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Test Code LHPED Luteinizing Hormone (LH), Pediatrics, Serum

Method Name

Chemiluminescent Immunoassay (CIA)

Specimen Type

Serum


Ordering Guidance


This test is only available for pediatric patients. If testing request is for a patient 18 years of age or older, order LH / Luteinizing Hormone (LH), Serum.



Specimen Required


Supplies: Sarstedt Aliquot Tube. 5 mL (T914)

Collection Container/Tube:

Preferred: Red top

Acceptable: Serum gel

Submission Container/Tube: Plastic vial

Specimen Volume: 0.25 mL

Collection Instructions:

1. Within 2 hours of collection, centrifuge the specimen.

2. For red top tubes, aliquot serum into a plastic vial immediately.

3. For serum gel tubes, serum may sit on gel refrigerated but must be aliquoted into a plastic vial within 4 hours.


Specimen Minimum Volume

0.13 mL

Specimen Stability Information

Specimen Type Temperature Time
Serum Refrigerated (preferred) 14 days
  Frozen  90 days

Reject Due To

Gross hemolysis Reject
Gross lipemia Reject
Gross icterus Reject

Clinical Information

Luteinizing hormone (LH) is a glycoprotein hormone consisting of 2 noncovalently bound subunits (alpha and beta). LH is produced by the anterior pituitary gland under regulation of the hypothalamic gonadotropin releasing hormone (GnRH) and feedback from gonadal steroid hormones. In children, LH, along with follicle-stimulating hormone (FSH), is used to diagnose precocious (early) and delayed puberty.

 

Precocious puberty refers to the appearance of physical and hormonal signs of pubertal development at an earlier age than is considered normal (before 8 years of age in girls and 9 years of age in boys). Evaluation of precocious puberty includes measurement of LH and FSH to determine whether gonadotropins are increased in relation to chronologic age (gonadotropin-dependent) or whether sex steroid secretion is occurring independent of LH and FSH (gonadotropin-independent). In gonadotropin-dependent precocious puberty, basal LH levels are often elevated into the pubertal range and show a pubertal (heightened) response to GnRH stimulation. In gonadotropin-independent precocious puberty, the LH level is low at baseline and fails to respond to GnRH stimulation.

 

Delayed puberty is defined clinically by the absence or incomplete development of secondary sexual characteristics by age 14 years in boys and by age 12 years in girls. Delayed puberty usually results from inadequate gonadal steroid secretion that, in turn, is most often caused by a defective gonadotropin secretion from the anterior pituitary, due to defective production of GnRH from the hypothalamus. Random measurements of LH and FSH, together with estradiol (girls) or testosterone (boys), are useful to distinguish between primary and secondary causes of delayed puberty.

Reference Values

Females

<1 year: <0.02-18.3 IU/L

1-8 years: <0.02-0.3 IU/L

9-10 years: <0.02-4.8 IU/L

11-13 years: <0.02-11.7 IU/L

14-17 years: <0.02-16.7 IU/L

 

Tanner Stages*

Stage I (1-8 years): <0.02-0.3 IU/L

Stage II: <0.02-4.1 IU/L

Stage IIl: 0.6-7.2 IU/L

Stage IV-V: 0.9-13.3 IU/L

*Puberty onset (transition from Tanner stage I to Tanner stage II) occurs for girls at a median age of 10.5 (± 2) years. There is evidence that it may occur up to 1 year earlier in obese girls and in African-American girls. Progression through Tanner stages is variable. Tanner stage V (adult) should be reached by age 18.

 

Males

<1 year: <0.02-5.0 IU/L

1-8 years: <0.02-0.5 IU/L

9-10 years: <0.02-3.6 IU/L

11-13 years: 0.1-5.7 IU/L

14-17 years: 0.8-8.7 IU/L

 

Tanner Stages*

Stage I (1-8 years): <0.02-0.5 IU/L

Stage II: 0.03-3.7 IU/L

Stage IIl: 0.09-4.2 IU/L

Stage IV-V: 1.3-9.8 IU/L

*Puberty onset (transition from Tanner stage I to Tanner stage II) occurs for boys at a median age of 11.5 (± 2) years. For boys there is no proven relationship between puberty onset and body weight or ethnic origin. Progression through Tanner stages is variable. Tanner stage V (adult) should be reached by age 18.

Day(s) Performed

Monday, Wednesday, Friday

Report Available

2 to 6 days

Performing Laboratory

Mayo Clinic Laboratories in Rochester

CPT Code Information

83002