Plasma citrulline concentration: a reliable marker of small bowel absorptive capacity independent of intestinal inflammation.
OBJECTIVE
Postabsorptive plasma citrulline concentration has been proposed as a reliable marker of small bowel absorptive capacity in short bowel patients. The aim of this study was to address the potentially confounding impact of intestinal inflammation.


METHODS
Fifty-five patients were selected according to diagnosis, small bowel length, and degree of bowel inflammation. (a) Crohn's disease (CD) with massive small bowel resection leaving </=50 cm (N = 6), (b) CD with 50-150 cm remaining (N = 9), (c) CD with no resection but active inflammation (high C-reactive protein [CRP] and Crohn's Disease Activity Index [CDAI] >220) (N = 7), (d) CD without resection or active inflammation (normal CRP and CDAI <150) (N = 9), (e) mesenteric infarction (MI) with resection leaving </=50 cm (N = 6), (f) MI leaving 50-150 cm (N = 6), (g) active celiac disease (N = 6), (h) healthy volunteers (N = 6). Postabsorptive fasting plasma citrulline was measured using reverse-phase, high performance liquid chromatography. Absorptive capacity and permeability were also measured after oral sugar-mix ingestion (5 g lactulose, 1 g L-rhamnose, 0.5 g D-xylose).


RESULTS
The plasma citrulline strongly correlated with small bowel length (P < 0.0001) and xylose absorption (P < 0.001). No correlation was found with CDAI, permeability, CRP, albumin, sedimentation rate, white cell count, or platelet count. Citrulline was significantly higher (P < 0.0004) in CD and MI patients with a remnant small bowel length of 50-150 cm (mean 21.0 micromol/L) than in those with length </=50 cm (mean 9.2 micromol/L).


CONCLUSIONS
Plasma citrulline concentration is a simple and reliable surrogate for small bowel absorptive capacity and is not influenced by intestinal inflammation.
Papadia
Cinzia
C
Department of Gastroenterology, University College Hospital, London, United Kingdom.
Sherwood
Roy A
RA
Kalantzis
Chrysostomos
C
Wallis
Katharina
K
Volta
Umberto
U
Fiorini
Erica
E
Forbes
Alastair
A
D000284:Administration, Oral; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000418:Albumins / Q000378:metabolism; D015415:Biomarkers / Q000097:blood; D001799:Blood Sedimentation; D002097:C-Reactive Protein / Q000378:metabolism; D002851:Chromatography, High Pressure Liquid; D002956:Citrulline / Q000097:blood*; D004338:Drug Combinations; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015212:Inflammatory Bowel Diseases / Q000097:blood* / Q000601:surgery / Q000652:urine; D007408:Intestinal Absorption / Q000502:physiology*; D007792:Lactulose / Q000008:administration & dosage; D007813:Laparotomy; D007958:Leukocyte Count; D008297:Male; D008875:Middle Aged; D010976:Platelet Count; D011379:Prognosis; D012372:ROC Curve; D012189:Retrospective Studies; D012210:Rhamnose / Q000008:administration & dosage; D012720:Severity of Illness Index; D014994:Xylose / Q000008:administration & dosage
D000418:Albumins; D015415:Biomarkers; D004338:Drug Combinations; D002956:Citrulline; D007792:Lactulose; D002097:C-Reactive Protein; D014994:Xylose; D012210:Rhamnose