Utility of Cerebrospinal Fluid and Serum Procalcitonin for the Diagnosis of Neonatal Meningitis

Diagnostic Accuracy of Procalcitonin in Bacterial Infections of the CNS: An Updated Systematic Review, Meta-Analysis, and Meta-Regression

OBJECTIVES

To evaluate diagnostic accuracy of serum and cerebrospinal fluid (CSF) procalcitonin for diagnosing CNS bacterial infections.

DATA SOURCES

We searched MEDLINE, Cochrane Central Register of Controlled Trials, and International Web of Science databases from January 1, 2016, to September 30, 2022.

STUDY SELECTION

Randomized controlled trials and observational studies, either prospective or retrospective, focusing on procalcitonin as a biomarker for CNS infections.

DATA EXTRACTION

We screened and extracted studies independently and in duplicate. We assessed risk of bias using the revised Quality Assessment for Studies of Diagnostic Accuracy tool. Data for diagnostic sensitivity and specificity were pooled using the bivariate or hierarchical model, as appropriate.

DATA SYNTHESIS

Of 5,347 citations identified, 23 studies were included. Overall, CSF procalcitonin showed slightly higher pooled sensitivity, specificity, and positive likelihood ratio compared with serum procalcitonin. In adults, pooled sensitivity of CSF procalcitonin was 0.89 (95% CI, 0.71-0.96), specificity 0.81 (95% CI, 0.66-0.91); pooled sensitivity of serum procalcitonin was 0.82 (95% CI, 0.58-0.94), specificity 0.77 (95% CI, 0.60-0.89). In children, pooled sensitivity of CSF procalcitonin was 0.96 (95% CI, 0.88-0.99), specificity 0.91 (95% CI, 0.72-0.97); pooled sensitivity of serum procalcitonin was 0.90 (95% CI, 0.75-0.97), specificity 0.83 (95% CI, 0.67-0.92). In post-neurosurgical patients, pooled sensitivity of CSF procalcitonin was 0.82 (95% CI, 0.53-0.95), specificity 0.81 (95% CI, 0.63-0.91); pooled sensitivity of serum procalcitonin was 0.65 (95% CI, 0.33-0.88), specificity 0.61 (95% CI, 0.41-0.78). Logistic regression revealed between-study heterogeneity higher for serum than CSF procalcitonin. For the latter, threshold variability was found as source of heterogeneity.

CONCLUSIONS

In children and critical post-neurosurgical patients, CSF procalcitonin gains superior sensitivity and specificity compared with serum procalcitonin. Overall, CSF procalcitonin appears to have a higher pooled positive likelihood ratio compared with serum procalcitonin.

Factors influencing procalcitonin in the cerebrospinal fluid of patients after neurosurgery and its diagnostic value for intracranial infection

OBJECTIVE

This study aimed to investigate the factors influencing Procalcitonin (PCT) in the cerebrospinal fluid (CSF) of patients with high fever and suspected intracranial infection after neurosurgery and its clinical application value.

METHODS

Between February 2021 and August 2022, CSF and serum samples were collected via lumbar puncture from patients with high fever and suspected intracranial infection in the Intensive Care Unit(ICU) of our hospital. Multivariate logistic regression analysis was performed to analyze the factors influencing elevated PCT in CSF. The diagnostic efficacy of each index was assessed using receiver operating characteristic (ROC) curves.

RESULTS

A total of 183 CSF samples were collected, of which 148 had increased PCT levels, including 73 cases of intracranial infection and 75 cases in the case‒control group. Multivariate logistic regression analysis showed that intracranial infection [OR = 0.117, 95% CI: 0.025-0.559; p < 0.01] and hemorrhagic CSF [OR = 0.162, 95% CI: 0.029-0.916; p < 0.04] were factors influencing CSF PCT, while trauma [OR = 3.43, 95% CI: 0.76-15.45; p < 0.12], epileptic seizure [OR = 0.00, 95% CI: 0.00; p < 0], age [OR = 1.02, 95% CI: 0.98-1.52; p < 0.32] and Glasgow Coma Scale (GCS) score [OR = 1.03, 95% CI: 0.78-1.32; p < 0.83] did not influence CSF PCT. The CSF PCT and serum PCT levels in the intracranial infection group and the case‒control group were 0.13 (0.11, 0.25) ng/ml and 0.14 (0.07, 0.25) ng/ml and 0.14 (0.08,0.32) ng/ml and 0.23 (0.13,0.48)ng/ml, respectively, with no statistically significant difference. The median values of CSF lactate in the intracranial infection group and the case‒control group were 6.45 (4.475, 8.325) mmol/l and 3.2 (2.02, 4.200) mmol/l, respectively, with a statistically significant difference between the groups.The areas under the ROC curve of CSF PCT, serum PCT,CSF lactate, CSF PCT combined with lactate were 0.59, 0.63, 0.82,and 0.83,respectively.

CONCLUSION

Intracranial infection and hemorrhagic CSF are influencing factors for elevated CSF PCT following neurosurgery. It should be noted that the diagnostic value of intracranial infection by CSF PCT elevated alone is limited, but the combination it with other indicators can help improve diagnostic efficacy.

Role of neonatal cerebrospinal fluid cytology in correlation to C-reactive protein, blood culture, risk factors and clinical outcomes in neonatal intensive care

Introduction

The number of neonatal cerebrospinal fluid (CSF) samples sent from the neonatal intensive care unit (NICU) for cytologic examination is rising, warranting accurate analysis and interpretation of the same. This study was taken up to assess the usefulness of CSF cell count and cytology in NICU settings, as it can be used even in a resource-limited setting.

Aim and Objective

1) To study the prevalence of cell count and cytologic changes in CSF from NICU and assess their usefulness in correlation to C-reactive protein, CSF neutrophil percentage, blood, CSF culture, and other biochemical parameters. 2) To correlate cell counts and cytology with age, period of gestation, presence, and absence of sepsis, seizures, intracranial hemorrhage, and their clinical follow-up.

Materials and Methods

A retrospective study was done on neonatal CSF samples submitted for cytology over one year (January-December 2016) in the Department of Pathology. CSF cell counts were retrieved, and cytosmears were reviewed for cellularity, cell type, proportion, and background and correlated with the biochemical, microbiological, and clinicoradiological findings.

Results

A total of 213 samples were included with 140 males and 73 females with an age range of 0-28 (mean: 7.3) days. The mean CSF cell count was 5.48/cu.mm (0-90 cells/cu.mm). The most frequent cytologic finding was occasional lymphocytes or acellular CSF (63.9%). The CSF leucocyte count and protein levels showed a significant correlation with s C-reactive protein. The CSF cytology showed a significant correlation between the age of the neonate and blood neutrophil percentage (P = 0.0158). History of intracranial hemorrhage showed a significantly higher frequency of the presence of red blood cells (P = 0.0147).

Conclusion

Accurate cell counts, cytology of neonatal CSF, and biochemical and microbiological workup can help diagnose and manage neonates in intensive care.

Diagnostic Utility of Cerebrospinal Fluid Procalcitonin in Neonatal Meningitis

We aimed to study the diagnostic utility of cerebrospinal fluid (CSF) procalcitonin (PCT) in neonates with meningitis. All the neonates with sepsis who qualified for lumbar puncture were prospectively evaluated. The neonates were classified into Meningitis and No meningitis group based on predefined criteria. CSF PCT was estimated in these neonates along with cytological and biochemical parameters. A total of 113 neonates were included in the study with 29 in the meningitis group and 84 in the no meningitis group. The median PCT levels were higher in babies with meningitis as compared to those without meningitis [0.194 (0.034-0.534) in meningitis group vs. 0.012 (0.012-0.012) ng/ml in no meningitis group, p < 0.001]. The area under curve for CSF PCT was 0.867 (0.77-0.95) and at a cut-off level of 0.120 ng/ml CSF PCT had a sensitivity of 83%, specificity of 84% and positive and negative predictive likelihood ratios of 5.35 and 0.20, respectively for the diagnosis of meningitis. CSF PCT has a good diagnostic accuracy similar to other parameters in the diagnosis of neonatal meningitis and can be considered as an additional diagnostic marker particularly when CSF culture is negative and cytochemical analysis is inconclusive.