Oxysterols, Plasma
Test Mnemonic
OXSTRL
CPT Codes
- 82542 - QTY (1)
Aliases
- Acid Sphingomyelinase Deficiency
- Niemann-Pick type A
- Niemann-Pick type B
- Niemann-Pick type C
Includes
- Cholestane-3beta,5alpha,6beta-triol
- 7-Ketocholesterol
- Lyso-sphingomyelin
- Interpretation
- Reviewed By
Performing Laboratory
Mayo Clinic Dpt of Lab Med & Pathology
Specimen Requirements
| Volume | Type | Container | Collect Temperature | Transport Temperature | Special Instructions |
|---|---|---|---|---|---|
| 0.3 mL | Plasma | EDTA (Lavender) | Place specimen on ice after draw. | Frozen, Critical | Chill specimen on ice and use refrigerated centrifuge (if possible) to separate plasma from cells. Without disturbing the buffy coat layer, transfer plasma to standard aliquot tube and freeze immediately. Separate specimens must be submitted when multiple tests are ordered. |
Alternate Specimen Requirements
| Volume | Type | Container | Collect Temperature | Transport Temperature | Special Instructions |
|---|---|---|---|---|---|
| 0.3 mL | Plasma | Sodium or Lithium heparin (Green) | Place specimen on ice after draw. | Frozen, Critical | Chill specimen on ice and use refrigerated centrifuge (if possible) to separate plasma from cells. Without disturbing the buffy coat layer, transfer plasma to standard aliquot tube and freeze immediately. Separate specimens must be submitted when multiple tests are ordered. |
| 0.3 mL | Plasma | ACD B (Yellow) | Place specimen on ice after draw. | Frozen, Critical | Chill specimen on ice and use refrigerated centrifuge (if possible) to separate plasma from cells. Without disturbing the buffy coat layer, transfer plasma to standard aliquot tube and freeze immediately. Separate specimens must be submitted when multiple tests are ordered. |
Stability
| Environmental Condition | Description |
|---|---|
| Frozen | After separation from cells: 65 days |
| Refrigerated | Unacceptable |
| Ambient | Unacceptable |
Days Performed
Tue, Thu
Turnaround Time
4 - 8 days
Methodology
| Name | Description |
|---|---|
| Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS) | |
| Precipitation |
Special Info
Chill specimen on ice and use refrigerated centrifuge (if possible) to separate plasma from cells. Without disturbing the buffy coat layer, transfer plasma to standard aliquot tube and freeze immediately. Separate specimens must be submitted when multiple tests are ordered. This test is New York State approved.
Clinical Info
This test is useful for investigating a possible diagnosis of Niemann-Pick disease types A, B, or C using plasma specimens. It is also useful for monitoring individuals with Niemann-Pick type C disease. An elevation of cholestane-3-beta, 5-alpha, 6-beta-triol is highly suggestive of Niemann-Pick disease type C (NPC). An elevation of lyso-sphingomyelin (LSM) is highly suggestive of Niemann-Pick type A or B (NPA or NPB) disease. An elevation of LSM 509 is suggestive of NPA, NPB, or NPC disease.
Clinical Limitation
This test is not useful for the identification of carriers. Nonspecific neonatal cholestasis may result in elevations of cholestane-3-beta, 5-alpha, 6-beta-triol and lyso-sphingomyelin 509.