In a prospective study of infants born to mothers who received anti-TNF agents during pregnancy, we detected the drugs until 12 months of age. There was an inverse correlation between the time from last exposure during pregnancy and drug concentration in the umbilical cord. Infliximab was cleared more slowly than adalimumab from the infants. The combination of an anti-TNF agent and thiopurine therapy during pregnancy increased the relative risk for infant infections almost 3-fold compared with anti-TNF monotherapy. Live vaccines therefore should be avoided for up to 1 year unless drug clearance is documented, and pregnant women should be educated on the risks of anti-TNF use.

NCT00851565.

SUMMARY BackgroundVitamin D has immune-regulatory functions in experimental colitis, and low vitamin D levels are present in Crohn's disease.

The pH of the gut lumen was measured in 39 healthy persons using a pH-sensitive, radiotransmitting capsule. Thirteen persons were studied twice. The location of the capsule was determined by X-ray. The pH rose from 6.4 in the duodenum to 7.3 in the distal part of the small intestine. In 17 persons the pH dropped by 0.1-0.8 pH units during the last hours of the small intestinal transit. The pH was 5.7 in the caecum, but rose to 6.6 in the rectum. Gastric residence time was 1.1 h, small intestinal transit was 8 h, and colonic transit time was 17.5 h (median values). The results provide a firmer basis for prediction of the level, and the rate of release of active substance from pH-dependent sustainedrelease oral preparations. I N T R O D U C T I O NThe biological availability of a tablet is influenced by a variety of factors including regional intestinal pH and regional intestinal transit times. These factors are of particular importance for the effect of some newly developed sustained-release 5-aminosalicylic acid preparations designed for the treatment of chronic inflam-Correspondence to :

Intraluminal gastrointestinal pH was measured in seven patients with active ulcerative colitis (four male, three female). A radiotelemetry capsule was used, and its location was determined by fluoroscopy. Satisfactory measurements were obtained from six, in all of whom pH levels were normal in the stomach and small intestine. Three patients also had normal pH values in the colon. However, in the remaining three patients very low pH levels (lowest values 2.3, 2.9, and 3.4) were found in the proximal parts of the colon. Five of the seven patients, including the three with low pH in the colon, underwent colectomy. The mechanism behind the low intraluminal pH in some patients with ulcerative colitis is speculative. Increased fecal concentrations of lactate occur in active disease, but some of the pH values measured in our study were below the pKa value of lactate. The study demonstrates that very low intraluminal pH levels in the colon occur in some patients with active ulcerative colitis. This might be an indicator of severe activity of the disease.