Non-invasive detection of low-intestinal lactase activity in children by use of a combined 13CO2/H2 breath test.
BACKGROUND
The aim of the study was to diagnose hypolactasia with a higher accuracy than with the traditional H2 breath test.


METHODS
We used a combined 13C-lactose 13CO2/H2 breath test, which was performed in 33 patients in whom lactase activity was measured.


RESULTS
Lactase activity was reduced in 13 cases. The sensitivity and specificity of the H2 test were 54% and 90%; those of the 13CO2 test 69% and 70%. False-negative results did not always occur in the same patients. In five of six patients with both test results abnormal, lactase activity was low. In 13 of 15 patients with both test results normal, lactase activity was normal. In 6 of 12 cases with only 1 test abnormal, lactase activity was low.


CONCLUSIONS
The combined H2/13CO2 breath test (sensitivity, 85%; specificity, 65%) is more adequate for diagnosis of hypolactasia than the H2 breath test alone.
Beatrix Children's Hospital, University Hospital Groningen, The Netherlands.
H A
HA
Koetse
F
F
Stellaard
C M
CM
Bijleveld
H
H
Elzinga
R
R
Boverhof
R
R
van der Meer
R J
RJ
Vonk
P J
PJ
Sauer
D000293:Adolescent; D000328:Adult; D001944:Breath Tests / Q000379:methods*; D002245:Carbon Dioxide / Q000378:metabolism*; D002247:Carbon Isotopes; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D006859:Hydrogen / Q000378:metabolism*; D007223:Infant; D007421:Intestine, Small / Q000201:enzymology* / Q000378:metabolism*; D043322:Lactase; D008297:Male; D011237:Predictive Value of Tests; D012016:Reference Values; D012680:Sensitivity and Specificity; D001616:beta-Galactosidase / Q000378:metabolism*
D002247:Carbon Isotopes; D002245:Carbon Dioxide; D006859:Hydrogen; D043322:Lactase; D001616:beta-Galactosidase