[Show abstract][Hide abstract] ABSTRACT: BACKGROUND: Histamine intolerance (HIT) is characterized by an imbalance between histamine intake and the capacity for histamine degradation. The main enzyme for metabolizing ingested histamine is diamine oxidase (DAO). Determining DAO activity in serum may be useful in diagnosing HIT. METHODS: Over a period of 3.5 years we recruited 316 subjects with clinically suspected HIT and 55 healthy controls. Serum DAO activity was measured with a quantitative enzyme immunoassay. Twenty patients with highly reduced DAO activity went on a histamine-free diet for 6-12 months. Afterwards, their DAO activity was determined again. RESULTS: We found that DAO activity was significantly lower in patients than in healthy control subjects (P < 0.0001). Furthermore, 54 patients had highly reduced serum DAO activity (< 40 HDU/ml). Their main symptoms involved the skin, gastrointestinal tract, respiratory system, and eyes. In all the 20 patients with highly reduced DAO activity, the main clinical symptoms typical of histamine intolerance disappeared after they adopted a histamine-free diet. Furthermore, the serum DAO activity values measured increased significantly (P < 0.0001). CONCLUSIONS: Our results suggest that determining DAO activity in serum is a useful tool in diagnosing HIT. Furthermore, our results showed the benefit of a histamine-free diet because after the diet the majority of symptoms disappeared and the serum DAO activity significantly increased.
Wiener klinische Wochenschrift 04/2013; · 0.81 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Diagnosis of allergy to Hymenoptera venom is usually confirmed with skin testing and measurement of specific serum IgE antibody, tests which are sometimes inconclusive. In these cases, additional in vitro tests are necessary. The aim of this study was to show the applicability of the basophil activation test in detecting sensitization to Hymenoptera venom and to compare the test sensitivity and clinical positive-predictive value with skin prick tests and measurement of allergen-specific serum IgE.
This prospective study was conducted between June 2004 and December 2007 and included a large group of 204 patients. All patients had a history of at least one systemic allergic reaction of Müller grades II-IV after a Hymenoptera sting. We compared results of the basophil activation test, specific serum IgE and skin prick tests with patients' clinical history and data on culprit insects.
The overall clinical sensitivities of the basophil activation test, specific serum IgE and skin prick tests were 90%, 76% and 64%, respectively; the clinical positive-predictive values of the three tests were 79%, 73% and 78% for bee venom, 86%, 59% and 43% for wasp venom; and 84%, 77% and 22% for both venoms.
Our results revealed a higher clinical sensitivity and comparable or better clinical positive-predictive value of basophil activation tests than skin prick tests and allergen-specific serum IgE in the detection of allergy to Hymenoptera venom.
Wiener klinische Wochenschrift 02/2009; 121(9-10):344-8. · 0.81 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Complement component 5a (C5a) might be involved in the formation of wheals in patients with chronic urticaria (CU). We sought to compare the in vitro responsiveness of basophils to C5a in patients with CU and in a control group.
Basophil surface expression of activation marker CD63 induced by C5a, anti-FcepsilonRI mAb or anti-IgE pAb was measured using flow cytometry in 17 patients with CU and in 10 healthy controls.
Patients with CU showed significantly greater basophil CD63 surface expression induced by C5a (median [interquartile range]; 16.4% [13-25.1]; P = 0.011) than the group of healthy controls (10.7% [7.2-16.8]). In contrast, basophil CD63 response to anti-IgE and anti-FcepsilonRI was lower in the CU group (12.3% [6-36.3]; 25.9% [12.5-60.5]) than in the control group (51.7% [6.7-84.3]; 62.1% [9.7-89.2]), although not statistically significant.
Results of this pilot study suggest that patients with CU might have an enhanced basophil response to stimulation with C5a, indicating that further studies in CU basophil responsiveness are needed.
Wiener klinische Wochenschrift 02/2009; 121(9-10):339-43. · 0.81 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Although immunotherapy is effective in allergic rhinitis, conjunctivitis, asthma and stinging insect hypersensitivity, it carries a risk of anaphylactic reactions.
In a 4-year retrospective survey, we investigated 1257 adult patients who had received venom or inhaled-allergen subcutaneous immunotherapy. The dose-increase phase was performed as the 2-day rush protocol for venom immunotherapy and the 6-week protocol for inhaled-allergen immunotherapy.
A total of 904 patients received venom immunotherapy and 353 patients inhaled-allergen immunotherapy. The prevalence of systemic reactions was 13.6%. The frequency of systemic reactions was higher during the maintenance phase than in the dose-increase phase (9.6% vs. 5.9%) and was highest in both phases of treatment with honeybee venom (P < 0.001). The majority of systemic reactions were mild. Five (0.4%) patients had reaction with a fall of blood pressure and were treated with adrenaline. There was no fatal outcome. The systemic side-effects during the dose-increase phase of venom immunotherapy occurred at a median dose of 46 microg (range 2-100 microg). Large local reactions occurred in 13.9% of patients without any significant difference between the allergens.
We have shown that systemic reactions are not rare even during maintenance phase in patients with a well tolerated dose-increase phase of treatment. The most prominent risk factor for systemic reactions was immunotherapy with honeybee extract.
Wiener klinische Wochenschrift 02/2009; 121(9-10):357-60. · 0.81 Impact Factor