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Test Code LAB4009 ALANINE AMINOTRANSFERASE (ALT), SGPT 

Important Note

Useful for diagnosing and monitoring of liver disease associated wtih hepatic necrosis.

Additional Codes

Labcorp 001545

Specimen Type

Preferred Sample:  Lithium Heparin Plasma (Light Green Top)
Alternate Sample: Serum Tube (SST, Gold, Corvac, Tiger, Red Top Tube)

 

Specimen Volume

Preferred: 1.0 mL

Minimum: 0.5 mL

Sample Stability

Room Temp: 3 days
Refrigerated: 7 days

Frozen: 60 Days (-40C)

Clinical Information

Alanine aminotransferase (ALT) is an enzyme that catalyzes the deamination of the amino acid alanine, one of the steps involved in the metabolism of proteins for energy. ALT is found in many tissues, but the highest levels are found in liver and kidney tissues. Tissue destruction leads to the release of the intracellular enzyme into the circulating blood. Markedly elevated serum ALT levels may be found in a variety of diseases which involve the liver, such as hepatitis, mononucleosis, and cirrhosis. ALT is also found in the kidneys, heart, and muscle tissues; however, very high levels of ALT are not usually observed in other disease processes, e.g., myocardial infarction. ALT is thus regarded as a reasonably specific indicator of liver disease. Increased ALT levels are often seen in conjunction with elevated aspartate aminotransferase (AST) levels, another indicator of hepatic disease, though it is more liver-specific, and remains elevated for longer.

Method

Enzymatic (NADH (without P-5'-P))

 

ALT present in the sample catalyzes the transfer of the amino group from L-alanine to α ketoglutarate, forming pyruvate and L-glutamate. Pyruvate in the presence of NADH and lactate dehydrogenase (LD) is reduced to L-lactate. In this reaction NADH is oxidized to NAD+. The reaction is monitored by measuring the rate of decrease in absorbance at 340 nm due to the oxidation of NADH to NAD+.

Test Components

ALT, U/L

Measuring Range 7 - 3258 U/L

Reporting Limits 7 – 16,290 U/L

If result after a 1:5 dilution is greater than 16,290 U/L, report out >16,290 U/L.

Limitations

  • Interferences from medication or endogenous substances may affect results.
  • Erythrocytes contain approximately 3 to 5 times more ALT than does serum.
    • Hemolysis can increase test results.

Reference Ranges

ALT, U/L
  Male Female
<1 Year 13 - 45
1-3 Years <46
3-6 Years 10 - 25
6-9 Years 10 - 35
9-11 Years 10 - 35 10 - 30
11-13 Years 10 - 55
13-15 Years 10 - 45 <31
>15 Years <45 <34


 

Turnaround Time

STAT: 1 hour
Routine: 4 hours

Test Schedule

Daily and STAT

CPT Codes

84460

IMO Code

IMO-PROC-30985599