Test Code LAB3358 Nitisinone Level
Clinical System Name
Nitisinone Level
Synonyms
Tyrosinemia monitoring; NTBC; Orfadin; Nityr;
Sample Requirements
Specimen: Whole blood
Container(s): Lt. Green/Lithium, Dark Green/Sodium Heparin, Red, Gold SST
Preferred Vol: 1.0 mL
Minimum Vol: 0.5 mL
Note:
Processing Instructions
Reject due to: n/a
Spin: Y
Aliquot: Y
Temp: - 20 C
Storage location: Transfer 0.5 mL plasma to plastic container. Freeze sample with copy of requisition in CPA Freezer, -20BG rack.
Off-site collection: Transfer 0.5 mL plasma to plastic container. Freeze plasma for storage and shipment.
Stability
Specimen Type | Temperature | Time |
---|---|---|
Plasma or serum | Room temp | 1 m |
Refrigerated | 6 m | |
Frozen | 1 y |
Availability
STAT | Performed | TAT |
---|---|---|
N | W | 3-8 d |
Performing Laboratory
Seattle Children's Laboratory
Department
Department: Biochemical Genetics
Location: Biochemical Genetics
Phone Number: (206) 987-2617
CPT Codes
80299
Methodology
Method: LC/MS/MS
Analytical Volume: 50 mcL plasma/serum
Limitations:
Reference Range
Treatment should lead to normalized porphyrin metabolism; a general target for blood levels is 40-60 mcmol/L. Succinylacetone should not be detectable in urine or plasma. It may take up to three months before the level of plasma succinylacetone is normalized after the start of nitisinone treatment.
The half life of NTBC is 54 hrs. The time of blood collection with respect to drug dosage is not critical, however, one should strive for consistency for any one patient i.e. drug administration at night and blood collection the next morning. A trough level is not necessary.