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Lipoprotein (a)
| Item | Value |
|---|---|
| Approval req'd? | No |
| Available Stat? | No |
| Test code | LPA |
| Performed by | Immunology |
| In House Availability | Monday, Wednesday, Friday (day shift) |
| Method | Nephelometry particle-enhanced |
| Patient Preparation | An 8 hour fast before specimen collection is preferred. |
| Container type | Gold top |
| Amount to Collect | 2 mL blood |
| Sample type | Serum |
| Preferred volume | 1 mL serum |
| Min. Volume | 0.3 mL serum |
| UCSF Rejection Criteria | Lipemic samples |
| Units | nmol/L |
| Normal range | < 75 nmol/L |
| Synonyms | Lp(a) |
| Stability | Room temperature 6 hours, refrigerated 2 weeks, frozen at -20C 3 months. |
| Turn around times | 2-5 days |
| Additional information | Lipoprotein(a) is a modified form of LDL in which a large glycoprotein, apo(a) is covalently bound to apo(B) by a disulfide bridge. Studies that evaluated Lp(a) as a predictor of cardiovascular events have had conflicting results. Some studies suggested that Lp(a) was an independent risk factor for CHD, while others showed no significant association. There may be a role for elevated Lp(a) levels in predicting CHD events in subjects with concomitant hypercholesterolemia. While a cutoff of 75 nmol/L is frequently used as indication of elevated Lp(a) there appears to be racial differences in the reference range for Lp(a) when studying different racial groups without evidence of coronary heart disease. Additionally the size of the Lp(a) particle can affect the quantitation of this molecule making inter-method comparisons difficult. If fasting is not observed for 12 hours, elevated levels of Lp(a) will be detected. References 1. Marcovina SM, et al. 1996. Differences in Lp[a] concentrations and apo[a] polymorphs between black and white Americans. J. Lipid Res. 37: 2569-2585. 2. Iso H, et al. 1996. Lipoprotein (a) and its correlates in Japanese and U.S. population samples. Ann. Epidemiol. 6: 324-330. 3. Nazir DJ and McQueen MJ. 1997. Monthly intra-individual variation in lipoprotein(a) in 22 normal subjects over 12 months. Clin Biochem. 30: 163-170. |
| CPT coding | 83695 |
| LOINC code | 49748-7 |
| Last Updated | 1/30/2013 11:43:26 AM |
| Entry Number | 623 |
If you have additional questions regarding this test, please call: 415-353-1667