Characteristics of Pediatric Crohn's Disease in Saudi Children: A Multicenter National Study.

Background and Aims. Crohn's disease (CD) is an evolving disease in KSA. Little is known about its characteristics in the Saudi population. The aims of this study were to describe the characteristics of Saudi children with CD and to determine whether the characteristics of CD in KSA are different from those seen in Western countries. Methods. In this study, children younger than eighteen years of age diagnosed with CD between January 2003 and December 2012 were included. Results. Of 330 patients identified, 186 (56.4%) were males. The median age at diagnosis was 15.8 years. A positive family history for IBD in first-degree relatives occurred in 13.6% of patients. The most common symptoms were abdominal pain (84.2%), weight loss (75.2%), and diarrhea (71.8%). The main disease location was ileocolonic (42.1%) and the main disease behavior was nonstricturing and nonpenetrating (63.6%). Perianal involvement was seen in 60 (18.2%) patients. Laboratory findings revealed anemia in 57.9% of patients, low albumin in 34.5%, and high CRP in 39.4%. Conclusions. Saudi children with CD have lower frequency of first-degree relatives with IBD, lower prevalence of early onset disease, longer diagnostic delay, higher prevalence of growth failure, and greater frequency of stricturing and penetrating disease behavior compared to Western patients.

Incidence of pediatric inflammatory bowel disease in Saudi Arabia: a multicenter national study.

BACKGROUND: Pediatric inflammatory bowel disease (IBD) is increasingly recognized in developing countries; however, the incidence and trend over time have not been reported. METHODS: This retrospective study included children diagnosed with IBD in gastroenterology centers in the Kingdom of Saudi Arabia between 2003 and 2012. The date of birth, date and age at diagnosis, gender, and final diagnosis were collected on special forms. Clinical, laboratory, imaging, endoscopy, and histopathology results were reviewed to confirm the final diagnosis. Descriptive statistics were used to compare ulcerative colitis and Crohn's disease in different age groups, and significance was assessed by the chi-square test. Incidence rates and trend over time were analyzed with the assumption of Poisson distribution. The incidence rate over time was compared in 2 periods (2003-2007 and 2008-2012). A P value of <0.05 and 95% confidence intervals were used to assess the significance and precision of the estimates. RESULTS: A total of 340 Saudi Arabian children aged 0 to 14 years were diagnosed. The mean incidence rate per 100,000 individuals was 0.2, 0.27, and 0.47 for ulcerative colitis, Crohn's disease, and IBD, respectively. Except for the 0- to 4-year age group, there was a significant increase in incidence over time. CONCLUSIONS: Although the incidence of pediatric IBD in Saudi Arabian children is lower than suggested in the Western literature, there is a significantly increasing trend over time. However, decreased trend in the younger age group over time is identified. Prospective studies will be important to identify the risk factors for IBD in different age groups.

Complete OATP1B1 and OATP1B3 deficiency causes human Rotor syndrome by interrupting conjugated bilirubin reuptake into the liver.

Bilirubin, a breakdown product of heme, is normally glucuronidated and excreted by the liver into bile. Failure of this system can lead to a buildup of conjugated bilirubin in the blood, resulting in jaundice. The mechanistic basis of bilirubin excretion and hyperbilirubinemia syndromes is largely understood, but that of Rotor syndrome, an autosomal recessive disorder characterized by conjugated hyperbilirubinemia, coproporphyrinuria, and near-absent hepatic uptake of anionic diagnostics, has remained enigmatic. Here, we analyzed 8 Rotor-syndrome families and found that Rotor syndrome was linked to mutations predicted to cause complete and simultaneous deficiencies of the organic anion transporting polypeptides OATP1B1 and OATP1B3. These important detoxification-limiting proteins mediate uptake and clearance of countless drugs and drug conjugates across the sinusoidal hepatocyte membrane. OATP1B1 polymorphisms have previously been linked to drug hypersensitivities. Using mice deficient in Oatp1a/1b and in the multispecific sinusoidal export pump Abcc3, we found that Abcc3 secretes bilirubin conjugates into the blood, while Oatp1a/1b transporters mediate their hepatic reuptake. Transgenic expression of human OATP1B1 or OATP1B3 restored the function of this detoxification-enhancing liver-blood shuttle in Oatp1a/1b-deficient mice. Within liver lobules, this shuttle may allow flexible transfer of bilirubin conjugates (and probably also drug conjugates) formed in upstream hepatocytes to downstream hepatocytes, thereby preventing local saturation of further detoxification processes and hepatocyte toxic injury. Thus, disruption of hepatic reuptake of bilirubin glucuronide due to coexisting OATP1B1 and OATP1B3 deficiencies explains Rotor-type hyperbilirubinemia. Moreover, OATP1B1 and OATP1B3 null mutations may confer substantial drug toxicity risks.