Test Details
Methodology
Chemiluminescence Immunoassay
Result Turnaround Time
Three times per week
Turnaround time is defined as the usual number of days from the date of pickup of a specimen for testing to when the result is released to the ordering provider. In some cases, additional time should be allowed for additional confirmatory or additional reflex tests. Testing schedules may vary.
Use
This test detects antibodies against HMGCR for diagnosis of necrotizing myopathy.
Limitations
1. Not all idiopathic inflammatory myopathy patients are positive for HMGCR antibodies.
2. Results of this assay should be used in conjunction with clinical findings and other serological tests.
3. Failure to adequately resuspend the HMGCR coated beads may yield lower values than if the beads are properly re-suspended.
4. The performance characteristics of this assay have not been established for matrices other than serum.
Specimen Requirements
Specimen
Serum
Volume
1 mL
Minimum Volume
0.5 mL
Container
Gel-barrier tube or red-top tube
Collection Instructions
If a red-top tube is used, transfer separated serum to a plastic transport tube.
Stability Requirements
| Temperature | Period |
|---|---|
| Room temperature | 48 hours |
| Refrigerated | 14 days |
| Frozen | 14 days |
| Freeze/thaw cycles | Stable x3 |
Storage Instructions
Refrigerate or freeze.
Causes for Rejection
Gross hemolysis; lipemia and icterus
References
Bottai M, Tjarnlund A, Santoni G, et al. EULAR/ACR classification criteria for adult and juvenile idiopathic inflammatory myopathies and their major subgroups: a methodology report. RMD Open. 2017 Nov 14;3(2):e000507. 29177080
Christopher-Stine L, Casciola-Rosen LA, Hong G, Chung T, Corse AM, Mammen AL. A novel autoantibody recognizing 200-kd and 100-kd proteins is associated with an immune-mediated necrotizing myopathy. Arthritis Rheum. 2010 Sep;62(9):2757-2766. 20496415
Musset L, Allenbach Y, Benveniste O, et al. Anti-HMGCR antibodies as a biomarker for immune-mediated necrotizing myopathies: A history of statins and experience from a large international multi-center study. Autoimmun Rev. 2016 Oct;15(10):983-993. 27491568
LOINC® Map
| Order Code | Order Code Name | Order Loinc | Result Code | Result Code Name | UofM | Result LOINC |
|---|---|---|---|---|---|---|
| 520385 | Anti-HMGCR Ab | 95726-6 | 520386 | Anti-HMGCR Ab | CU | 95726-6 |
| Order Code | 520385 | |||||
| Order Code Name | Anti-HMGCR Ab | |||||
| Order Loinc | 95726-6 | |||||
| Result Code | 520386 | |||||
| Result Code Name | Anti-HMGCR Ab | |||||
| UofM | CU | |||||
| Result LOINC | 95726-6 |