Early postoperative serum S100β levels predict ongoing brain damage after meningioma surgery: a prospective observational study

INTRODUCTION: Elevated serum levels of S100β, an astrocyte-derived protein, correlate with unfavourable neurological outcomes following cardiac surgery, neurotrauma, and resuscitation. This study evaluated whether pre-/postoperative serum S100β levels correlate with unfavourable clinical and radiological findings in patients undergoing elective meningioma resection. METHODS: In 52 consecutive patients admitted for meningioma surgery, serum S100β levels were determined upon admission and immediately, 24 hours, and 48 hours after surgery. All patients underwent complete pre- and postoperative neurological examination and mini-mental state examination. Radiological evaluation included preoperative magnetic resonance imaging (MRI) and postoperative computed tomography. Tumour volume, brain edema, and bleeding volume were calculated using BrainSCAN™ software. RESULTS: Preoperative S100β levels did not correlate with the tumour characteristics demonstrated by preoperative MRI (for example, tumour volume, edema volume, ventricular asymmetry, and/or midline shift). Preoperative serum S100β levels (0.065 ± 0.040 μg/l) were significantly lower than the levels measured immediately (0.138 ± 0.081 μg/l), 24 hours (0.142 ± 0.084 μg/l), and 48 hours (0.155 ± 0.119 μg/l) postoperatively (p < 0.0001). Significantly greater postcraniotomy S100β levels were observed with prolonged surgery (p = 0.039), deterioration in the mini-mental state examination (p = 0.005, 0.011, and 0.036 for pre versus immediate, 24 hours, and 48 hours postsurgery, respectively), and with postoperative brain computed tomography evidence of brain injury; bleeding was associated with higher serum S100β levels at 24 and 48 hours after surgery (p = 0.046, 95% confidence interval [CI] -0.095 to -0.001 and p = 0.034, 95% CI -0.142 to -0.006, respectively) as was the presence of midline shift (p = 0.005, 95% CI -0.136 to -0.025 and p = 0.006, 95% CI -0.186 to -0.032, respectively). Edema was associated with higher serum S100β levels immediately (p = 0.022, 95% CI -0.092 to -0.007) and at 48 hours after surgery (p = 0.017, 95% CI -0.142 to -0.026). The degree of elevation in S100β levels at 24 and 48 hours after surgery also correlated with the severity of midline shift and edema. CONCLUSION: In patients with meningioma, serum S100β levels perform poorly as an indicator of tumour characteristics but may suggest ongoing postcraniotomy injury. Serum S100β levels may serve as a potentially useful early marker of postcraniotomy brain damage in patients undergoing elective meningioma resection

Serum S100B levels after meningioma surgery: A comparison of two laboratory assays

<p>Abstract</p> <p>Background</p> <p>S100B protein is a potential biomarker of central nervous system insult. This study quantitatively compared two methods for assessing serum concentration of S100B.</p> <p>Methods</p> <p>A prospective, observational study performed in a single tertiary medical center. Included were fifty two consecutive adult patients undergoing surgery for meningioma that provided blood samples for determination of S100B concentrations. Eighty samples (40 pre-operative and 40 postoperative) were randomly selected for batch testing. Each sample was divided into two aliquots. These were analyzed by ELISA (Sangtec) and a commercial kit (Roche Elecsys^®) for S100B concentrations. Statistical analysis included regression modelling and Bland-Altman analysis.</p> <p>Results</p> <p>A parsimonious linear model best described the prediction of commercial kit values by those determined by ELISA (y = 0.045 + 0.277*x, x = ELISA value, R²= 0.732). ELISA measurements tended to be higher than commercial kit measurements. This discrepancy increased linearly with increasing S100B concentrations. At concentrations above 0.7 μg/L the paired measurements were consistently outside the limits of agreement in the Bland-Altman display. Similar to other studies that used alternative measurement methods, sex and age related differences in serum S100B levels were not detected using the Elecsys^®(p = 0.643 and 0.728 respectively).</p> <p>Conclusion</p> <p>Although a generally linear relationship exists between serum S100B concentrations measured by ELISA and a commercially available kit, ELISA values tended to be higher than commercial kit measurements particularly at concentrations over 0.7 μg/L, which are suggestive of brain injury. International standardization of commercial kits is required before the predictive validity of S100B for brain damage can be effectively assessed in clinical practice.</p

Gliomas display a microRNA expression profile reminiscent of neural precursor cells

Gliomas express many genes that play a role in neural precursor cells (NPCs), but no direct comparison between glioma and stem cell (SC) gene expression profiles has been performed. To investigate the similarities and differences between gliomas and SCs, we compared the microRNA (miRNA) expression signatures of glial tumors, embryonic SCs (ESCs), NPCs, and normal adult brains from both human and mouse tissues. We demonstrated that both human gliomas (regardless of their grade) and methylcholanthrene-induced mouse glioma shared an miRNA expression profile that is reminiscent of NPCs. About half of the miRNAs expressed in the shared profile clustered in seven genomic regions susceptible to genetic/epigenetic alterations in various cancers. These clusters comprised the miR17 family, mir183-182, and the SC-specific clusters mir367-302 and mir371-373, which are upregulated in gliomas, ESCs, and NPCs. The bipartite cluster of 7 + 46 miRNAs on chromosome 14q32.31, which might represent the largest tumor suppressor miRNA cluster, was downregulated in the shared expression profile. This study provides the first evidence for association between these clusters and gliomas. Despite the broad similarity in the miRNA expression profiles, 15 miRNAs showed disparate expression between SC and gliomas. Ten miRNAs belong to the 2 SC-specific clusters and the remaining (mir135b, mir141, mir205, mir200C, and mir301a) have been previously shown to associate with malignancies. Our finding showed that all gliomas displayed NPC-like miRNA signatures, which may have implications for studies of glioma origins. Furthermore, careful study of the 15 miRNAs that differ in expression between SCs and gliomas, particularly those 5 that are not SC-specific, may enhance our understanding of gliomagenesis