Study of Liver Function in Infants with Atopic Dermatitis Using the ¹³C-Methacetin Breath Test

Abstract

Serum glutamic-oxaloacetic transaminase (GOT) levels were determined in 214 infants (133 males and 81 females) with atopic dermatitis during their first visit to the Department of Allergy, National Children’s Hospital, Tokyo, Japan. Compared with the normal hospital range, their levels were found to be significantly higher, a tendancy which was more conspicuous in lower age groups. We carried out a ¹³C-methacetin breath test (MBT), administering the stable-isotope-labeled compound to 11 children with higher serum GOT values and 5 within the normal range to investigate hepatic metablism of methacetin in infants with atopic dermatitis. ¹³C-methacetin was given orally, and the ¹³CO₂ level in the breath was determined immediately before and after administration, by mass spectrometry. Compared to the normal controls, the atopic infants demonstrated significantly lower ¹³CO₂ peak excretion and delayed peak time. The clearance rate of ¹³CO₂was also decreased. These results suggest some relationship between atopic dermatitis and liver function in infants.

13C-methacetin breath test reproducibility study reveals persistent CYP1A2 stimulation on repeat examinations

“…While designing the study protocol we decided to adopt the currently accepted mode of administration of 13 C-methacetin, namely a fixed oral dose of 75 mg [5,6,8,13,15,20,37,38] . It should be noted, however, that formerly other body mass adjusted dosage regimens were applied, encompassing 5 mg/kg in the pioneer work by Krumbiegel et al [39] , then 2 mg/kg [7,11,12,40] , as well as 1 mg/ kg [10,41] , and finally Iikura et al [42] applied in infants 0.5 mg/kg 13 C-methacetin. Taking into account the investigative nature of our research, we generously took as many as 19 samples of breath air throughout 3 h. This approach appears to be precedential in nature, because for routine clinical use just a few measurement points are usually considered [15,42] .…”

“…It should be noted, however, that formerly other body mass adjusted dosage regimens were applied, encompassing 5 mg/kg in the pioneer work by Krumbiegel et al [39] , then 2 mg/kg [7,11,12,40] , as well as 1 mg/ kg [10,41] , and finally Iikura et al [42] applied in infants 0.5 mg/kg 13 C-methacetin. Taking into account the investigative nature of our research, we generously took as many as 19 samples of breath air throughout 3 h. This approach appears to be precedential in nature, because for routine clinical use just a few measurement points are usually considered [15,42] . Nine samples were collected in the study by Zipprich et al [13] (at 10, 20, 30, 40, 50, 60, 80, 100 and 120 min after application of the substrate), and twelve samples of the expiratory air-every 15 min for 3 h of observation -were taken by Ciccocioppo et al [41] .…”

Que peut apporter l'analyse isotopique en flux continu à la recherche et aux utilisations biomédicales ?

“…La mesure de l'enrichissement en 13 C et de la production de 13 CO 2 lors du stress oxydatif, par dilution isotopique inverse du CO 2 produit à partir des différents isotopomères du 13 C glucose métabolisé par 5.10 5 cellules stimulées par du PMA, a permis de montrer la prépondé-rance du shunt des hexoses monophosphates, le recyclage du glucose et l'absence de glycolyse lors de l'activation des polynucléaires neutrophiles. Les avantages de la CF-IRMS sont évidents si l'on compare aux premiers travaux qui utilisaient les traceurs au 14 C. Le nombre de cellules utilisées avec le marquage au 13 C et l'IRMS est 100 fois inférieur à celui nécessaire lors des études conduites avec le 14 C. De plus, le marquage spécifique sur les sites 1,2 et 6 apporte des renseignements capitaux quant aux voies métaboliques utilisées. Il est de plus possible par la méthode de dilution isotopique inverse de calculer le volume de CO 2 généré par les cellules lors de leur activation.…”

“…Au contraire, l'utilisation de substrats spécifiques marqués avec un isotope du carbone conduit à la production de CO 2 marqué, et permet d'obtenir une spécificité et une sensibilité excellente. Les premières applications ont fait appel au 14 C, mais l'emploi du 13 C parait particulièrement intéres-sant.…”

The Expression of IL–4, IL–6 and TNF–α in the Liver of Food–Sensitized Mice after Oral Challenge

“…An association of food allergy and increased levels of serum transaminases was found in the patients with food–induced atopic dermatitis, and then the serum transaminase levels returned to the normal levels after food elimination treatment [1]. However, the cause of the liver damage in patients with food allergy is still unclear.…”