Pleocytosis is not fully responsible for low CSF glucose in meningitis

Abstract

Objective: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.Methods: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.Results: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 (R2 = 36%, p < 0.001) and repeated CSF sampling (R2 = 46%, p < 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.Conclusions: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.

AIDS-associated Talaromyces marneffei central nervous system infection in patients of southwestern China

“…Low CSF glucose level may be related to glucose utilization by microorganisms, and the degree of hypoglycemia is directly correlated with the inflammatory process [13]. A previous study speculated that the low CSF glucose level can be used as a marker for the diagnosis of microbial meningitis [14]. Our results showed that the CSF profile of AIDS-associated T. marneffei CNS infection is extremely similar to those of other types of fungal meningitis, especially cryptococcal meningitis.…”

“…Among them, one had positive results in both blood culture and bone marrow culture, one had a positive result in blood culture, and one patient had a positive result in urine culture. The median duration of CSF culture for T. marneffei was 11.5 days (IQR [6][7][8][9][10][11][12][13][14]) ( Table 2).…”

Bacterial Infections of the Central Nervous System

“…Hypoglycorrhachia (low CSF glucose concentration) is a cardinal feature of bacterial meningitis. 16 CSF glucose concentration < 40 mg/dL or CSF-to-serum ratio < 0.40 is worrisome for bacterial meningitis. A normal CSF-to-serum glucose ratio is 0.6.…”

Gambaran Cairan Serebrospinal pada Pasien Anak dengan Infeksi Susunan Saraf Pusat di Rumah Sakit Rujukan Jawa Barat

“…katabolisme glukosa oleh patogen. 10 Patogen juga akan memicu reaksi inflamasi sehingga terjadi kenaikan jumlah leukosit pada LCS. Perubahan komposisi ini memberikan efek perubahan warna dan mengeruhnya LCS sehingga analisis yang dapat dilakukan adalah tingkat perubahan dari tiap parameter tersebut.…”

“…Karenanya, meskipun terjadi infeksi yang berat dan ekstensif kadar glukosa tidak menurun sebanyak patogen lain. 10 Hingga saat ini, masih belum ditemukan patofisiologi yang jelas mengenai perubahan spesifik dari tiap parameter LCS, seperti yang dilaporkan oleh Thuong. 13 Pemeriksaan LCS juga dipengaruhi oleh prosedur pengambilan sampel yang kurang tepat, kadar patogen itu sendiri, dan penggunaan antibiotik yang dapat mengakibatkan hasil pemeriksaan LCS mengalami perubahan atau tampak normal.…”