Mutations in RPSA and NKX2-3 link development of the spleen and intestinal vasculature.

Idiopathic intestinal varicosis is a developmental disorder defined by dilated and convoluted submucosal veins in the colon or small bowel. A limited number of families with idiopathic intestinal varices has been reported, but the genetic cause has not yet been identified. We performed whole-exome and targeted Sanger sequencing of candidate genes in five intestinal varicosis families. In four families, mutations in the RPSA gene were found, a gene previously linked to congenital asplenia. Individuals in these pedigrees had intestinal varicose veins and angiodysplasia, often in combination with asplenia. In a further four-generation pedigree that only showed intestinal varicosities, the RPSA gene was normal. Instead, a nonsense mutation in the homeobox gene NKX2-3 was detected which cosegregated with the disease in this large family with a LOD (logarithm of the odds) score of 3.3. NKX2-3 is a component of a molecular pathway underlying spleen and gut vasculature development in mice. Our results provide a molecular basis for familial idiopathic intestinal varices. We provide evidence for a relationship between the molecular pathways underlying the development of the spleen and intestinal mucosal vasculature that is conserved between humans and mice. We propose that clinical management of intestinal varices, should include assessment of a functional spleen.

Exhaled breath condensate nitrite--methodological problems of sample collection.

BACKGROUND: Exhaled breath condensate (EBC) analysis is a promising new method to monitor airway inflammation, however there are still multiple open methodological questions. The purpose of this study was therefore to investigate methodological influences on nitrite in EBC (surface contamination, flow dependency, storage time and inter- and within day variability). MATERIAL/METHODS: EBC samples of 10 healthy children, 10 healthy adults and 71 asthmatic children were collected and nitrite was analysed using the Griess reaction. Collector devices where either air-dried after disinfection or stored in distilled water till usage. Repeatability measurements were performed at three different times during one day and on five consecutive days. Flow dependency was analysed at 200 and 400 ml/s expiratory flow and storage stability was investigated at several time points within the first three hours after collection of the sample. In a preliminary study EBC nitrite was analysed in asthmatic children of different severity. RESULTS: Surface contamination appears to have a profound influence on nitrite levels and both within-day and inter-day variability is high. We found no flow dependency, and storage stability was satisfying although with considerable variety in several samples. There were no significant differences between the nitrite levels of the different asthmatic subgroups nor between the asthmatic children and the controls. CONCLUSIONS: These data indicate that EBC nitrite is a substance with a wide variety of influencing factors and different sources of origin. This has to be kept in mind when using exhaled nitrite as a biomarker for airway inflammation.

Exhaled breath condensate pH in infants and children with acute and recurrent wheezy bronchitis.

The analysis of exhaled breath condensate (EBC) is a promising new method to measure airway inflammation. So far only limited data exist about methodological issues of EBC sampling in infants and young children. We evaluated 18 children with acute wheezy bronchitis (median age 24.3 months (min-max: 4-89.9)), 54 children with recurrent wheezy bronchitis (median age 52.5 months (7.2-94.8)), and 32 healthy controls (median age 49.6 months (25.3-67.8)). EBC was sampled with a modified commercially available EBC-sampler, pH was measured after deaeration. EBC volume was significantly correlated to age (r = 0.56, P < 0.001). EBC pH was significantly decreased in all patients compared to the healthy controls (acute wheezy bronchitis 7.87 (7.16-8.19), P = 0.003, recurrent wheezy bronchitis 7.86 (6.95-8.39), P = 0.002, and healthy controls 8.04 (7.81-8.87), respectively). There were no significant differences of the EBC pH between the disease groups. When divided into different subgroups, an influence of inhaled steroid treatment was found with steroid-naive recurrent wheezers having significantly lower EBC pH levels compared to healthy controls (7.80 (6.95-8.37), P = 0.018), but not so steroid treated (7.94 (7.24-8.39), P = 0.055). Both, recurrent wheezers with or without a positive allergy test had significantly lower EBC pH compared to healthy controls (7.91 (6.95-8.37), P = 0.007 and 7.82 (7.32-8.39), P = 0.005, respectively). This study indicates that EBC can be collected with a modified commercially available EBC sampler in infants and young children. Further studies need to be performed to evaluate the relevance and meaning of pH differences of EBC in this age group.

Intestinal microvascular malformations and congenital asplenia in an adolescent possibly expanding the phenotype of Ivemark syndrome.

Intestinal vascular malformations in children and adolescents are rare but must be considered in the differential diagnosis of gastrointestinal bleeding and chronic anemia. We report a 16-year-old girl who developed chronic iron-deficiency anemia due to recurrent bleeding from multiple angiodysplastic lesions of the stomach, duodenum, and jejunum. The cause of blood loss remained unclear for several years while the girl received numerous blood transfusions. Diagnosis was finally established by capsule endoscopy and double-balloon enteroscopy. Treatment was effectively carried out by argon plasma coagulation. Many systemic vascular malformation syndromes are associated with gastrointestinal lesions. However, as no extraintestinal vascular lesions were present in our patient, diagnosis of a known vascular malformation syndrome seemed unlikely. In addition to the microvascular intestinal malformations, we found a familial congenital asplenia without apparent infectious complications. Thus, the reported case possibly constitutes a so far unpublished variant of the Ivemark syndrome without macrovascular malformations but instead with microvascular malformations. We therefore envison that in times of refined diagnostic techniques the phenotype of the Ivemark syndrome might be expanded by including microvascular malformations.