Baud Maxime O, Vitt Jeffrey R, Robbins Nathaniel M, Wabl Rafael, Wilson Michael R, Chow Felicia C, Gelfand Jeffrey M, Josephson S Andrew, Miller Steve
Department of Neurology (M.O.B., J.R.V., N.M.R., M.R.W., F.C.C., J.M.G., S.A.J.) and Department of Laboratory Medicine (S.M.), University of California, San Francisco; and Department of Neurology (R.W.), University of Michigan, Ann Arbor. N.M.R. is currently affiliated with the Department of Neurology, Dartmouth Geisel School of Medicine.
Neurol Neuroimmunol Neuroinflamm. 2017 Dec 22;5(1):e425. doi: 10.1212/NXI.0000000000000425. eCollection 2018 Jan.
The mechanism of hypoglycorrhachia-low CSF glucose-in meningitis remains unknown. We sought to evaluate the relative contribution of CSF inflammation vs microorganisms (bacteria and fungi) in lowering CSF glucose levels.
We retrospectively categorized CSF profiles into microbial and aseptic meningitis and analyzed CSF leukocyte count, glucose, and protein concentrations. We assessed the relationship between these markers using multivariate and stratified linear regression analysis for initial and repeated CSF sampling. We also calculated the receiver operating characteristics of CSF glucose and CSF-to-serum glucose ratios to presumptively diagnose microbial meningitis.
We found that increasing levels of CSF inflammation were associated with decreased CSF glucose levels in the microbial but not aseptic category. Moreover, elevated CSF protein levels correlated more strongly than the leukocyte count with low CSF glucose levels on initial ( = 36%, < 0.001) and repeated CSF sampling ( = 46%, < 0.001). Hypoglycorrhachia (<40 mg/dL) was observed in 50.1% of microbial cases, but only 9.6% of aseptic cases, most of which were neurosarcoidosis. Absolute CSF glucose and CSF-to-serum glucose ratios had similar low sensitivity and moderate-to-high specificity in diagnosing microbial meningitis at thresholds commonly used.
The main driver of hypoglycorrhachia appears to be a combination of microbial meningitis with moderate to high degrees of CSF inflammation and proteins, suggesting that the presence of microorganisms capable of catabolizing glucose is a determinant of hypoglycorrhachia in meningitis. A major notable exception is neurosarcoidosis. Low CSF glucose and CSF-to-serum glucose ratios are useful markers for the diagnosis of microbial meningitis.
脑膜炎时脑脊液低糖（脑脊液葡萄糖水平降低）的机制尚不清楚。我们试图评估脑脊液炎症与微生物（细菌和真菌）在降低脑脊液葡萄糖水平方面的相对作用。
我们回顾性地将脑脊液检查结果分为微生物性脑膜炎和无菌性脑膜炎，并分析脑脊液白细胞计数、葡萄糖和蛋白质浓度。我们使用多变量和分层线性回归分析对初次和重复脑脊液采样评估这些指标之间的关系。我们还计算了脑脊液葡萄糖和脑脊液与血清葡萄糖比值的受试者工作特征曲线，以推测诊断微生物性脑膜炎。
我们发现，在微生物性脑膜炎而非无菌性脑膜炎类别中，脑脊液炎症水平升高与脑脊液葡萄糖水平降低相关。此外，在初次（r = 36%，P < 0.001）和重复脑脊液采样时（r = 46%，P < 0.001），脑脊液蛋白质水平升高与脑脊液葡萄糖水平降低的相关性比白细胞计数更强。在50.1%的微生物性脑膜炎病例中观察到脑脊液低糖（<40 mg/dL），但在无菌性脑膜炎病例中仅为9.6%，其中大多数为神经结节病。在常用阈值下，绝对脑脊液葡萄糖和脑脊液与血清葡萄糖比值在诊断微生物性脑膜炎时具有相似的低敏感性和中度至高特异性。
脑脊液低糖的主要驱动因素似乎是微生物性脑膜炎与中度至高度脑脊液炎症和蛋白质的结合，这表明能够分解葡萄糖的微生物的存在是脑膜炎时脑脊液低糖的一个决定因素。一个主要的显著例外是神经结节病。脑脊液葡萄糖水平低和脑脊液与血清葡萄糖比值是诊断微生物性脑膜炎的有用指标。
