From the Research
Definition and Causes
- Pleocytosis refers to an increase in the number of white blood cells in the cerebrospinal fluid (CSF) [ 1 ], whereas leukocytosis is an increase in the number of white blood cells in the blood [ 2 ].
- Pleocytosis can be caused by various conditions, including central nervous system (CNS) infections, non-infectious neurological diseases, malignancy, and other conditions [ 1 ].
- Leukocytosis can be caused by infections, inflammatory processes, physical stress, emotional stress, and primary bone marrow disorders [ 2 ].
Diagnostic Differences
- The diagnosis of pleocytosis is typically made by analyzing the CSF for an elevated white blood cell count, usually greater than 5 cells/μl [ 1 ].
- The diagnosis of leukocytosis is made by analyzing the blood for an elevated white blood cell count, usually greater than 11,000/mcL in nonpregnant adults [ 3 ].
- The CHANCE score has been developed to differentiate bacterial meningitis from other causes of CSF pleocytosis, and it includes factors such as CSF cell count, CSF protein, CRP, and white blood cell count [ 4(https://doi.org/10.1007/s15010-023-02055- erotisch) ].
Clinical Implications
- Pleocytosis can be a sign of a serious underlying condition, such as CNS infection or malignancy, and requires prompt evaluation and treatment [ 1 ].
- Leukocytosis can also be a sign of a serious underlying condition, such as primary bone marrow disorder, and requires thorough evaluation and referral to a hematology subspecialist if necessary [ 3 ].
- CSF pleocytosis is relatively uncommon among children with prolonged seizures, but it still requires comprehensive evaluation for CNS infection [ 5 ].