Background: Increased numbers of mast cells and mast cell activation in distal gut segments are associated with symptom onset and severity in irritable bowel syndrome (IBS). Although upper gut symptoms are common, mast cells have not been thoroughly evaluated in proximal gut in IBS patients.

The jejunal mucosa of IBS-D patients displays disrupted apical junctional complex integrity associated with mast cell activation and clinical manifestations. These results provide evidence for the organic nature of IBS-D, a heretofore model disease of functional gastrointestinal disorders.

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In patients with hereditary angioedema, the prophylactic use of a subcutaneous C1 inhibitor twice weekly significantly reduced the frequency of acute attacks. (Funded by CSL Behring; COMPACT EudraCT number, 2013-000916-10 , and ClinicalTrials.gov number, NCT01912456 .).

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Background: The diagnosis of anaphylaxis is based on clinical history since no reliable biological marker is currently available to confirm the diagnosis. Objective: It was the aim of this study to determine sequential serum tryptase concentrations during anaphylaxis and to evaluate its potential as a diagnostic marker. Methods: We performed a prospective study including patients with acute anaphylaxis (according to the National Institute of Allergy and Infectious Disease/Food Allergy and Anaphylaxis Network criteria) attending the emergency department. Demographic characteristics, anaphylactic triggers, specific risk factors, clinical characteristics and management of anaphylaxis were recorded. Serum tryptase was measured at 1–2 h (T1), 4–6 h (T2) and 12–24 h (T3) following onset of the episode and at basal conditions (TB). Results: A total of 102 patients were included (63 females, mean age 47.4 ± 19.1 years). Tryptase concentration at T1 (19.3 ± 15.4 µg/l) was significantly higher than at T2, T3 and TB (all <11.4 µg/l; p < 0.0001). Importantly, tryptase was not raised in 36.3% of cases; furthermore, in 60.6% of these patients, no changes were observed in tryptase levels comparing T1 and TB (ΔT1–TB = 0). Tryptase was more frequently elevated in more severe anaphylaxis (p < 0.0001) and positively correlated with the grades of severity (p < 0.001, r = 0.49). Anaphylaxis was more severe and tryptase concentration higher when the causative agent was a drug compared to food, both at T1 (p = 0.045) and at TB (p = 0.019). Age and coronary risk factors were associated with more severe anaphylaxis (p = 0.001). Conclusion: Tryptase is a biomarker related to the severity of anaphylaxis. However, since its concentration remains unaltered in a considerable number of patients during acute anaphylaxis, there is a need for more reliable diagnostic biological tests.

Co-factor enhanced food allergy should be considered when assessing food, alcohol, exercise and NSAID allergic reactions.

Background and Objective: There is little information on pregnancy and delivery in patients with hereditary angioedema due to C1 inhibitor deficiency (C1INH-HAE). The aim of this study was to describe the effect of pregnancy and deliveries on symptoms of C1INH-HAE and review the need for and safety of treatments available during the study period. Methods: Retrospective review using a purpose-designed questionnaire of 61 C1INH-HAE patients from 5 hospitals specialized in the management of HAE in Spain. The outcomes measured were number of pregnancies, changes in symptoms during pregnancy and delivery, mode of delivery, type of anesthesia during delivery, treatments received, and tolerance of treatments. Results: We reviewed 125 full-term pregnancies (89 without a prior diagnosis of C1INH-HAE), 14 miscarriages, and 4 induced abortions. Patients reported an increased frequency of C1INH-HAE symptoms in 59.2% of pregnancies (74/125) and the presence of symptoms throughout pregnancy in 40% (50/125). Prophylactic C1INH-HAE therapy was used during 9 (7.2%) of the 125 pregnancies. Nine patients-in 11 pregnancies (8.8 %)-received treatment for acute attacks. Most deliveries (n=110, 88%) were vaginal. A cesarean section was necessary in 15 cases (12%). Short-term prophylaxis with pdhC1INH was administered before 14 deliveries (11.2 %); 111 deliveries (88.8 %) were performed without premedication and were well tolerated. Anesthesia was used in 51 deliveries (40.8%). Conclusions: Pregnancy has a variable influence on the clinical expression of C1INH-HAE. Attacks tend to occur more frequently but not to increase in severity. Vaginal delivery was mostly well tolerated. pdhC1INH prophylaxis should be administered prior to cesarean delivery and is also recommended before vaginal delivery if there are additional risk factors. pdhC1INH should always be available in the delivery room.