Histamine, Urine (Sendout)

Ordering Recommendation: Aid in evaluation of patient with allergic signs and symptoms, such as anaphylaxis. May assist when diagnosing and monitoring mast-cell activation disorders or when evaluating histamine production over a longer time frame.

For evaluating patients for diseases of immediate hypersensitivity or mast cell proliferation (mastocytosis), the preferred screening test is Tryptase [TRYPT]. Test results are highly dependent on appropriate sample collection.

Ordering Requirements: This test requires approval by the Lab Medicine Resident (LMR) on-call. Contact the resident via the paging operator at (206) 598-6190.

Referance Intervals:

Random or 24-hour urine collection in a preservative-free container.

• Timed collections should be refrigerated during collection and expedited to the lab after completion. Urine must be aliquoted and frozen within 6 hours after collection is complete.

Outside Laboratories:

• For timed collections, mix specimen well. Measure and record total volume. Document the collection interval and total volume on the requisition.
• Transfer 4 mL urine (min 1 mL) to a separate, screw-top plastic vial, leaving room at the top for expansion.
• Freeze urine aliquot immediately at -20°C. Transport on dry ice.

Stability: Frozen (Critical): 6 months; Refrigerated: 6 hours*; Ambient: Unacceptable.

• *Note: For timed specimens, refrigerate during collection. Sample is stable for 6 hours after the collection is complete.

• For timed collections, mix specimen well. Measure and record total volume. Document the collection interval and total volume on the requisition.
• Transfer 4 mL urine (min 1 mL) to a separate, screw-top plastic vial, leaving room at the top for expansion. Freeze urine aliquot immediately at -20°C.

Sendouts:

• Order ARUP Test: 0070038
• Interfaced: Yes [Interface: 602; Department: ARPZ]

Stability: Frozen (Critical): 6 months; Refrigerated: 6 hours*; Ambient: Unacceptable.

• *Note: For timed specimens, refrigerate during collection. Sample is stable for 6 hours after the collection is complete.