Diagnosis of histamine intolerance (HIT) has been based on low serum diamine oxidase (DAO) values, functional gastrointestinal disorders and improvement of symptoms with a histamine-reduced diet (HRD). In a retrospective analysis of outpatients’ charts we identified 101 patients with HIT. After a median of 13 months, a questionnaire was distributed to the patients so that they could be classified into four diet-compliance groups. Calculated with all 101 patients we found an increase of serum DAO values due to a HRD. In the 63 patients that completed the questionnaire, we found that 50 patients had improvement of symptoms or no continuing symptoms. A significant increase of serum DAO levels was found in the patients with strict and occasional diet compliance. Therefore, we demonstrate that a HRD is not only improving symptoms in HIT, but is causing an increase in serum DAO values that correlates with the degree of diet compliance.

BACKGROUND:

Histamine intolerance is thought to trigger manifold clinical symptoms after ingesting histamine-rich food due to reduced activity of diamine oxidase (DAO). No study has hitherto systematically assessed daily fluctuations of histamine levels and DAO activities in symptomatic patients. The aim of the study was to investigate the presence of histamine intolerance, to therefore establish day profiles of histamine levels and DAO activities, and to compare the results between patients with suspected histamine intolerance, food allergy and healthy controls.

METHODS:

We determined day profiles of histamine plasma levels and DAO serum activities in 33 patients with suspected histamine intolerance, in 21 patients with proven food allergy and in 10 healthy control patients. Clinical symptoms, food intolerances and further clinical and laboratory chemical parameters were evaluated.

RESULTS:

Twenty-four percent (8 of 33) suspected histamine-intolerant patients showed elevated histamine levels during the day. That might be caused by constantly and significantly reduced DAO activities in these patients compared to food-allergic and control patients. The remaining 25 patients presented normal histamine levels and DAO activities, but an increased prevalence of multiple food intolerances compared to the other subgroup of suspected histamine-intolerants. There was no correlation between subjective complaints and serological histamine parameters in patients with suspected histamine intolerance.

CONCLUSIONS:

We determined by daily profiling that decreased DAO activities correlated with elevated histamine levels in a subgroup of suspected histamine-intolerants. This finding discriminates these patients from food intolerant individuals with similar clinical symptoms and strongly suggests the presence of histamine intolerance.

© 2017 EAACI and John Wiley and Sons A/S. Published by John Wiley and Sons Ltd.

Human extravillous trophoblast (EVT) invasion of the pregnant uterus constitutes a pivotal event for the establishment of the maternal-fetal interface. Compromised EVT function manifesting in inadequate arterial remodeling is associated with the severe pregnancy disorder early-onset preeclampsia (eoPE).

Recent studies suggest that EVTs invade the entire uterine vasculature including arteries, veins and lymphatics in the first trimester of pregnancy. We therefore hypothesized that EVT-derived factors accumulate in the circulation of pregnant women early in gestation and may serve to predict eoPE.

In contrast to published literature, we demonstrate that placenta-associated diamine oxidase(DAO) is not expressed by maternal decidual cells but solely by EVTs, especially when in close proximity to decidual vessels.

Cultures of primary EVTs express and secret large amounts of bioactive DAO.

ELISA measurements indicate a pregnancy-specific rise in maternal DAO plasma levels around gestational week (GW) 7 coinciding with vascular invasion of EVTs.

Strikingly, DAO levels from eoPE cases were significantly lower (40%) compared to controls in the first trimester of pregnancy but revealed no difference at mid gestation. Furthermore, DAO-containing pregnancy plasma rapidly inactivates pathophysiologically relevant histamine levels.

This study represents the first proof of concept suggesting EVT-specific signatures as diagnostic targets for the prediction of eoPE.

Tyramine and histamine are the main dietary bioactive amines related to acute adverse health effects. Dry fermented sausages can easily accumulate high levels of these hazards and are frequently consumed in Spain. The present work aims to assess the exposure to tyramine and histamine from the consumption of dry fermented sausages by the Spanish population and to assess the risk to suffer acute health effects from this exposure. A probabilistic estimation of the exposure to these hazards was derived combining probability distributions of these amines in dry fermented sausages (n = 474) and their consumption by the Spanish population. The mean dietary exposure to tyramine and histamine was 6.2 and 1.39 mg/meal, respectively. The risk of suffering hypertensive crisis or histamine intoxication by healthy population due to tyramine or histamine intake, respectively, exclusively from dry fermented sausages, can be considered negligible. For individuals under treatment with MAOI drugs, the probability to surpass the safe threshold dose (6 mg/meal) was estimated as 34%. For patients with histamine intolerance, even the presence of this amine in food is not tolerable and it could be estimated that 7000 individuals per million could be at risk to suffer the related symptoms after consuming dry fermented sausages.

The treatment and prevention of migraine within the last decade has become largely pharmacological. While there is little doubt that the advent of drugs (e.g. triptans) has helped many migraine sufferers to lead a normal life, there is still little knowledge with respect to the factors responsible for precipitating a migraine attack. Evidence from biochemical and behavioural studies from a number of disciplines is integrated to put forward the proposal that migraine is part of a cascade of events, which together act to protect the organism when confronted by a metabolic challenge.

The aim of this retrospective study was to analyze the concomitant prevalence rates for lactose malabsorption (LM), fructose malabsorption (FM), and histamine intolerance (HI) in patients with so far unexplained gastrointestinal (GI) symptoms. A total of 439 outpatients, who presented unclear abdominal discomfort, underwent lactose (50 g) and fructose (25 g) hydrogen (H₂) breath tests. Additionally, serum diamine oxidase (DAO) measurements were performed. Individuals with low serum DAO activity (<10 U/mL), GI symptoms, and response to histamine-free diet were diagnosed with HI. Of all 439 patients, 341 (77.7%) were found with 7 various GI conditions. In total, 94 (21.4%), 31 (7.1%), and 100 (22.8%) individuals presented LM, FM, or HI only, whereas 116 (26.4%) patients showed an overlap of GI entities investigated here. Interestingly, 89 out of 241 (36.9%) individuals with carbohydrate malabsorption were also diagnosed with HI (LM + HI: 52 [11.8%], FM + HI: 23 [5.2%], and LM + FM + HI 14 [3.2%] individuals). In conclusion different combinations of LM, FM, and HI are present in individuals with unclear abdominal discomfort/pain. In clinical practice we suggest testing for LM, FM, and additional HI in the diagnostic work-up of these patients. Depending on these various diagnoses possible, patients should get an individualized dietary advice.

BACKGROUND:

Present in several types of food, bioactive amines are described as organic bases of low molecular weight, which constitute a potential health risk. An awareness of amine levels in foods today is therefore important in relation to food safety and patient care. This review aims to emphasise the need to unify the information on the content of biogenic amines in foods and prevent patients’ misunderstanding.

METHODS:

Selective literature search for relevant publications in PubMed and other scientific data bases combined with further data from the World Wide Web on histamine and other amines content in foods.

RESULTS:

Available reference sources do not reflect a homogeneous consensus, and the variation between foods makes it impossible for dieticians to accurately estimate amines content to correctly advise patients.

CONCLUSIONS:

To achieve the goal of collecting reliable information, all methods and tools used in analytical studies should be standardised and information exposed to patients should be verified.

Copyright © 2016 SEICAP. Published by Elsevier España, S.L.U. All rights reserved.