IL-11 induces NLRP3 inflammasome activation in monocytes and inflammatory cell migration to the central nervous system.

The objective of this study is to examine IL-11-induced mechanisms of inflammatory cell migration to the central nervous system (CNS). We report that IL-11 is produced at highest frequency by myeloid cells among the peripheral blood mononuclear cell (PBMC) subsets. Patients with relapsing-remitting multiple sclerosis (RRMS) have an increased frequency of IL-11+ monocytes, IL-11+ and IL-11R+ CD4+ lymphocytes, and IL-11R+ neutrophils in comparison to matched healthy controls. IL-11+ and granulocyte-macrophage colony-stimulating factor (GM-CSF)+ monocytes, CD4+ lymphocytes, and neutrophils accumulate in the cerebrospinal fluid (CSF). The effect of IL-11 in-vitro stimulation, examined using single-cell RNA sequencing, revealed the highest number of differentially expressed genes in classical monocytes, including up-regulated NFKB1, NLRP3, and IL1B. All CD4+ cell subsets had increased expression of S100A8/9 alarmin genes involved in NLRP3 inflammasome activation. In IL-11R+-sorted cells from the CSF, classical and intermediate monocytes significantly up-regulated the expression of multiple NLRP3 inflammasome-related genes, including complement, IL18, and migratory genes (VEGFA/B) in comparison to blood-derived cells. Therapeutic targeting of this pathway with αIL-11 mAb in mice with RR experimental autoimmune encephalomyelitis (EAE) decreased clinical scores, CNS inflammatory infiltrates, and demyelination. αIL-11 mAb treatment decreased the numbers of NFκBp65+, NLRP3+, and IL-1ß+ monocytes in the CNS of mice with EAE. The results suggest that IL-11/IL-11R signaling in monocytes represents a therapeutic target in RRMS.

Retinal vasculopathy with cerebral leukoencephalopathy (RVCL): A rare mimic of tumefactive MS.

OBJECTIVE: We report a series of 2 brothers who each developed tumefactive brain lesions, initially thought to have brain tumors or tumefactive multiple sclerosis (MS), but who were ultimately diagnosed with a rare autosomal dominant condition known as retinal vasculopathy with cerebral leukoencephalopathy (RVCL). METHODS: Case series and literature review. RESULTS: We present 2 brothers who developed tumefactive right frontal brain lesions leading to gait disturbances and cognitive changes. Both brothers also had nonspecific brain calcifications and T2-hyperintense lesions, and both had ophthalmic and liver disease of unclear etiology. The first brother had been extensively evaluated by various specialists, underwent inconclusive brain and liver biopsies, and was ultimately unsuccessfully treated for a diagnosis of tumefactive MS. The second brother also underwent unrevealing evaluation with CSF analysis and brain biopsy. Further family history revealed that the patients' father developed a tumefactive brain lesion in the 1980s and had been diagnosed with CNS vasculitis. Given the familial link, RVCL was suspected, and genetic analysis confirmed the diagnosis with a 3-prime repair exonuclease 1 (TREX1) C-terminal mutation. CONCLUSION: The presence of tumefactive brain lesions, nonspecific brain calcifications, liver disease, and retinal vasculopathy, coupled with suggestive family history, led to the RVCL diagnosis. This report contributes to the limited understanding of RVCL, which can cause brain lesions that mimic gliomas or tumefactive MS. Recognition of this entity may prevent unnecessary invasive procedures and inappropriate therapeutic interventions, and would allow for proper counseling of family members.

Diagnostic delay in progressive multifocal leukoencephalopathy.

We investigated delay in diagnosing progressive multifocal leukoencephalopathy (PML). The median time from initial symptom to diagnosis was 74 days (range 1-1643) in 111 PML patients seen at our institution from 1993 to 2015. Another diagnosis was considered before PML in nearly two-thirds, and more than three-quarters of patients suffered from diagnostic delay greater than 1 month, irrespective of their underlying immunosuppressive condition. Extended diagnostic delay occurred more frequently in patients with possible PML, and among HIV (+) patients with higher CD4(+) T-cell counts at symptom onset. Prompt diagnosis may improve survival of PML in so far as immune reconstitution can be effected, and prevent unnecessary interventions.

Interleukin-7 treatment of PML in a patient with idiopathic lymphocytopenia.

OBJECTIVE: To describe the compassionate use of interleukin-7 (IL-7) for treatment of progressive multifocal leukoencephalopathy (PML) in the setting of idiopathic CD8+ greater than CD4+ lymphocytopenia. METHODS: A 66-year-old HIV-seronegative man presented with progressive language dysfunction. MRI showed hyperintense lesions in the left hemispheric white matter with mild contrast enhancement. A brain biopsy performed 4 months after symptom onset established the diagnosis of PML. The patient had profound lymphocytopenia with absolute lymphocyte count (ALC) at 168 cells/µL, 87 CD4+ T cells/µL, and 7 CD8+ T cells/µL. There was no evidence of hematologic malignancy or rheumatologic disease. RESULTS: The patient received 3 intramuscular injections of IL-7 at a dose of 10 µg/kg per week with no adverse effects. ALC peaked at 595 cells/µL, CD4+ T cells at 301 cells/µL, and CD8+ T cells at 34 cells/µL 3 weeks after completion of treatment. His lesions on MRI stabilized and neurologic examination mildly improved. JCV-specific T-cell responses measured by intracellular cytokine staining were not altered after treatment with IL-7 but there was a marked increase in regulatory T cells. CONCLUSION: This case further supports the investigational use of IL-7 in patients who develop PML in the setting of ICL. CLASSIFICATION OF EVIDENCE: This study provides Class IV evidence that for patients with ICL and PML, IL-7 improves PML-related-outcomes. The study is rated Class IV because it is a case report.

Challenges in the diagnosis and treatment of CNS demyelinating disorders in Zambia.

Demyelinating disease occurs in a population of black adult Zambians whose genetic and environmental risk factors for multiple sclerosis are thought to be rare. The diagnosis of demyelinating disease was based predominantly on compatible clinical history and neurologic exam findings, and in some cases, more definitely established by cerebrospinal fluid exam and imaging findings. When available, laboratory studies excluded other known causes of CNS demyelination. Timely evaluation and treatment with disease-modifying therapies was related to the patient's employment status. Lack of financial means to go abroad was a major hurdle in a patient's ability to receive treatment. Significant barriers often prohibit timely diagnosis and prevent proper management of these patients.

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.

Novel syndromes associated with JC virus infection of neurons and meningeal cells: no longer a gray area.

PURPOSE OF REVIEW: The availability of a growing number of immunomodulatory medications over the past few years has been associated with various JC virus (JCV)-associated brain syndromes in patients with autoimmune diseases, including multiple sclerosis, Crohn's disease, and psoriasis that had not been previously recognized as predisposing factors for progressive multifocal leukoencephalopathy. This review covers the three novel syndromes discovered in the last decade that are caused by JCV infection of neurons and meningeal cells. RECENT FINDINGS: For more than 30 years, JCV was thought to exclusively infect oligodendrocytes and astrocytes in the white matter of the brain of immunosuppressed individuals. We now recognize that JCV-infected glial cells are frequently located at the gray-white matter junction or exclusively within the gray matter causing demyelination in the cortex. Mutations in JCV can trigger a change in tropism leading to involvement of other cell types, such as neurons and meningeal cells, causing clinically distinct entities. These new features of JCV infection provide challenges for clinicians taking care of affected patients and investigators studying the biology of this polyomavirus, its pathogenesis, and tropism. SUMMARY: We hope that increasing awareness of these syndromes will lead to early diagnosis, and pave the way for new avenues of research to better understand all aspects of JCV pathogenesis and develop efficient therapies for our patients. However, we need to remain vigilant and open to the possibility that additional JC variants or yet unknown polyomaviruses may also be associated with neurological diseases.