Luteinizing Hormone (LH)
Label Mnemonic: LH
Epic Lab Code: LAB88
Downtime Form: A-1a Doctor/Provider Orders - Pathology Core and Specialty Care Nursery
Chemistry
6240 RCP
356-3527
Specimen(s):
Plasma
Collection Medium:
Plasma Separator Tube 4.5 mL
Alternate Collection Media:
Call laboratory for additional acceptable specimen collection containers.
Minimum:
3 mL whole blood in light green top tube or TWO Microtainer®® devices.
Testing Schedule:
24 hrs/day, 7 days a week, including holidays.
Turn Around Time:
1 hour (upon receipt in laboratory)
Reference Range:
FEMALES - menstruating: Follicular phase 2.4 - 12.6 mIU/mL Ovulation phase 14.0 - 95.6 mIU/mL Luteal phase 1.0 - 11.4 mIU/mL Postmenopause 7.7 - 58.5 mIU/mL MALES: 1.7 - 8.6 mIU/mL AGE MALES FEMALES Prepubertal <0.5 mIU/mL <0.5 mIU/mL Tanner II 0.2-2.8 mIU/mL 0.1-4.1 mIU/mL Tanner III 1.2-3.9 mIU/mL 0.2-9.2 mIU/mL Tanner IV 0.9-4.4 mIU/mL 0.7-8.6 mIU/mL Tanner V 1.8-5.3 mIU/mL 0.5-7.3 mIU/mL
Comments:
This assay may be significantly impacted by high-dose biotin (>5 mg dose) taken within previous 12 hours. High concentrations of biotin may lead to falsely decreased results. These concentrations may be found in patients taking over-the-counter supplements with biotin content much higher than nutritional requirements for biotin. Specimens should not be collected until at least 12 hours after the last dose.

New immunoassay method instituted 3/21/00 at 0900.
Test Limitations:
The assay is unaffected by icterus (bilirubin is less than 66 mg/dL), hemolysis (Hb is less than 1000 mg/dL), lipemia (Intralipid is less than 1900 mg/dL) and biotin is less than 50 ng/mL (criterion: recovery within plus or minus 10% of initial value). No interference was observed from rheumatoid factors up to a concentration of 1500 U/mL. No high dose hook effect at LH concentrations of up to 1150 mIU/mL In vitro tests were performed on 17 commonly used pharmaceuticals. No interference with the assay was found. Samples of neonates have not been tested with LH assay. As with all tests containing monoclonal antibodies, erroneous findings may be obtained from samples taken from patients who have been treated with monoclonal mouse antibodies or who have received them for diagnostic purposes. In rare cases interference due to extremely high titers of antibodies to streptavidin and ruthenium can occur. LH reagent contains additives which minimize these effects. For diagnostic purposes, the LH findings should always be assessed in conjunction with the patient's medical history, clinical examination and other findings.
Methodology:
Electrochemiluminescence Immunoassay
CPT Code:
83002
 
See Additional Information:
Biotin Interference with Immunoassays