Csf Method; Intended Use; Principles Of The Procedure - Siemens ADVIA 2120 Operator's Manual

CSF Method

Intended Use

The ADVIA 2120/2120i Hematology Cerebrospinal Fluid (CSF) assay is
intended for in vitro diagnostic use in the quantitative determination of blood
cells in cerebrospinal fluid (CSF) specimens. The CSF assay provides leukocyte
(CSF WBC) and erythrocyte (CSF RBC) counts as well as absolute and
percentage counts for the CSF WBC differential. To arrive at a diagnosis and a
course of treatment, results from the CSF assay should be used in conjunction
with other diagnostic information and the attending health-care professional's
evaluation of the patient's condition.

Principles of the Procedure

Hematological analysis of CSF specimens has historically been performed in
laboratories using manual cell counting and differentiation methods. Blood cells
in normal CSF samples are usually present in very low numbers. The WBC count
can provide important clinical information for the differential diagnosis of
various cerebral diseases. The WBC count in CSF is used in the diagnosis of
bacterial meningitis, differential diagnosis of viral and fungal meningitis,
encephalitis, neurological disorders, the diagnosis of leukemias with CSF
involvement, and for monitoring patient therapy for leukemias and lymphomas.
An elevated WBC count with increased proportions of polymorphonuclear cells
is usually an indication of bacterial meningitis. In viral meningoencephalitis, the
cell counts may be lower with a predominance of mononuclear cells. An
unusually elevated RBC count can be an indication of cerebral hemorrhage or a
traumatic spinal tap.
The ADVIA 120 CSF assay provides a rapid, automated analysis of CSF samples
by counting and distinguishing certain cell types. When using the ADVIA 120
CSF assay, the CSF sample is mixed with ADVIA 120 CSF reagent, which
spheres and fixes the cells. After a minimum 4-minute to 4-hour incubation
period, the prepared sample is then aspirated directly into the ADVIA 120
system. The cells are then detected and enumerated based on light scatter and
absorbance measurements using the ADVIA 120 laser optics. A scatter versus
scatter and scatter versus absorbance cytogram is displayed with the thresholds
and results automatically calculated for each sample. Reportable parameters are
WBC and RBC counts along with absolute and percentage counts for neutrophils,
lymphocytes, monocytes, polymorphonuclear (PMN), and mononuclear (MN)
cells. A research-use-only eosinophil count is also given.
Regulatory Information 9-33