Association between microglial activation and serum kynurenine pathway metabolites in multiple sclerosis patients

Microglial activation associates with MS progression but it is unclear what drives their persistent pro-inflammatory state. Metabolites of the kynurenine pathway (KP), the main metabolism route of tryptophan, can influence the function of brain innate immune cells.To investigate whether tryptophan metabolites in blood associate with TSPO-PET measurable microglial activation in MS brain.Microglial activation was detected using PET imaging and the TSPO-binding radioligand [11C]PK11195. Distribution volume ratios (DVR) for specific [11C]PK11195-binding in the normal appearing white matter (NAWM), lesions, and thalamus were calculated. Ultrahigh performance liquid chromatography-tandem mass spectrometry was used to measure serum levels of tryptophan and kynurenine pathway metabolites.The study cohort consisted of 48 MS patients. Increased DVR in the NAWM and thalamus correlated with decreased serum 3-hydroxykynurenine level (R = -0.31, p = 0.031 and R = -0.32, p = 0.028). Increased EDSS correlated with decreased 3-hydroxykynurenine and xanthurenic acid (R = -0.36, p = 0.012 and R = -0.31, p = 0.034) and increased DVR in the NAWM and thalamus (R = 0.33, p = 0.023 and R = 0.34, p = 0.020, respectively).This clinical study demonstrates an association between low serum 3-hydroxykynurenine and high microglial activation in MS. Further investigations are warranted for elucidation of the biological mechanisms behind this association

Treatment with Cladribine Tablets Beyond Year 4: A Position Statement by Southeast European Multiple Sclerosis Centers

Based on the results of the pivotal CLARITY study, cladribine tablets were approved for use in the European Union in 2017 as a high-efficacy therapy for highly active relapsing-remitting multiple sclerosis (MS). Cladribine tablets are used as an induction therapy: half of the total dose is given in year 1 and the other half in year 2. In the CLARITY Extension trials, repeating the dose routinely in years 3 and 4, was not associated with significantly improved disease control. However, there is very limited evidence on how to manage people with MS (pwMS) beyond year 4, which is increasingly important because more and more patients are now ≥ 4 years after cladribine treatment. Overall, postapproval data show that treatment with two cladribine cycles effectively controls disease activity in the long term. However, there is general agreement that some pwMS with suboptimal response could benefit from retreatment. This study reviews the practical aspects of using cladribine tablets, summarizes the evidence from clinical trials and real-world studies on the safety and efficacy of cladribine, and proposes a treatment algorithm developed by expert consensus for pwMS previously treated with cladribine. In brief, we propose that additional courses of cladribine tablets should be considered in patients with minimal (no relapses, 1-2 new lesions) or moderate (1 relapse, 3-4 new lesions) disease activity, while significant disease activity (> 1 relapse, > 3 new lesions) or progression should warrant a switch to another high-efficacy treatment (HET). More evidence is needed to improve the treatment guidelines for pwMS who previously received cladribine

The Tryptophan-Kynurenine Metabolic System Is Suppressed in Cuprizone-Induced Model of Demyelination Simulating Progressive Multiple Sclerosis

Progressive multiple sclerosis (MS) is a chronic disease with a unique pattern, which is histologically classified into the subpial type 3 lesions in the autopsy. The lesion is also homologous to that of cuprizone (CPZ) toxin-induced animal models of demyelination. Aberration of the tryptophan (TRP)-kynurenine (KYN) metabolic system has been observed in patients with MS; nevertheless, the KYN metabolite profile of progressive MS remains inconclusive. In this study, C57Bl/6J male mice were treated with 0.2% CPZ toxin for 5 weeks and then underwent 4 weeks of recovery. We measured the levels of serotonin, TRP, and KYN metabolites in the plasma and the brain samples of mice at weeks 1, 3, and 5 of demyelination, and at weeks 7 and 9 of remyelination periods by ultra-high-performance liquid chromatography with tandem mass spectrometry (UHPLC-MS/MS) after body weight measurement and immunohistochemical analysis to confirm the development of demyelination. The UHPLC-MS/MS measurements demonstrated a significant reduction of kynurenic acid, 3-hydoxykynurenine (3-HK), and xanthurenic acid in the plasma and a significant reduction of 3-HK, and anthranilic acid in the brain samples at week 5. Here, we show the profile of KYN metabolites in the CPZ-induced mouse model of demyelination. Thus, the KYN metabolite profile potentially serves as a biomarker of progressive MS and thus opens a new path toward planning personalized treatment, which is frequently obscured with immunologic components in MS deterioration

A longitudinally extensive H3 K27M-mutant diffuse midline glioma in an elderly patient clinically mimicking central nervous system inflammation: a case report

Diffuse midline gliomas, H3 K27M-mutant, World Health Organization (WHO) grade IV represent a distinct glioma entity with a predominantly paediatric presentation and remarkably poor prognosis. This report presents a case of a 73-year-old woman with a diffuse midline glioma, H3 K27M-mutant, WHO grade IV with a remarkable longitudinal extension, extending from the cervical myelon to the basal ganglia. On imaging, the lesion was predominantly suggestive of inflammatory oedema, and it was clinically associated with progressive hemi- and later tetraparesis with severe autonomic and bulbar symptoms. Laboratory examinations suggested a generalized inflammatory process; however, neither infectious nor autoimmune aetiology could be confirmed. Biopsy was deemed unfeasible given the critical localization. Presuming a seronegative autoimmune encephalomyelitis, high-dose corticosteroid therapy and plasma exchanges were conducted, resulting in a modest but transient relief. The patient passed away two months after hospitalization. Neuropathological examination of the lesion revealed a high-grade diffuse glioma with H3 K27M mutation (grade IV). Although originally considered as a paediatric entity, our case confirms reports from recent years that diffuse midline gliomas, H3 K27M-mutant, WHO grade IV can occur in adults, even among the elderly, and can mimic inflammatory alterations, posing diagnostic difficulty. Our case is one of the oldest patients reported with this pathology, the oldest with an extensive diffusely infiltrating growth pattern, and with the most extensive lesion reported in adulthood

Treatment of relapsing multiple sclerosis in Hungary – consensus recommendation from the Hungarian neuroimmunology society

Multiple sclerosis (MS) may impact quality of life, careers and family plans of the affected individuals. The current treatments with disease modifying therapies aim to prevent people with MS (pwMS) from disability accumulation and progression. Different countries have different reimbursement policies resulting in inequalities in patient care among geographical regions. Access to anti-CD20 therapies for relapsing MS is restricted in Hungary because therapy of individual cases only is reimbursed. In the light of the latest research and national guidelines, 17 Hungarian MS experts agreed on 8 recommendations regarding relapsing pwMS using the Delphi round method. Strong agreement (> 80%) was achieved in all except one recommendation after three rounds, which generated a fourth Delphi round. The experts agreed on treatment initiation, switch, follow-up and discontinuation, as well as on special issues such as pregnancy, lactation, elderly population, and vaccination. Well-defined national consensus protocols may facilitate dialogue between policymakers and healthcare professionals and thus contribute to better patient care in the long run

Kappa free light chains is a valid tool in the diagnostics of MS: A large multicenter study

To validate kappa free light chain (KFLC) and lambda free light chain (LFLC) indices as a diagnostic biomarker in multiple sclerosis (MS).We performed a multicenter study including 745 patients from 18 centers (219 controls and 526 clinically isolated syndrome (CIS)/MS patients) with a known oligoclonal IgG band (OCB) status. KFLC and LFLC were measured in paired cerebrospinal fluid (CSF) and serum samples. Gaussian mixture modeling was used to define a cut-off for KFLC and LFLC indexes.The cut-off for the KFLC index was 6.6 (95% confidence interval (CI) = 5.2-138.1). The cut-off for the LFLC index was 6.9 (95% CI = 4.5-22.2). For CIS/MS patients, sensitivity of the KFLC index (0.88; 95% CI = 0.85-0.90) was higher than OCB (0.82; 95%CI = 0.79-0.85; p < 0.001), but specificity (0.83; 95% CI = 0.78-0.88) was lower (OCB = 0.92; 95% CI = 0.89-0.96; p < 0.001). Both sensitivity and specificity for the LFLC index were lower than OCB.Compared with OCB, the KFLC index is more sensitive but less specific for diagnosing CIS/MS. Lacking an elevated KFLC index is more powerful for excluding MS compared with OCB but the latter is more important for ruling in a diagnosis of CIS/MS