Pre- and Postictal Changes in the Innate Immune System: Cause or Effect?

INTRODUCTION: Recent studies have shown that inflammatory processes might play a role in epileptogenesis. Their role in ictogenesis is much less clear. The aim of this study was to investigate peri-ictal changes of the innate immune system by analyzing changes of immune cells, as well as pro- and anti-inflammatory cytokines. METHODS: Patients with active epilepsy admitted for video-EEG monitoring for presurgical evaluation were included. Blood was sampled every 20 min for 5 h on 3 consecutive days until a seizure occurred. After a seizure, additional samples were drawn immediately, as well as 1 and 24 h later. To analyze the different populations of peripheral blood mononuclear cells, all samples underwent FACS for CD3, CD4, CD8, CD56, CD14, CD16, and CD19. For cytokine analysis, we used a custom bead-based multiplex immunoassay for IFN-γ, IL-1ß, IL-1RA, IL-4, IL-6, IL-10, IL-12, IL-17, MCP-1, MIP-1α, and TNFα. RESULTS: Fourteen patients with focal seizures during the sampling period were included. Natural killer (NK) cells showed a negative correlation (ρ = -0.3362, p = 0.0195) before seizure onset and an immediate increase to 1.95-fold afterward. T helper (TH) and B cells decreased by 2 and 8%, respectively, in the immediate postictal interval. Nonclassical and intermediate monocytes decreased not until 1 day after the seizures, and cytotoxic T (TC) cells showed a long-lasting postictal increase by 4%. IL-10 and MCP-1 increased significantly after seizures, and IL-12 decreased in the postictal phase. DISCUSSION/CONCLUSION: Our study argues for a role of the innate immune system in the pre- and postictal phases. NK cells might be involved in preictal changes or be altered as an epiphenomenon in the immediate preictal interval.

Switching the manufacturer of antiepileptic drugs is associated with higher risk of seizures: A nationwide study of prescription data in Germany.

OBJECTIVE: Despite bioequivalence, the exchangeability of antiepileptic drugs in clinical settings is disputed. Therefore, we investigated the risk for recurrent seizures after switching the manufacturer of the same drug in a large German cohort. METHODS: Anonymous patient data from practice neurologists throughout Germany between 2011 and 2016 were collected using the IMS Disease Analyzer database (QuintilesIMS, Frankfurt, Germany). People with epilepsy were included if at least 2 prescriptions within 360 days and 1 within 180 days prior to the index date were available. The cohort was separated into a seizure group and seizure-free controls. Both groups were matched 1:1 according to age, gender, insurance status, and treating physician. The risk for breakthrough seizures after a manufacturer switch of the same antiepileptic drug was analyzed using multivariate regression models. RESULTS: A total of 3,530 people with epilepsy were included (each group, n = 1,765; age = 53.7 ± 19.8 years). Patients with seizures had switched the drug manufacturer more often than controls (26.8% vs 14.2%; odds ratio [OR] = 1.35, 95% confidence interval [CI] = 1.08-1.69, p = 0.009), both from branded to generic (5.5% vs 2.4%; OR = 1.85, 95% CI = 1.30-2.64, p < 0.001) and between generic drugs (14.7% vs 7.1%; OR = 1.45, 95% CI = 1.13-1.87, p = 0.004). INTERPRETATION: In previously seizure-free patients, switching the manufacturer of antiepileptic medications was associated with a higher risk for seizure recurrence. Our retrospective approach does not allow us to determine whether other changes in medical care at the same time could contribute to the recurrence. However, it would be prudent to avoid switching the manufacturer of anticonvulsants in seizure-free patients. Ann Neurol 2018;84:918-925.

The debate: Treatment after the first seizure-The PRO.

According to current diagnosis criteria, first seizures constitute beginning epilepsy when they carry recurrence risks of ≥60% over the next 10 years. This is frequently the case and warrants AED treatment. Evidence argues against deferring treatment when provoking factors such as sleep deprivation are reported. There are several characteristics of first seizures which markedly increase recurrence risk but not clearly beyond 60%. This includes status epilepticus or seizure flurries at first manifestation or focal semiology indicating focal epilepsy. In this situation, there are still various medical, social and individual aspects supporting early initiation of AED. Modern AED allow this safely and at low dosages.

Fatal lymphomatoid granulomatosis with primary CNS-involvement in an immunocompetent 80-year-old woman.

An 80-year-old woman presented with weight loss, fatigue, dizziness and a brain stem lesion. Extensive work-up revealed lymphomatoid granulomatosis (LYG) with primary clinical manifestation in the central nervous system (CNS), a rare Epstein-Barr virus-driven multisystem lymphoproliferative disorder, to be causative for the symptoms. Immunochemotherapy consisting of rituximab and temozolomide was started, but the disease progressed and the patient subsequently died. Histology, diagnostic criteria, differential diagnosis and treatment options for LYG with CNS involvement are discussed. This case demonstrates that LYG with CNS involvement may necessitate more aggressive treatment approaches than combination therapy with rituximab and temozolomide.

Chronic valproate or levetiracetam treatment does not influence cytokine levels in humans.

PURPOSE: There is growing evidence that complex interactions between seizures and the immune system shape the course of epilepsy. However, systematic analyses of the effects of antiepileptic drugs (AED) on the immune system in humans are rare. We performed a prospective study on the influence of the widely used AED valproate and levetiracetam on interictal immunological parameters. METHODS: 36 patients were prospectively included. 15 were started on valproate (5 female (33%), age 54±27 years, 12 (80%) on monotherapy), 21 on levetiracetam (10 female (48%), age 45±19 years, 17 (81%) on monotherapy). Before treatment and after 3 months, we performed a differential blood count and analyzed the distribution of CD3(+)CD4(+)-, CD3(+)CD8(+)- and CD4(+)CD25(+)-leukocyte subsets using flow cytometry. In addition, we determined the concentrations of IL-1ß, IL-6, TNF-α and MCP-1 in the peripheral blood using ELISAs. RESULTS: Valproate intake resulted in a significant decrease of the total white blood count (6.96±1.23/nl vs. 6.13±1.57/nl, p=0.026) and of absolute count and percentage of neutrophils (4.60±1.05/nl vs. 3.69±1.30/nl, p=0.01; 65.4±7.9% vs. 59.5±11.5%, p=0.01, respectively). The percentage of CD3(+)CD4(+)-lymphocytes dropped significantly (50.4±10.9% vs. 45.3±12.3%, p=0.002). Levetiracetam treatment resulted in a decrease of the percentage of CD4(+)CD25(+)-lymphocytes (26.1±8.0% vs. 21.5±9.2%, p=0.01) but did not significantly alter absolute counts. Neither valproate nor levetiracetam were associated with significant changes in cytokines. CONCLUSION: Valproate intake results in profound changes of white blood cell count and subset distribution. Cytokine levels were not influenced by valproate or levetiracetam.

Further evidence for plasma progranulin as a biomarker in bipolar disorder.

BACKGROUND: A recent study suggested that progranulin (encoded by the fronto-temporal dementia risk gene GRN) plasma levels are decreased in bipolar disorder (BD). Replication of this finding is however lacking. METHODS: Progranulin plasma levels of bipolar patients (n=104) and healthy controls (n=80) were measured by enzyme-linked immunosorbent assay (ELISA). Participants were also genotyped for three single nucleotide polymorphisms (SNPs) in the GRN gene (rs2879096, rs4792938 and rs5848), and the effect of genetic variation on progranulin levels was examined. RESULTS: Plasma progranulin levels were decreased in BD (ANCOVA, p=0.001). Furthermore, age was significantly and positively correlated with plasma progranulin (Pearson׳s correlation, r=0.269, p<0.001). Also, lithium treatment but no other medication had a significant effect on progranulin plasma levels (ANCOVA, p=0.007). Specifically in BD, the GRN SNP rs5848 was associated with progranulin plasma levels (Kruskal-Wallis test, p<0.005). LIMITATIONS: Subgroup analysis regarding bipolar I vs. bipolar II subtype and polarity of the episode at sampling (manic vs. depressed vs. mixed vs. rapid cycling vs. euthymic) could only be performed with limited validity due to the relatively small sample size. The suitability of peripheral progranulin as a biomarker for BD is limited due to the overlap between patients and controls. CONCLUSION: The findings strengthen the evidence for progranulin being involved in pathomechanisms of bipolar disorder, and suggest a genetic determinant of progranulin concentrations that is relevant specifically in bipolar patients.

Progranulin gene variability and plasma levels in bipolar disorder and schizophrenia.

Basing on the assumption that frontotemporal lobar degeneration (FTLD), schizophrenia and bipolar disorder (BPD) might share common aetiological mechanisms, we analyzed genetic variation in the FTLD risk gene progranulin (GRN) in a German population of patients with schizophrenia (n = 271) or BPD (n = 237) as compared with 574 age-, gender- and ethnicity-matched controls. Furthermore, we measured plasma progranulin levels in 26 German BPD patients as well as in 61 Italian BPD patients and 29 matched controls.A significantly decreased allelic frequency of the minor versus the wild-type allele was observed for rs2879096 (23.2 versus 34.2%, P<0.001, OR:0.63, 95%CI:0.49-0.80), rs4792938 (30.7 versus 39.7%, P = 0.005, OR: 0.70, 95%CI: 0.55-0.89) and rs5848 (30.3 versus 36.8, P = 0.007, OR: 0.71, 95%CI: 0.56-0.91). Mean±SEM progranulin plasma levels were significantly decreased in BPD patients, either Germans or Italians, as compared with controls (89.69±3.97 and 116.14±5.80 ng/ml, respectively, versus 180.81±18.39 ng/ml P<0.001) and were not correlated with age.In conclusion, GRN variability decreases the risk to develop BPD and schizophrenia, and progranulin plasma levels are significantly lower in BPD patients than in controls. Nevertheless, a larger replication analysis would be needed to confirm these preliminary results.