Improvement of progressive multifocal leukoencephalopathy after cidofovir therapy in a patient with a destructive polyarthritis

Progressive multifocal leukoencephalopathy in patients treated with rituximab: a 20-year review from the Southern Network on Adverse Reactions

Progressive multifocal leukoencephalopathy (PML) is a serious and usually fatal CNS infection caused by the John Cunningham virus. CD4⁺ and CD8⁺ T-cell lymphopenia, resulting from HIV infection, chemotherapy, or immunosuppressive therapy, are primary risk factors for PML. Following its introduction in 1997, the immunomodulatory anti-CD20 monoclonal antibody, rituximab, has received regulatory approval worldwide for treatment of non-Hodgkin lymphoma, rheumatoid arthritis, chronic lymphocytic leukaemia, granulomatosis with polyangiitis, microscopic polyangiitis, and pemphigus vulagris. Rituximab leads to prolonged B-lymphocyte depletion, potentially allowing John Cunningham viral infection to occur. Six unexpected cases of PML infection developing in rituximab-treated patients were first reported in 2002. We review 20 years of information on clinical findings, pathology, epidemiology, proposed pathogenesis, and risk-management issues associated with PML infection developing after rituximab treatment. Since the first case series report of 52 cases of rituximab-associated PML among patients with non-Hodgkin lymphoma or chronic lymphocytic leukaemia in 2009, updated and diligent pharmacovigilance efforts have provided reassurance that this fatal toxicity is a rare clinical event with concurring causal factors. International harmonisation of safety warnings around rituximab-associated PML should be considered, with these notifications listing rituximab-associated PML under a section titled warnings and precautions as is the case in most countries, rather than a boxed warning as is the case in the USA.

T cell deficiencies as a common risk factor for drug associated progressive multifocal leukoencephalopathy

Progressive multifocal leukoencephalopathy (PML) is a disease of the central nervous system caused by neuropathogenic prototypes of ubiquitous community-acquired JC virus (JCV). The disease became of particular concern following its association with certain therapies that modulate immune system function without heavy immunosuppression. Due to lack of prophylactic/treatment options and poor outcomes, which often include severe disability or death, PML is a considerable concern for development of new drugs that interfere with immune system functions. In this review of clinical and research findings, we discuss the evidence that deficiencies in CD4⁺ T helper cells, cytotoxic CD8⁺ T cells, and interferon gamma are of crucial importance for development of PML under a variety of circumstances, including those associated with use of various drugs, regardless of differences in their mechanisms of action. These deficiencies apparently enable transformation of the harmless JCV archetype into neuropathogenic prototypes, but the site(s), and the mechanisms, of this transformation are yet to be elucidated. Here we discuss the evidence for brain as one of the sites of this transformation, and propose a model of PML pathogenesis that emphasizes the central role of T cell deficiencies in the two life cycles of the JCV, one non-pathogenic and one neuropathogenic. Finally, we conclude that the development of clinical grade T cell functional tests and more consistent use of already available laboratory tests for T cell subset analysis would greatly aid the effort to more accurately predict and assess the magnitude of PML risk for concerned therapeutic interventions.

Progressive multifocal leukoencephalopathy in the absence of immunosuppression

A 69-year-old woman presented with a cortical hand syndrome progressing over several weeks. MRI brain showed characteristic appearances of progressive multifocal leukoencephalopathy (PML), confirmed by detection of the JC virus in CSF, despite the absence of any evidence of immunosuppression. Treatment with mirtazapine, mefloquine and cidofovir did not affect the progression of the disease, which was fatal within 7 months of presentation. This report adds to the small case literature that suggests that PML can occur in immunocompetent people, albeit extremely rarely.

Atypical progressive multifocal leukoencephalopathy in a patient with antisynthetase syndrome

Antisynthetase syndrome is a disorder belonging to the dermatomyositis/polymyositis group, with high rates of morbidity and mortality. We herein present the case of a 71-year-old man who was diagnosed with antisynthetase syndrome and treated with rituximab. Almost three years later, the patient showed right-sided hemiparesis that ultimately progressed to complete hemiplegia and advancing cognitive deterioration with a poor clinical outcome. The neuropathological diagnosis was progressive multifocal leukoencephalopathy. Treatment with rituximab for antisynthetase syndrome itself plays a fundamental role in the development of infectious complications.

Insights into the mechanism of action of cidofovir and other acyclic nucleoside phosphonates against polyoma- and papillomaviruses and non-viral induced neoplasia

Acyclic nucleoside phosphonates (ANPs) are well-known for their antiviral properties, three of them being approved for the treatment of human immunodeficiency virus infection (tenofovir), chronic hepatitis B (tenofovir and adefovir) or human cytomegalovirus retinitis (cidofovir). In addition, cidofovir is mostly used off-label for the treatment of infections caused by several DNA viruses other than cytomegalovirus, including papilloma- and polyomaviruses, which do not encode their own DNA polymerases. There is considerable interest in understanding why cidofovir is effective against these small DNA tumor viruses. Considering that papilloma- and polyomaviruses cause diseases associated either with productive infection (characterized by high production of infectious virus) or transformation (where only a limited number of viral proteins are expressed without synthesis of viral particles), it can be envisaged that cidofovir may act as antiviral and/or antiproliferative agent. The aim of this review is to discuss the advances in recent years in understanding the mode of action of ANPs as antiproliferative agents, given the fact that current data suggest that their use can be extended to the treatment of non-viral related malignancies.

Progressive multifocal leukoencephalopathy

Treatment of progressive multifocal leukoencephalopathy (PML) in a patient with exogenous immunosuppression starts with discontinuation of immunosuppressive medication. The restored host immunity will clear JC virus, the cause of PML, from the brain via cell-mediated immune mechanisms. Patients with solid-organ transplants will lose the transplanted organ, however, and patients who have autoimmune disorders may experience exacerbation of their underlying disease. These factors need to be weighed against the potentially fatal nature of PML. If the patient's immunosuppression is AIDS-related, highly active antiretroviral therapy (HAART) should be initiated if it has not previously been used. If the patient is already receiving HAART, the therapy should be changed to optimize treatment, with the goals of a nondetectable HIV viral load and normalization or near normalization of the CD4 count. For non-AIDS PML patients, daily intravenous cytosine arabinoside for 5 days can be offered if the patient is not pancytopenic and can tolerate a chemotherapeutic agent. For AIDS patients with PML or failing non-AIDS patients with neurologic deterioration, cidofovir can be considered. These therapies can be offered if neurologic stabilization satisfies the quality-of-life goals for the patient. For patients intolerant of other therapies or unsuited to them, oral mirtazapine or risperidone can be considered. The safety of these agents has been established in the treatment of psychiatric disease, but their efficacy has not yet been proven. Small interfering RNA (siRNA) therapy holds the promise of specific antiviral therapy, but delivery methods, safety, and efficacy are yet to be established.

Drug-induced PML: a global agenda for a global challenge

The occurrence of severe adverse events such as progressive multifocal leukoencephalopathy (PML) has the potential to limit the benefits of highly efficacious medicines being developed to fulfill unmet clinical needs across therapeutic areas. Following an Expert meeting in London in July 2011 (http://www.ema.europa.eu/docs/en_GB/document_library/Report/2011/09/WC500111562.pdf), a research agenda, highlighting methodological, clinical, and communication elements, to mitigate the risk and improve the management of drug-induced PML has been agreed upon.

Antiviral drugs for viruses other than human immunodeficiency virus

Most viral diseases, with the exception of those caused by human immunodeficiency virus, are self-limited illnesses that do not require specific antiviral therapy. The currently available antiviral drugs target 3 main groups of viruses: herpes, hepatitis, and influenza viruses. With the exception of the antisense molecule fomivirsen, all antiherpes drugs inhibit viral replication by serving as competitive substrates for viral DNA polymerase. Drugs for the treatment of influenza inhibit the ion channel M(2) protein or the enzyme neuraminidase. Combination therapy with Interferon-α and ribavirin remains the backbone treatment for chronic hepatitis C; the addition of serine protease inhibitors improves the treatment outcome of patients infected with hepatitis C virus genotype 1. Chronic hepatitis B can be treated with interferon or a combination of nucleos(t)ide analogues. Notably, almost all the nucleos(t) ide analogues for the treatment of chronic hepatitis B possess anti-human immunodeficiency virus properties, and they inhibit replication of hepatitis B virus by serving as competitive substrates for its DNA polymerase. Some antiviral drugs possess multiple potential clinical applications, such as ribavirin for the treatment of chronic hepatitis C and respiratory syncytial virus and cidofovir for the treatment of cytomegalovirus and other DNA viruses. Drug resistance is an emerging threat to the clinical utility of antiviral drugs. The major mechanisms for drug resistance are mutations in the viral DNA polymerase gene or in genes that encode for the viral kinases required for the activation of certain drugs such as acyclovir and ganciclovir. Widespread antiviral resistance has limited the clinical utility of M(2) inhibitors for the prevention and treatment of influenza infections. This article provides an overview of clinically available antiviral drugs for the primary care physician, with a special focus on pharmacology, clinical uses, and adverse effects.

The next ten stories on antiviral drug discovery (part E): advents, advances, and adventures

This review article presents the fifth part (part E) in the series of stories on antiviral drug discovery. The ten stories belonging to this fifth part are dealing with (i) aurintricarboxylic acid; (ii) alkenyldiarylmethanes; (iii) human immunodeficiency virus (HIV) integrase inhibitors; (iv) lens epithelium‐derived growth factor as a potential target for HIV proviral DNA integration; (v) the status presens of neuraminidase inhibitors NAIs in the control of influenza virus infections; (vi) the status presens on respiratory syncytial virus inhibitors; (vii) tricyclic (1,N‐2‐ethenoguanine)‐based acyclovir and ganciclovir derivatives; (viii) glycopeptide antibiotics as antivirals targeted at viral entry; (ix) the potential (off‐label) use of cidofovir in the treatment of polyoma (JC and BK) virus infections; and (x) finally, thymidine phosphorylase as a target for both antiviral and anticancer agents. © 2009 Wiley Periodicals, Inc. Med Res Rev, 31, No. 1, 118–160, 2010

Progressive multifocal leucoencephalopathy after autologous bone marrow transplantation: a treatment option

A patient with multiple myeloma was treated with high-dose chemotherapy followed by two autologous bone marrow transplantations (ABMTs). Nine months after the second ABMT the patient complained of severe left hemiparesis, paraesthesias, left homonymous visual field defects and gait ataxia. She was diagnosed with progressive multifocal leucoencephalopathy (PML) confirmed by detection of JC virus (JCV) DNA and prescribed cidofovir every other week and mirtazapine daily. Her symptoms and signs remained stable and after 6 months the JCV DNA was undetectable in the cerebrospinal fluid. Repeated MRI scans demonstrated the stabilisation of demyelinating lesion volume; after more than 2 years of follow-up the patient's neurological examination does not show significant variations. Combination of cidofovir and mirtazapine may be helpful in the treatment of PML in HIV-negative patients.

Brain magnetic resonance imaging in adults with asthma

BACKGROUND

In individuals with asthma, potential central nervous system changes can occur as a consequence of their asthma or therapy. Clinical trials of anti-asthmatic therapies might benefit from using magnetic resonance imaging (MRI) to assess potential brain abnormalities.

PURPOSE

As part of the clinical safety evaluation of a monoclonal antibody directed against interleukin-9 for the treatment of asthma, we assessed whether brain MRI is an appropriate screening tool to evaluate potential neurotoxicity.

METHODS

Brain MRIs were conducted as part of a prespecified safety evaluation in adults aged 19 to 47 years with mild to moderate asthma treated with either the investigational monoclonal antibody or placebo. An independent neuroradiologist performed a blinded review of brain MRI scans obtained at baseline before dosing and day 28 after dosing from two separate clinical studies.

RESULTS

Fifteen brain MRI abnormalities were noted in 13 of 21 subjects with asthma (62%). Nonspecific deep white matter hyperintensities (24%), perivascular space (24%), and abnormal anatomic findings (14%) were noted either at baseline or follow-up. Only 8 of 21 subjects (38%) with asthma had normal brain MRI results.

CONCLUSIONS

The high rate of incidental brain MRI findings suggests that these abnormalities are relatively common in patients with asthma. Thus, brain MRI may not be an appropriate screening tool to evaluate potential neurotoxicity in subjects during routine clinical studies without a baseline examination. Due to artifacts simulating lesions, an experienced radiologist should interpret all brain MRI results.

Hexadecyloxypropyl-cidofovir (CMX001) suppresses JC virus replication in human fetal brain SVG cell cultures

JC virus (JCV) is a polyomavirus that infects human oligodendrocytes, leading to development of progressive multifocal leukoencephalopathy (PML), an often fatal demyelinating disease occurring in immunocompromised individuals. Currently there are no effective therapies for the treatment of PML that result in clearance of JCV from the brain. Cidofovir (CDV) is an acyclic nucleoside phosphonate that inhibits DNA polymerases and has been used for the treatment of PML. However, CDV demonstrated little efficacy as a treatment for PML and causes substantial side effects to patients. To improve efficacy and reduce the toxicity of CDV, a lipid-ester derivative, CMX001, was generated by Chimerix and is currently in multicenter phase II clinical trials for the prevention or control of cytomegalovirus infection in hematopoietic stem cell transplant recipients and of BK virus in the urine of stem cell or renal allograft recipients. CMX001 caused minimal cytotoxic effects in human fetal brain SVG cells when used at concentrations between 0.01 μM and 0.1 μM. CMX001 resulted in a dose-dependent decrease in the number of JCV-infected cells during initial infection and nearly eliminated JCV-infected cells during an established infection. In addition, CMX001 treatment resulted in a 60% reduction in JCV DNA copy number during initial infection, which suggests that suppression of JCV infection by CMX001 is likely due to inhibition of virus DNA replication. This study demonstrates that CMX001 suppresses JCV infection at concentrations that have limited toxicity to human brain cells, indicating its potential use to limit JCV replication in infected patients.

Progressive multifocal leucoencephalopathy in an immunocompetent patient with favourable outcome. A case report

BACKGROUND

To report the clinical course of PML in an apparently immunocompetent patient treated with cidofovir.

CASE PRESENTATION

A 35-year-old immunocompetent man who developed progressive hemianopsia, aphasia, and limb weakness underwent repeated MRI scans of the brain, spinal fluid analyses, and brain biopsy. Before diagnosis was established based on brain biopsy, he was consecutively treated with methylprednisolone, acyclovir, ceftriaxone and plasmapheresis, but he deteriorated rapidly suggestive of the immune reconstitution inflammatory syndrome (IRIS). He started to recover two weeks after the initiation of treatment with cidofovir and has had no relapse at 3 1/2 years of follow-up. MRI has shown marked improvement.

CONCLUSIONS

PML should be considered in immunocompetent patients with a typical clinical course and MRI findings compatible with PML. Treatment with cidofovir should be considered as early as possible in the disease course.

Progressive multifocal leukoencephalopathy: a national estimate of frequency in systemic lupus erythematosus and other rheumatic diseases

OBJECTIVE

Progressive multifocal leukoencephalopathy (PML) is a rare, typically fatal, central nervous system demyelinating disease that results from reactivation of the JC virus, which generally occurs in immunosuppressed hosts. The aim of this study was to generate a national estimate of the frequency of PML among patients with rheumatic diseases.

METHODS

Data were obtained from the Nationwide Inpatient Sample database. This is a 20% sample of all hospital discharges, weighted to represent the entire US inpatient population. Data were analyzed for the years 1998-2005 inclusive, representing 297,797,180 hospital discharges. Cases of PML, systemic lupus erythematosus (SLE), and other rheumatic diseases were identified by diagnostic codes from the International Classification of Diseases, Ninth Revision, Clinical Modification.

RESULTS

A total of 9,675 cases of PML were identified. The majority were associated with human immunodeficiency virus (HIV; 7,934 patients [82.00%]), hematologic cancers (813 patients [8.40%]), and solid cancers (274 patients [2.83%]). Among the rheumatic diseases, 43 cases of PML (0.44%) were associated with SLE, 24 (0.25%) with rheumatoid arthritis (RA), and 25 (0.26%) with other connective tissue diseases (CTDs). When patients with other potential risk factors for PML (HIV, malignancy, bone marrow or other organ transplantation) were excluded, the rates of PML per 100,000 discharges coded for SLE, RA, and other CTDs were 4, 0.4 and 2, respectively, compared with a rate of PML in the background population of 0.2/100,000 discharges.

CONCLUSION

This study was confined to hospitalized patients with rheumatic diseases, and it was also limited by the lack of information regarding immunosuppressive therapy. Nevertheless, the findings suggest that, although rare overall, PML occurs more commonly in SLE than in other rheumatic diseases.

Clinical vigilance for progressive multifocal leukoencephalopathy in the context of natalizumab use

Natalizumab therapy for patients with multiple sclerosis (MS) has been associated with both improved clinical outcomes and an increased incidence of progressive multifocal leukoencephalopathy (PML). We provide details of the etiology and recent history of PML as associated with immunosuppressive disease states, including MS. Furthermore, it offers clinical guidance on differentiating PML from a MS relapse and a review of the current treatment options for patients suspected of having developed the complication.

Progressive multifocal leukoencephalopathy developed in incomplete Heerfordt syndrome, a rare manifestation of sarcoidosis, without steroid therapy responding to cidofovir

Progressive multifocal leukoencephalopathy (PML) is a severe demyelinating disease of the central nervous system caused by the JC virus; the mortality rate is high and it is usually refractory to treatment. In non-HIV patients, PML occurs as a late consequence of hematologic malignancies or during prolonged immunosuppression for transplantation or autoimmune disease. We describe a 34-year-old PML patient with incomplete Heerfordt syndrome, a rare type of sarcoidosis, who had not received any immunosuppressants, including steroids, at the onset and who was clinically and radiologically responsive to the antiviral drug cidofovir.

Central nervous system infections in immunocompromised patients: update on diagnostics and therapy

Infections of the central nervous system (CNS) are increasingly reported in patients with malignancies. Heavily immunocompromised patients like those after allogeneic stem cell transplantation (SCT) or previous T cell depleting treatment regimens (e.g. with fludarabine or alemtuzumab) are at highest risk for cerebral infections. The spectrum of causative organisms may vary greatly, depending on the underlying malignancy, its treatment and various other factors. Toxoplasma gondii and fungi are the leading causative organisms in patients after allogeneic SCT, but also viruses such as herpes simplex virus or JC virus may be detected in these patients. Definitive diagnosis of cerebral infection still remains a high challenge, although diagnostics have improved by the wide availability of imaging techniques and polymerase chain reaction in recent years. Novel therapeutic options are arising, particularly for fungal CNS infections. Here, we summarise aspects on epidemiology, clinical symptoms and prognosis of CNS infections in patients with malignancies. Additionally, we give an overview on the diagnostics and management of cerebral infections in these patients including evidence evaluation of efficacy of treatment.

Update on PML: lessons from the HIV uninfected and new insights in pathogenesis and treatment

Significant advances in our understanding of progressive multifocal leukoencephalopathy (PML) and its causative agent, JC virus, have been made since PML was first described 50 years ago. However, immune reconstitution remains the only proven, effective therapy in this devastating central nervous system disorder. Early diagnosis and adjustments of immune suppressants and modulator agents are critical in managing PML in HIV-negative patients. This review summarizes recent advances in our understanding of PML in HIV-uninfected patients in oncology, rheumatology, organ transplantation, and idiopathic immune deficiency and in association with novel therapeutics. Brain MRI data from our case series of brain biopsy-proven HIV-negative PML patients indicate the presence of an inflammatory/immune reaction in brain tissues, which was confirmed by immunocytologic analysis. Future studies to better understand PML pathogenesis in HIV-negative individuals may help uncover new potential therapeutic targets and improve PML outcomes.

JC virus agnoprotein inhibits in vitro differentiation of oligodendrocytes and promotes apoptosis

Productive infection of oligodendrocytes, which are responsible for the formation of myelin sheath in the central nervous system, with the human neurotropic virus JC virus (JCV) causes the fatal demyelinating disease progressive multifocal leukoencephalopathy (PML). In addition to encoding T antigen and the capsid proteins, which are produced at the early and late phases of the infection cycle, respectively, JCV encodes a small regulatory protein named agnoprotein that is important for successful completion of the virus life cycle. Here we used bipotential CG-4 cells to examine the impact of agnoprotein on oligodendrocyte differentiation and survival in the absence of JCV lytic infection. We demonstrate that the expression of agnoprotein delayed the formation of complex outgrowth networks of the cells during oligodendrocyte differentiation. These alterations were accompanied by high levels of DNA damage, induction of proapoptotic proteins, and suppression of prosurvival signaling. Accordingly, apoptosis was significantly increased upon the induction of CG-4 cells toward differentiation in cells expressing agnoprotein. These observations provide the first evidence for the possible involvement of agnoprotein, independent from its role in viral replication, in a series of biological events that may contribute to the pathological features seen in PML lesions.