Intestinal malabsorption of D-xylose: comparison of test modalities in patients with celiac disease.
OBJECTIVE
The aim of the study was to compare three different D-xylose test modalities for small intestinal malabsorption, using patients with celiac disease and healthy persons as experimental models.


METHODS
Ninety-one untreated celiac patients, 98 treated celiac patients, and 43 healthy subjects performed the (13)C-D-xylose breath test. 1-h plasma D-xylose levels were measured in 48 untreated patients, 41 treated patients and 41 healthy controls. 4-h urine D-xylose excretion was measured in 47 untreated patients, 51 treated patients and 42 healthy controls. 100 mg of (13)C-D-xylose and 5 g of D-xylose were dissolved in 250 ml tap water and given orally. (13)CO(2) was measured in breath every 30 min for 4 h. Blood was sampled after 1 h, and urine collected after 4 h.


RESULTS
Test sensitivity/specificity for celiac disease was 88%/84% with the (13)C-D-xylose breath test, 65%/71% with the 1-h plasma D-xylose test, and 55%/74% with the 4-h urine D-xylose excretion test. Breath test results improved significantly in the treated celiac group compared to untreated patients, but were not normalized compared to healthy controls. No difference was found between 1-h plasma D-xylose levels and 4-h urinary D-xylose excretion in treated celiac patients and healthy controls.


CONCLUSIONS
The (13)C-D-xylose breath test was superior to D-xylose testing in plasma and urine for assessment of small intestinal malabsorption with considerably higher sensitivity and specificity for untreated celiac disease.
Tveito
Kari
K
Department of Medicine, Lovisenberg Diakonale Hospital, Oslo, Norway. kari.tveito@akersykehus.no
Brunborg
Cathrine
C
Bratlie
Jorunn
J
Askedal
Mia
M
Sandvik
Leiv
L
Lundin
Knut E A
KE
Skar
Viggo
V
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001944:Breath Tests / Q000379:methods; D002245:Carbon Dioxide / Q000032:analysis; D002247:Carbon Isotopes; D002446:Celiac Disease / Q000175:diagnosis / Q000378:metabolism*; D002851:Chromatography, High Pressure Liquid; D003937:Diagnosis, Differential; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007408:Intestinal Absorption / Q000502:physiology*; D007421:Intestine, Small / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D012372:ROC Curve; D012189:Retrospective Studies; D014994:Xylose / Q000378:metabolism*; D055815:Young Adult
D002247:Carbon Isotopes; D002245:Carbon Dioxide; D014994:Xylose