The Serum S100B Level as a Biomarker of Enteroglial Activation in Patients with Ulcerative Colitis.

Objective. Recent studies have demonstrated that enteric glial cells (EGC) participate in the homeostasis of the gastrointestinal tract. This study investigated whether enteroglial markers, including S100B protein and glial fibrillary acidic protein (GFAP), can serve as noninvasive indicators of EGC activation and disease activity in UC patients. Methods. This clinical prospective study included 35 patients with UC and 40 age- and sex-matched controls. The diagnosis of UC was based on standard clinical, radiological, endoscopic, and histological criteria. Clinical disease activity was evaluated using the Modified Truelove-Witts Severity Index. Serum samples were analyzed for human GFAP and S100B using commercial enzyme-linked immunosorbent assay kits. Results. GFAP was not detected in the serum of either UC patients or controls (P > 0.05). However, we found a significant (P < 0.001) decrease in the serum S100B levels in the UC patients. No correlation between the serum S100B level and the disease activity or duration was observed (P > 0.05). The serum S100B levels did not differ between UC patients with active disease (24 patients, 68.6%) or in remission (11 patients, 31.4%) (P > 0.05). Conclusions. Ulcerative colitis patients had significantly lower serum S100B levels, while GFAP was of no diagnostic value in UC patients.

Elevated neurofilament light chain (NFL) mRNA levels in prediabetic peripheral neuropathy.

Evidence suggests that peripheral nerve injury occurs during the early stages of disease with mild glycemic dysregulation. Two proteins, neuron-specific enolase (NSE) and neurofilament light chain (NFL), have been examined previously as possible markers of neuronal damage in the pathophysiology of neuropathies. Herein, we aimed to determine the potential value of circulatory NSE and NFL mRNA levels in prediabetic patients and in those with peripheral neuropathy. This prospective clinical study included 45 prediabetic patients and 30 age- and sex-matched controls. All prediabetic patients were assessed with respect to diabetes-related microvascular complications, such as peripheral neuropathy, retinopathy and nephropathy. mRNA levels of NSE and NFL were determined in the blood by real-time polymerase chain reaction. NSE mRNA levels were similar between prediabetic and control groups (p > 0.05), whereas NFL mRNA levels were significantly higher in prediabetics than in controls (p < 0.001). NSE mRNA levels did not significantly differ between prediabetic patients with and without peripheral neuropathy (p > 0.05), while NFL mRNA levels were significantly higher in prediabetics with peripheral neuropathy than in those without (p = 0.038). According to correlation analysis, NFL mRNA levels were positively correlated with the Douleur Neuropathique 4 questionnaire score in prediabetic patients (r = 0.302, p = 0.044). This is the first study to suggest blood NFL mRNA as a surrogate marker for early prediction of prediabetic peripheral neuropathy, while NSE mRNA levels may be of no diagnostic value in prediabetic patients.

Is serum S100B protein an useful biomarker in migraine?

Experimental data have demonstrated a role for S100B protein through the release of proinflammatory cytokines, following trigeminal nerve activation, implicated in the pathology of migraine. We investigated serum levels of S100B protein, as a peripheral glial biomarker, in patients with migraine. In total, 49 migraineurs and 35 age- and gender-matched controls were enrolled in this prospective clinical study. The migraine diagnosis was made according to the International Classification of Headache Disorders II diagnostic criteria. Serum samples were obtained for the measurement of S100B levels from all participants and were analyzed using commercial enzyme-linked immunosorbent assay kits. Serum S100B levels were significantly lower in migraineurs than controls (p < 0.001). S100B levels did not significantly differ in migraineurs with or without aura (p > 0.05). In addition, there was no correlation between serum S100B levels and headache characteristics, including attack severity, frequency and duration, and disease duration (p > 0.05). These findings suggest that serum S100B levels were significantly decreased in migraine patients, but further research is needed to ascertain the contribution of S100B in the clinical evaluation of migraine.

S100B as a glial cell marker in diabetic peripheral neuropathy.

Evidence suggests that acute and chronic hyperglycemia can cause oxidative stress in the peripheral nervous system which, in turn, can promote the development of diabetic neuropathy. Recent studies have found increased expression of glial fibrillary acidic protein (GFAP) and S100B, both of which are indicators of glial reactivity, in the neural and retinal tissues of diabetic rats. For the first time in the literature, the serum levels of GFAP and S100B were assessed in patients with diabetes to evaluate the potential of these factors to serve as peripheral glial biomarkers of diabetes and to investigate their relationship to diabetic peripheral neuropathy. This prospective clinical study included 72 patients with type 2 diabetes mellitus and 50 age- and sex-matched control subjects. All diabetic patients were assessed with respect to diabetes-related microvascular complications, such as peripheral neuropathy, retinopathy, and nephropathy. Serum samples were analyzed for human GFAP and S100B using a commercially available Enzyme-linked Immuno Sorbent Assay kit. GFAP was not detected in the serum samples of either diabetic or control patients (p>0.05). However, we found a statistically significant decrease in S100B serum levels in patients with diabetes compared with control participants (p<0.001). No associations between serum S100B levels and the presence of diabetic peripheral neuropathy or other microvascular complications were observed (p>0.05). The findings of markedly decreased serum levels of S100B may possibly indicate a neuroprotective effect of S100B, whereas GFAP may be of no diagnostic value in human patients with diabetes.