Interleukin-6 levels are increased in temporal lobe epilepsy but not in extra-temporal lobe epilepsy

Abstract

Previous studies have reported activation of inflammatory cytokines in seizures, but clinical characteristics of epilepsy associated with cytokine activation have not been well established. In this study, serum levels of interleukin-6 (IL-6) and interleukin-1 receptor antagonist (IL-1RA) were measured, and clinical characteristics of epilepsy were assessed in 86 well-evaluated patients with refractory focal epilepsy and in 5 patients with controlled focal epilepsy. Epilepsy was evaluated based on patient histories, electroclinical findings, and high-resolution brain MRI scans. Sixty-three healthy blood donors served as controls. IL-6 concentrations were chronically increased in epilepsy patients (11%) compared with healthy controls (0%) (P = 0.007). Increased levels of IL-6 were more prevalent in patients with temporal lobe epilepsy (TLE) compared to patients with extra-TLE (P = 0.028). Also the mean and the median serum levels of IL-6 were higher in patients with TLE than in patients with extra-TLE (P = 0.042). Concentrations of IL-1RA were not significantly different in patients compared with controls. Indicated by increased levels of IL-6 in TLE, epilepsy type is important in determining chronic overproduction of cytokines in refractory focal epilepsy. The results may reflect a chronic immunological process in the brain in patients with refractory epilepsy.

The Effects of Vagus Nerve Stimulation on Pro- and Anti-Inflammatory Cytokines in Children with Refractory Epilepsy: An Exploratory Study

“…For example, the study included a relatively small number of patients who suffered from different epilepsy syndromes. This might have limited the possibility of detecting significant effects as there is evidence that plasma cytokine concentrations differ between various etiologies and pathologies [33,35,37]. In addition, the relatively low responder rate may have affected an association between the anticonvulsive effectiveness of VNS and any cytokine changes.…”

“…IL-6 is a cytokine with both pro- and anti-inflammatory characteristics that mediates the acute phase reaction and fever. The predictive value of IL-6 is particularly interesting since IL-6 is the most consistently and chronically changed circulating cytokine in epilepsy [32,33,34]. However, other investigators failed to detect any cytokine changes that were of potential predictive value [18], possibly due to the fact that the changes were evaluated in epileptic adults using whole blood samples in vitro that were stimulated with lipopolysaccharide.…”

“…Firstly, VNS did not alter interictal cytokine levels. Since epilepsy patients are known to have altered interictal cytokine levels [32,33,34], we specifically determined whether VNS changed cytokine levels more than 12 h after a seizure. Nevertheless while these cytokine levels were unchanged, we cannot exclude the possibility that VNS treatment inhibits cytokine changes at a different time point.…”

Temporal Lobe Epilepsy and Autoimmunity

“…(2009) çalış-masında IL-6 seviyesi ile eksitatör bir nörotransmitter olan glutamik asit miktarları arasında da korelasyon olduğu ve düzeylerin TLE'de arttığı ancak ekstratemporal epilepsilerde bu durumun olmadığı bulunmuştur. [19] Başka bir klinik ça-lışma ile IL-6'nın hem fokal hem de jeneralize nöbetlerden sonra plazmadaki miktarının arttığı gösterilmiştir. [20] TLE ile sitokinler arasındaki ilişkiyi araştıran bir diğer klinik çalış-mada da dirençli fokal epilepsilerde postiktal dönemde TLE grubunda IL-6 değerleri artmış olarak saptamış ancak TLE dışındaki diğer gruplarda plazma IL-6 seviyesinde artış saptanmamıştır.…”

Epilepsy and Autoimmunity: Basic Physiopathological Mechanisms

“…[13] Proinflamatuvar sitokinlerin ve birçok otoantikorların TLE'lerle ilişkili olduğu bilinmektedir. [16,17] Birçok immünolojik ürünün epilepsi ve TLE üzerindeki etkisi Şekil 2'de özetlenmiştir.…”