Luteinizing Hormone (LH)

Label Mnemonic:	LH
Epic 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 test is also performed in the Iowa River Landing (IRL) clinical laboratory (for specimens drawn at that site).

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