Lactose Tolerance Test, 5 Specimens

Test Code

7675

CPT Codes
82951, 82952 (x2)

Includes

Fasting specimen, 1/2-hour, 1-hour, 2-hour, and 3-hour specimens

Preferred Specimen

1 mL plasma (x5) collected in each of five fluoride/oxalate (gray-top) tubes

Patient Preparation

Note: This test cannot be performed at a patient service center because of the preparation step required for the lactol solution.

Fasting required. Fasting is defined as no consumption of food or beverage other than water for at least 8 hours before testing.

Minimum Volume

0.5 mL (x5)

Other Acceptable Specimens

Plasma collected in (x5): Sodium or lithium heparin (green-top) tubes • Serum (separated from cells immediately) collected in a plastic screw-cap vials or spun SST • Whole blood collected in fluoride/oxalate (gray-top) tube

Instructions

Immediately after a fasting specimen is obtained, have patient ingest a 50 g dose of lactose (supplied by the laboratory). Draw subsequent specimens 1/2, 1, 2 and 3 hours later. Label each with the specific draw time.

Note: Children should receive 1.75g lactose per kg ideal body weight, up to 50g.
Serum and plasma submissions must be separated from cells.

Transport Temperature

Room temperature

Specimen Stability

Fluoride/oxalate plasma
Room temperature: 7 days
Refrigerated: 7 days
Frozen: 28 days

Heparinized plasma
Room temperature: 48 hours
Refrigerated: 7 days
Frozen: 28 days

Serum
Room temperature: 4 days
Refrigerated: 7 days
Frozen: 28 days

Whole blood
Room temperature: 24 hours
Refrigerated: 72 hours
Frozen: Unacceptable

Reject Criteria (Eg, hemolysis? Lipemia? Thaw/Other?)

Unspun serum separator tube • Anticoagulants other than lithium or sodium heparin or fluoride/oxalate • (Red-top) or non-plasma separator (green-top) tubes

Methodology
Spectrophotometry (SP)

Setup Schedule

Set up: Daily; Report available: Next day

Reference Range

See Laboratory Report

Clinical Significance

Results may be used to evaluate deficiency of small bowel mucosal lactase, which may be associated with intolerance to lactose, manifested by diarrhea and other symptoms following ingestion of milk.

Performing Laboratory
Quest Diagnostics Nichols Institute
14225 Newbrook Drive
Chantilly, VA 20153

The CPT Codes provided in this document are based on AMA guidelines and are for informational purposes only. CPT coding is the sole responsibility of the billing party. Please direct any questions regarding coding to the payor being billed. Any Profile/panel component may be ordered separately. Reflex tests are performed at an additional charge.