Progressive multifocal leukoencephalopathy (PML) in a patient with lymphoma treated with rituximab: A case report and literature review

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.

Good Gone Bad: Complications of Chemotherapy, Immunotherapy, and Radiotherapy on the CNS

With recent advancements in cancer therapy, especially immunotherapy, overall survival of many cancers has increased and patient toxicity has been reduced. However, many complications of traditional cancer therapy are still prevalent and complications of novel therapies are just beginning to appear. The neuroradiologist may be the first to visualize signs of these complications on imaging. This article describes the notable imaging findings of several unique and characteristic complications of CNS cancer therapy, including toxicities of chemotherapies, immunotherapies, and radiotherapy. Complications of chemotherapeutic agents covered include methotrexate-induced and disseminated necrotizing leukoencephalopathy, and chemotherapy-induced myelopathy. Immunotherapy complications included are Tacrolimus-related Optic Neuropathy, Rituximab and Immune reconstitution inflammatory syndrome-associated Progressive Multifocal Leukoencephalopathy, Bevacizumab-associated late radiation-induced neurotoxicity, and Ipilimumab-induced hypophysitis. Lastly, radiation-induced neurotoxicities are covered, including myelopathy, radiation necrosis, cerebral atrophy, leukoencephalopathy, optic neuropathy, mineralizing microangiopathy, stroke-like migraine attacks, osteonecrosis, and vasculopathies. Neuroradiologists will increasingly encounter patients who have undergone treatment with more than 1 therapeutic modality, resulting in overlapping findings as well. Recognition of the common complications of these therapies on imaging is critical to minimizing the effects of these potential short- and long-term complications.

Central Nervous System Complications Among Oncology Patients

Cancer treatment related injury to the central nervous system (CNS) is well-recognized in the setting of brain-directed radiation therapies and conventional and novel systemic anticancer therapies. Late-delayed treatment-induced CNS complications frequently result in permanent neurologic disability. Therapeutic options are supportive with limited clinical benefit, whereby alteration or discontinuation of the overall antineoplastic treatment plan is frequently necessary to prevent further neurologic injury. Better identification of patients at high risk for developing late CNS toxicities, neuroprotective strategies with modification of existing antineoplastic treatment regimens, and research efforts directed at earlier recognition and improved treatment of central neurologic complications are paramount.

Host-Immune Interactions in JC Virus Reactivation and Development of Progressive Multifocal Leukoencephalopathy (PML)

With the advent of immunomodulatory therapies and the HIV epidemic, the impact of JC Virus (JCV) on the public health system has grown significantly due to the increased incidence of Progressive Multifocal Leukoencephalopathy (PML). Currently, there are no pharmaceutical agents targeting JCV infection for the treatment and the prevention of viral reactivation leading to the development of PML. As JCV primarily reactivates in immunocompromised patients, it is proposed that the immune system (mainly the cellular-immunity component) plays a key role in the regulation of JCV to prevent productive infection and PML development. However, the exact mechanism of JCV immune regulation and reactivation is not well understood. Likewise, the impact of host factors on JCV regulation and reactivation is another understudied area. Here we discuss the current literature on host factor-mediated and immune factor-mediated regulation of JCV gene expression with the purpose of developing a model of the factors that are bypassed during JCV reactivation, and thus are potential targets for the development of therapeutic interventions to suppress PML initiation. Graphical Abstract.

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.

Long-term tolerability, safety and efficacy of rituximab in neuromyelitis optica spectrum disorder: a prospective study

BACKGROUND

Neuromyelitis optica spectrum disorder (NMOSD) is a B-cell-mediated disease with autoimmunity towards the astrocyte water channel aquaporin-4 (AQP-4) in the central nervous system.

OBJECTIVE

To assess the long-term safety and efficacy in NMOSD patients receiving maintenance therapy with B-cell-depleting agent rituximab for more than 2 years.

METHOD

NMOSD patients were included prospectively from 2014 to 2018 and received continuous cycles of rituximab infusions biannually. Incidence of adverse events (AE), serious AEs (SAE), and infusion-related AEs were evaluated through monthly phone calls and neurological examination every 4 months.

RESULTS

A total of 44 NMOSD patients were included, of those 30 were treatment naive (68%). The mean age was 37.2 years with 79.5% females. With overall observation period of 31.6 ± 7.3 months (24-48 months), tolerability was assessed as satisfactory in most cases. We observed infusion reactions (mostly mild) in 31.8% of patients and 31.8% never experienced any AEs after a mean 5.1 cycles of rituximab therapy. Rituximab was also beneficial in terms of improvement in relapse rate (from 0.26 ± 0.54 to 0, P = 0.003) and Expanded Disability Status Scale (from 4.1 ± 1.8 to 3.1 ± 1.8, P < 0.001). Stratification according to AQP4-IgG serostatus showed no difference between groups.

CONCLUSION

Rituximab treatment is well tolerated, safe, and efficacious with a minor risk of mild infusion reactions for NMOSD patients.

Progressive Multifocal Leukoencephalopathy Following Combined Rituximab-Based Immune-Chemotherapy for Post-transplant Lymphoproliferative Disorder in a Renal Transplant Recipient: A Case Report

BACKGROUND

Transplant recipients are at risk of developing progressive multifocal leukoencephalopathy (PML), an opportunistic infection due to reactivation of JC virus. Post-transplant lymphoproliferative disorders (PTLDs) represent a common malignancy in this population, and antiCD20-therapy has become an established component of its treatment.

CASE PRESENTATION

We describe the first case of a renal allograft transplant recipient with PTLD who received rituximab-based immune-chemotherapy and developed PML shortly thereafter. Despite early suspicion and diagnosis, the disease ran a relentlessly progressive course, and the patient succumbed to his illness shortly thereafter.

CONCLUSION

PML should be strongly suspected whenever unusual neurologic symptoms appear in the context of immunosuppression. Clinicians and patients should be aware of the potential for PML after rituximab therapy.

Progressive multifocal leukoencephalopathy and hematologic malignancies: a single cancer center retrospective review

Progressive multifocal leukoencephalopathy (PML) is an uncommon opportunistic infection with high morbidity and mortality. This is an institutional review board-approved retrospective review of medical records identified by diagnostic coding for PML or John Cunningham virus (JCV) from 2000 to 2015. Inclusion criteria were cerebrospinal fluid (CSF) positive for JCV by polymerase chain reaction or brain biopsy-proven PML in non-HIV patients. There were 16 patients, 12 of whom were men (75%); the median age was 56 years (range, 31-71 years). All had hematologic malignancies (5 [31%] had chronic lymphocytic leukemia, 3 [19%] had acute myeloid leukemia, 3 had [19%] mantle cell lymphoma, and 1 patient each had acute lymphoblastic leukemia, Hodgkin lymphoma, myeloma, or B-cell lymphoma). One patient received no cancer-directed therapy. Of the remaining 15 patients, all received conventional chemotherapy, and 9 (60%) underwent transplant. Thirteen patients (87%) received immunomodulating therapy (predominantly rituximab). The median time from cancer diagnosis to PML diagnosis was 48.5 months. PML was diagnosed a median of 2.1 months from symptom onset; however, the median time to PML diagnosis was 5.4 months for the 4 patients presenting with a cerebellar syndrome. PML was diagnosed by CSF in 12 patients and brain biopsy in 4 following negative CSF test results. Median survival from PML diagnosis was 4.3 months for the 11 patients on treatment and 0.87 months for the 5 without treatment. PML still occurs in patients with hematologic malignancies in the absence of treatment. Twenty-five percent of our patients required brain biopsy for diagnosis, and diagnosis was delayed when the clinical presentation was unusual, such as a cerebellar syndrome.

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.

Drug-associated progressive multifocal leukoencephalopathy: a clinical, radiological, and cerebrospinal fluid analysis of 326 cases

The implementation of a variety of immunosuppressive therapies has made drug-associated progressive multifocal leukoencephalopathy (PML) an increasingly prevalent clinical entity. The purpose of this study was to investigate its diagnostic characteristics and to determine whether differences herein exist between the multiple sclerosis (MS), neoplasm, post-transplantation, and autoimmune disease subgroups. Reports of possible, probable, and definite PML according to the current diagnostic criteria were obtained by a systematic search of PubMed and the Dutch pharmacovigilance database. Demographic, epidemiologic, clinical, radiological, cerebrospinal fluid (CSF), and histopathological features were extracted from each report and differences were compared between the disease categories. In the 326 identified reports, PML onset occurred on average 29.5 months after drug introduction, varying from 14.2 to 37.8 months in the neoplasm and MS subgroups, respectively. The most common overall symptoms were motor weakness (48.6 %), cognitive deficits (43.2 %), dysarthria (26.3 %), and ataxia (24.1 %). The former two also constituted the most prevalent manifestations in each subgroup. Lesions were more often localized supratentorially (87.7 %) than infratentorially (27.4 %), especially in the frontal (64.1 %) and parietal lobes (46.6 %), and revealed enhancement in 27.6 % of cases, particularly in the MS (42.9 %) subgroup. Positive JC virus results in the first CSF sample were obtained in 63.5 %, while conversion after one or more negative outcomes occurred in 13.7 % of cases. 52.2 % of patients died, ranging from 12.0 to 83.3 % in the MS and neoplasm subgroups, respectively. In conclusion, despite the heterogeneous nature of the underlying diseases, motor weakness and cognitive changes were the two most common manifestations of drug-associated PML in all subgroups. The frontal and parietal lobes invariably constituted the predilection sites of drug-related PML lesions.

Rituximab in autoimmune thrombotic thrombocytopenic purpura: A success story

Despite a significant improvement of thrombotic thrombocytopenic purpura (TTP) prognosis since the use of plasma exchange, morbidity and mortality remained significant because of poor response to standard treatment or exacerbations and relapses. Rituximab, a chimeric monoclonal antibody directed against the B-lymphocyte CD20 antigen, has shown a particular interest in this indication. Recent studies also reported strong evidence for its efficiency in the prevention of relapses. This review addresses these recent progresses and still opened questions in this topic: should rituximab be proposed in all patients at the acute phase? Should all patients benefit from a preemptive treatment? Is the infectious risk acceptable in this context?