Neurological complications of immune reconstitution in HIV-infected populations

Atypical Demyelinating Disorders: MR Imaging Features, Atypical Triggers, and Etiopathogenesis

Atypical demyelinating lesions (ADLs) can be idiopathic, occurring as isolated and self-limited events, or can appear in different stages of relapsing demyelinating diseases. Not infrequently, ADLs occur in inflammatory syndromes associated with exogenous or endogenous toxic factors, metabolic imbalance, or infectious agents. It is important to recognize imaging patterns that indicate an inflammatory/demyelinating substrate in central nervous system lesions and to investigate potential triggers or complicating factors that might be associated. The prognostic and treatment strategies of ADLs are influenced by the underlying etiopathogenesis.

Multiple faces of multiple sclerosis in the era of highly efficient treatment modalities: Lymphopenia and switching treatment options challenges daily practice

The expanded treatment landscape in relapsing-remitting multiple sclerosis (MS) has resulted in highly effective treatment options and complexity in managing disease- or drug-related events during disease progression. Proper decision-making requires thorough knowledge of the immunobiology of MS itself and an understanding of the main principles behind the mechanisms that lead to secondary autoimmunity affecting organs other than the central nervous system as well as opportunistic infections. The immune system is highly adapted to both environmental and disease-modifying agents. Immune reconstitution following cell depletion or cell entrapment therapies eliminates pathogenic aspects of the disease but can also lead to distorted immune responses with harmful effects. Atypical relapses occur with second-line treatments or after their discontinuation and require appropriate clinical decisions. Lymphopenia is a result of the mechanism of action of many drugs used to treat MS. However, persistent lymphopenia and cell-specific lymphopenia could result in disease exacerbation, secondary autoimmunity, or the emergence of opportunistic infections. Clinicians treating patients with MS should be aware of the multiple faces of MS under novel, efficient treatment modalities and understand the intricate brain-immune cell interactions in the context of an altered immune system. MS relapses and disease progression still occur despite the current treatment modalities and are mediated either by failure to control effector mechanisms inherent to MS pathophysiology or by new drug-related mechanisms. The multiple faces of MS due to the highly adapted immune system of patients impose the need for appropriate switching therapies that safeguard disease remission and further clinical improvement.

Involvement of lncRNA TUG1 in HIV-1 Tat-Induced Astrocyte Senescence

HIV-1 infection in the era of combined antiretroviral therapy has been associated with premature aging. Among the various features of HIV-1 associated neurocognitive disorders, astrocyte senescence has been surmised as a potential cause contributing to HIV-1-induced brain aging and neurocognitive impairments. Recently, lncRNAs have also been implicated to play essential roles in the onset of cellular senescence. Herein, using human primary astrocytes (HPAs), we investigated the role of lncRNA TUG1 in HIV-1 Tat-mediated onset of astrocyte senescence. We found that HPAs exposed to HIV-1 Tat resulted in significant upregulation of lncRNA TUG1 expression that was accompanied by elevated expression of p16 and p21, respectively. Additionally, HIV-1 Tat-exposed HPAs demonstrated increased expression of senescence-associated (SA) markers-SA-β-galactosidase (SA-β-gal) activity and SA-heterochromatin foci-cell-cycle arrest, and increased production of reactive oxygen species and proinflammatory cytokines. Intriguingly, gene silencing of lncRNA TUG1 in HPAs also reversed HIV-1 Tat-induced upregulation of p21, p16, SA-β gal activity, cellular activation, and proinflammatory cytokines. Furthermore, increased expression of astrocytic p16 and p21, lncRNA TUG1, and proinflammatory cytokines were observed in the prefrontal cortices of HIV-1 transgenic rats, thereby suggesting the occurrence of senescence activation in vivo. Overall, our data indicate that HIV-1 Tat-induced astrocyte senescence involves the lncRNA TUG1 and could serve as a potential therapeutic target for dampening accelerated aging associated with HIV-1/HIV-1 proteins.

Suspected Central Nervous System Infections in HIV-Infected Adults

Objectives: To study the differential diagnosis of HIV-infected patients with suspected central nervous system (CNS) infections and the association of CD4 counts with the final diagnosis. Methods: We analyzed HIV-infected patients from a prospective cohort study on the diagnostic accuracy of clinical and laboratory characteristics in adults with suspected CNS infections in an academic hospital in Amsterdam, the Netherlands, who underwent cerebrospinal fluid (CSF) examination. Results: Thirty-four (9.4%) out of 363 patients with suspected CNS infections were HIV-positive of whom 18 (53%) were diagnosed to have CNS infection, with median CD4 counts of 255 cells/μl. The spectrum of CNS infections consisted of progressive multifocal leukoencephalopathy in three patients (17%); cryptococcal meningoencephalitis, toxoplasma encephalitis, angiostrongylus eosinophilic meningitis, and HIV encephalitis each in two (11%); and cytomegalovirus encephalitis, neurosyphilis, tuberculous meningoencephalitis, histoplasma encephalitis, and varicella-zoster virus meningitis each in one (6%). Clinical characteristics and blood parameters did not differ between HIV-infected patients with CNS infections and other diagnoses. The best predictor for CNS infections was the CSF leukocyte count (AUC = 0.77, 95 CI% 0.61-0.94). The diagnosis of CNS infection was not associated with the CD4 count (median 205 vs. 370, p = 0.21). Two patients (11%) with CNS infections died and two (11%) had neurological sequelae. Conclusions: Half of the patients with suspected CNS infections are diagnosed with a CNS infection, and this was not related to CD4 counts. The best predictor for CNS infections was the CSF leukocyte count.

Progressive multifocal leukoencephalopathy and the spectrum of JC virus-related disease

Progressive multifocal leukoencephalopathy (PML) is a devastating CNS infection caused by JC virus (JCV), a polyomavirus that commonly establishes persistent, asymptomatic infection in the general population. Emerging evidence that PML can be ameliorated with novel immunotherapeutic approaches calls for reassessment of PML pathophysiology and clinical course. PML results from JCV reactivation in the setting of impaired cellular immunity, and no antiviral therapies are available, so survival depends on reversal of the underlying immunosuppression. Antiretroviral therapies greatly reduce the risk of HIV-related PML, but many modern treatments for cancers, organ transplantation and chronic inflammatory disease cause immunosuppression that can be difficult to reverse. These treatments — most notably natalizumab for multiple sclerosis — have led to a surge of iatrogenic PML. The spectrum of presentations of JCV-related disease has evolved over time and may challenge current diagnostic criteria. Immunotherapeutic interventions, such as use of checkpoint inhibitors and adoptive T cell transfer, have shown promise but caution is needed in the management of immune reconstitution inflammatory syndrome, an exuberant immune response that can contribute to morbidity and death. Many people who survive PML are left with neurological sequelae and some with persistent, low-level viral replication in the CNS. As the number of people who survive PML increases, this lack of viral clearance could create challenges in the subsequent management of some underlying diseases.

In this Review, Cortese et al. provide an overview of the pathobiology and evolving presentations of progressive multifocal leukoencephalopathy and other diseases caused by JC virus, and discuss emerging immunotherapeutic approaches that could increase survival.

Progressive multifocal leukoencephalopathy (PML) is a rare, debilitating and often fatal disease of the CNS caused by JC virus (JCV).

JCV establishes asymptomatic, lifelong persistent or latent infection in immune competent hosts, but impairment of cellular immunity can lead to reactivation of JCV and PML.

PML most commonly occurs in patients with HIV infection or lymphoproliferative disease and in patients who are receiving natalizumab for treatment of multiple sclerosis.

The clinical phenotype of PML varies and is shaped primarily by the host immune response; changes in the treatment of underlying diseases associated with PML have changed phenotypes over time.

Other clinical manifestations of JCV infection have been described, including granule cell neuronopathy.

Survival of PML depends on reversal of the underlying immunosuppression; emerging immunotherapeutic strategies include use of checkpoint inhibitors and adoptive T cell transfer.

Acquired Holmes Tremor in a Human Immunodeficiency Virus Immune Reconstitution Inflammatory Syndrome Patient Treated with Deep Brain Stimulation

BACKGROUND

The authors present a case of a 66-year-old male who was diagnosed with human immunodeficiency virus, and his medical course of highly active antiretroviral therapy was complicated with the development of immune reconstitution inflammatory syndrome, which led to development of movement disorder consisting of right-sided resting tremor, neck dystonia, and jaw clenching.

CASE DESCRIPTION

The patient's symptoms resembled that of rubral tremor, and he underwent placement of a deep brain stimulation electrode into the left ventral intermediate nucleus of the thalamus with significant improvement of symptoms.

CONCLUSIONS

This is the first reported case in the literature of a human immunodeficiency virus-positive patient's treatment course complicated with immune reconstitution inflammatory syndrome with neurologic manifestation, which was refractory to medical therapy and thus treated with deep brain stimulation.

Cognitive impairment severity in relation to signs of subclinical Wernicke's encephalopathy in HIV and alcoholism comorbidity

OBJECTIVES

The comorbidity of HIV infection and alcoholism (ALC) is prevalent. Wernicke's encephalopathy, a neurological disorder resulting from thiamine depletion, has been generally associated with alcoholism but has also been reported in HIV infection. This study examined whether subclinical Wernicke's encephalopathy signs could contribute to the heterogeneity of cognitive and motor deficits observed in individuals with both disease conditions (HIV+ALC).

DESIGN

Sixty-one HIV+ALC individuals and 59 controls were assessed on attention and working memory, production, immediate and delayed episodic memory, visuospatial abilities, and upper limb motor function.

METHODS

Using Caine criteria (dietary deficiency, oculomotor abnormality, cerebellar dysfunction, and altered mental state), HIV+ALC individuals were classified by subclinical Wernicke's encephalopathy risk factors.

RESULTS

Signs of subclinical Wernicke's encephalopathy were present in 20% of the HIV+ALC participants. For attention/working memory, delayed memory, and upper limb motor function, HIV+ALC Caine 2+ (i.e. meeting two or three criteria) demonstrated the most severe deficits, scoring lower than HIV+ALC Caine 1 (i.e. meeting one criterion), HIV+ALC Caine 0 (i.e. meeting no criteria), and controls.

CONCLUSION

The high prevalence of subclinical signs of Wernicke's encephalopathy and relevance to performance indicate that this condition should be considered in assessment of HIV-infected individuals, especially when alcoholism comorbidity is known or suspected. Above and beyond clinical factors, such as depression, alcoholism and HIV disease-related variables, AIDS, hepatitis C and drug history known to mediate neuropsychological performance, subclinical Wernicke's encephalopathy signs could partly explain the heterogeneity in patterns and severity of cognitive and motor impairments in HIV-infected individuals with alcoholism comorbidity.

Non-traumatic perforation of the jejunum in a human immunodeficiency virus-infected patient receiving combination antiretroviral therapy: A case report

RATIONALE

Non-traumatic bowel perforation caused by cytomegalovirus (CMV) and Mycobacterium avium complex (MAC) infections has become rare among patients with acquired immunodeficiency syndrome (AIDS) in the era of combination antiretroviral therapy (cART); however, CMV-associated and MAC-related immune reconstitution inflammatory syndrome (IRIS) has subsequently emerged owing to the wide use of integrase inhibitor-based regimens. Here we report a case of spontaneous perforation of the jejunum in a patient with human immunodeficiency virus (HIV) infection with good compliance to cART.

PATIENT CONCERNS

A 32-year-old HIV-infected man developed CMV disease and DMAC infection, as unmasking IRIS, 3 days after the initiation of cART. After appropriate treatment for opportunistic infections, intermittent fever with enlarged lymph nodes in the abdomen occurred as paradoxical IRIS. The patient was administered prednisolone with subsequent tapering according to his clinical condition.

DIAGNOSES

Unexpected perforation of hollow organ during the titration of steroid dose with clinical presentations of severe abdominal pain was diagnosed by chest radiography.

INTERVENTIONS

He underwent surgical repair with peritoneal toileting smoothly.

OUTCOMES

He was discharged well with a clean surgical wound on post-operative day 10.

LESSONS

Bowel perforation may be a life-threatening manifestation of IRIS in the era of cART. Steroids should be avoided, if possible, to decrease the risk of bowel perforation, especially in IRIS occurred after opportunistic diseases involving the gastrointestinal tract.

Subtle Cryptococcal Immune Reconstitution Inflammatory Syndrome

Patients with HIV and opportunistic infections (OIs), such as tuberculosis and cryptococcosis, have been recognised to have immune reconstitution inflammatory syndrome (IRIS) following initiation of highly active antiretroviral therapy (HAART). The initiation of HAART boosts CD4 T cells, which result in exacerbations of OIs. We have identified deterioration of neural lesion in imaging after the initiation of HAART in a patient with HIV/cryptococcal infection, although patient's clinical conditions have not deteriorated. It is evident that IRIS is in subtlety. This has been possible because of prompt treatment with antifungal drugs for the cryptococcal infection, followed by early initiation of HAART.

A Kidney Transplant Recipient With Fulminant Progressive Multifocal Leukoencephalopathy-Immune Reconstitution Inflammatory Syndrome: A Rare Clinical Outcome and Review of the Literature

Progressive multifocal leukoencephalopathy is a devastating disease affecting the central nervous system that may be seen in immunocompromised patients. We present a case of a kidney transplant recipient who received tacrolimus, mycophenolic acid, and prednisone and who developed motor deficits, altered cognition, and speech abnormalities, which culminated in a coma. The diagnosis was made by detecting John Cunningham polyomavirus DNA with polymerase chain reaction and observing characteristic findings on magnetic resonance imaging. Soon after immunosuppressive therapy was withdrawn, the patient's clinical status deteriorated due to immune reconstitution inflammatory syndrome, and prednisone was administered. Unfortunately, the patient died about 9 months after onset of symptoms. This case serves to illustrate the fulminant progression of progressive multifocal leukoencephalopathy and the possible complications that may arise when treating it.

The Aging Brain With HIV Infection: Effects of Alcoholism or Hepatitis C Comorbidity

As successfully treated individuals with Human Immunodeficiency Virus (HIV)-infected age, cognitive and health challenges of normal aging ensue, burdened by HIV, treatment side effects, and high prevalence comorbidities, notably, Alcohol Use Disorders (AUD) and Hepatitis C virus (HCV) infection. In 2013, people over 55 years old accounted for 26% of the estimated number of people living with HIV (~1.2 million). The aging brain is increasingly vulnerable to endogenous and exogenous insult which, coupled with HIV infection and comorbid risk factors, can lead to additive or synergistic effects on cognitive and motor function. This paper reviews the literature on neuropsychological and in vivo Magnetic Resonance Imaging (MRI) evaluation of the aging HIV brain, while also considering the effects of comorbidity for AUD and HCV.

Lymphocyte-Dominant Encephalitis and Meningitis in Simian Immunodeficiency Virus-Infected Macaques Receiving Antiretroviral Therapy

A retrospective neuropathologic review of 30 SIV-infected pigtailed macaques receiving combination antiretroviral therapy (cART) was conducted. Seventeen animals with lymphocyte-dominant inflammation in the brain and/or meninges that clearly was morphologically distinct from prototypic SIV encephalitis and human immunodeficiency virus encephalitis were identified. Central nervous system (CNS) infiltrates in cART-treated macaques primarily comprised CD20⁺ B cells and CD3⁺ T cells with fewer CD68⁺ macrophages. Inflammation was associated with low levels of SIV RNA in the brain as shown by in situ hybridization, and generally was observed in animals with episodes of cerebrospinal fluid (CSF) viral rebound or sustained plasma and CSF viremia during treatment. Although the lymphocytic CNS inflammation in these macaques shared morphologic characteristics with uncommon immune-mediated neurologic disorders reported in treated HIV patients, including CNS immune reconstitution inflammatory syndrome and neurosymptomatic CSF escape, the high prevalence of CNS lesions in macaques suggests that persistent adaptive immune responses in the CNS also may develop in neuroasymptomatic or mildly impaired HIV patients yet remain unrecognized given the lack of access to CNS tissue for histopathologic evaluation. Continued investigation into the mechanisms and outcomes of CNS inflammation in cART-treated, SIV-infected macaques will advance our understanding of the consequences of residual CNS HIV replication in patients on cART, including the possible contribution of adaptive immune responses to HIV-associated neurocognitive disorders.

Imaging spectrum of immunomodulating, chemotherapeutic and radiation therapy-related intracranial effects

OBJECTIVE

A wide range of treatment-related side effects result in specific neurologic symptoms and signs and neuroimaging features. Even to the most seasoned neuroradiologist, elucidating therapy-related side effects from other common mimics can be challenging. We provide a pictorial survey of some common and uncommon medication-induced and therapy-related neuroimaging manifestations, discuss pathophysiology and common pitfalls in imaging and diagnosis.

METHODS

A case-based review is utilized to depict scenarios on a routine basis in a general radiology or neuroradiology practice such as medication-induced posterior reversible encephalopathy syndrome to the more challenging cases of pseudoprogression and pseudoregression in temozolmide and bevacizumab therapy in gliobastoma treatment protocols.

CONCLUSION

Knowledge of the treatment-induced imaging abnormalities is essential in the accurate interpretation and diagnosis from the most routine to most challenging of clinical situations. We provide a pictorial review for the radiologist to employ in order to be an invaluable provider to our clinical colleagues and patients.

Diagnosis and Treatment of Progressive Multifocal Leukoencephalopathy Associated with Multiple Sclerosis Therapies

Progressive multifocal leukoencephalopathy (PML) is a rare, but serious, complication encountered in patients treated with a select number of disease-modifying therapies (DMTs) utilized in treating multiple sclerosis (MS). PML results from a viral infection in the brain for which the only demonstrated effective therapy is restoring the perturbed immune system-typically achieved in the patient with MS by removing the offending therapeutic agent or, in the case of HIV-associated PML, treatment with highly active antiretroviral therapies. Other therapies for PML remain either ineffective or experimental. Significant work to understand the virus and host interaction has been undertaken, but lack of an animal model for the disorder has significantly hindered progress, especially with respect to development of treatments. Strategies to limit risk of PML with natalizumab, a drug that carries a uniquely high risk for the development of the disorder, have been developed. Identifying factors such as positive JC virus antibody status that increase PML risk, at least in theory, should decrease the incidence rate of the disease. Whether other risk factors for PML can be identified and validated or unique strategies should be employed in association with other DMTs that predispose to PML and whether this has a salutary effect on outcome remains to be demonstrated. Identifying PML early, then promptly eliminating drug in the case of natalizumab-associated PML has demonstrated better outcomes, but the complication of PML continues to carry significant morbidity and mortality. While the scientific community has yet to identify targeted therapy with proven efficacy against JCV or PML there are several candidates being studied.

Immune Reconstitution Inflammatory Syndrome Unmasking or Worsening AIDS-Related Progressive Multifocal Leukoencephalopathy: A Literature Review

Incidence of progressive multifocal leukoencephalopathy (PML) in HIV-infected patients has declined in the combined antiretroviral therapy (cART) era although a growing number of acquired immunodeficiency syndrome (AIDS)-related PML-immune reconstitution inflammatory syndromes (PML-IRIS) have been published during the same period. Therapeutic management of PML-IRIS is not consensual and mainly relies on corticosteroids. Our main aim was, in addition to provide a thoughtful analysis of published PML-IRIS cases, to assess the benefit of corticosteroids in the management of PML-IRIS, focusing on confirmed cases. We performed a literature review of the 46 confirmed cases of PML-IRIS cases occurring in HIV-infected patients from 1998 to September 2016 (21 unmasking and 25 paradoxical PML-IRIS). AIDS-related PML-IRIS patients were mostly men (sex ratio 4/1) with a median age of 40.5 years (range 12-66). Median CD4 T cell count before cART and at PML-IRIS onset was 45/μl (0-301) and 101/μl (20-610), respectively. After cART initiation, PML-IRIS occurred within a median timescale of 38 days (18-120). Clinical signs were motor deficits (69%), speech disorders (36%), cognitive disorders (33%), cerebellar ataxia (28%), and visual disturbances (23%). Brain MRI revealed hyperintense areas on T2-weighted sequences and FLAIR images (76%) and suggestive contrast enhancement (87%). PCR for John Cunningham virus (JCV) in cerebrospinal fluid (CSF) was positive in only 84% of cases; however, when performed, brain biopsy confirmed diagnosis of PML in 90% of cases and demonstrated histological signs of IRIS in 95% of cases. Clinical worsening related to PML-IRIS and leading to death was observed in 28% of cases. Corticosteroids were prescribed in 63% of cases and maraviroc in one case. Statistical analysis failed to demonstrate significant benefit from steroid treatment, despite spectacular improvement in certain cases. Diagnosis of PML-IRIS should be considered in HIV-infected patients with worsening neurological symptoms after initiation or resumption of effective cART, independently of CD4 cell count prior to cART. If PCR for JCV is negative in CSF, brain biopsy should be discussed. Only large multicentric randomized trials could potentially demonstrate the possible efficacy of corticosteroids and/or CCR5 antagonists in the management of PML-IRIS.

Dynamic of CSF and serum biomarkers in HIV-1 subtype C encephalitis with CNS genetic compartmentalization-case study

Despite the effective suppression of viremia with antiretroviral therapy, HIV can still replicate in the central nervous system (CNS). This was a longitudinal study of the cerebrospinal fluid (CSF) and serum dynamics of several biomarkers related to inflammation, the blood-brain barrier, neuronal injury, and IgG intrathecal synthesis in serial samples of CSF and serum from a patient infected with HIV-1 subtype C with CNS compartmentalization.The phylogenetic analyses of plasma and CSF samples in an acute phase using next-generation sequencing and F-statistics analysis of C2-V3 haplotypes revealed distinct compartmentalized CSF viruses in paired CSF and peripheral blood mononuclear cell samples. The CSF biomarker analysis in this patient showed that symptomatic CSF escape is accompanied by CNS inflammation, high levels of cell and humoral immune biomarkers, CNS barrier dysfunction, and an increase in neuronal injury biomarkers with demyelization. Independent and isolated HIV replication can occur in the CNS, even in HIV-1 subtype C, leading to compartmentalization and development of quasispecies distinct from the peripheral plasma. These immunological aspects of the HIV CNS escape have not been described previously. To our knowledge, this is the first report of CNS HIV escape and compartmentalization in HIV-1 subtype C.

An Overview of Human Immunodeficiency Virus Type 1-Associated Common Neurological Complications: Does Aging Pose a Challenge?

With increasing survival of patients infected with human immunodeficiency virus type 1 (HIV-1), the manifestation of heterogeneous neurological complications is also increasing alarmingly in these patients. Currently, more than 30% of about 40 million HIV-1 infected people worldwide develop central nervous system (CNS)-associated dysfunction, including dementia, sensory, and motor neuropathy. Furthermore, the highly effective antiretroviral therapy has been shown to increase the prevalence of mild cognitive functions while reducing other HIV-1-associated neurological complications. On the contrary, the presence of neurological disorder frequently affects the outcome of conventional HIV-1 therapy. Although, both the children and adults suffer from the post-HIV treatment-associated cognitive impairment, adults, especially depending on the age of disease onset, are more prone to CNS dysfunction. Thus, addressing neurological complications in an HIV-1-infected patient is a delicate balance of several factors and requires characterization of the molecular signature of associated CNS disorders involving intricate cross-talk with HIV-1-derived neurotoxins and other cellular factors. In this review, we summarize some of the current data supporting both the direct and indirect mechanisms, including neuro-inflammation and genome instability in association with aging, leading to CNS dysfunction after HIV-1 infection, and discuss the potential strategies addressing the treatment or prevention of HIV-1-mediated neurotoxicity.

HIV Immune Recovery Inflammatory Syndrome and Central Nervous System Paracoccidioidomycosis

The immune reconstitution inflammatory syndrome (IRIS) is a deregulated inflammatory response to invading microorganisms. It is manifested when there is an abrupt change in host immunity from an anti-inflammatory and immunosuppressive state to a pro-inflammatory state as a result of rapid depletion or removal of factors that promote immune suppression or inhibition of inflammation. The aim of this paper is to discuss and re-interpret the possibility of association of paracoccidioidomycosis (PCM) with IRIS in the central nervous system (CNS) in a case from Brazil published by Silva-Vergara ML. et al. (Mycopathologia 177:137-141, 6). An AIDS patient who was not receiving medical care developed pulmonary PCM successfully treated with itraconazole. The patient developed central nervous system PCM (NPCM) after starting the ARV therapy with recovery of immunity and control of HIV viral load, although it was not interpreted as IRIS by the authors, it fulfills the criteria for CNS IRIS. This could be the first case of NPCM associated with IRIS described. Although not frequent, IRIS must be considered in PCM patients and HIV, from endemic areas or patients that traveled to endemic areas, receiving ARV treatment and with worsening symptoms.

HIV and Cocaine Impact Glial Metabolism: Energy Sensor AMP-activated protein kinase Role in Mitochondrial Biogenesis and Epigenetic Remodeling

HIV infection and cocaine use have been identified as risk factors for triggering neuronal dysfunction. In the central nervous system (CNS), energy resource and metabolic function are regulated by astroglia. Glia is the major reservoir of HIV infection and disease progression in CNS. However, the role of cocaine in accelerating HIV associated energy deficit and its impact on neuronal dysfunction has not been elucidated yet. The aim of this study is to elucidate the molecular mechanism of HIV associated neuropathogenesis in cocaine abuse and how it accelerates the energy sensor AMPKs and its subsequent effect on mitochondrial oxidative phosphorylation (OXPHOS), BRSKs, CDC25B/C, MAP/Tau, Wee1 and epigenetics remodeling complex SWI/SNF. Results showed that cocaine exposure during HIV infection significantly increased the level of p24, reactive oxygen species (ROS), ATP-utilization and upregulated energy sensor AMPKs, CDC25B/C, MAP/Tau and Wee1 protein expression. Increased ROS production subsequently inhibits OCR/ECAR ratio and OXPHOS, and eventually upregulate epigenetics remodeling complex SWI/SNF in CHME-5 cells. These results suggest that HIV infection induced energy deficit and metabolic dysfunction is accelerated by cocaine inducing energy sensor AMPKs, mitochondrial biogenesis and chromatin remodeling complex SWI/SNF activation, which may lead to neuroAIDS disease progression.

Incidence and prognosis of immune reconstitution inflammatory syndrome in HIV-associated progressive multifocal leucoencephalopathy

BACKGROUND AND PURPOSE

Progressive multifocal leucoencephalopathy-associated immune reconstitution inflammatory syndrome (PML-IRIS) is the paradoxical worsening or unmasking of preexisting infection with JC virus attributable to a rapid recovery of the immune system after highly active antiretroviral therapy (HAART) initiation. We investigated the incidence and factors associated with PML-IRIS in HIV-infected patients. We also studied its influence on mortality of PML and the effect of corticosteroid therapy.

METHODS

Single-center retrospective analysis of HIV-infected patients diagnosed with PML from 1996 to 2012 who received HAART.

RESULTS

Among 59 PML patients treated with HAART, 18 (30.51%) developed PML-IRIS (five delayed PML-IRIS, 13 simultaneous PML-IRIS). Patients who developed IRIS had lower CD4 counts prior to treatment (102 vs. 68.5, P < 0.05) and experienced a greater decline in HIV-RNA levels in response to HAART (2.5log vs. 2.95log, P < 0.05). Gadolinium enhancement on MRI was observed in 31.25% of PML-IRIS cases versus 2.56% of PML non-IRIS (P < 0.01). Survival rates were higher in patients with PML-IRIS compared to those with PML non-IRIS. Eight patients received corticosteroids, five of which had a good outcome. Patients who died were severely ill when treatment was initiated whereas patients who survived were treated before major neurological deterioration occurred.

CONCLUSIONS

Nearly one-third of HIV-infected patients with PML develop IRIS after initiating HAART. Patients severely immunocompromised who experience a rapid virological response to HAART have a higher risk for PML-IRIS. There was a trend for lower mortality in patients with IRIS. Early treatment with corticosteroids might be useful.

Diagnostic Performance of Brain MRI in Immune Reconstitution Inflammatory Syndrome

BACKGROUND AND PURPOSE

Central nervous system immune reconstitution inflammatory syndrome (CNS-IRIS) significantly negatively impacts the human immunodeficiency virus (HIV)-infected population on combination antiretroviral therapy (cART). We sought to determine the diagnostic performance of several magnetic resonance imaging (MRI) features for CNS-IRIS in a cohort of HIV+ patients recently started on cART.

METHODS

Our radiologic database was searched from January 2003 to September 2014 retrospectively for patients diagnosed with HIV and worsening symptoms on cART. A total of 20 patients with HIV were identified; patients were classified as having CNS-IRIS on the basis of established clinical criteria (8 patients; 12 age- and sex-matched controls). Brain MR images were obtained at a single post-cART timepoint during hospitalization for acute neurologic deterioration and blindly interpreted by two experienced neuroradiologists for the presence of four variables: intrinsic T1 hyperintensity, marginal reduced diffusion, and marginal enhancement or perivascular enhancement.

RESULTS

Although each individual finding showed moderate predictive accuracy, the combination of MR findings demonstrated good test characteristics: sensitivity 88% (confidence interval [CI] 62-98), specificity 79% (58-93), positive predictive value 71% (44-90%), and negative predictive value 83% (CI 52-98%). In addition, this final diagnosis demonstrated good predictive accuracy, area under curve .78 (CI .63-.91), and moderate inter-reader agreement, κ = .55.

CONCLUSIONS

Our findings suggest that although each individual MR finding shows only moderate diagnostic performance, the combined assessment of experienced neuroradiologists has good predictive accuracy. The absence of any described MRI findings makes the diagnosis of CNS-IRIS highly unlikely.

Neuro OIs: developed and developing countries

PURPOSE OF REVIEW

To review recent studies that address the pathogenesis, diagnosis and treatment of HIV positive patients with cryptococcal and tuberculous meningitis and progressive multifocal leukoencephalopathy in resource-different settings.

RECENT FINDINGS

Central nervous system opportunistic infections remain globally prevalent in HIV+ populations. Several recent papers have highlighted the urgent need for rapid point of care tests in low-income settings for cryptococcal and tuberculous meningitis, better access to antifungal therapy for cryptococcal meningitis and better treatment strategies for tuberculous meningitis. In one recent study of 299 HIV+ patients with cryptococcal meningitis, amphotericin plus flucytosine was associated with less mortality and disability compared to amphotericin alone. In a study of patients with tuberculous meningitis in Indonesia, short-term, high dose rifampicin and moxifloxacin, designed to achieve higher levels of anti-TB drugs in the brain, saw significantly reduced patient mortality at 6 months. The timing of ART initiation in patients with central nervous system opportunistic infections remains challenging and a recent study reported that deferred vs early antiretroviral therapy was associated with better survival outcomes in patients diagnosed with cryptococcal meningitis. Recent studies have reported on predictors of immune reconstitution inflammatory syndrome for patients with central nervous system opportunistic infections, but require validation in resource-different settings.

SUMMARY

Recent studies related to the diagnosis and treatment of central nervous system opportunistic infections in HIV+ populations show promising findings. Increased funding and research commitment are required to maintain this positive momentum and to achieve improved global outcomes for people who develop central nervous system opportunistic infections.

Mitochondrial DNA depletion syndrome causing liver failure

BACKGROUND

Mitochondrial DNA depletion syndromes are disorders of Mitochondrial DNA maintenance causing varied manifestations, including fulminant liver failure.

CASE CHARACTERISTICS

Two infants, presenting with severe fatal hepatopathy.

OBSERVATION

Raised serum lactate, positive family history (in first case), and absence of other causes of acute liver failure.

OUTCOME

Case 1 with homozygous mutation, c.3286C>T (p.Arg1096Cys) in POLG gene and case 2 with compound heterozygous mutations, novel c.408T>G (p.Tyr136X) and previously reported c.293C>T (p.Pro98Leu), in MPV17 gene.

MESSAGE

Mitochondrial DNA depletion syndrome is a rare cause of severe acute liver failure in children.

Partial recovery after severe immune reconstitution inflammatory syndrome in a multiple sclerosis patient with progressive multifocal leukoencephalopathy

Progressive multifocal leukoencephalopathy (PML) is a rare and severe complication of natalizumab therapy in patients with multiple sclerosis and it may be accompanied by immune reconstitution inflammatory syndrome (IRIS). Here, we describe a case of abnormally severe IRIS, which occurred 2 months after natalizumab-associated PML in a 38-year-old woman affected by multiple sclerosis. The patient was John Cunningham virus-positive and was treated for 21 months when she developed PML. The subsequent IRIS diffusely afflicted the brain, producing edema and signs of intracranial hypertension, with a clinically severe form compromising the state of consciousness, requiring intensive care and high-dosage steroid treatment. Nevertheless, she survived and partially recovered. There is still difficulty in differentiating PML progression from IRIS onset and there is not a clear description in the literature about different clinical forms of IRIS, prognostic factors and guidelines to properly treat this complication in order to reduce the residual disability of the patient surviving this treatment complication.

Varicella zoster virus central nervous system immune reconstitution inflammatory syndrome presenting in a child

A HIV-positive child presented with acute onset of right hemiplegia, facial palsy and dysphasia 4 weeks after commencing highly active antiretroviral therapy. Magnetic resonance imaging confirmed a left-sided cerebral infarct. Cerebrospinal fluid polymerase chain reaction was positive for varicella zoster virus. This is the first reported pediatric case of varicella zoster virus-related immune reconstitution inflammatory syndrome involving the central nervous system.

Where does HIV hide? A focus on the central nervous system

PURPOSE OF REVIEW

To review the literature on infection and evolution of HIV within the brain in the context for understanding the nature of the brain reservoir and its consequences.

RECENT FINDINGS

HIV-1 in the brain can evolve in separate compartments within macrophage/microglia and astrocytes. The virus adapts to the brain environment to infect these cells and brain-specific mutations can be found in nearly all genes of the virus. The virus evolves to become more neurovirulent.

SUMMARY

The brain is an ideal reservoir for the HIV. The brain is a relatively immune privileged site and the blood-brain barrier prevents easy access to antiretroviral drugs. Further, the virus infects resident macrophages and astrocytes which are long-lived cells and causes minimal cytopathology in these cells. Hence as we move towards developing strategies for eradication of the virus from the peripheral reservoirs, it is critical that we pay close attention to the virus in the brain and develop strategies for maintaining it in a latent state failure of which could result in dire consequences.

Increases in brain white matter abnormalities and subcortical gray matter are linked to CD4 recovery in HIV infection

MRI alterations in the cerebral white (WM) and gray matter (GM) are common in HIV infection, even during successful combination antiretroviral therapy (CART), and their pathophysiology and clinical significance are unclear. We evaluated the association of these alterations with recovery of CD4+ T cells. Seventy-five HIV-infected (HIV+) volunteers in the CNS HIV Anti-Retroviral Therapy Effects Research study underwent brain MRI at two visits. Multi-channel morphometry yielded volumes of total cerebral WM, abnormal WM, cortical and subcortical GM, and ventricular and sulcal CSF. Multivariable linear regressions were used to predict volumetric changes with change in current CD4 and detectable HIV RNA. On average, the cohort (79 % initially on CART) demonstrated loss of total cerebral WM alongside increases in abnormal WM and ventricular volumes. A greater extent of CD4 recovery was associated with increases in abnormal WM and subcortical GM volumes. Virologic suppression was associated with increased subcortical GM volume, independent of CD4 recovery. These findings suggest a possible link between brain alterations and immune recovery, distinct from the influence of virologic suppression. The association of increasing abnormal WM and subcortical GM volumes with CD4+ T cell recovery suggests that neuroinflammation may be one mechanism in CNS pathogenesis.

CNS-immune reconstitution inflammatory syndrome in the setting of HIV infection, part 2: discussion of neuro-immune reconstitution inflammatory syndrome with and without other pathogens

SUMMARY

While the previous review of CNS-IRIS in the HIV-infected patient on highly active antiretroviral therapy (Part 1) dealt with an overview of the biology, pathology, and neurologic presentation of this condition and a discussion of the atypical imaging findings in PML-IRIS and cryptococcal meningitis-IRIS due to the robust inflammatory response, the current review (Part 2) discusses the imaging findings in other commonly encountered organisms seen in association with CNS-IRIS, namely, VZV, CMV, HIV, Candida organisms, Mycobacterium tuberculosis, and Toxoplasma gondii. Also described is the imaging appearance of CNS-IRIS when not associated with a particular organism. Recognition of these imaging findings will give credence to the diagnosis of CNS-IRIS and will allow the clinician to institute changes in medical management, if necessary, so that immune reconstitution and improved patient outcome can occur with time.

A case report of simultaneous PML-IRIS during corticosteroids tapering in a patient with an anti-synthetase syndrome

We report a case of simultaneous progressive multifocal leukoencephalopathy-associated immune reconstitution inflammatory syndrome (PML-IRIS) during corticosteroid tapering in a patient with an anti-synthetase syndrome. We describe the challenges associated with the diagnosis and the management of this emerging inflammatory neurological condition in this immunocompromised patient with a severe rheumatic disease. We highlight that, in the setting of IRIS, the low-level of the JC virus viral load requires a sensitive PCR assay before excluding PML.

Progressive multifocal leukoencephalopathy: why gray and white matter

Since it was first described in 1958, progressive multifocal leukoencephalopathy (PML), a demyelinating disease of the brain caused by the polyomavirus JC (JCV), has evolved tremendously. It was once considered a noninflammatory disease that affected exclusively oligodendrocytes and astrocytes in the white matter of immunosuppressed individuals and was almost always fatal. Today, we understand that PML can present during the course of an immune reconstitution inflammatory syndrome and that it affects a broader range of individuals, including patients with minimal immunosuppression and those who are treated with novel immunomodulatory medications. Furthermore, JCV-infected glial cells are frequently located at the gray matter-white matter junction or within the gray matter, causing demyelinating lesions within cortical areas. Finally, JCV variants can also infect neurons, leading to the recognition of two distinct clinical entities: JCV granule cell neuronopathy and JCV encephalopathy.

Metabolic profile of PML lesions in patients with and without IRIS: an observational study

OBJECTIVE

To characterize progressive multifocal leukoencephalopathy (PML) lesions by contrast-enhanced MRI and evaluate their metabolism using proton magnetic resonance spectroscopy ((1)H- MRS) in the setting of immune reconstitution inflammatory syndrome (IRIS).

METHODS

A total of 42 patients with PML underwent a clinical evaluation as well as brain MRI and (1)H-MRS at baseline and 3, 6, and 12 months later. The presence of IRIS was determined based on clinical and laboratory criteria. Ratios of N-acetylaspartate (NAA), choline (Cho), myo-inositol (mI), and lipid/lactate (Lip1 and Lip2) to creatine (Cr) were measured and correlated with the presence of contrast enhancement (CE) in PML lesions.

RESULTS

IRIS occurred in 16 of 28 (57.1%) PML survivors (PML-S) and 1 of 14 (7.1%) PML progressors (PML-P). Lesions of patients with PML-IRIS showed significantly higher Cho/Cr (p = 0.0001), mI/Cr (p = 0.02), Lip1/Cr (p < 0.0001), and Lip2/Cr (p = 0.002) ratios and lower NAA/Cr (p = 0.02) ratios than patients with PML who did not have IRIS. An elevated Cho/Cr ratio was associated with CE within the (1)H-MRS voxel, whereas lipid/Cr ratios were elevated in PML-IRIS lesions independently of CE. Follow-up until 33 months from PML onset showed persistent elevation of the mI/Cr ratio in lesions of patients with PML-IRIS. A Lip1/Cr ratio greater than 1.5 combined with the presence of CE yielded a 79% probability of IRIS compared with 13% in the absence of these criteria.

CONCLUSION

(1)H-MRS is a valuable tool to recognize and track IRIS in PML and may prove useful in the clinical management of these patients.

CNS-immune reconstitution inflammatory syndrome in the setting of HIV infection, part 1: overview and discussion of progressive multifocal leukoencephalopathy-immune reconstitution inflammatory syndrome and cryptococcal-immune reconstitution inflammatory syndrome

SUMMARY

While uncommon, CNS-IRIS developing after the initiation of HAART in the setting of HIV-related severe immunosuppression is characterized by an intense inflammatory reaction to dead or latent organisms or to self-antigens due to a heightened but dysregulated immune response. While this reaction can range from mild to fulminating, encompassing a very wide clinical spectrum, it is important to recognize because changes in medical management may be necessary to prevent neurologic decline and even death. Once contained, however, this inflammatory response can be associated with improved patient outcome as immune function is restored. Among the infectious organisms that are most commonly associated with CNS-IRIS are the JC virus and Cryptococcus organisms, which will be the subject of this review. CD8 cell infiltration in the leptomeninges, perivascular spaces, blood vessels, and even parenchyma seems to be the pathologic hallmark of CNS-IRIS. While recognition of CNS-IRIS may be difficult, the onset of new or progressive clinical symptoms, despite medical therapy and despite improved laboratory data, and the appearance on neuroimaging studies of contrast enhancement, interstitial edema, mass effect, and restricted diffusion in infections not typically characterized by these findings in the untreated HIV-infected patient should raise the strong suspicion for CNS-IRIS. While CNS-IRIS is a diagnosis of exclusion, the neuroradiologist can play a critical role in alerting the clinician to the possibility of this syndrome.

Simultaneous PML-IRIS after discontinuation of natalizumab in a patient with MS

OBJECTIVE

Progressive multifocal leukoencephalopathy (PML) is a severe complication of natalizumab therapy in patients with multiple sclerosis (MS), which is often accompanied by an immune reconstitution inflammatory syndrome (IRIS) after removal of the drug. We describe a patient with MS who presented with simultaneous PML-IRIS 2 months after stopping natalizumab for other reasons.

CASE REPORT AND RESULTS

The patient had widespread PML and severe IRIS. He received corticosteroids and displayed a vigorous JC virus-specific cellular immune response. Elevated myoinositol and lipid/creatine peaks measured in PML lesions by proton magnetic resonance spectroscopy ((1)H-MRS) corresponded to episodes of contrast enhancement on MRI scans and persisted after the enhancement subsided. He demonstrated steady clinical improvement, but developed marked residual atrophy in areas affected by PML and inflammation, as well as seizures.

CONCLUSIONS

New enhancing white matter lesions, occurring after discontinuation of natalizumab, can be the manifestation of PML-IRIS rather than an MS exacerbation. Elevated myoinositol and lipid/creatine peaks appear to be more sensitive markers of inflammation in PML lesions than contrast enhancement. (1)H-MRS may become useful as a biomarker for PML-IRIS by helping clinicians determine the need for corticosteroid administration and anticipate continuing clinical recovery.

Progressive multifocal leukoencephalopathy: a review of the neuroimaging features and differential diagnosis

Progressive multifocal leukoencephalopathy (PML) is an uncommon and often fatal demyelinating disease of human central nervous system, which is caused by reactivation of the polyomavirus JC (JCV). PML generally occurs in patients with profound immunosuppression such as AIDS patients. Recently, a number of PML cases have been associated with administration of natalizumab for treatment of multiple sclerosis (MS) patients. Diagnosis and management of PML became a major concern after its occurrence in multiple sclerosis patients treated with natalizumab. Diagnosis of PML usually rests on neuroimaging in the appropriate clinical context and is further confirmed by cerebrospinal fluid polymerase chain reaction (PCR) for JCV DNA. Treatment with antiretroviral therapies in HIV-seropositive patients or discontinuing natalizumab in MS patients with PML may lead to the development of immune reconstitution inflammatory syndrome (IRIS) which presents with deterioration of the previous symptoms and may lead to death. In patients under treatment with monoclonal antibodies in routine practice, or new ones in ongoing clinical trials, differentiating PML from new MS lesions on brain MRI is critical for both the neurologists and neuroradiologists. In this review, we discuss the clinical features, neuroimaging manifestations of PML, IRIS and neuroimaging clues to differentiate new MS lesions from PML. In addition, various neuroimaging features of PML on the non-conventional MR techniques such as diffusion-weighted imaging (DWI), diffusion tensor imaging (DTI), and MR spectroscopy (MRS) are discussed.

Immune reconstitution is not a prognostic factor in progressive multifocal leukoencephalopathy

Progressive multifocal leukoencephalopathy (PML) is typically associated with minimal inflammation; however, patients may develop an inflammatory response due to immune reconstitution (IRIS). The authors aimed to determine if characteristics and outcomes of PML are altered in those with IRIS. A retrospective records review was performed on 87 patients diagnosed with PML at Johns Hopkins, 27 of which had a syndrome consistent with IRIS. Gadolinium enhancement on MRI occurred in 44.4% of cases of PML-IRIS versus 5.1% in PML (p<0.05), and thus had low diagnostic sensitivity and specificity. In HIV+ cases, CD4 counts were lower in those who later developed IRIS (mean 34.8 vs. 71.7, p<0.05) and was predictive of the development of IRIS (p<0.05). Improved prognosis was seen with higher cerebrospinal fluid (CSF) white blood cell counts and protein levels, but not for gadolinium enhancement and there were no differences in survival for PML versus PML-IRIS.

Reversible dementia in a patient with central nervous system escape of human immunodeficiency virus

HIV-associated neurocognitive disorders (HAND) are a group of conditions ranging from asymptomatic neurocognitive impairment to disabling dementia. The clinical spectrum and pathogenesis of these disorders is changing in the era of highly active antiretroviral therapy (HAART). High levels of HIV may exist in the cerebrospinal fluid (CSF) of some patients despite suppression of serum viral loads by HAART. We report a case of a 51-year-old male with profound levels of HIV in the CSF despite low serum levels. Adjusting his HAART regimen based on HIV genotype susceptibility data and a CNS Penetrating Effectiveness (CPE) score resulted in a dramatic improvement in cognitive function. Progressive dementia in this context is a rare but emerging trend and may be reversible.