ARUP's Laboratory Test Directory

Lactate Dehydrogenase, Isoenzymes : 0020413

Mnemonic: LDISO

Ordering Recommendation: Do not use to detect myocardial injury. Cardiac troponins [troponin I (0090613)or troponin T (0098803)] are the recommended tests for diagnosis and management of acute coronary syndrome. In rare cases, this test may be used to evaluate elevated lactate dehydrogenase associated with non-cardiac muscle injury.
Methodology: Quantitative Enzymatic/Electrophoresis
Performed: Sun-Sat
Reported: 1-2 days
Specimen Required: Collect: Serum separator tube (SST) or plain red.

Specimen Preparation: Do not refrigerate or freeze. Allow specimen to clot completely at room temperature. Separate serum from cells ASAP or within 2 hours of collection. Transfer 1 mL serum to an ARUP Standard Transport Tube. (Min: 0.6 mL)

Storage/Transport Temperature: Room temperature.

Unacceptable Conditions: Specimens collected with EDTA, potassium oxalate, or sodium fluoride anticoagulants. Frozen, refrigerated, or hemolyzed specimens.

Stability (collection to initiation of testing): After separation of cells: Ambient: 1 week; Refrigerated: Unacceptable; Frozen: Unacceptable
Reference Interval:
LD-1: 14-27%
LD-2: 29-42%
LD-3: 18-30%
LD-4: 8-15%
LD-5: 6-23%

Lactate Dehydrogenase, Total:
0 up to 30 days: 200-465 U/L
1-17 months: 200-450 U/L
18 months-10 years: 165-430 U/L
11-16 years: 127-287 U/L
17 years and older: 105-230 U/L
Note: LD-1 and LD-2 are elevated in hemolyzed specimens and serum which has not been separated from cells.  LD-3, LD-4, and LD-5 are labile at low temperatures, and are erroneously low in specimens that have been refrigerated or frozen.
CPT Code(s): 83625; 83615
Cross References: Isoenzymes, LD (Lactate Dehydrogenase, Isoenzymes), LD Isoenzymes (Lactate Dehydrogenase, Isoenzymes), LDH Isoenzymes (Lactase Dehydrogenase, Isoenzymes)