Urinary neopterin is a valuable tool in monitoring Crohn's disease activity.
BACKGROUND
The aim was to investigate the relation between urinary neopterin and the Crohn's Disease Activity Index (CDAI) and to compare its ability to discriminate active versus inactive CD with serum C-reactive protein (CRP).


METHODS
In all, 217 urinary samples for neopterin measurement were obtained in a cohort of 93 consecutive patients with CD and 66 samples in 33 healthy volunteers. Clinical parameters were recorded and blood samples for CRP were collected as well.


RESULTS
Whereas patients with inactive CD showed similar levels of urinary neopterin excretion than healthy volunteers (163 +/- 8 versus 142 +/- 7 nmol/mol of creatinine, respectively; P = 0.1), urinary neopterin excretion from mild to severe active CD was significantly higher (302 +/- 15 nmol/mol of creatinine; P < 0.001). Serum CRP levels were higher in active CD (14.8 +/- 2.1 mg/L) compared with inactive CD (5.6 +/- 0.8 mg/L; P < 0.001). Urinary neopterin excretion, and to a lesser degree CRP, were positively and significantly correlated with CDAI (r = 0.64 and 0.43, respectively, P < 0.001). Based on the cutoff of 183 nmol/mol of creatinine for urinary neopterin, the sensitivity and specificity of urinary neopterin to discriminate between active and inactive CD were 73% and 82%, respectively, and the positive and negative predictive values were 80% and 78%, respectively.


CONCLUSIONS
Urinary neopterin excretion is an objective, valuable, simple, and noninvasive biomarker to detect and follow fluctuations of CD activity. Further work is warranted to study its clinical value and relation to mucosal healing.
Service de Gastroentérologie, Centre Hospitalier Lyon-Sud, Pierre-Bénite, France. nancey@cervilyon.inserm.fr
S
S
Nancey
A
A
Perret-Liaudet
D
D
Moussata
I
I
Graber
G
G
Boschetti
B
B
Renaud
D
D
Kaiserlian
J M
JM
Reimund
B
B
Flourié
D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D000704:Analysis of Variance; D015415:Biomarkers / Q000032:analysis; D002097:C-Reactive Protein / Q000032:analysis*; D016022:Case-Control Studies; D015331:Cohort Studies; D003424:Crohn Disease / Q000097:blood* / Q000652:urine*; D018450:Disease Progression; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D008991:Monitoring, Physiologic / Q000379:methods; D019798:Neopterin / Q000378:metabolism / Q000652:urine*; D011336:Probability; D011379:Prognosis; D012372:ROC Curve; D012016:Reference Values; D018570:Risk Assessment; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D012737:Sex Factors; D016482:Urinalysis; D055815:Young Adult
D015415:Biomarkers; D019798:Neopterin; D002097:C-Reactive Protein