Dosage of lactate in the cerebrospinal fluid in infectious diseases of the central nervous system

The value of elevated cerebrospinal fluid lactate concentrations in post-neurosurgical bacterial meningitis

Bacterial meningitis is a serious complication after neurosurgery and has a high mortality rate. Early diagnosis and timely treatment are crucial or will have disastrous consequences. The classic triad of bacterial meningitis lacks sensitivity and specificity. Therefore, the diagnosis of post-neurosurgical bacterial meningitis relies on cerebrospinal fluid. But traditional cerebrospinal fluid parameters are not completely reliable in diagnosing post-neurosurgical bacterial meningitis. Previous studies have found that CSF lactate concentration is related to bacterial meningitis. But, after the craniocerebral operation, the cerebrospinal fluid of most patients is bloody. Whether red blood cells interfere with diagnosing PNBM based on lactate concentration is limited. In the current study, we further analysis on whether red blood cells interfere with diagnosing PNBM based on lactate concentration. This study aimed to investigate the value of cerebrospinal fluid lactate concentrations in post-neurosurgical bacterial meningitis. A prospective observational study was performed on 62 patients at Kunshan First People's Hospital's intensive care unit affiliated with Jiangsu University. We found that erythrocytes do not affect cerebrospinal fluid lactate, and elevated lactate concentrations can be used as a marker for postoperative bacterial meningitis.

Study of cerebrospinal fluid levels of lactate, lactate dehydrogenase and adenosine deaminase in the diagnosis and outcome of acute meningitis

BACKGROUND

Meningitis is a serious clinical health issue in most developing countries. Late diagnosis and treatment result in significant morbidity and mortality. This research aims to study the utility of CSF lactate, lactate dehydrogenase (LDH), and adenosine deaminase (ADA) as diagnostic markers in acute meningitis, and to differentiate among varied aetiologies of acute meningitis and their outcomes.

METHOD

A cross-sectional observational case-control study was conducted in 30 patients of suspected meningitis of varied aetiologies and 30 controls without any pre-existing neurological disorder and who underwent lumbar puncture during spinal anesthesia. A fresh CSF sample was collected in a heparinized vial following an aseptic lumbar puncture. The levels of lactate, LDH and ADA were estimated and recorded.

RESULT

CSF lactate was significantly elevated in bacterial meningitis (BM) and cryptococcal meningitis, with 100% sensitivity when compared to controls. Elevated LDH was found only in BM, hence elevated LDH levels may strongly signify bacterial etiology. Significantly elevated ADA levels were noted in tuberculous meningitis. Significantly elevated levels of lactate and ADA were suggestive of slower clinical recovery and a prolonged hospital stay (p < 0.001).

CONCLUSION

Estimation of CSF lactate, LDH, and ADA levels is a rapid, inexpensive and simple procedure and can play a major role in the early differentiation of bacterial, viral, tuberculous, and fungal meningitis. This would facilitate the initiation of appropriate treatment as early as possible, thereby decreasing mortality and complications.

Score for Differentiating Pleural Tuberculosis from Malignant Effusion

Differential diagnosis of lymphocytic pleural effusions between tuberculous (TBE) and malignant (ME) effusion is usually difficult in daily practice. Our aim was to develop a score to differentiate TBE from ME effusions. A cohort of 138 consecutive patients with pleural effusion was prospectively studied from May 2014 through June 2017. Glucose, lactate dehydrogenase (LDH), proteins, white cell count, lactic acid, and pH in the pleural fluid were measured. Pleural effusions other than lymphocytic, patients with a final diagnosis other than tuberculosis or malignancy, and patients who met Light’s criteria for transudate were excluded. Eighty-two samples (47 TBE and 35 ME) were included in the analysis. Using logistic regression analysis and Wald test, we developed a score including age, glucose, proteins, and lactic acid. The receiver operating characteristic curve (ROC) for the score was determined, and the area under the curve (AUC) was calculated. A cutoff of eight points was required to achieve 93.5% sensitivity, 78% specificity, and a likelihood ratio of 4.26 to distinguish tuberculosis from malignant pleural effusion. The AUC of the score was 0.915 (95% CI = 0.82–0.96).

Cerebrospinal fluid lactate in post-neurosurgical bacterial meningitis diagnosis

BACKGROUND

Differential diagnosis between post-neurosurgical bacterial meningitis (PNBM) and aseptic meningitis is difficult. Inflammatory and biochemical cerebrospinal fluid (CSF) changes mimic those classically observed after CNS surgery. CSF lactate assay has therefore been proposed as a useful PNBM marker.

OBJECTIVE

To evaluate the diagnostic accuracy of CSF lactate as a PNBM marker in patients hospitalized after a neurosurgical procedure.

METHODS

Between July 2005 and June 2009, a prospective clinical study, in which all patients with clinical suspicion of PNBM were enrolled, was conducted at our neurosurgical Intensive Care Unit. PNBM diagnosis was categorized as proven, probable or negative before the analysis.

RESULTS

Seventy-nine patients, 51 males with a mean age of 50 years (range 32-68 years) were included. Surgery was elective in 76% patients, mostly for brain tumors (57%); thirty PNBM episodes were identified. CSF parameters were significantly different in glucose concentration (27 mg% vs. 73 mg%, p<0.001), lactate (8 mmol/L vs. 2.8 mmol/L, p<0.001), CSF neutrophil pleocytosis (850 mm(-3) vs. 10mm(-3), p<0.001), and protein levels (449 mg% vs. 98 mg%) between the PNBM and non-PNBM groups. The ROC curve that best fits PNBM diagnosis is lactate.

CONCLUSION

Increased CSF lactate is a useful PNBM marker, with better predictive value than CSF hypoglycorrhachia or pleocytosis. Lactate levels ≥ 4 mmol/L showed 97% sensitivity and 78% specificity, with a 97% negative predictive value.

Cerebrospinal fluid lactate and pyruvate concentrations and their ratio

OBJECTIVES

Determinations of cerebrospinal fluid (CSF) lactate and pyruvate concentrations and CSF lactate:pyruvate (L/P) ratios are important in several clinical settings, yet published normative data have significant limitations. We sought to determine a large dataset of stringently-defined normative data for CSF lactate and pyruvate concentrations and CSF L/P ratios.

DESIGN AND METHODS

We evaluated data from 627 patients who had determinations of CSF lactate and/or CSF pyruvate from 2001 to 2011 at the Cleveland Clinic. Inclusion in the normal reference population required normal CSF cell counts, glucose and protein and routine serum chemistries and absence of progressive brain disorder, epilepsy, or seizure within 24h. Brain MRI, if done, showed no evidence of tumor, acute changes or basal ganglia abnormality. CSF cytology, CSF alanine and immunoglobulin levels, and oligoclonal band analysis were required to be normal, if done. Various inclusion/exclusion criteria were compared.

RESULTS

92 patients fulfilled inclusion/exclusion criteria for a reference population. The 95% central intervals (2.5%-97.5%) for CSF lactate and pyruvate levels were 1.01-2.09mM and 0.03-0.15mM, respectively, and 9.05-26.37 for CSF L/P. There were no significant gender-related differences of CSF lactate or pyruvate concentrations or of CSF L/P. Weak positive correlations between the concentration of CSF lactate or pyruvate and age were noted.

CONCLUSIONS

Using stringent inclusion/exclusion criteria, we determined normative data for CSF lactate and pyruvate concentrations and CSF L/P ratios in a large, well-characterized reference population. Normalcy of routine CSF and blood analytes are the most important parameters in determining reference intervals for CSF lactate and pyruvate.

Quantification of cerebrospinal fluid lactic acid in the differential diagnosis between HIV chronic meningitis and opportunistic meningitis

BACKGROUND

Approximately 40% of HIV infected patients have chronic meningitis at various stages during the infection, 59% are asymptomatic. This is a diagnosis of exclusion and a confounding factor in cerebrospinal fluid (CSF) analysis, any other causes of chronic meningitis by opportunistic or co-infection must be ruled out. The aim of this study was to analyze CSF lactic acid (LA) as an adjuvant biomarker in chronic meningitis due to HIV.

METHODS

CSF LA was quantified in 223 CSF samples by the Dimension AR (Dade Behring, Deerfield, IL, USA), distributed into nine groups: 1) HIV positive with an increase in CSF WBCs (n=17); 2) HIV positive with normal CSF (n=20); 3) enterovirus meningitis (n=33); 4) Herpesviridae meningoencephalitis (n=30); 5) fungal meningitis (n=25); 6) tuberculosis (TB) meningitis (n=17); 7) toxoplasmosis (n=18); 8) neurosyphilis (n=6); 9) control group (n=57).

RESULTS

CSF LA (median; IQR) was higher in samples with TB meningitis (5.5; 2.9-7.5 mmol/L) and Cryptococcus neoformans meningitis (3.9; 2.7-5.8 mmol/L) compated with samples with HIV chronic meningitis (1.7; 1.4-1.9 mmol/L) and other groups (p ≤ 0.0001). For the diagnosis of HIV chronic meningitis, using a cut-off of 3.5 mmol/L, CSF LA showed high sensitivity and negative predictive value, although low specificity.

CONCLUSIONS

CSF LA helps to discriminate between C. neoformans or TB meningitis and HIV chronic meningitis: CSF LA can be included with the methods currently used to identify these specific pathogens, though it does not replace them. It is rapid, inexpensive and easy to perform, and can be used in developing countries.

Quantitation of cerebrospinal fluid lactic acid in infectious and non-infectious neurological diseases

BACKGROUND

The differential diagnosis between bacterial and viral meningitis is not easy in some cases. Cerebrospinal fluid (CSF) analysis is essential for establishing this diagnosis. The objectives were to quantitate lactic acid (LA) concentrations in bacterial and viral meningitis, and other central nervous system (CNS) diseases in order to evaluate the diagnostic utility of CSF LA for discriminating bacterial from viral meningitis.

METHODS

CSF LA was measured in 139 CSF samples from seven groups: viral meningitis with classic CSF; suspicion of viral meningitis with neutrophils in CSF; bacterial meningitis; non-infectious neurological diseases; chronic meningitis; traumatic lumbar puncture (LP) and normal CSF.

RESULTS

CSF LA was higher in bacterial meningitis 8.7 + 5.4 mmol/L compared with viral meningitis (1.9 + 0.6) and the other groups (p < 0.0001). CSF LA in the groups with viral meningitis was not different compared to groups with non-infectious CNS diseases and chronic meningitis. The ability of CSF LA to discriminate bacterial from viral meningitis showed a sensitivity of 80% and specificity of 97%, positive predictive value (PPV) of 94%, and negative predictive value (NPV) of 89%.

CONCLUSIONS

CSF LA is a powerful test to discriminate bacterial from viral meningitis with high sensitivity, specificity and predictive values. CSF LA can help in the cases with diagnostic uncertainty.

Factors associated to the positive cerebrospinal fuid culture in the tuberculous meningitis

Central nervous system involvement is the most common neurological complication in the course of tuberculosis. The lack of rapid and sensitive tests delays the early diagnosis. Here, we retrospectively reviewed the cerebrospinal fluid (CSF) examination of 30 patients with tuberculous meningitis confirmed by bacteriological tests (culture and/or polymerase chain reaction). The purpose of the present study was to determine the CSF parameters associated to the positive CSF culture for Mycobacterium tuberculosis in tuberculous meningitis. We found higher frequency of positive CSF culture in patients infected with HIV as well in patients with high number of neutrophils and high protein content (characteristic in the early or acute-stage patients), which suggests that the positive culture found in these patients may be associated with the presence of high bacillary load in CSF occurring in these stages.