Progressive Multifocal Leukoencephalopathy during Tocilizumab Treatment for Rheumatoid Arthritis

Progressive multifocal leukoencephalopathy in rheumatoid arthritis and biological therapies: a case report and review of the literature

BACKGROUND

Progressive multifocal leukoencephalopathy is a rare but potentially fatal disease caused by infection of the central nervous system with John Cunningham polyomavirus. Progressive multifocal leukoencephalopathy mainly occurs in immunocompromised patients, including patients on biological and targeted synthetic therapies, such as multiple sclerosis and rheumatoid arthritis patients. Early diagnosis of progressive multifocal leukoencephalopathy is crucial for patient survival. We describe a case of progressive multifocal leukoencephalopathy with significant diagnostic delay in a rheumatoid arthritis patient using rituximab. Additionally, we give an overview of available literature on progressive multifocal leukoencephalopathy in rheumatoid arthritis patients using biologicals, focusing on the diagnostic difficulties and delays, to raise awareness of this adverse event among physicians treating rheumatoid arthritis patients with immunosuppressants.

CASE PRESENTATION

A 69-year-old white man of Dutch descent with rheumatoid arthritis treated with rituximab presented to a neurology outpatient clinic, complaining of difficulties in word-finding and reading without problems in visual acuity, several weeks after a mild traumatic head injury (patient's delay). Brain computed tomography-scan showed two hypodense white-matter lesions, initially considered to be of vascular origin (doctor's delay). However, magnetic resonance imaging, performed more than a week later, showed lesions consistent with progressive multifocal leukoencephalopathy. Immunosuppressants were then immediately discontinued. The patient agreed to repeat magnetic resonance imaging and lumbar puncture. Initial John Cunningham polyomavirus polymerase chain reaction on cerebrospinal fluid was negative. However, a subsequent lumbar puncture confirmed the diagnosis. The patient rejected experimental treatment with pembrolizumab and passed away a month after the initial presentation.

CONCLUSIONS

This case report emphasizes the need for increased awareness and importance of timely recognition of potential progressive multifocal leukoencephalopathy in rheumatoid arthritis patients using immunosuppressive therapies. A total of 26 other cases of rheumatoid arthritis patients using biologicals who developed progressive multifocal leukoencephalopathy were identified from the literature, and we reviewed their cases. Most (24; 92%) cases occurred during rituximab or TNF-alpha inhibitor use. There was a mean delay of 2.5 months between symptom onset and diagnosis. Information on predisposing risk factors such as lymphopenia was often not reported. Physicians and patients should be aware of the symptoms of progressive multifocal leukoencephalopathy, as early diagnosis and immediate withdrawal of immunosuppressants is crucial to improve the chance of survival. This case report highlights the importance of awareness in recognizing progressive multifocal leukoencephalopathy symptoms in nontraditional populations.

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.

Docking and Molecular Dynamics Study to Identify Novel Phytobiologics from Dracaena trifasciata against Metabolic Reprogramming in Rheumatoid Arthritis

Enhancement of glycolysis and glutaminolysis are the two most common modalities associated with metabolic reprogramming in rheumatoid arthritis (RA). This enhancement is concomitant to the upregulation of hexokinase 2 (HK2) and glutaminase 1 (GLS1). Hence, the current study was undertaken to identify potential phytobiological inhibitors against HK2 and GLS1, from Dracaena (Sansevieria) trifasciata, an indigenous ethnomedicinal plant found in Pakistan, using computational analysis. Phytobiologics from Dracaena trifasciata were assessed for their ability to co-inhibit HK2 and GLS1 via molecular docking and molecular dynamics simulations. The results underscored seven phytobiologics with promising binding affinities for both HK2 and GLS1. Molecular dynamics simulations further elucidated that all seven identified phytobiologics inhibited HK2 by forming stable complexes but only five amongst the seven had the potential to form stable complexes with GLS1 in real time, thereby implying the potential of co-inhibition for these five compounds. Compound 28MS exhibited an equally strong binding profile for both HK2 (−8.19 kcal/mol) and GLS1 (−8.99 kcal/mol). Furthermore, it exhibited a similar trend in stability during simulation for both targets. Our results serve as a primer for a more lucid understanding towards co-inhibition of HK2 and GLS1 using multiple computational approaches. The identified phytobiologics should undergo in-vitro and in-vivo validation to corroborate their therapeutic potential in RA.

Role of IL-6 in the commitment of T cell subsets

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IL-6 is a non-redundant differentiation factor for Th17 cells and Tfh cells.

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The induction of ROR-γt⁺ Treg cells in the lamina propria depends on IL-6.

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Generation of distinct T helper cell subsets might depend on different IL-6 signaling modalities.

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IL-6-directed therapies must consider the disease-relevant IL-6 signaling modality.

IL-6 gained much attention with the discovery that this cytokine is a non-redundant differentiation factor for Th17 cells and T follicular helper cells. Adaptive immune responses to fungi and extracellular bacteria are impaired in the absence of IL-6. IL-6 is also required for the induction of ROR-γt⁺ Treg cells, which are gatekeepers of homeostasis in the gut lamina propria in the presence of commensal bacteria. Conversely, severe immunopathology in T cell-mediated autoimmunity is mediated by Th17 cells that rely on IL-6 for their generation and maintenance. Recently, it has been discovered that the differentiation of these distinct T helper cell subsets may be linked to distinct signaling modalities of IL-6. Here, we summarize the current knowledge on the mode of action of IL-6 in the differentiation and maintenance of T cell subsets and propose that a context-dependent understanding of the impact of IL-6 on T cell subsets might inform rational IL-6-directed interventions in autoimmunity and chronic inflammation.