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

Perivascular enhancement pattern: Identification, diagnostic spectrum and practical approach - A pictorial review

Perivascular spaces (PVS) are fluid-filled structures that form the immediate peripheral environment of small cerebral vessels. They are a central component of the glymphatic system, which plays a crucial role in maintaining cerebral homeostasis. Their involvement in central nervous system diseases is currently a major focus of research, particularly in neuroimaging. Pathological enhancement of PVS on post-contrast MRI sequences creates a distinctive pattern due to their topography. As with other intracranial enhancement patterns, a differential diagnosis approach can be applied to perivascular enhancement (PVE). However, it is particularly challenging due to the rarity and complexity of the conditions involved. This article aims to facilitate the recognition of PVE pattern, to highlight the various causal conditions and to propose a practical diagnostic approach.

MRI changes in cryptococcal meningoencephalitis exacerbated by antifungal treatment due to post-infectious inflammatory syndrome: A case report

Cryptococcal meningitis is one of the most common fungal meningitis in adults and causes disabling morbidity and mortality worldwide. The occurrence of postinfectious inflammatory response syndrome during cryptococcal meningitis treatment presents a diagnostic challenge. This time course seems paradoxical because patients show worsening symptoms and imaging findings. However, laboratory data improve with antifungal treatments. Herein, we present a case of an older woman diagnosed with cryptococcal meningitis who later developed postinfectious inflammatory response syndrome. Despite the initial antifungal treatment and improvements in cerebrospinal fluid analysis results, the patient's neurological condition deteriorated; imaging findings worsened. Magnetic resonance imaging at the time of postinfectious inflammatory response syndrome showed more prominent meningeal enhancement and brain edema, consistent with postinfectious inflammatory response syndrome, combined with negative repeat cerebrospinal fluid cultures for cryptococcal species. This case highlights the importance of considering postinfectious inflammatory response syndrome when patients with cryptococcal meningitis show clinical worsening during treatment. Prompt corticosteroid therapy significantly improves patient outcomes. Radiologists and clinicians should be aware of postinfectious inflammatory response syndrome to provide appropriate therapeutic options and improve prognosis in patients with cryptococcal meningitis.

Fatal outcome of BK virus encephalitis in an allogeneic stem cell transplantation recipient

BK virus (BKV) encephalitis is a rare complication after hematopoietic stem cell transplantation (HSCT). A 43-year-old woman with recurrent follicular lymphoma after autologous HSCT received allogeneic bone marrow transplantation from a human leukocyte antigen-matched related donor. Neutrophil engraftment was achieved on post-transplant day 13. Memory loss and noncooperative attitude toward the medical staff were observed on day 16, and her mental status worsened progressively. Magnetic resonance imaging (MRI) showed nonspecific findings on day 19; however, cerebrospinal fluid (CSF) analysis including real-time polymerase chain reaction on day 20 revealed elevated levels of BKV 4.67 × 104 copy/mL. BKV encephalitis was diagnosed based on CSF findings, intravenous administration of immunoglobulin and cidofovir was started, and the immunosuppressive agent dose was reduced. Diffusion-weighted MRI on day 28 showed signal abnormalities in the bilateral periventricular white matter. Although the follow-up CSF analysis on day 35 was negative for BKV, her mental status and MRI findings did not improve, and she died on day 55 because of respiratory failure. This case emphasizes the importance of considering BKV encephalitis as a differential diagnosis of post-transplant encephalitis, considering the central nervous system-associated immune reconstitution inflammatory syndrome in patients with worsening central nervous system findings after eradication of BKV in the CSF.

John Cunningham Virus and Progressive Multifocal Leukoencephalopathy: A Falsely Played Diagnosis

Progressive Multifocal Leukoencephalopathy (PML) is a possibly fatal demyelinating disease and John Cunningham Polyomavirus (JCPyV) is believed to cause this condition. The so-called JCPyV was initially reported in lymphoma and Human Immunodeficiency Virus (HIV) cases, whereas nowadays, its incidence is increasing in Multiple Sclerosis (MS) cases treated with natalizumab (Tysabri). However, there are conflicting literature data on its pathology and diagnosis, whereas some misdiagnosed reports exist, giving rise to further questions towards the topic. In reality, the so-called PML and the supposed JCPyV are not what they seem to be. In addition, novel and more frequent PML-like conditions may be reported, especially after the Coronavirus Disease 2019 (COVID-19) pandemic.

[Progressive multifocal leukoencephalopathy in HIV-positive individuals]

The article discusses the historical aspect and modern ideas about the etiology and pathogenesis of progressive multifocal leukoencephalopathy in patients with HIV infection. An analysis and synthesis of literature data on the clinical presentation of this pathology was carried out. The possibilities and limitations of laboratory and instrumental diagnostic methods, including neuroimaging methods, are discussed in detail. The pathomorphological signs of the disease in HIV-positive individuals are covered.

Brain opportunistic infections and tumors in people living with HIV - still a challenge in efficient antiretroviral therapy era

The aim of the study was to evaluate the incidence of brain opportunistic pathologies and survival in patients living with HIV from a Romanian tertiary center. A 15-year prospective observational study of brain opportunistic infections diagnosed in HIV-infected patients was performed at Victor Babes Hospital, Bucharest, between January 2006 and December 2021. Characteristics and survival were compared related to modes of HIV acquisition and type of opportunistic infection. A total of 320 patients were diagnosed with 342 brain opportunistic infections (incidence 9.79 per 1000 person-years), 60.2% males with median age at diagnosis of 31 years (IQR 25, 40). Median CD4 cell count and VL were 36/μL (IQR 14, 96) and 5.1 log10 copies/mL (IQR 4, 5.7) respectively. The routes of HIV acquisition were heterosexual (52.6%), parenteral route in early childhood (31.6%), injecting drug use (12.9%), men having sex with men (1.8%), and vertical (1.2%). The most common brain infections were progressive multifocal leukoencephalopathy (31.3%), cerebral toxoplasmosis (26.9%), tuberculous meningitis (19.3%), and cryptococcal meningitis (16.7%). Patients infected by parenteral mode in early childhood were younger at diagnosis of both opportunistic infection and HIV (p < 0.001 and p < 0.001, respectively), developed more frequently PML (p < 0.001), and had the lowest early (p = 0.002) and late (p = 0.019) mortality rates. Risk factors for shorter survival were age > 30 years (p = 0.001), injecting drug use (p = 0.003), CD4 +  < 100/μL (p = 0.007), and VL > 5 log10 copies/mL at diagnosis (p < 0.001). The incidence and mortality rate of brain opportunistic infections were high and did not decrease significantly during the study period, due to late presentation or non-adherence to ART.

Atypical presentation of progressive disseminated histoplasmosis in a patient recently diagnosed with AIDS

Opportunistic infections, including progressive disseminated histoplasmosis (PDH), may have variable and surprising presentations in patients with AIDS. This can be either a primary infection or reactivation of a latent infection. Latent infections may occur due to being unmasked by the immune reconstitution inflammatory syndrome after the initiation of combined antiretroviral therapy. PDH can be difficult to diagnose in patients with AIDS due to its variable presentation and many overlapping symptoms with other opportunistic infections. Serum and urine antigen testing are highly sensitive and typically used as the initial diagnostic test to workup suspected PDH. However, negative antigen and antibody tests do not rule out Histoplasmosis capsulatum infection and suspicion should remain high for PDH in the right clinical context. A definitive diagnosis may require biopsy-proven narrow-based budding yeast. We present an interesting patient with AIDS who presented with worsening cognitive decline and was ultimately diagnosed with PDH based on biopsy histopathology in the setting of negative antigen and antibody testing.

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.

Biotypes of HIV-associated neurocognitive disorders based on viral and immune pathogenesis

PURPOSE OF REVIEW

HIV-associated neurocognitive disorders (HAND) continues to be prevalent in people living with HIV despite antiretroviral therapy. However, understanding disease mechanisms and identifying therapeutic avenues has been challenging. One of the challenges is that HAND is a heterogeneous disease and that patients identified with similar impairments phenotypically may have very different underlying disease processes. As the NeuroAIDS field is re-evaluating the approaches used to identify patients with HIV-associated neurological impairments, we propose the subtyping of patients into biotypes based on viral and immune pathogenesis.

RECENT FINDINGS

Here we review the evidence supporting subtyping patients with HIV-associated neurological complications into four biotypes: macrophage-mediated HIV encephalitis, CNS viral escape, T-cell-mediated HIV encephalitis, and HIV protein-associated encephalopathy.

SUMMARY

Subtyping patients into subgroups based on biotypes has emerged as a useful approach for studying heterogeneous diseases. Understanding biotypes of HIV-associated neurocognitive impairments may therefore enable better understanding of disease mechanisms, allow for the development of prognostic and diagnostic markers, and could ultimately guide therapeutic decisions.

Metastatic Squamous Cell Carcinoma Presenting as Symptom of AIDS

The development of metastatic cutaneous squamous cell carcinoma in an otherwise healthy and young individual should prompt physicians to investigate for an underlying cause of immunosuppression. The following case presents an individual who underwent Mohs surgery of a poorly differentiated squamous cell carcinoma. Four months following Mohs surgery, the patient presented with lymphadenopathy and new skin nodules. Metastatic disease or infection were included in the differential diagnosis. An immunosuppression work-up was completed and the patient was diagnosed with human immunodeficiency virus (HIV). Treatment with antiretroviral therapy was initiated 1 month prior to treatment of the metastatic disease with an immunomodulator, cemimplimab-rwlc. This contribution highlights the importance of determining the immunological status of a patient who presents with metastatic disease following a complete tumor clearance.

MRI imaging features of HIV-related central nervous system diseases: diagnosis by pattern recognition in daily practice

With the advent of antiretroviral therapy (ART), the prognosis of people infected with human immunodeficiency virus (HIV) has improved, and the frequency of HIV-related central nervous system (CNS) diseases has decreased. Nevertheless, mortality from HIV-related CNS diseases, including those associated with ART (e.g., immune reconstitution inflammatory syndrome) remains significant. Magnetic resonance imaging (MRI) can improve the outlook for people with HIV through early diagnosis and prompt treatment. For example, HIV encephalopathy shows a diffuse bilateral pattern, whereas progressive multifocal leukoencephalopathy, HIV-related primary CNS lymphoma, and CNS toxoplasmosis show focal patterns on MRI. Among the other diseases caused by opportunistic infections, CNS cryptococcosis and CNS tuberculosis have extremely poor prognoses unless diagnosed early. Immune reconstitution inflammatory syndrome shows distinct MRI findings from the offending opportunistic infections. Although distinguishing between HIV-related CNS diseases based on imaging alone is difficult, in this review, we discuss how pattern recognition approaches can contribute to their early differentiation.

JC Polyomavirus and Transplantation: Implications for Virus Reactivation after Immunosuppression in Transplant Patients and the Occurrence of PML Disease

The JC polyomavirus (JCPyV/JCV) is a member of the Polyomaviridae family and is ubiquitious in the general population, infecting 50–80% of individuals globally. A primary infection with JCV usally results in an asymptomatic, persistent infection that establishes latency in the renourinary tract. Reactivation from latency via iatrogenic immununosuppression for allograft transplantation may result in organ pathology and a potential life-threatening neuropathological disease in the form of progressive multifocal leukoencephalopathy (PML). Currently, no treatment exists for PML, a rare complication that occurs after transplantation, with an incidence of 1.24 per 1000 persons a year among solid organ transplant patients. PML is also observed in HIV patients who are immununosuppressed and are not receiving antiretroviral therapy, as well as individuals treated with biologics to suppress chronic inflammatory responses due to multiple sclerosis, Crohn’s disease, non-Hodgkin’s lymphoma, rheumatoid arthritis, and other autoimmune-mediated hematological disorders. Here, we describe the proposed mechanisms of JCV reactivation as it relates to iatrogenic immunosuppression for graft survival and the treatment of proinflammatory disease, such as biologics, proposed trafficking of JCV from the renourinary tract, JCV central nervous system dissemination and the pathology of PML in immunosuppressed patients, and potential novel therapeutics for PML disease.

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.

Fifty Years of JC Polyomavirus: A Brief Overview and Remaining Questions

In the fifty years since the discovery of JC polyomavirus (JCPyV), the body of research representing our collective knowledge on this virus has grown substantially. As the causative agent of progressive multifocal leukoencephalopathy (PML), an often fatal central nervous system disease, JCPyV remains enigmatic in its ability to live a dual lifestyle. In most individuals, JCPyV reproduces benignly in renal tissues, but in a subset of immunocompromised individuals, JCPyV undergoes rearrangement and begins lytic infection of the central nervous system, subsequently becoming highly debilitating-and in many cases, deadly. Understanding the mechanisms allowing this process to occur is vital to the development of new and more effective diagnosis and treatment options for those at risk of developing PML. Here, we discuss the current state of affairs with regards to JCPyV and PML; first summarizing the history of PML as a disease and then discussing current treatment options and the viral biology of JCPyV as we understand it. We highlight the foundational research published in recent years on PML and JCPyV and attempt to outline which next steps are most necessary to reduce the disease burden of PML in populations at risk.

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.

Postinfectious inflammatory response syndrome in HIV-uninfected and nontransplant men after cryptococcal meningitis

Aim: The aim of our study was to describe the characteristics of postinfectious inflammatory response syndrome (PIIRS) in HIV-uninfected and nontransplant men after cryptococcal meningitis (CM). Patients & methods: A case-control study was designed to compare HIV-uninfected and nontransplant male CM patients with and without PIIRS. Results: CM-PIIRS patients had increased rates of hearing loss, V-P shunt placement, amphotericin B treatment, higher cerebrospinal fluid pressures and Cryptococcus counts in the first CM episode. CM-PIIRS episode was characterized by higher frequencies of headache and fever, higher C-reactive protein, erythrocyte sedimentation rate, cerebrospinal fluid white blood cell (WBC) counts and modified Rankin Score. Brain MRI scans revealed the high signal lesions on axial flair imaging. Receipt of corticosteroid therapy was associated with lower rates of fever and better modified Rankin Score scores at 1 month after treatment. Conclusion: CM-PIIRS episode differs to the initial presentation, may help to identify which patients are at risk to develop PIIRS. Steroids therapy could be beneficial.

Susceptibility-Weighted MR Imaging Hypointense Rim in Progressive Multifocal Leukoencephalopathy: The End Point of Neuroinflammation and a Potential Outcome Predictor

BACKGROUND AND PURPOSE

Progressive multifocal leukoencephalopathy (PML) represents a life-threatening demyelinating disorder of the brain caused by reactivation of a rare opportunistic infection with JC Polyomavirus. The aims of this study were to describe the incidence of a susceptibility-weighted imaging hypointense rim in patients with multifocal leukoencephalopathy and to explore the histologic correlates and prognostic value of the rim with regard to the clinical outcome.

MATERIALS AND METHODS

This retrospective study included 18 patients with a definite diagnosis of progressive multifocal leukoencephalopathy. Ten patients were HIV-positive, 3 patients had natalizumab-associated progressive multifocal leukoencephalopathy, 1 patient had multiple myeloma, 3 patients had a history of lymphoma, and 1 was diagnosed with acute myeloid leukemia. Patients were divided into short- (up to 12 months) and long-term (>12 months) survivors. A total of 93 initial and follow-up MR imaging examinations were reviewed. On SWI, the presence and development of a hypointense rim at the periphery of the progressive multifocal leukoencephalopathy lesions were noted. A postmortem histologic examination was performed in 2 patients: A rim formed in one, and in one, there was no rim.

RESULTS

A total of 73 progressive multifocal leukoencephalopathy lesions were observed. In 13 (72.2%) patients, a well-defined thin, linear, hypointense rim at the periphery of the lesion toward the cortical side was present, while in 5 (27.8%) patients, it was completely absent. All 11 long-term survivors and 2 short-term survivors presented with a prominent SWI-hypointense rim, while 5/7 short-term survivors did not have this rim.

CONCLUSIONS

The thin, uniformly linear, gyriform SWI-hypointense rim in the paralesional U-fibers in patients with definite progressive multifocal leukoencephalopathy might represent an end-point stage of the neuroinflammatory process in long-term survivors.

Simultaneous Development of Progressive Multifocal Leukoencephalopathy and Cryptococcal Meningitis during Methotrexate and Infliximab Treatment

Progressive multifocal leukoencephalopathy (PML) is a demyelinating disease of the central nervous system caused by reactivation of the JC virus under an immunosuppressed state. This condition carries a high risk of cryptococcal meningitis. We herein report a 65-year-old woman who simultaneously developed PML and cryptococcal meningitis and presented with bilateral sixth nerve palsy. She had been treated with methotrexate and infliximab for rheumatoid arthritis. Her symptoms improved with antifungal drug treatment and discontinuation of immunosuppression therapy. Although concurrent PML and cryptococcal meningitis is rare, it should be considered in immunosuppressed patients.

Inflammatory natalizumab-associated PML: baseline characteristics, lesion evolution and relation with PML-IRIS

BACKGROUND AND OBJECTIVE

Natalizumab-associated progressive multifocal leukoencephalopathy (NTZ-PML) patients may show imaging signs suggestive of inflammation at diagnosis ('inflammatory PML'), reminiscent of PML-immune reconstitution inflammatory syndrome (PML-IRIS). We investigated the imaging characteristics of inflammatory NTZ-PML lesions and PML-IRIS to determine differentiating and overlapping features.

METHODS

We scored the presence, localisation and pattern of imaging characteristics of inflammation on brain MRI scans of inflammatory NTZ-PML patients. The imaging characteristics were followed up until the occurrence of PML-IRIS.

RESULTS

Ten out of the 44 NTZ-PML patients included showed signs suggestive of inflammation at the time of diagnosis. The inflammation pattern at diagnosis was similar to the pattern seen at PML-IRIS, with contrast enhancement representing the most frequent sign of inflammation (90% at diagnosis, 100% at PML-IRIS). However, the severity of inflammation differed, with absence of swelling and low frequency of perilesional oedema (10%) at diagnosis, as compared with the PML-IRIS stage (40%).

CONCLUSION

Patterns of inflammation at the time of PML diagnosis and at the PML-IRIS stage overlap but differ in their severity of inflammation. This supports histopathological evidence that the inflammation seen at both stages of the same disease shares a similar underlying pathophysiology, representing the immune response to the JC virus to a variable extend.

Neuroimaging in Central Nervous System Infections

Radiologic imaging is often employed to supplement clinical evaluation in cases of suspected central nervous system (CNS) infection. While computed tomography (CT) is superior for evaluating osseous integrity, demineralization, and erosive changes and may be more readily available at many institutions, magnetic resonance imaging (MRI) has significantly greater sensitivity for evaluating the cerebral parenchyma, cord, and marrow for early changes that have not yet reached the threshold for CT detection. For these reasons, MRI is generally superior to CT for characterizing bacterial, viral, fungal, and parasitic infections of the CNS. The typical imaging features of common and uncommon CNS infectious processes are reviewed.

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.

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.

Immune Reconstitution Inflammatory Syndrome (IRIS): What pathologists should know

Antiretroviral therapy has significantly improved the quality and length of life for those patients able to access effective and sustained treatment. The resulting restoration of the immune response is associated with a change in the clinical presentation of opportunistic infections, and the histologic reaction to pathogens. A complex combination of alterations in host response across the stages of HIV infection has been documented over the past 3 decades. The defects are seen in both acute and chronic phases of inflammation and involve innate and adaptive immunity. In advanced stages of HIV infection, the marked disruption of lymphoid tissue and loss of follicular dendritic cells limits the host's ability to process antigen and mount specific responses to pathogens. There are qualitative and quantitative defects in CD4 T cells due to HIV infection. The resulting indirect effects include loss of cytokine production, dysregulation of B-cell function, loss of cellular mediated immunity and "holes" in the immunologic repertoire that may not be restored with the use of antiretroviral therapy. Immune reconstitution allows the host to respond to and control infection, but a significant number of patients will have atypical inflammatory syndromes during the recovery period. We briefly discuss the impact of HIV infection on the immune system and give an overview of the spectrum of conditions attributed to the Immune Reconstitution Inflammatory syndrome (IRIS).

Neurotuberculosis immune reconstitution inflammatory syndrome in the setting of HIV infection: A case report and review of literature

Immune reconstitution inflammatory syndrome (IRIS) is an exaggerated immune response which can occur with various coinfections in human immunodeficiency virus (HIV) infected patients, of which the most commonly implicated in central nervous system (CNS)-IRIS are progressive multifocal leukoencephalopathy (PML), cryptococcosis, and tuberculosis (TB). TB-IRIS is a known complication of pulmonary TB or TB lymphadenitis coinfection in HIV infected patients who are on antituberculosis treatment (ATT) after the initiation of antiretroviral therapy (ART). However, development of IRIS in extrapulmonary TB such as CNS TB is very rare. Our case is that of an isolated CNS-TB-IRIS, presenting as increase in the size and perilesional edema of the ring enhancing lesions in the brain, which was observed in two sequential magnetic resonance imaging done over a period of 2 months in a retropositive patient who presented with clinical deterioration after commencement of ART. As prompt diagnosis was made and specific management aimed at IRIS was started without delay, the patient improved symptomatically.

Integrated therapy for HIV and cryptococcosis

Cryptococcosis has been one of the most common opportunistic infections and causes of mortality among HIV-infected patients, especially in resource-limited countries. Cryptococcal meningitis is the most common form of cryptococcosis. Laboratory diagnosis of cryptococcosis includes direct microscopic examination, isolation of Cryptococcus from a clinical specimen, and detection of cryptococcal antigen. Without appropriate treatment, cryptococcosis is fatal. Early diagnosis and treatment is the key to treatment success. Treatment of cryptococcosis consists of three main aspects: antifungal therapy, intracranial pressure management for cryptococcal meningitis, and restoration of immune function with antiretroviral therapy (ART). Optimal integration of these three aspects is crucial to achieving successful treatment and reducing the mortality. Antifungal therapy consists of three phases: induction, consolidation, and maintenance. A combination of two drugs, i.e. amphotericin B plus flucytosine or fluconazole, is preferred in the induction phase. Fluconazole monotherapy is recommended during consolidation and maintenance phases. In cryptococcal meningitis, intracranial pressure rises along with CSF fungal burden and is associated with morbidity and mortality. Aggressive control of intracranial pressure should be done. Management options include therapeutic lumbar puncture, lumbar drain insertion, ventriculostomy, or ventriculoperitoneal shunt. Medical treatment such as corticosteroids, mannitol, and acetazolamide are ineffective and should not be used. ART has proven to have a great impact on survival rates among HIV-infected patients with cryptococcosis. The time to start ART in HIV-infected patients with cryptococcosis has to be deferred until 5 weeks after the start of antifungal therapy. In general, any effective ART regimen is acceptable. Potential drug interactions between antiretroviral agents and amphotericin B, flucytosine, and fluconazole are minimal. Of most potential clinical relevance is the concomitant use of fluconazole and nevirapine. Concomitant use of these two drugs should be cautious, and patients should be monitored closely for nevirapine-associated adverse events, including hepatotoxicity. Overlapping toxicities of antifungal and antiretroviral drugs and immune reconstitution inflammatory syndrome are not uncommon. Early recognition and appropriate management of these consequences can reinforce the successful integrated therapy in HIV-infected patients with cryptococcosis.

MRI characteristics of early PML-IRIS after natalizumab treatment in patients with MS

OBJECTIVE

The early detection of MRI findings suggestive of immune reconstitution inflammatory syndrome (IRIS) in natalizumab-associated progressive multifocal leukoencephalopathy (PML) is of crucial clinical relevance in terms of treatment decision-making and clinical outcome. The aim of this study was to investigate the earliest imaging characteristics of PML-IRIS manifestation in natalizumab-treated patients with multiple sclerosis and describe an imaging pattern that might aid in the early and specific diagnosis.

METHODS

This was a retrospective study assessing brain MRI of 26 patients with natalizumab-associated PML presenting with lesions suggestive of PML-IRIS during follow-up. MRI findings were evaluated considering the imaging findings such as mass effect, swelling, contrast enhancement, new perivascular T2 lesions and signs suggestive of meningeal inflammation.

RESULTS

Contrast enhancement was the most common imaging sign suggestive of PML-IRIS, seen in 92.3% of the patients (with patchy and/or punctuate pattern in 70.8% and 45.8% respectively), followed by new T2 lesions with a perivascular distribution pattern (34.6%). In those patients with contrast enhancement, the enhancement was present in the lesion periphery in 95.8% of the patients. Contrast-enhancing lesions with a perivascular distribution pattern outside of the PML lesion were observed in 33.3% of the patients. The most common overall pattern was contrast enhancement in the border of the PML lesion with either a patchy or punctuate appearance in 88.5% of all patients.

CONCLUSIONS

Contrast enhancement is the most common earliest sign of natalizumab-associated PML-IRIS with a frequent imaging pattern of contrast-enhancing lesions with either a patchy or punctuate appearance in the border of the PML lesion.

Update and New Directions in Therapeutics for Neurological Complications of HIV Infections

The pace of therapeutic developments in HIV presents unique challenges to the neurologist caring for patients. Combination antiretroviral therapy (cART) is remarkably effective in suppressing viral replication, preventing, and often even reversing disease progression. Still, not every patient benefits from cART for a variety of reasons, ranging from the cost of therapy and the burden of lifelong daily treatment to side effects and inadequate access to medical care. Treatment failure inevitably leads to disease progression and opportunistic complications. Many of these complications, even those that are treatable, produce permanent neurological disability. With ART, immune recovery itself may paradoxically lead to severe neurological disease; strategies for managing so-called immune reconstitution inflammatory syndrome are beginning to show benefits. Effective cART may nevertheless leave in its wake persistent neurocognitive impairment. Treatments for persistent impairment despite virologic suppression and good immune recovery are being tested but are not yet proven. As we shall see, these treatments target several proposed mechanisms including cerebral small vessel disease, which is highly prevalent in HIV. Most recently, an ambitious initiative has been undertaken to develop interventions to eradicate HIV. This will require elimination of all infectious forms of viral nucleic acid throughout the body. The influence of these interventions on the brain remains to be characterized. Meanwhile, clinical investigators continue to develop antiretroviral treatments that optimize effectiveness, convenience, and tolerability, while minimizing long-term toxicities.

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.

Neurological immune reconstitution inflammatory response: riding the tide of immune recovery

PURPOSE OF REVIEW

This manuscript reviews current reports about clinical aspects of immune reconstitution inflammatory syndrome (IRIS), with a particular emphasis on IRIS in the setting of progressive multifocal leukoencephalopathy (PML) and to a lesser extent on cryptococcal meningitis and HIV.

RECENT FINDINGS

PML prognosis has been radically improved, as it has become possible to provide immune reconstitution, although some remaining morbidity and mortality results from excess inflammation. Similar pathologic responses are seen less often, but remain clinically important in cryptococcal meningitis, and HIV. Early diagnosis and active management of PML results in optimal outcomes with survival of 75% or higher in multiple recent series. These finding apply both to natalizumab and HIV-associated PML. Cryptococcal meningitis is frequently complicated by IRIS, and early treatment with antifungal therapy preceding HIV therapy provides optimal outcomes. HIV IRIS is reduced by early therapy, which is now recommended, but even on therapy, chronic dysregulated immune responses may play important roles in ongoing HIV-associated neurocognitive disease (HAND), which is common, as well as rare but more dramatic subacute encephalopathies.

SUMMARY

The clinician must actively monitor and treat both opportunistic infection and the inflammatory response that is essential to recovery but may itself augment disease and injury.

Punctate and curvilinear gadolinium enhancing lesions in the brain: a practical approach

INTRODUCTION

Cerebral punctate and curvilinear gadolinium enhancements (PCGE) correspond to opacification of small vessel lumen or its perivascular areas in case of blood-brain barrier (BBB) disruption. We will discuss the possible causes of intra-parenchymal central nervous system PCGE.

METHODS

Our review is based on French database including patients presenting with central nervous system PCGE and literature search using PubMed database with the following keywords: punctate enhancement, linear enhancement, and curvilinear enhancement. Disorders which displayed linear leptomeningeal or periventricular enhancements without intra-parenchymal PCGE are excluded of this review.

RESULTS

Among our 39 patients with PCGE, 16 different diagnoses were established. After combining our PCGE causes with those described in the literature, we propose a practical approach. Besides physiologic post-contrast enhancement of small vessels, three pathologic conditions may exhibit PCGE: (1) small collateral artery network seen in Moyamoya syndrome, (2) small veins congestions related to developmental or acquired venous outflow disturbance, and (3) disorders causing small vessels BBB disruption indicated by T2 and FLAIR hyperintensities in the corresponding areas of PCGE. Disruption of the BBB could be caused by a direct injury of the endothelial cell, as in posterior reversible encephalopathy syndrome, Susac syndrome, and radiochemotherapy-induced injuries, or by an angiocentric cellular infiltrate, as in inflammatory disorders, demyelinating diseases, host immune responses fighting against infections, prelymphoma states, lymphoma, and in CLIPPERS.

CONCLUSION

PCGE may conceal several causes, including physiological and pathological conditions. Nevertheless, a practical approach could improve its management and limit the indications of brain biopsy to very specific situations.

Spectrum of imaging appearances of intracranial cryptococcal infection in HIV/AIDS patients in the anti-retroviral therapy era

Cryptococcus neoformans infection is the most common fungal infection of the central nervous system (CNS) in advanced human immunodeficiency virus (HIV) and acquired immunodeficiency syndrome (AIDS) patients, but remains a relatively uncommon CNS infection in both the immunocompromised and immunocompetent patient population, rendering it a somewhat elusive and frequently overlooked diagnosis. The morbidity and mortality associated with CNS cryptococcal infection can be significantly reduced by early recognition of the imaging appearances by the radiologist in order to focus and expedite clinical management and treatment. The emergence and evolution of anti-retroviral therapy have also impacted significantly on the imaging appearances, morbidity, and mortality of this neuro-infection. The constellation of varied imaging appearances associated with cryptococcal CNS infection in the HIV and AIDS population in the era of highly active anti-retroviral therapy (HAART) will be presented in this review.

Redefining the HIV epidemic in Nigeria: from national to state level

BACKGROUND

Governments are increasingly recognizing the need to focus limited HIV resources on specific geographic areas and specific populations to have a greater impact. Nigeria, with the second largest HIV epidemic in the world, is an important example of where more localized programming has the potential to improve the efficiency of the HIV response.

METHODS

Using Spectrum software we modelled the Nigerian HIV epidemic using two methods: First, we created national HIV estimates using trends in urban and rural areas. Second, we created national HIV estimates using trends from each of the 37 states in Nigeria and aggregated these results. In both instances we used HIV surveillance data from antenatal clinics and household surveys and aggregated the trends to determine the national epidemic.

RESULTS

The state models showed divergent trends in the 37 states. Comparing the national results calculated from the two methods resulted in different conclusions. In the aggregated state files, adult HIV incidence in Nigeria was stable between 2005 and 2013 (change of -6%), whereas the urban and rural file suggested incidence was decreasing over the same time (change of -50%). This difference was also reflected in the HIV prevalence trends, although the two methods showed similar trends in AIDS-related mortality. The two models had similar adult HIV prevalence in 2013: 3.0% (2.0-4.5%) in the aggregated state files versus 3.2% (3.0-3.5%) in the urban/rural file.

CONCLUSION

The state-level estimates provide insight into the variations of the HIV epidemic in each state and provide useful information for programme managers. However, the reliability of the results is highly dependent on the amount and quality of data available from each sub-national area.

Neuroimaging of HIV-associated cryptococcal meningitis: comparison of magnetic resonance imaging findings in patients with and without immune reconstitution

To determine the frequency, imaging characteristics, neuroanatomical distribution and dynamics of magnetic resonance imaging findings in HIV-associated cryptococcal meningitis in immunocompromised patients we compared patients without antiretroviral therapy with patients undergoing immune reconstitution. Neuroimaging and clinical data of 21 consecutive patients presenting to a German HIV centre in a 10-year period between 2005 and 2014 were reviewed. We identified eight patients with magnetic resonance imaging findings related to cryptococcal disease: five patients without antiretroviral therapy and three patients receiving effective antiretroviral therapy resulting in immune reconstitution. The pattern of magnetic resonance imaging manifestations was different in the two groups. In patients not on antiretroviral therapy, pseudocysts (n = 3) and lacunar ischaemic lesions (n = 2) were detected. Contrast-enhancing focal leptomeningeal and/or parenchymal lesions were found in all patients under immune reconstitution (n = 3). Magnetic resonance imaging lesions suggestive of leptomeningitis or meningoencephalitis were detected in all patients with a recurrence of cryptococcal meningitis under immune reconstitution, which differs from the classical magnetic resonance imaging findings in patients without antiretroviral therapy. In antiretroviral therapy-treated patients with past medical history of cryptococcal meningitis, detection of contrast-enhancing focal meningeal and/or parenchymal lesions should prompt further investigations for a recurrence of cryptococcal meningitis under immune reconstitution.

Immune reconstitution inflammatory syndrome in HIV-infected patients

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

When smear and molecular diagnostics fail: identification of tuberculosis in advanced HIV infection using the newly developed urine lipoarabinomannan lateral-flow assay

In HIV infection, progression of immunodeficiency is associated with increased risk of paucibacillary and disseminated forms of tuberculosis (TB). As a result, the clinical presentation may be atypical and the conventional diagnostic assays often unreliable, resulting in significant treatment delays. Here, we report a case of HIV-associated immune reconstitution inflammatory syndrome and TB meningitis. Although the smear and molecular assays were negative, Mycobacterium tuberculosis was identified in our patient using the new Determine-lipoarabinomannan (LAM) lateral-flow urine 'dip-stick' assay. This case report illustrates the clinical value of this assay for the diagnosis of TB in a subgroup of HIV-infected patients with advanced immunodeficiency. Also, although two recent studies have evaluated the use of the Determine TB-LAM assay in clinical settings, to the best of our knowledge, this is the first case report of TB diagnosed using this novel assay.

The chameleon of neuroinflammation: magnetic resonance imaging characteristics of natalizumab-associated progressive multifocal leukoencephalopathy

Natalizumab is a monoclonal antibody against α4-integrin approved for the treatment of multiple sclerosis (MS) due to a positive effect on clinical and magnetic resonance imaging (MRI) outcome measures. However, one relatively rare but serious side effect of this drug is a higher risk of developing progressive multifocal leukoencephalopathy (PML). Since the FDA approval, more than 300 natalizumab-associated PML cases have been documented among more than 100,000 treated MS patients. MRI is a crucial tool in the surveillance of patients treated with natalizumab in order to detect possible signs of PML in the asymptomatic stage. Although classical imaging characteristics of PML are well established, MRI findings in natalizumab-associated PML, particularly in early disease stages, show rather new and heterogeneous imaging findings including different patterns of inflammation with contrast enhancement. This review provides a comprehensive overview of the heterogeneous imaging findings in natalizumab-associated PML in the context of the underlying pathophysiology, histopathology, and the diagnostic procedure. We describe the MRI patterns of PML lesion evolution and complications including immune reconstitution inflammatory syndrome (IRIS). Finally, we present guidelines to differentiate MRI findings in PML from inflammatory demyelinating lesions, to facilitate the early diagnosis of PML in patients treated with natalizumab.

Neuroimaging features of immune reconstitution inflammatory syndrome in a patient with AIDS successfully treated for neurocryptococcosis

The use of highly active antiretroviral therapy (HAART) has significantly reduced the incidence and progression of HIV-associated cryptococcosis. However, an early complication of HAART is the immune reconstitution inflammatory syndrome (IRIS), which may affect the CNS. The authors report a patient successfully treated for cryptococcosis and HIV who presented a late manifestation of IRIS. Neuroimaging aspects and management of CNS-IRIS in this patient are discussed in this paper.

Drug induced increases in CNS dopamine alter monocyte, macrophage and T cell functions: implications for HAND

Central nervous system (CNS) complications resulting from HIV infection remain a major public health problem as individuals live longer due to the success of combined antiretroviral therapy (cART). As many as 70 % of HIV infected people have HIV associated neurocognitive disorders (HAND). Many HIV infected individuals abuse drugs, such as cocaine, heroin or methamphetamine, that may be important cofactors in the development of HIV CNS disease. Despite different mechanisms of action, all drugs of abuse increase extracellular dopamine in the CNS. The effects of dopamine on HIV neuropathogenesis are not well understood, and drug induced increases in CNS dopamine may be a common mechanism by which different types of drugs of abuse impact the development of HAND. Monocytes and macrophages are central to HIV infection of the CNS and to HAND. While T cells have not been shown to be a major factor in HIV-associated neuropathogenesis, studies indicate that T cells may play a larger role in the development of HAND in HIV infected drug abusers. Drug induced increases in CNS dopamine may dysregulate functions of, or increase HIV infection in, monocytes, macrophages and T cells in the brain. Thus, characterizing the effects of dopamine on these cells is important for understanding the mechanisms that mediate the development of HAND in drug abusers.