Category
SPECIAL CHEMISTRY.
Sub Category
ENDOCRINE
Synonyms/Aliases
SOMATOTROPIN; SOMATOTROPHIC HORMONE
Abbreviations
GH; HGH
Type
INDIVIDUAL TEST
Results
RESULTS READY/ REPORTED IN 7 WORKING DAYS
Method
IMMUNOASSAY.
Temp
FROZEN (-20°C) PREFERRED OR REFRIGERATED. THERE IS LIMITED STABILITY AT ROOM (AMBIENT) TEMPERATURE AND THIS SHOULD BE AVOIDED.
Setup
BATCHED.
Components Parameters
NOT APPLICABLE
PRE-ANALYTIC CONSIDERATIONS
Test Ordering Instructions
FILL OUT TEST REQUEST FORM FULLY & LEGIBLY. TO SCREEN FOR GIGANTISM & ACROMEGALY, CONSIDER IGF-1 OR GROWTH HORMONE SUPPRESSION TEST AS ALTERNATE TESTS (BETTER SCREENING TESTS). TO EVALUATE FOR DWARFISM/ SHORT STATURE, CONSIDER GROWTH HORMONE STIMULATION TEST (SPECIFY STIMULANT) AS ALTERNATIVE.
Patient preparation
10-12 HOUR FASTING (FASTING MEANS THAT ONLY WATER AND PRESCRIBED MEDICATION IF ANY ARE PERMITTED DURING THE FASTING PERIOD); 30 MINUTES REST PRIOR TO COLLECTION.
Sample type
SERUM.
Container/ preservative
SERUM SEPARATOR TUBE (SST/ GEL) OR PLAIN (RED TOP) VACUTAINER.
Sample volume
AT LEAST 2ML
Rejection criteria
LABELING ISSUE (UNLABELED/ MISLABELED); MISSING REQUEST FORM; MISMATCH BETWEEN REQUEST FORM & SAMPLE DETAILS; MISSING AGE/ GENDER; WRONG SAMPLE TYPE; INSUFFICIENT SAMPLE.
Other Instructions
CENTRIFUGE SST (SERUM GEL TUBES) WITHIN 1-2 HOURS OF COLLECTION. CENTRIFUGE RED TOP VACUTAINERS AND ALIQUOT SERUM WITHIN 1-2 HOURS OF COLLECTION. THE SEPARATION VIAL MUST BE LABELED WITH AT LEAST 2 PATIENT IDENTIFIERS AND THE SAMPLE TYPE.
Reference intervals
AGE & GENDER APPROPRIATE VALUES ARE PROVIDED ON THE REPORT.
Clinical Utility
DIAGNOSIS OF GROWTH DISORDERS E.G. SHORT STATURE/ DWARFISM, GIGANTISM, ACROMEGALY FROM PITUITARY & HYPOTHALAMIC DISORDERS. EVALUATION OF GROWTH HORMONE EXCESS AND GROWTH HORMONE DEFICIENCY. EVALUATION OF PITUITARY TUMORS. FURTHER TESTS (AS APPLICABLE): STIMULATION TESTS (FOR SUSPECTED GH DEFICIENCY), SUPPRESSION TESTS (FOR SUSPECTED GH EXCESS), IGF-1.
Test Limitations/ Confounders
INTERFERENCE CAN ARISE FROM EATING (FASTING REQUIRED), DRUGS, STRESS, EXERCISE (COLLECT SAMPLES AFTER REST). IMMUNOASSAY INTERFERENCE CAN GIVE RISE TO SPURIOUS RESULTS. SUCH INTERFERENCE CAN ARISE FROM PRESENCE OF HETEROPHILE ANTIBODIES, ANTI-ANIMAL ANTIBODIES, AUTOANTIBODIES, PARAPROTEINS, BIOTIN ETC. RESULTS SHOULD ALWAYS BE CORRELATED WITH CLINICAL FINDINGS. HORMONE IS RELEASED IN A PULSATILE MANNER & RAPIDLY CLEARED THEREFORE NORMAL VALUES MAY NOT RULE OUT DISEASE.