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

Abstract

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.

Keywords: Hemorrhage; meningitis; preterm.

Graph 1

Distribution of cases based on maturity at birth

Graph 2

Distribution of cases based on the clinical diagnosis at the time of admission into the neonatal intensive care unit

Graph 3

Showing cellular composition of the cytocentrifuged cerebrospinal fluid smears. (Others include two samples from two preterm babies. One showed hemosiderin-laden macrophages along with numerous RBCs, while the other showed arachnoid and choroid plexus cells in a background of many RBCs)

Figure 1

CSF of a neonate with no CNS abnormality showing occasional lymphocytes only (Leishman stain, 1000X)

Graph 4

Relationship between cerebrospinal fluid (CSF) cell count, CSF neutrophil percentage, and period of gestation

Graph 5

Subgroup analysis of cerebrospinal fluid (CSF) cell count in various clinical categories (x axis: clinical categories; y-axis shows CSF cell count/cu.mm)

Figure 2

Smear showing numerous RBCs with upper inset showing few macrophages in aggregates. The lower inset highlights hemosiderin laden macrophages. (Leishman stain 40X; upper inset: Leishman stain 1000X and lower inset Perls stain, 1000X)

Figure 3

Cytocentrifuged CSF of a case of meningitis showing numerous neutrophils with few lymphocytes (Leishman stain, 1000X)