV infection or reactivation of latent infection. It is a complication that requires prompt diagnosis and treatment. The present case is that of a 28-year-old immunocompetent man, who presented with fever, rash and acute-onset spastic paraparesis with bladder involvement. Causes such as herpes simplex 1 and 2, cytomegalovirus, enterovirus and Epstein-Barr virus infection were ruled out. On evaluation, he was diagnosed with acute primary disseminated VZV infection with parainfectious transverse myelitis, based on positive cerebrospinal fluid multiplex PCR (PCR) and serum VZV IgM antibodies. He was treated with intravenous acyclovir and steroids, with which he improved significantly.

[Immune reconstitution inflammatory syndrome and rebound syndrome in multiple sclerosis patients who stopped disease modification therapy: current understanding and a case report]

More and more multiple sclerosis patients have been receiving treatment with new immunomodulatory drugs. Its discontinuation because of side-effects, lack of efficacy or pregnancy has been increasing as well. This paper reviews such severe complications of natalizumab and fingolimod cessation as immune reconstitution inflammatory syndrome (IRIS) and rebound. The short history, immunopathogenesis and diagnostic criteria of IRIS in individuals with human immunodeficiency virus infection are covered. Clinical and radiological presentations as well as possible pathogenic mechanisms of IRIS in patients treated with natalizumab and fingolimod are discussed. The authors also report the case of a woman with multiple sclerosis treated with fingolimod, who experienced a severe relapse when she stopped treatment. Diagnostic criteria and prognostic factors for IRIS and rebound are needed in patients with multiple sclerosis who discontinue the new disease modification therapy.

Graves' disease as immune reconstitution disease in HIV-positive patients is associated with naive and primary thymic emigrant CD4(+) T-cell recovery

OBJECTIVE

Immune restoration disease (IRD) can develop in HIV-infected patients following antiretroviral therapy (ART) initiation as unmasking or paradoxical worsening of opportunistic infections and, rarely, autoimmune phenomena. Although IRD usually occurs in the first months of ART during memory CD4 T-cell recovery, Graves' disease occurs as a distinctive late-onset IRD and its pathogenesis is unclear.

DESIGN

Seven patients who developed Graves' disease following ART initiation from the primary HIV care clinic at the National Institutes of Health were retrospectively identified and each was matched with two HIV-infected controls based on age, sex, and baseline CD4 T-cell count. Laboratory evaluations on stored cryopreserved samples were performed.

METHODS

Immunophenotyping of peripheral blood mononuclear cells (PBMCs), T-cell receptor excision circle (TREC) analysis in PBMCs, measurement of serum cytokines, and luciferase immunoprecipitation systems (LIPS) analysis for autoimmune antibodies were performed on stored samples for cases and controls at baseline and longitudinally following ART initiation. TSH/thyrotropin receptor (TSH-R) antibody testing was performed on serum from cases. Data were analyzed using nonparametric testing.

RESULTS

In comparison with controls, the proportion of naive CD4 T cells increased significantly (P = 0.0027) in the Graves' disease-IRD patients. TREC/10 PBMCs also increased significantly following ART in Graves' disease-IRD patients compared with controls (P = 0.0071). Similarly, LIPS analysis demonstrated increases in nonthyroid-related autoantibody titers over time following ART in cases compared with controls.

CONCLUSION

Our data suggest that Graves' disease-IRD, in contrast to early-onset IRD, is associated with naive and primary thymic emigrant CD4 T-cell recovery and inappropriate autoantibody production.

Late onset CNS immune reconstitution inflammatory syndrome in an immunocompetent patient

Immune reconstitution inflammatory syndrome (IRIS) refers to the presence of paradoxical clinical deterioration attributable to immune system recovery during highly active antiretroviral therapy (HAART). We present an immunocompetent patient with multifocal leukoencephalopathy on HAART, with central nervous system (CNS) IRIS pathology of unknown infectious etiology. CNS IRIS pathology should be suspected in patients on longstanding HAART without immune reconstitution, presenting with unexplained leukoencephalopathy.

Pathogenesis of the immune reconstitution inflammatory syndrome in HIV-infected patients

PURPOSE OF REVIEW

The immune reconstitution inflammatory syndrome (IRIS) is an important clinical complication in HIV-infected patients initiating antiretroviral therapy. This review focuses on the latest literature pertaining to the pathogenesis of IRIS.

RECENT FINDINGS

The clinical manifestations of IRIS are heterogeneous due to the variety of opportunistic infections that are associated with this inflammatory syndrome. However, the disproportionate inflammation is a defining hallmark for which common mechanisms are suspected. Lymphopenia-induced proliferation in the context of systemic immune activation, presence of high antigenic exposure and a wider availability of interleukin-7 contribute to the exacerbated immune response underlying IRIS. Defect in pathogen clearance by phagocytes might favor high pathogen burden, which in turn is thought to activate both innate immune cells and pathogen-specific T cells upon correction of the CD4 T-cell lymphopenia, predisposing to IRIS. This common scenario might be further invigorated by functional impairments among regulatory T cells.

SUMMARY

Further insight into the cellular mechanisms driving IRIS is urgently needed. Understanding the relative contribution of distinct effector and regulatory T-cell subsets, and innate immune components to IRIS is required to inspire future therapeutic approaches.

A fatal case of kaposi sarcoma due to immune reconstitution inflammatory syndrome

The prevalence of AIDS-related Kaposi sarcoma (KS) has markedly declined in the era of highly active antiretroviral therapy (HAART) although it remains one of the most common AIDS-defining malignancies. Although immune reconstitution inflammatory syndrome (IRIS)-related KS (IRIS-KS) represents only a fraction of the IRIS cases, it can be a life-threatening situation. This report describes a fatal case of IRIS-KS. A 32-year-old man with HIV/AIDS was initiated on HAART and experienced rapid immunological and virological response to therapy. He subsequently experienced progressively severe dyspnea and papulonodular skin lesions and was admitted to the hospital with hypoxic respiratory failure. Bronchoscopy revealed numerous friable endobronchial lesions. Histopathology of a skin lesion was consistent with KS. The relatively rapid progression of disease in the setting of improvement in immune function after initiating HAART suggested IRIS-KS. This report reviews previously published cases of IRIS-KS and describes risk factors, immunopathogenesis and treatment options.

Superficial thrombophlebitis: A new clinical manifestation of the immune reconstitution inflammatory syndrome in a patient with HIV infection

Skin manifestations of immune reconstitution inflammatory syndrome in response to highly active antiretroviral therapy may account for up to 50% of the clinical presentations in this syndrome. Viable or dying infective antigens, host antigens, tumoral antigens, and others may target immune reconstitution inflammatory syndrome, resulting in a wide spectrum of clinical manifestations. We describe a 26-year-old HIV-infected man who had started highly active antiretroviral therapy a few months earlier. He developed multiple linear nodules following the superficial veins in both legs. Histopathologic examination demonstrated a mostly septal panniculitis with features of superficial thrombophlebitis. We propose that superficial thrombophlebitis should be added to the list of clinical manifestations of this newly observed immune restoration disease.

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: recent developments and implications for antiretroviral treatment in resource-limited settings

PURPOSE OF REVIEW

We review literature published over the past 2 years regarding the immunopathogenesis, epidemiology, clinical spectrum and outcomes of immune reconstitution disease in patients receiving antiretroviral treatment. Particular attention is drawn to data relevant to resource-limited settings.

RECENT FINDINGS

In high-income countries, immune reconstitution disease occurs in association with a largely predictable spectrum of pathogens, including the herpesviruses, Mycobacterium tuberculosis and Mycobacterium avium complex, Cryptococcus neoformans and hepatitis viruses. Dermatological manifestations are most frequent. In resource-limited settings, patients accessing antiretroviral treatment programmes typically have advanced immunodeficiency, which increases risk of immune reconstitution disease. M. tuberculosis and C. neoformans have emerged as the key causes of morbidity and mortality associated with immune reconstitution disease. An increasing number of 'tropical' infections, including leprosy, schistosomiasis, strongyloidiasis, leishmaniasis, histoplasmosis and many nontuberculous mycobacteria, are also now recognised to provoke immune reconstitution disease but the overall spectrum and relative importance of these organisms remain to be defined. Better characterisation of immune reconstitution disease in these settings is needed to enable development of guidelines regarding prevention, diagnosis and management.

SUMMARY

While immune reconstitution disease in high-income countries has been clinically and epidemiologically well described, much remains to be learned in resource-limited settings in which immune reconstitution disease is emerging as a significant cause of morbidity and mortality.

Management of patients with the immune reconstitution inflammatory syndrome

A significant proportion of patients present with the immune reconstitution inflammatory syndrome (IRIS) after commencing antiretroviral therapy (ART). This syndrome is most frequently associated with infective causes. The lack of evidence-based treatment guidelines poses challenges in the management of these patients. Alternative causes for deterioration should be excluded, and optimization of treatment for the underlying opportunistic infection is essential. In addition, anti-inflammatory or immunomodulatory therapy may be considered, particularly in severe cases. Corticosteroids, the only treatment for which clinical trial data exist (for treating paradoxical tuberculosis-associated IRIS), are the treatment most frequently used in IRIS. Limited anecdotal reports of benefit exist for other agents, including NSAIDs, pentoxifylline, montelukast, thalidomide, and hydroxychloroquine. Therapeutic procedures (eg, aspiration of pus collections) play an important role in some patients. Interruption of ART may be considered in life-threatening forms of IRIS.

Immune reconstitution inflammatory syndrome in HIV-infected patients receiving antiretroviral therapy : pathogenesis, clinical manifestations and management

The use of antiretroviral therapy (ART) to treat HIV infection, by restoring CD4+ cell count and immune function, is associated with significant reductions in morbidity and mortality. Soon after ART initiation, there is a rapid phase of restoration of pathogen-specific immunity. In certain patients, this results in inflammatory responses that may result in clinical deterioration known as 'the immune reconstitution inflammatory syndrome' (IRIS). IRIS may be targeted at viable infective antigens, dead or dying infective antigens, host antigens, tumour antigens and other antigens, giving rise to a heterogeneous range of clinical manifestations. The commonest forms of IRIS are associated with mycobacterial infections, fungi and herpes viruses. In most patients, ART should be continued and treatment for the associated condition optimized, and there is anecdotal evidence for the use of corticosteroids in patients who are severely affected. In this review, we discuss research relating to pathogenesis, the range of clinical manifestations, treatment options and prevention issues.

Immune reconstitution inflammatory syndrome (IRIS): review of common infectious manifestations and treatment options

The immune reconstitution inflammatory syndrome (IRIS) in HIV-infected patients initiating antiretroviral therapy (ART) results from restored immunity to specific infectious or non-infectious antigens. A paradoxical clinical worsening of a known condition or the appearance of a new condition after initiating therapy characterizes the syndrome. Potential mechanisms for the syndrome include a partial recovery of the immune system or exuberant host immunological responses to antigenic stimuli. The overall incidence of IRIS is unknown, but is dependent on the population studied and its underlying opportunistic infectious burden. The infectious pathogens most frequently implicated in the syndrome are mycobacteria, varicella zoster, herpesviruses, and cytomegalovirus (CMV). No single treatment option exists and depends on the underlying infectious agent and its clinical presentation. Prospective cohort studies addressing the optimal screening and treatment of opportunistic infections in patients eligible for ART are currently being conducted. These studies will provide evidence for the development of treatment guidelines in order to reduce the burden of IRIS. We review the available literature on the pathogenesis and epidemiology of IRIS, and present treatment options for the more common infectious manifestations of this diverse syndrome and for manifestations associated with a high morbidity.

Disorders of immune reconstitution in patients with HIV infection responding to antiretroviral therapy

Patients with HIV infection who were very immunodeficient before achieving a virologic response to antiretroviral therapy (ART) may experience various disorders of immune reconstitution. Immune restoration disease occurs in approximately 10% to 50% of patients and results from the restoration of a pathogen-specific immune response that causes immunopathology and presents as tissue inflammation or cellular proliferative disease. Opportunistic infections occur in no more than 5% of patients, but approximately one half of these patients have higher than expected CD4 T-cell counts and appear to have residual immune dysfunction. Autoimmune disease may arise because the reconstituted immune system confers an increased susceptibility to immune dysregulation but there may be different mechanisms because Graves' disease presents after a median time of about 2 years of ART whereas systemic lupus erythematosus presents earlier. Persistent CD4 T-cell deficiency (< 500/microL) affects up to 60% of patients and appears to reflect depletion of the naïve T-cell pool that results from low production and/or increased turnover of cells.

Dermatologic Manifestations of the Immune Reconstitution Inflammatory Syndrome

The immune reconstitution inflammatory syndrome (IRIS) represents a diverse range of immunopathologic reactions resulting in clinical deterioration that may occur as immune function is partially restored in HIV-infected patients receiving highly active antiretroviral therapy. Approximately half of IRIS events are dermatologic, and dermatologic IRIS is described in relation to a wide range of conditions, the commonest being herpes zoster and herpes simplex. Most cases of IRIS result in mild and moderate symptoms, but non-dermatologic manifestations related to IRIS have resulted in death. This article covers certain general issues related to IRIS and then focuses on the spectrum of dermatologic manifestations.

Evidence base for using corticosteroids to treat HIV-associated immune reconstitution syndrome

Most of the evidence supporting the use of corticosteroids (steroids) for immune reconstitution syndrome (IRS) comes from case reports or retrospective series and is of low quality. However, when steroids are used, they have usually been associated with clinical improvement or resolution of IRS. Except in the case of hepatitis B- or C-associated IRS, there have been no reports of worsening of the IRS or adverse outcome due to steroid use. After ruling out other conditions which can mimic IRS, clinicians should strongly consider steroids when managing IRS associated with mycobacterial or fungal pathogens when there is severe disease, or when other measures have failed.

Immune reconstitution inflammatory syndrome in HIV

PURPOSE OF REVIEW

The purpose of this review is to describe the epidemiology, clinical features, putative immune mechanisms and management of immune reconstitution inflammatory syndrome (IRIS) using data published in the last 2 years.

RECENT FINDINGS

Ever more conditions are reported as IRIS events. These most frequently occur with mycobacterial (tuberculosis or Mycobacterium avium complex infection) or cryptococcal disease (each in approximately 30% of cases). Definitions have been proposed for its clinical diagnosis. These suffer from a lack of prospective studies to support their predictive value. The immunopathogenesis of IRIS appears to be related to the interaction between HAART-induced changes in host immune response and the presence of (usually microbial) antigen. Increasing evidence exists that this might be an anatomically compartmentalized phenomenon, such that immune responses may be localized to specific tissue sites such as the brain. This has implications for the use of simple blood tests, such as CD4 count or change in viral load, when assessing risk of IRIS. Treatment options include immune modulation, though supportive care is typically all that is required, unless symptoms are prolonged, significant or life-threatening.

SUMMARY

IRIS is common and will become more so as HAART is rolled out worldwide. Clear clinical definitions are required to avoid its over-diagnosis due to misclassification of other conditions.

Incidence and Risk Factors for Immune Reconstitution Inflammatory Syndrome in an Ethnically Diverse HIV Type 1-Infected Cohort

BACKGROUND

It is estimated that 10%-25% of patients who start highly active antiretroviral therapy (HAART) experience immune reconstitution inflammatory syndrome (IRIS). Our objective was to determine the incidence, clinical spectrum, and predictors of IRIS in an ethnically diverse cohort of patients initiating HAART.

METHODS

A retrospective study of all patients starting HAART between 1 January 2000 and 31 August 2002 at a human immunodeficiency virus (HIV) clinic in London was performed. All laboratory measurements and data on antiretroviral therapies were obtained from the clinic database. Medical records were reviewed to identify clinical events consistent with IRIS during the 6 months after HAART was initiated.

RESULTS

A total of 199 patients were included, of whom 50.8% were male, 59.3% were black African, 29.1% were white, and 10.5% were black Caribbean. The median baseline CD4 cell count and HIV RNA load were 174x10(6) cells/L (interquartile range [IQR], 82-285x10(6) cells/L) and 37,830 copies/mL (IQR, 4809-149,653 copies/mL), respectively. Forty-four patients (22.7%) experienced an IRIS event at a median of 12 weeks after HAART initiation (IQR, 4-24 weeks after initiation); 22 events (50%) involved genital herpes, 10 (23%) involved genital warts, 4 (9.0%) involved molluscum contagiosum, and 4 (9.0%) involved varicella zoster virus infection. Five patients had mycobacterial infections, 4 had hepatitis B, 1 had Pneumocystis jirovecci infection, and 1 had Kaposi sarcoma. The strongest independent predictors of IRIS were younger age at initiation of HAART (P=.003), baseline CD4 cell percentage of <10% (odds ratio [OR], 2.97; IQR, 1.17-7.55) compared with >15%, and ratio of CD4 cell percentage to CD8 cell percentage of <0.15 (OR, 3.45; 95% confidence interval, 1.27-9.1) compared with >0.3.

CONCLUSIONS

Approximately one-quarter of patients who start HAART experience an IRIS event. The majority are dermatological, in particular genital herpes and warts. Patients with advanced immunodeficiency at HAART initiation are at greatest risk of developing IRIS and should be appropriately screened and monitored.

Illness of immune reconstitution: Recognition and management

Some individuals who initiate highly active antiretroviral therapy (HAART) develop new or worsening opportunistic infections or malignancies despite improvements in surrogate markers of HIV-1 infection. These events of paradoxical clinical worsening, also known as immune reconstitution syndromes (IRS), are increased in individuals with prior opportunistic infections or low CD4+ T-cell nadirs. They are thought to result from reconstitution of the immune system's ability to recognize pathogens or tumor antigens that were previously present, but clinically asymptomatic. There is no consensus regarding the diagnostic criteria or pathogenesis of IRS. Knowledge of their presentation and treatment is largely based on case reports. With the introduction of HAART into resource-limited settings, it is likely that significantly more and distinct forms of IRS will be observed. Prospective studies of the incidence and treatment of IRS in multiple settings are critical to better understand their pathogenesis and optimal management.

Immune restoration disease after antiretroviral therapy

Suppression of HIV replication by highly active antiretroviral therapy (HAART) often restores protective pathogen-specific immune responses, but in some patients the restored immune response is immunopathological and causes disease [immune restoration disease (IRD)]. Infections by mycobacteria, cryptococci, herpesviruses, hepatitis B and C virus, and JC virus are the most common pathogens associated with infectious IRD. Sarcoid IRD and autoimmune IRD occur less commonly. Infectious IRD presenting during the first 3 months of therapy appears to reflect an immune response against an active (often quiescent) infection by opportunistic pathogens whereas late IRD may result from an immune response against the antigens of non-viable pathogens. Data on the immunopathogenesis of IRD is limited but it suggests that immunopathogenic mechanisms are determined by the pathogen. For example, mycobacterial IRD is associated with delayed-type hypersensitivity responses to mycobacterial antigens whereas there is evidence of a CD8 T-cell response in herpesvirus IRD. Furthermore, the association of different cytokine gene polymorphisms with mycobacterial or herpesvirus IRD provides evidence of different pathogenic mechanisms as well as indicating a genetic susceptibility to IRD. Differentiation of IRD from an opportunistic infection is important because IRD indicates a successful, albeit undesirable, effect of HAART. It is also important to differentiate IRD from drug toxicity to avoid unnecessary cessation of HAART. The management of IRD often requires the use of anti-microbial and/or anti-inflammatory therapy. Investigation of strategies to prevent IRD is a priority, particularly in developing countries, and requires the development of risk assessment methods and diagnostic criteria.