Homogentisic acid interference in routine urine creatinine determination.
We report the artifactual elevation of homogentisic acid (HGA) in urine from alkaptonuric patients after replacing the creatinine method (Jaffe reaction) in our laboratory with an automated enzymatic method. Samples with elevated HGA by GC-MS had lower creatinine values as determined by the enzymatic method than by the Jaffe reaction. The low creatinine values were due to interference by HGA in the enzymatic method. The enzymatic method is unsuitable for creatinine determination in urine of patients with alkaptonuria.
Biochemical Genetics Laboratory, Mayo Clinic College of Medicine, Rochester, MN 55905, USA.
Perry R
PR
Loken
Mark J
MJ
Magera
Wendy
W
Introne
Silvia
S
Tortorelli
Dimitar
D
Gavrilov
Devin
D
Oglesbee
Piero
P
Rinaldo
Dietrich
D
Matern
Kimiyo
K
Raymond
D000474:Alkaptonuria / Q000652:urine; D016477:Artifacts; D003404:Creatinine / Q000652:urine*; D006713:Homogentisic Acid / Q000652:urine*; D006801:Humans
D003404:Creatinine; D006713:Homogentisic Acid