Oxysterols, Blood Spot
Use
This test is used to investigate a possible diagnosis of acid sphingomyelinase deficiency, also known as Niemann-Pick disease type A or B, using dried blood spots. It is important for early diagnosis to provide the best patient management. However, it is not recommended for diagnosing Niemann-Pick type C disease, where plasma oxysterols offer better sensitivity. Additionally, the test is not useful for identifying carriers of these diseases.
Special Instructions
This test should not be ordered for Niemann-Pick type C disease diagnosis. Instead, plasma oxysterols should be considered for higher accuracy. When ordered with related tests like Glucopsychosine, Blood Spot or Cerebrotendinous Xanthomatosis, Blood Spot, the test OXYBS will be canceled and replaced by a panel test (HSMBS).
Limitations
The test using dried blood spots has lower clinical sensitivity and specificity for diagnosing Niemann-Pick type C compared to plasma tests, having sensitivities of 75% versus 98%. Nonspecific neonatal cholestasis may lead to false positives, showing increased cholestane-3-beta, 5-alpha, 6-beta-triol and lyso-sphingomyelin 509. Normal results do not exclude the possibility of Niemann-Pick type C when using dried blood spots.
New York Approved
Methodology
Mass Spectrometry (LC-MS/MS)
Biomarkers
LOINC Codes
- 92741-8
- 92757-4
- 92749-1
- 59462-2
- 18771-6
Result Turnaround Time
3-7 days
Related Documents
For more information, please review the documents below
Specimen
Whole Blood
Volume
2 Blood spots
Minimum Volume
1 Blood spot
Container
Filter Paper
Collection Instructions
Let blood dry completely on the filter paper at ambient temperature for at least 3 hours. Do not expose to heat or direct sunlight. Stack specimens only when dry. Keep specimen dry.
Storage Instructions
Store refrigerated (preferred) or ambient for up to 10 days, frozen for up to 59 days on filter paper.
Causes for Rejection
Shows serum rings, insufficient specimen, layering or multiple applications.
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | 10 days |
| Refrigerated | 10 days |
| Frozen | 59 days |