IgG/Albumin Ratios, CSF/Blood (Sendout)

Useful for: Aiding in the diagnosis of multiple sclerosis and other central nervous system inflammatory conditions.

Ordering Requirements: This test requires both CSF and a blood sample collected within 7 days of each other or testing will be cancelled by Mayo Clinic Laboratories. See IgG/Albumin Ratios, Blood (Sendout) [XSFIGS] for accompanying blood collection test.

IgG Index, CSF and IgG, Serum: Nephelometry

Albumin: Photometric

Interpretation:

Cerebrospinal fluid (CSF) IgG synthesis rate indicates the rate of increase in the daily CSF production of IgG in milligrams per day. A result greater than 12 mg/24 h is elevated.

A CSF IgG index greater than 0.70 is elevated and indicative of increased synthesis of IgG.

Collect 1 mL CSF in a sterile vial.

• Preferred: Collection vial number 2.

Note: This test also requires serum collected within 7 days of CSF collection. See IgG/Albumin Ratios, Blood (Sendout) [XSFIGS].

Outside Laboratories:

• This test requires both CSF and serum samples obtained within 7 days of each other.
• CSF: Store and transport CSF sample refrigerated.
• Blood: See IgG/Albumin Ratios, Blood (Sendout) [XSFIGS].
• Indicate "CSF" or "serum" on the sample labels.
• Send serum and CSF samples in the same package to avoid delays. Transport with a cold pack.

Stability (CSF): Refrigerated (Preferred): 28 days; Frozen: 28 days; Ambient: 14 days.

Refrigerate CSF in a sterile vial.

This test must be ordered with IgG/Albumin Ratios, Blood (Sendout) [XSFIGS]. If serum and CSF samples arrive together at the lab, an HC1 task is not needed. Forward both samples to the Sendouts bench. If a CSF sample is received without blood:

1. Review open HC1 Tasks and/or the patient's record in Sunquest Inquiry to determine if the XSFIGS sample was previously received in lab. If so, receive the RCSRAT order and deliver all samples to Sendouts.
2. If CSF is received without an existing XSFIGS order, create a task in HC1 to hold the CSF sample (refrigerated) while waiting for the blood. Do not deliver to Sendouts until both samples are received.
3. Contact the provider or client as needed if the other sample is not received in a timely manner.

Sendouts:

• Order Mayo test: SFIG
• Interfaced: Yes [Interface: 601; Workskeet: MARF]
• Wait for both CSF (RCSRAT) and serum (XSFIGS) samples before batching the order across the interface.
• Write the sample type ("CSF" or "serum") on the sample labels.
• Rubberband the serum and CSF samples together.
• Batch the RCSRAT order outbound over the interface. Track both CIDs to USENT.
  • The XSFIGS code is for serum collection only, and will not batch separately.

Stability (CSF): Refrigerated (Preferred): 28 days; Frozen: 28 days; Ambient: 14 days.