CSF Leukocyte

1. See Also
   1. Cerebrospinal Fluid Examination
   2. Cerebrospinal Fluid
   3. Lumbar Puncture
2. Normal Findings
   1. No Polymorphonuclear Lymphocytes (Neutrophils)
      1. Normal CSF may have 1-2 PMNs present
   2. Adults: 5 or less WBC/mm3
   3. Newborns: 20 or less WBC/mm3
3. Correction of WBCs for CSF RBC
   1. One WBC for every 500-1000 CSF RBCs
4. Cell Differential
   1. Differential does not distinguish bacterial from viral
      1. Lymphocyte predominance in 10% Bacterial Meningitis
   2. Monocytes (Up to 50 cells/mm3)
      1. Guillain-Barre Syndrome
      2. Multiple Sclerosis
   3. Eosinophils
      1. Intracranial parasite infection
      2. Aseptic Meningitis
      3. Malignancy
      4. Ventriculoperitoneal shunt
5. Pleocytosis (WBCs in CSF) Causes
   1. Bacterial Meningitis
      1. PMNs predominate
      2. CSF WBCs >100/mm3 in 99% of cases (>1000 for most)
   2. Viral Meningitis
      1. Lymphocytes predominate
      2. CSF WBCs usually <100/mm3
   3. Chronic intracranial inflammation (Lymphocytes)
   4. Subarachnoid Hemorrhage
   5. Thrombosis
   6. Infectious Mononucleosis
   7. CNS Parasitic infection (Eosinophils predominate)
   8. Carcinomatous Meningitis (<100 cells)
6. Examination pointers
   1. Acetic acid lyses CSF RBCs but leaves CSF WBCs intact
   2. Methylene blue distinguishes PMNs and Lymphocytes
7. References
   1. Kooiker in Roberts (1998) Procedures in ER, p. 1067-75
   2. Ravel (1995) Lab Medicine, Mosby, p. 294-9
   3. Tunkel in Mandell (2000) Infectious Disease, p. 974-8
   4. Seehusen (2003) Am Fam Physician 68:1103-8