PML-IRIS in patients with HIV infection: clinical manifestations and treatment with steroids

Progressive Multifocal Leukoencephalopathy in HIV-Uninfected Individuals

Progressive multifocal leukoencephalopathy (PML) is a demyelinating disease of the central nervous system (CNS) caused by the human neurotropic polyomavirus JC (JCV). The disease occurs virtually exclusively in immunocompromised individuals, and, prior to the introduction of antiretroviral therapy, was seen most commonly in the setting of HIV/AIDS. More recently, however, the incidence of PML in HIV-uninfected persons has increased with broader use of immunosuppressive and immunomodulatory medications utilized in a variety of systemic and neurologic autoimmune disorders. In this review, we discuss the epidemiology and clinical characteristics of PML in HIV-uninfected individuals, as well as diagnostic modalities and the limited treatment options. Moreover, we describe recent findings regarding the neuropathogenesis of PML, with specific focus on the unique association between PML and natalizumab, a monoclonal antibody that prevents trafficking of activated leukocytes into the CNS that is used for the treatment of multiple sclerosis.

Rehabilitation outcome of progressive multifocal leukoencephalopathy in HIV-positive patients: a report of two cases

PURPOSE

To describe the rehabilitation treatment and outcome of progressive multifocal leukoencephalopathy (PML) in the context of Human Immunodeficiency Virus (HIV).

METHOD

The medical history of two HIV-positive patients with PML was reviewed; information on their neurological impairments, rehabilitation treatment and outcome was gathered.

RESULTS

The patients, a 47-year-old married man and a 34-year-old single man, both suffered from dense right hemiplegia and motor aphasia. Their rehabilitation course was delayed and prolonged: they were suitable for intensive multidisciplinary rehabilitation only 8 months or more after the initial presentation. Their treatment in outpatient rehabilitation daycare three times a week, that lasted 7 months on average, resulted in slow and steady functional improvement. At the end of the rehabilitation treatment, both patients were living at home, able to express themselves, and able to walk independently with an assistive device. They remained with moderate disability (modified Rankin scale of 3).

CONCLUSION

PML patients require prolonged multidisciplinary rehabilitation treatment; however, considerable progress can be achieved. Implications for Rehabilitation Progressive multifocal leukoencephalopathy (PML) is a disabling disease occurring in particular in the context of Human Immunodeficiency Virus (HIV). Presently a growing number of HIV-positive PML patients eventually survive the disease and remain with severe neurological impairments. PML patients require prolonged multidisciplinary rehabilitation treatment, and considerable progress can be achieved.

Polyomavirus Persistence

Mammalian polyomaviruses are characterized by establishing persistent infections in healthy hosts and generally causing clinical disease only in hosts whose immune systems are compromised. Despite the fact that these viruses were discovered decades ago, our knowledge of the mechanisms that govern viral persistence and reactivation is limited. Whereas mouse polyomavirus has been studied in a fair amount of detail, our understanding of the human viruses in particular is mostly inferred from experiments aimed at addressing other questions. In this review, we summarize the state of our current knowledge, draw conclusions when possible, and suggest areas that are in need of further study.

Predictors and characteristics of seizures in survivors of progressive multifocal leukoencephalopathy

This study aims to determine the risk factors for epileptogenesis and characteristics of seizures in patients with progressive multifocal leukoencephalopathy (PML) who survive more than 1 year from onset of neurological symptoms (PML survivors). We reviewed clinical data including seizure history and MR imaging studies from PML survivors evaluated at our institution between 1997 and 2014. PML progressors who passed away within 1 year and patients with a history of seizures prior to PML diagnosis were excluded from the analysis. Of 64 PML survivors, 28 (44 %) developed seizures. The median time from the onset of PML symptoms to the first seizure was 5.4 months (range 0-159) and 64 % of patients with seizures had them within the first year. The presence of juxtacortical PML lesions was associated with a relative risk of seizures of 3.5 (p < 0.02; 95 % confidence interval (CI) 1.3-9.4) in multivariate analyses. Of all seizure types, 86 % were focal and 60 % most likely originated from the frontal lobes. Among seizure patients, 89 % required treatment, including one (54 %), two (25 %), or three (10.5 %) antiepileptic drugs. Seizures are a frequent complication in PML and can develop throughout the entire course of the disease. However, late onset seizures did not signify PML relapse. Seizures may require treatment with multiple antiepileptic medications and are a significant co-morbidity in PML.

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.

Progressive Multifocal Leukoencephalopathy in a HIV Negative, Immunocompetent Patient

Progressive multifocal leukoencephalopathy (PML) is a rare demyelinating disease most common in immunodeficient patients. It occurs due to reactivation of the John Cunningham Virus (JCV) and carries a poor prognosis, with a median life expectancy of 6 months. We report a case of a 66-year-old man with a history of HCV related cirrhosis (HCV) and hepatocellular carcinoma (HCC) who was found to have PML in the setting of a negative viral load in the CSF and a CD4+ >200. He initially presented with two weeks of mild confusion and word-finding difficulty concerning for hepatic encephalopathy. An MRI was notable for extensive T2/FLAIR hyperintensity signal in the left temporal lobe. Brain biopsy was positive for JCV. PML is rare in immunocompetent individuals, especially in the setting of a negative viral load. It is possible, however, that transient states of immunosuppression may have been responsible in this case. Although viral load was reported as negative, virus may still have been detected but was below the quantifiable threshold. It is important for clinicians to note that a negative result does not necessarily exclude the possibility of PML, and care should be taken to review lab values on viral load in closer detail.

Detection of cases of progressive multifocal leukoencephalopathy associated with new biologicals and targeted cancer therapies from the FDA's adverse event reporting system

OBJECTIVE

To identify and summarize FDA's Adverse Event Reporting System (FAERS) cases of progressive multifocal leukoencephalopathy (PML) associated with biological and targeted cancer therapies (BTCT) that were approved between 2009 and 2015.

METHODS

FAERS was searched using each BTCT name as primary or secondary suspect drug and the adverse reaction of PML. Among BTCTs with >2 case reports of PML, proportional reporting ratios (PRR) and 95% confidence intervals (CI) were calculated.

RESULTS

Among 49 new BTCTs, 82 cases of PML were found for 16 drugs. Significant PRR signals were found among 7 (14.6%) BTCTs including: brentuximab (24.5, CI:14.8-40.6), ofatumumab (16.3, CI:9.6-27.4), alemtuzumab (9.9, CI:6.0-16.4), obinutuzumab (7.4, CI:2.4-22.8), ibrutinib (5.6 CI:3.0-10.5), belimumab (4.5 CI:2.3-9.0), and idelalisib (4.1, CI:1.3-12.6). Among the 82 cases with significant signals, confirmation of the diagnosis of PML using objective criteria was found in 56% of the cases. A limitation of FAERS data is that missing data are common.

CONCLUSIONS

When using BTCTs, clinicians and patients consider the risk of PML versus the therapeutic benefit, particularly when used in combination with other drugs which may cause PML, such as rituximab. It is important to recognize that PML may occur in some conditions, such as chronic lymphocytic leukemia, regardless of drug therapy.

Opportunistic Neurologic Infections in Patients with Acquired Immunodeficiency Syndrome (AIDS)

Infections of the central nervous system (CNS) in individuals with human immunodeficiency virus (HIV) remain a substantial cause of morbidity and mortality despite the introduction of highly active antiretroviral therapy (HAART) especially in the resource-limited regions of the world. Diagnosis of these infections may be challenging because findings on cerebrospinal fluid (CSF) analysis and brain imaging are nonspecific. While brain biopsy provides a definitive diagnosis, it is an invasive procedure associated with a relatively low mortality rate, thus less invasive modalities have been studied in recent years. Diagnosis, therefore, can be established based on a combination of a compatible clinical syndrome, radiologic and CSF findings, and understanding of the role of HIV in these infections. The most common CNS opportunistic infections are AIDS-defining conditions; thus, treatment of these infections in combination with HAART has greatly improved survival.

CNS infections in patients with hematological disorders (including allogeneic stem-cell transplantation)-Guidelines of the Infectious Diseases Working Party (AGIHO) of the German Society of Hematology and Medical Oncology (DGHO)

Diagnosis of CNS infections remains a great challenge in patients with hematological disorders since symptoms might both be masked and be mimicked by other conditions such as metabolic disturbances or consequences from antineoplastic treatment. Thus, awareness of this complication is crucial and any suspicion of a CNS infection should lead to timely and adequate diagnostics and treatment to improve the outcome in this population.

Infections of the central nervous system (CNS) are infrequently diagnosed in immunocompetent patients, but they do occur in a significant proportion of patients with hematological disorders. In particular, patients undergoing allogeneic hematopoietic stem-cell transplantation carry a high risk for CNS infections of up to 15%. Fungi and Toxoplasma gondii are the predominant causative agents. The diagnosis of CNS infections is based on neuroimaging, cerebrospinal fluid examination and biopsy of suspicious lesions in selected patients. However, identification of CNS infections in immunocompromised patients could represent a major challenge since metabolic disturbances, side-effects of antineoplastic or immunosuppressive drugs and CNS involvement of the underlying hematological disorder may mimic symptoms of a CNS infection. The prognosis of CNS infections is generally poor in these patients, albeit the introduction of novel substances (e.g. voriconazole) has improved the outcome in distinct patient subgroups. This guideline has been developed by the Infectious Diseases Working Party (AGIHO) of the German Society of Hematology and Medical Oncology (DGHO) with the contribution of a panel of 14 experts certified in internal medicine, hematology/oncology, infectious diseases, intensive care, neurology and neuroradiology. Grades of recommendation and levels of evidence were categorized by using novel criteria, as recently published by the European Society of Clinical Microbiology and Infectious Diseases.

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.

Recurrence of progressive multifocal leukoencephalopathy despite immune recovery in two HIV seropositive individuals

We present two cases of recurrent progressive multifocal leukoencephalopathy (PML) in patients with long standing virally suppressed human immunodeficiency virus (HIV) and normal CD4+ T cell count who were taking stable regimens of highly active antiretroviral therapy (HAART). This has significant implications for other patients with a past history of PML, not just those with HIV but also those on medications such as natalizumab or fumarates.

Treatment options for progressive multifocal leukoencephalopathy in HIV-infected persons: current status and future directions

Progressive multifocal encephalopathy (PML) caused by JC virus was frequently encountered in AIDS patients before combination antiretroviral therapy (cART). Incidence decreased and the outcome improved with cART. The immune reconstitution with cART is beneficial for HIV-infected patients and is an effective treatment for PML. However, when it is excessive an inflammatory response immune syndrome might occur with deterioration of PML. So far, no specific therapy has proven efficacious in small clinical trials in spite of some optimistic case reports. Combination of drugs targeted at different stages of JC virus life cycle seems to have a better effect. Passive and active immune therapies, immune competence "boosters" appear promising. New future approaches such as gene editing are not far away.

Progressive multifocal leukoencephalopathy: current treatment options and future perspectives

Progressive multifocal leukoencephalopathy (PML) is a rare but debilitating and frequently fatal viral disease of the central nervous system, primarily affecting individuals with chronically and severely suppressed immune systems. The disease was relatively obscure until the outbreak of HIV/AIDS, when it presented as one of the more frequent opportunistic infections in this immune deficiency syndrome. It attracted additional attention from the medical and scientific community following the discovery of significant PML risk associated with natalizumab, a monoclonal antibody used for treatment of relapsing-remitting multiple sclerosis. This was followed by association of PML with other immunosuppressive or immunomodulating drugs. PML is currently untreatable disease with poor outcomes, so it is a significant concern when developing new immunotherapies. Current prophylaxis and treatment of PML are focused on immune reconstitution, restoration of immune responses to JC virus infection, and eventual suppression of immune reconstitution inflammatory syndrome. This approach was successful in reducing the incidence of PML and improved survival of PML patients with HIV infection. However, the outcome for the majority of PML patients, regardless of their medical history, is still relatively poor. There is a high unmet need for both prophylaxis and treatment of PML. The aim of this review is to discuss potential drug candidates for prophylaxis and treatment of PML with a critical review of previously conducted and completed PML treatment studies as well as to provide perspectives for future therapies.

Natalizumab in multiple sclerosis: discontinuation, progressive multifocal leukoencephalopathy and possible use in children

In the early 1990s, attention was drawn to the migration of immune cells into the central nervous system via the blood-brain barrier. The literature showed that lymphocytes binding to the endothelium were successfully inhibited by an antibody against α4β1 integrin. These biological findings resulted in the development of a humanized antibody to α4 integrin - natalizumab (NTZ) - to treat multiple sclerosis (MS). Here, we provide a systematic review and meta-analysis on the efficacy and safety of natalizumab, trying to answer the question whether its use may be recommended both in adult and in pediatric age groups as standard MS treatment. Our results highlight the improvement of clinical and radiological findings in treated patients (p < 0.005), confirming NTZ efficacy. Nevertheless, if NTZ is shown to be efficient, further studies should be performed to evaluate its safety and to target the MS profile that could benefit from this treatment.

Broadly neutralizing human monoclonal JC polyomavirus VP1-specific antibodies as candidate therapeutics for progressive multifocal leukoencephalopathy

In immunocompromised individuals, JC polyomavirus (JCPyV) may mutate and gain access to the central nervous system resulting in progressive multifocal leukoencephalopathy (PML), an often fatal opportunistic infection for which no treatments are currently available. Despite recent progress, the contribution of JCPyV-specific humoral immunity to controlling asymptomatic infection throughout life and to eliminating JCPyV from the brain is poorly understood. We examined antibody responses against JCPyV major capsid protein VP1 (viral protein 1) variants in the serum and cerebrospinal fluid (CSF) of healthy donors (HDs), JCPyV-positive multiple sclerosis patients treated with the anti-VLA-4 monoclonal antibody natalizumab (NAT), and patients with NAT-associated PML. Before and during PML, CSF antibody responses against JCPyV VP1 variants show "recognition holes"; however, upon immune reconstitution, CSF antibody titers rise, then recognize PML-associated JCPyV VP1 variants, and may be involved in elimination of the virus. We therefore reasoned that the memory B cell repertoire of individuals who recovered from PML could be a source for the molecular cloning of broadly neutralizing antibodies for passive immunization. We generated a series of memory B cell-derived JCPyV VP1-specific human monoclonal antibodies from HDs and a patient with NAT-associated PML-immune reconstitution inflammatory syndrome (IRIS). These antibodies exhibited diverse binding affinity, cross-reactivity with the closely related BK polyomavirus, recognition of PML-causing VP1 variants, and JCPyV neutralization. Almost all antibodies with exquisite specificity for JCPyV, neutralizing activity, recognition of all tested JCPyV PML variants, and high affinity were derived from one patient who had recovered from PML. These antibodies are promising drug candidates for the development of a treatment of PML.

Development of primary central nervous system lymphoma associated with human immunodeficiency virus and JC virus infection

We report here a case of a 37-year-old man with human immunodeficiency virus (HIV) infection followed by JC virus (JCV) infection and primary central nervous system lymphoma (PCNSL). The patient had been infected with HIV type 1 due to blood products for hemophilia A during infancy. He had progression of nervous symptoms and was diagnosed with progressive multifocal leukoencephalopathy (PML) clinically at the age of 36, when his CD4-positive lymphocyte counts ranged between 350 and 450/μl. Oral mefloquine, intravenous methylprednisolone pulse therapy, and intravenous immunoglobulin were not effective for the PML, and the patient entered a vegetative state. Brain biopsy revealed JCV infection without pathological findings of PML. Eight months after the clinical diagnosis of PML, he developed respiratory failure and brain magnetic resonance imaging revealed a mass lesion in the brain stem. The patient died 19 months after the diagnosis of PML. Autopsy findings were compatible with PCNSL. EBV-encoded small RNA-1-positive cells were not detected. We present a case of JCV-positive PCNSL with HIV infection complicated with clinical PML.

Imaging of the brain in patients with human immunodeficiency virus infection

Neurologic disease in acquired immunodeficiency syndrome (AIDS) patients is related either to opportunistic pathogens or to direct central nervous system (CNS) invasion by the human immunodeficiency virus. Despite the increasing availability of antiretroviral therapy, opportunistic infections continue to afflict patients in the developing world and in other populations with limited access to appropriate treatment. Classic CNS infections in the setting of AIDS include toxoplasmosis, cryptococcosis, progressive multifocal leukoencephalopathy, and cytomegalovirus encephalitis. Additionally, AIDS patients are far more susceptible to acquiring CNS tuberculosis and neurosyphilis, both of which exhibit altered disease characteristics in the setting of immunosuppression. Neuroimaging is a crucial component of the diagnostic work-up of these conditions, and findings include, but are not limited to, intracranial mass lesions, white matter disease, meningoencephalitis, vascular complications, and hydrocephalus. Though various disease processes can produce imaging findings that overlap with one another, certain characteristic patterns may suggest a particular pathogen, and advanced imaging techniques and laboratory tests allow for definitive diagnosis. Knowledge of the imaging patterns seen in the setting of AIDS-related CNS disease is vital to the neuroradiologist, whose interpretation may guide decisions related to treatment and further work-up.

Immune reconstitution inflammatory syndrome in a patient with progressive multifocal leukoencephalopathy

Progressive multifocal leukoencephalopathy (PML) is a severe opportunistic infection of the central nervous system. A 52-year-old man with HIV infection, recently started on antiretroviral therapy, presented with symptoms of mental cloudiness, blurry vision and ataxia. MRI of the brain showed nodular perivascular space enhancement with surrounding vasogenic oedema and midline shift. A lumbar puncture revealed non-inflammatory cerebrospinal fluid and was positive for JC virus. As the patient developed worsening symptoms in the setting of initiation of antiretroviral therapy with immune recovery, a diagnosis of JC virus-associated immune reconstitution inflammatory syndrome (IRIS) was made. With recent literature on the use of CCR5 antagonist maraviroc in PML, our patient was started on maraviroc and noted to have improvement in PML IRIS. This is the first case of an HIV-positive patient successfully treated for PML IRIS with maraviroc, as verified by our literature review; also, our case has clinical implications in improving outcome in PML IRIS.

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.

New insights into immune reconstitution inflammatory syndrome of the central nervous system

PURPOSE OF REVIEW

To highlight the importance of immune reconstitution inflammatory syndrome affecting the brain in HIV-infected individuals in the absence of opportunistic infections. To describe the varied clinical manifestations, unifying pathophysiological features and discuss the principles of management of this syndrome.

RECENT FINDINGS

Immune reconstitution inflammatory syndrome within the brain is commonly seen in patients with HIV infection upon initiation of antiretroviral drugs. The fulminant forms occur in the face of opportunistic infections or uncontrolled viral replication within the brain. In this case, the enhanced immune response is targeted against the microbial agent, and the brain suffers bystander damage. Treatment requires the combination of the antimicrobial agent, continued antiretrovirals and in some cases corticosteroids. It is increasingly being recognized that despite adequate control of viral replication in the brain, some patients develop a chronic form of T cell encephalitis which appears to be driven by continued production of HIV-Tat protein. In others, the immune response may be targeted against the host antigens in the brain.

SUMMARY

In patients with central nervous system-immune reconstitution inflammatory syndrome, the use of corticosteroids and strategies that prevent T cell migration into the brain may be needed. Extreme caution is necessary if viral eradication strategies are to be employed that involve activation of viral reservoirs, as these patients may be at risk for developing central nervous system-immune reconstitution inflammatory syndrome.

Neurological complications of HIV infection in pre-HAART and HAART era: a retrospective study

The introduction of highly active anti-retroviral therapy (HAART) led to a radical change in the natural history of HIV infection and of the associated neurological opportunistic infections. However, the mortality of central nervous system (CNS) complications and opportunistic infections is still high in untreated HIV-infected individuals or in patients unaware of their HIV infection. We describe the outcome of HIV-infected patients followed at a single center for AIDS-related neurological syndromes in the 16 years following the introduction of HAART, and compare the findings with those in patients admitted up to 1996. We have conducted a retrospective study of patients with HIV infection or AIDS (based on WHO criteria and classified according to the 1993 CDC criteria) admitted during 20 years (January 1992 to March 2012) to the Infectious Diseases Unit of the University of Verona for the presence of focal or widespread CNS lesion on neuroimaging. Clinical history, CD4 cell count, HIV-RNA level, neurological examination, imaging, cerebrospinal fluid examination and eventual cerebral biopsy results were reviewed as well as the final neurological diagnosis and the treatment. The survival time from the clinical onset of the neurologic syndrome to death was calculated for each patient who died. A statistical analysis was performed comparing data collected up to and after 1996, i.e., before and after HAART introduction. Among 1043 patients with HIV infection or AIDS admitted to the Infectious Diseases Unit of the University of Verona between January 1992 and March 2012, 114 had a CNS lesion. The following diseases were observed: neurotoxoplasmosis (NT), progressive multifocal leukoencephalopathy), primary central nervous system lymphoma (PCNSL), the severe form of HIV-associated neurocognitive disorder, cryptococcal encephalitis (CE) and lesions of undetermined origin. The follow-up period was 4 weeks to 72 months both in the pre-HAART and HAART era. Cerebral lesions were detected in 53/243 patients (21.8%) in the pre-HAART era and in 61/801 patients (7.6%) in the HAART era (p < 0.001). Most patients who developed a neurological complication in the HAART period (40/59, 67.8%) were untreated or did not know to be HIV-infected; in particular, 27.9% of patients with a CNS lesion in the HAART era were unaware of their HIV infection vs 13.2% in the pre-HAART era (p < 0.05). Some patients were not virologically suppressed (14/59, 23.7%) or were immunological non-responders (undetectable viral load, with CD4 count <200 cells/μL; 4/59, 6.8%). Other statistically significant data were the mean age at the onset of neurological complications (32.6 ± 5.4 years in the pre-HAART, 40.3 ± 9.5 in the HAART group, p < 0.001) and the mean CD4 cell count at the onset of illness (median of 38 cells/µL (2-215) in the pre-HAART, 77 cells/µL (2-752) in the HAART group; p < 0.001). In the HAART era a reduction of PCNSL and NT was observed. Our results, while confirming a decrease in the incidence of opportunistic infections of the CNS in the HAART era, show that late presentation of patients with HIV infection remains an important issue in our catchment area.

Update on opportunistic infections in the era of effective antiretroviral therapy

Despite enormous improvements in effectiveness of treatment for HIV infection, opportunistic infections continue to occur in those who have not yet been diagnosed with HIV and in those who are not receiving antiretroviral therapy. This review focuses on tuberculosis and cryptococcal infections, the most common opportunistic infections (OIs) in patients living with human immunodeficiency virus infection around the world, as well as on new developments in progressive multifocal leukoencephalopathy and pneumocystis pneumonia. In the sections on these conditions, updates on diagnosis, treatment, and complications, as well as information on when to start antiretroviral therapy is provided. The article concludes with a discussion of new data on 2 vaccine-preventable OIs, human papillomavirus and varicella-zoster virus.

Immunology of progressive multifocal leukoencephalopathy

The high prevalence of asymptomatic JC polyomavirus (JCV) infection in the general population indicates coexistence with the human host and efficient immune control in healthy individuals. For unknown reasons, kidney-resident archetypic JCV strains can turn into neurotropic JCV strains which in hereditary or acquired states of immunodeficiency cause opportunistic infection and cytolytic destruction of glial cells or granule cell neurons resulting in progressive multifocal demyelination in the central nervous system (CNS) or cerebellar atrophy, respectively. Immunomodulatory or immunosuppressive therapies with specific monoclonal antibodies including natalizumab, efalizumab, and rituximab have increased the risk of progressive multifocal leukoencephalopathy (PML) among treated patients, highlighting that symptomatic JCV infection of the CNS is associated with disturbances of adaptive immunity affecting B cells, antibodies, and CD4(+) and/or CD8(+) T cells. To date, no specific therapy to overcome PML is available and the only way to eliminate the virus from the CNS is to reconstitute global immune function. However, since the identification of JCV as the causative agent of PML 40 years ago, it is still not fully understood which components of the immune system prevent the development of PML and which immune mechanisms are involved in eliminating the virus from the CNS. This review gives an update about adaptive JCV-specific immune responses.

Immune reconstitution disorders in patients with HIV infection: from pathogenesis to prevention and treatment

An immune reconstitution disorder occurs in up to 40 % of severely immunodeficient HIV patients who commence antiretroviral therapy (ART), with an immune reconstitution inflammatory syndrome (IRIS) being encountered most commonly. Differences in the immunopathogenesis of an IRIS associated with different types of pathogen have become apparent but common features have also been defined. These include severe immunodeficiency prior to commencing ART associated with a high pathogen load and 'compensatory' immune responses, particularly innate immune responses, which inadequately control the pathogen and increase the risk of immunopathology as the immune system recovers on ART. Prevention of an IRIS may be achieved by optimising therapy for opportunistic infections before ART is commenced, delaying ART or using immunomodulatory therapy to prevent or suppress the immune response that causes the immunopathology. However, further clinical studies are required to examine these options in a systematic manner for the various types of IRIS.

Progressive multifocal leukoencephalopathy therapy

Progressive multifocal leukoencephalopathy (PML) is caused by the JC virus in the setting of chronic immune deficiency. Developing therapy has been challenged by the rarity of the disease as well as the complexity of patients in whom it develops. Several small trials directed at presumptive antiviral therapies have failed to show convincing clinical efficacy. However, the prognosis of PML has evolved from an almost uniformly fatal encephalitis to a disease where a majority of patients survive. This improvement in outlook has been driven by effective immune reconstitution strategies for the underlying disease, most prominently the improved therapy for human immunodeficiency virus and ability to reverse the effects of natalizumab. While a rapid acting and effective antiviral therapy remains a sought for goal, optimal immune reconstitution to control JC virus without causing brain-damaging immune reconstitution inflammatory syndrome (IRIS) currently is the most practical approach to treat PML.

Immune system's role in viral encephalitis

Viral infections can be a major thread for the central nervous system (CNS), therefore, the immune system must be able to mount a highly proportionate immune response, not too weak, which would allow the virus to proliferate, but not too strong either, to avoid collateral damages. Here, we aim at reviewing the immunological mechanisms involved in the host defense in viral CNS infections. First, we review the specificities of the innate as well as the adaptive immune responses in the CNS, using several examples of various viral encephalitis. Then, we focus on three different modes of interactions between viruses and immune responses, namely human Herpes virus-1 encephalitis with the defect in innate immune response which favors this disease; JC virus-caused progressive multifocal leukoencephalopathy and the crucial role of adaptive immune response in this example; and finally, HIV infection with the accompanying low grade chronic inflammation in the CNS in some patients, which may be an explanation for the presence of cognitive disorders, even in some well-treated HIV-infected patients. We also emphasize that, although the immune response is generally associated with viral replication control and limited cellular death, an exaggerated inflammatory reaction can lead to tissue damage and can be detrimental for the host, a feature of the immune reconstitution inflammatory syndrome (IRIS). We will briefly address the indication of steroids in this situation.

Mucor hiemalis mediated 14α-hydroxylation on steroids: in vivo and in vitro investigations of 14α-hydroxylase activity

Transformation of testosterone and progesterone into synthetically challenging 14α-hydroxy derivatives was achieved by using fungal strain Mucor hiemalis. Prolonged incubation led to the formation of corresponding 6β/7α,14α-dihydroxy metabolites. The position and stereochemistry of newly introduced hydroxyl group was determined by detailed spectroscopic analyses. The time course experiment indicated that fungal strain initiated transformation by hydroxylation at 14α-position followed by at 6β- or 7α-positions. Studies using cell-free extracts suggest that the 14α-hydroxylase activity is NADPH dependent and belongs to the cytochrome P450 family.

Immune Reconstitution Inflammatory Syndrome in Acquired Immune Deficiency Syndrome related to Cryptococcal Meningoencephalitis

Background. Highly active antiretroviral therapy (HAART) has contributed to reducing the occurrence of opportunistic infections and mortality in human immunodeficiency virus (HIV) infected patients. However, a paradoxical worsening of clinical signs and symptoms among patients during HAART may occur. Immune reconstitution inflammatory syndrome (IRIS) is described as a paradoxical deterioration of clinical status on initiation of HAART in patients with HIV infection. Case Report. We describe the case of a 41-year-old man with opportunistic cryptococcal encephalitis who exhibited neurological and radiological deterioration during the course of HAART. A diagnosis of central nervous system (CNS)-IRIS was based on a decrease of HIV-RNA viral load greater than 1 log, with an increase in CD4⁺ T-cell count from baseline. Conclusions. Differential diagnosis of this paradoxical deterioration in clinical and neurological status from overwhelming opportunistic infection is important; it enables an avoidance of unnecessary diagnostic procedures and proper management of this HIV-associated CNS disorder.

Hyperintense cortical signal on magnetic resonance imaging reflects focal leukocortical encephalitis and seizure risk in progressive multifocal leukoencephalopathy

OBJECTIVE

To determine the frequency of hyperintense cortical signal (HCS) on T1-weighted precontrast magnetic resonance (MR) images in progressive multifocal leukoencephalopathy (PML) patients, its association with seizure risk and immune reconstitution inflammatory syndrome (IRIS), and its pathologic correlate.

METHODS

We reviewed clinical data including seizure history, presence of IRIS, and MR imaging scans from PML patients evaluated at our institution between 2003 and 2012. Cases that were diagnosed either using cerebrospinal fluid JC virus (JCV) polymerase chain reaction, brain biopsy, or autopsy, and who had MR images available were included in the analysis (n=49). We characterized pathologic findings in areas of the brain that displayed HCS in 2 patients and compared them with isointense cortex in the same individuals.

RESULTS

Of 49 patients, 17 (34.7%) had seizures and 30 (61.2%) had HCS adjacent to subcortical PML lesions on MR images. Of the 17 PML patients with seizures, 15 (88.2%) had HCS compared with 15 of 32 (46.9%) patients without seizures (p=0.006). HCS was associated with seizure development with a relative risk of 4.75 (95% confidence interval=1.2-18.5, p=0.006). Of the 20 patients with IRIS, 16 (80.0%) had HCS compared with 14 of 29 (49.3%) patients without IRIS (p=0.04). On histological examination, HCS areas were associated with striking JCV-associated demyelination of cortical and subcortical U fibers, significant macrophage infiltration, and a pronounced reactive gliosis in the deep cortical layers.

INTERPRETATION

Seizures are a frequent complication in PML. HCS is associated with seizures and IRIS, and correlates histologically with JCV focal leukocortical encephalitis.

Long-term safety and efficacy of natalizumab in relapsing-remitting multiple sclerosis: impact on quality of life

Natalizumab was the first monoclonal antibody to be approved for the treatment of relapsing-remitting multiple sclerosis (RRMS) based on its short-term efficacy and overall tolerability. However, the incidence of treatment-associated progressive multifocal leukoencephalopathy (PML), an infection of the brain caused by the John Cunningham virus, jeopardized this efficacious treatment from the beginning. Eight years after licensing of natalizumab, long-term studies confirm the considerable and sustained efficacy of natalizumab, although the PML complication still threatens one of the most successful treatments available for RRMS. During these years, considerable progress has been made in identification of risk factors that allow more effective management of PML risk. In addition, long-term studies to define better when to start or stop treatment and to optimize treatment strategies after cessation of natalizumab are ongoing, and hopefully will improve management and will allow natalizumab to remain as a valuable therapeutic option for patients with highly active RRMS.

Progressive multifocal leukoencephalopathy in pediatric patients: case report and literature review

Progressive multifocal leukoencephalopathy is a rare, demyelinating disease of the central nervous system caused by JC virus. Fewer than 30 cases have been reported in HIV- and non-infected children. We report the case of a 15-year-old girl with progressive multifocal leukoencephalopathy and AIDS who presented with nystagmus, dysarthria and ataxia. Following combined antiretroviral therapy, she developed immune reconstitution inflammatory syndrome, which proved fatal.

Central nervous system diseases due to opportunistic and coinfections

With the widespread use of combination antiretroviral therapy (cART), the incidence of central nervous system (CNS) opportunistic infections and coinfections has significantly decreased. This review focuses on the clinical presentation, diagnostic laboratory and radiologic findings, as well as the treatment of neurosyphilis, progressive multifocal leukoencephalopathy, primary CNS lymphoma, and toxoplasmosis, which are CNS opportunistic infections and coinfections that are most relevant to clinicians in North America.

Acute disseminated encephalomyelitis

Acute disseminated encephalomyelitis (ADEM) is an acute multifocal demyelinating disease of the central nervous system that typically follows an infectious illness. Its clinical course in most cases is monophasic; however, relapsing ADEM is rarely seen, which poses a diagnostic challenge for distinguishing this disease from multiple sclerosis (MS). Although typically encountered in children, it also occurs in adults with disease characteristics slightly different from the pediatric cases. Formerly, ADEM occurred particularly often in children with measles. However, the illness most often follows a non-descript viral or even bacterial infectious illness. ADEM occurs throughout the world, and may even be more common in less-developed countries, where MS is rare, than in developed ones, where MS is common. Children seldom get MS as opposed to adults, indicating that ADEM constitutes a distinct entity from MS. The prognosis of ADEM is generally good, but severe neurologic sequelae after ADEM are occasionally seen. In this chapter, the etiology, clinical/laboratory/radiologic characteristics, treatment options, and prognosis of ADEM are discussed.

Central nervous system immune reconstitution inflammatory syndrome

Central nervous system immune reconstitution inflammatory syndrome (CNS-IRIS) develops in 9 %-47 % of persons with HIV infection and a CNS opportunistic infection who start antiretroviral therapy and is associated with a mortality rate of 13 %-75 %. These rates vary according to the causative pathogen. Common CNS-IRIS events occur in relation to Cryptococcus, tuberculosis (TB), and JC virus, but several other mycobacteria, fungi, and viruses have been associated with IRIS. IRIS symptoms often mimic the original infection, and diagnosis necessitates consideration of treatment failure, microbial resistance, and an additional neurological infection. These diagnostic challenges often delay IRIS diagnosis and treatment. Corticosteroids have been used to treat CNS-IRIS, with variable responses; the best supportive evidence exists for the treatment of TB-IRIS. Pathogenic mechanisms vary: Cryptococcal IRIS is characterized by a paucity of cerebrospinal inflammation prior to antiretroviral therapy, whereas higher levels of inflammatory markers at baseline predispose to TB meningitis IRIS. This review focuses on advances in the understanding of CNS-IRIS over the past 2 years.

Significant improvement following combination treatment with mefloquine and mirtazapine in a patient with progressive multifocal leukoencephalopathy after allogeneic peripheral blood stem cell transplantation

We report a case of a 40-year-old female who developed progressive multifocal leukoencephalopathy (PML), which is associated with JC virus reactivation, after allogeneic hematopoietic cell transplantation. As she had been suffering from graft-versus-host disease and lung damage after pneumocystis pneumonia, the administration of calcineurin inhibitor and steroid could not be discontinued. However, she showed a favorable improvement in clinical symptoms and imaging findings after treatment with the anti-malarial drug, mefloquine and a serotonin receptor blocker, mirtazapine. Continuation of the treatment for eight months finally led to the clearance of the JC virus from her cerebrospinal fluid. She currently shows no neurological disturbance and has resumed her daily activities. PML due to the severe immunosuppressive condition has been reported as a fatal complication after allo-SCT. Our case suggests that combination treatment with mefloquine and mirtazapine may be of great value for the treatment for PML patients in the post allo-SCT setting, although it is difficult to say whether the combination treatment alone led to improvement. Further clinical study is needed to clarify the efficacy of these drugs for the treatment of PML.