Necati Balamtekin

Evaluation of lansoprazole as a probe for assessing cytochrome P450 2C19 activity and genotype-phenotype correlation in childhood.

PurposeLansoprazole, a cytochrome P450 2C19 (CYP2C19) substrate, has been widely used in children to manage acid-related diseases. CYP2C19 exhibits marked genetic polymorphisms, and distribution of these polymorphisms varies among different ethnic groups. There is limited data regarding the use of probe drugs for determining CYP2C19 activity in children. The aim of this study was to evaluate lansoprazole as an in vivo phenotyping probe for assessing CYP2C19 activity in children.MethodsThe CYP2C19*2, *3, and *17 variants were determined in 244 children. Three hours after a single oral dose of lansoprazole (n = 94) or omeprazole (n = 19), plasma lansoprazole and 5-hydroxy lansoprazole or omeprazole and 5-hydroxy omeprazole concentrations were analyzed by high-performance liquid chromatography.ResultsThe CYP2C19*17 was the most frequent variant allele (24.4%). The group of patients with CYP2C19*17*17 genotype had a 70% lower (p < 0.05) mean lansoprazole plasma concentration compared with the CYP2C19*1*1 genotype group, whereas the CYP2C19*2*2 group had 6.9-fold higher (p < 0.01) mean lansoprazole plasma concentration. Lansoprazole metabolic ratios (lansoprazole/5-hydroxy-lansoprazole) were found to be significantly lower in the *17*17 [mean ± standard deviation (SD); 2.8 ± 2.1] group and higher in the *2*2 group (63.5 ± 12.2) compared with that of the *1*1 genotype group (6.1 ± 4.5).ConclusionAccording to our results from a Turkish pediatric population, lansoprazole is a suitable probe drug for phenotyping CYP2C19. The CYP2C19*2 and *17 variants should be taken into consideration in predicting the clinical outcome of therapy with lansoprazole in the pediatric population.

Ulcerative colitis associated with Takayasu's arteritis in a child

Takayasus arteritis (TA) and ulcerative colitis (UC) are chronic inflammatory diseases of unknown aetiology, and their coexistence is very rare.

Differences in the prevalence of obesity in children with celiac disease.

o the Editor: We read with great interest the article writtenby Venkatasubramani et al entitled ‘‘Obesity in PediatricCeliac Disease’’ (1). In their retrospective study of 143 childrenwith celiac disease, 5% had a body mass index above the 95thpercentile at the time of diagnosis. As a result they concludethatobesityisnotararefindinginnewlydiagnosedceliacpatients.We previously reported 220 newly diagnosed celiac patients(7.2 4.3 years) in our center between 2000 and 2008 and foundthat only 1 patient (0.45%) hada body mass index above the 95thpercentile (2). It is well known that obesity is an epidemic in theUnited States because of the prevalence of fast-food nutrition (3).Therefore, the differences in the prevalence of obesity in celiacdisease in different cultures may be related to dietary habits andeconomic conditions.Necati Balamtekin, Go¨khan Baysoy, and Hu¨lya DemirHacettepe UniversityEtlik-Ankara, Turkey

A rare cause of carpal tunnel syndrome in childhood: Benign recurrent intrahepatic cholestasis

Carpal tunnel syndrome and benign recurrent intrahepatic cholestasis are rare conditions in childhood. Benign intrahepatic cholestasis is characterized by repeated self-limited attacks of cholestasis that can start at any age and last from weeks to months. The patients are asymptomatic between these attacks. We report a 16 year-old male patient with benign recurrent intrahepatic cholestasis who developed carpal tunnel syndrome during a cholestatic attack. He was admitted with complaints of jaundice, pruritus and pain, tingling and muscle weakness in both hands for 15 days. Nerve conduction studies revealed findings compatible with carpal tunnel syndrome. He was started on ursodeoxycholic acid, fat soluble vitamins and cholestyramine and cholestasis regressed after four weeks of therapy. With the improvement of cholestasis, the symptoms of carpal tunnel syndrome also disappeared. In conclusion, benign recurrent intrahepatic cholestasis can be a rare cause of carpal tunnel syndrome in childhood. We also advocate treating the underlying disease as an appropriate conservative treatment before surgery.