A Liquid Chromatography-Mass Spectrometry Assay for Determination of Perampanel and Concomitant Antiepileptic Drugs in the Plasma of Patients With Epilepsy Compared With a Fluorescent HPLC Assay.

BACKGROUND: Perampanel is a novel noncompetitive selective antagonist at the postsynaptic ionotropic alpha-amino-3-hydroxy-5-methyl-4-isoxazoleproprionic acid (AMPA) glutamate receptor, which is approved as an adjunctive agent for the treatment of partial-onset seizure with or without secondary generalization and for primary generalized tonic-clonic seizure in patients with epilepsy who are at least 12 years of age. Limited information is available about the clinical utility of therapeutic drug monitoring of perampanel and therapeutic ranges are so far not established. Therefore, perampanel titration should be performed especially in case of insufficient success of the drug. METHODS: The authors developed a selective and sensitive LC-MS/MS (liquid chromatography-mass spectrometry) assay to monitor perampanel concentrations in plasma, which was compared to a commercially available high-performance liquid chromatography kit with fluorescent detection. Perampanel and the internal standard were extracted from plasma samples by a simple protein precipitation. The method allows the simultaneous quantification of perampanel and several other antiepileptic drugs (AEDs). RESULTS: Data were evaluated according to EMA guidelines for bioanalytical method validation. Extraction recovery of perampanel from human plasma was consistently above 98%. No matrix effect was found. Analytical interferences by other AEDs were not observed. The method was linear in the range from 2.5 to 2800 ng/mL. Intra-assay and interassay reproducibility analyses demonstrated accuracy and precision within acceptance criteria. Data collected from 95 patients, given perampanel as their maintenance antiepileptic therapy, showed a very strong correlation between the 2 methods. CONCLUSIONS: The assay allows for highly sensitive and selective quantification of perampanel and concomitant AEDs in patient plasma samples and can be easily implemented in clinical settings. Our findings are in agreement with previously published data in patients comedicated with enzyme inducer AEDs, but seem to indicate a possible interaction in patients treated with the enzyme inhibitor drug valproic acid.

Anti-amyloid ß autoantibodies in cerebral amyloid angiopathy-related inflammation: implications for amyloid-modifying therapies.

OBJECTIVE: Cerebral amyloid angiopathy-related inflammation (CAA-ri) is characterized by vasogenic edema and multiple cortical/subcortical microbleeds, sharing several aspects with the recently defined amyloid-related imaging abnormalities (ARIA) reported in Alzheimer's disease (AD) passive immunization therapies. Herein, we investigated the role of anti-amyloid ß (Aß) autoantibodies in the acute and remission phases of CAA-ri. METHODS: We used a novel ultrasensitive technique on patients from a retrospective multicenter case-control study, and evaluated the anti-Aß autoantibody concentration in the cerebrospinal fluid (CSF) of 10 CAA-ri, 8 CAA, 14 multiple sclerosis, and 25 control subjects. Levels of soluble Aß40, Aß42, tau, P-181 tau, and APOE genotype were also investigated. RESULTS: During the acute phase of CAA-ri, anti-Aß autoantibodies were specifically increased and directly correlated with Aß mobilization, together with augmented tau and P-181 tau. Following clinical and radiological remission, autoantibodies progressively returned to control levels, and both soluble Aß and axonal degeneration markers decreased in parallel. INTERPRETATION: Our data support the hypothesis that the pathogenesis of CAA-ri may be mediated by a selective autoimmune reaction against cerebrovascular Aß, directly related to autoantibody concentration and soluble Aß. The CSF dosage of anti-Aß autoantibodies with the technique here described can thus be proposed as a valid alternative tool for the diagnosis of CAA-ri. Moreover, given the similarities between ARIA developing spontaneously and those observed during immunization trials, anti-Aß autoantibodies can be considered as novel potential biomarkers in future amyloid-modifying therapies for the treatment of AD and CAA.

Plasma cytokine levels in migraineurs and controls.

BACKGROUND: The vasoactive peptide, calcitonin gene-related peptide (CGRP), is released from primary afferent neurons in the trigemino-vascular circulation during migraine headache. CGRP at physiological concentrations and possibly via stimulation of its selective receptors on T-cells, triggers the secretion of cytokines. Cytokines play an important role in several physiological and pathological settings such as immunology, inflammation, and pain. OBJECTIVE: To investigate plasma levels of pro- and anti-inflammatory cytokines in migraineurs and healthy controls. METHODS: We studied 25 migraine patients, during and outside attacks, and 18 healthy control subjects measuring plasma levels of IL-6, IL-10, tumor necrosis factor alpha (TNFalpha), IL-4, IL-1 beta, and IL-2 using ELISA. RESULTS: Circulating levels of IL-10, TNFalpha, and IL-1 beta during attacks were significantly higher in comparison to their levels outside attacks (P=.0003, P=.03, and P=.05, respectively). IL-10 and TNF serum levels were higher in patients studied soon after headache onset and lower over time (P=.004 and P=.05). CONCLUSION: Our results suggest that TNFalpha, IL-1 beta, and IL-10 may be involved in the pathogenesis of migraine attacks.