CEREBROSPINAL FLUID (CSF) IGG INDEX

General Information

HLAB/HOL Code: CSFIG
UPHSM LIS Test #: 9934
Schedule:
Testing Time:
Testing Lab: Labcorp

Specimen Info
Only 1 specimen type required, unless otherwise specified

Volume: 1.5 (0.7) mL serum and 1 (0.5) mL CSF
Temperature: Refrigerate
Tube Type: Serum and Spinal Fluid
Collection Info:
Specimen:  Serum and cerebrospinal fluid (CSF)

Volume:  1.5 mL serum and 1 mL CSF

Minimum Volume:  0.7 mL serum and 0.5 mL CSF

Container:  Red-top tube or gel-barrier tube and sterile (CSF) container

Special Instructions:  The third tube of a routinely obtained three-tube set of CSF should be used for these studies.

Storage Instructions:  Refrigerate

Methods

CSF IgG, CSF albumin, and serum IgG: immunologic; serum albumin: spectrophotometry; ratio and index by calculation

Clinical Utilities

Use:  Detect and measure the level of IgG production by the central nervous
system; has been applied to the diagnosis of multiple sclerosis along with
CSF IgG synthesis rate and CSF immunoglobulin “oligoclonal” bands

Limitations:  Conditions in which lymphoreticular elements of the CNS produce
immunoglobulins will result in false-positive (in relation to multiple sclerosis) elevations.
Such conditions include, but are not limited to, aseptic meningitis, lymphoma,
neurosyphilis, Guillain-Barré syndrome, and cerebral lupus erythematosus. These
conditions, however, are either uncommon or are not frequently associated with
an increased IgG index.

CPT Codes

82040
82042
82784 (x2)

Test Includes:  IgG and albumin quantitation in both serum and spinal fluid; CSF IgG:CSF albumin ratio; CSF IgG index


* The CPT codes provided are based on AMA guidelines and are for informational purposes only. CPT coding
is the sole responsibility of the billing party. Please direct any questions regarding coding to the payer being billed.

Reference Range

Index: 0.0-0.7