Histamine intolerance (HIT) is a common adverse reaction to food where elimination and reintroduction of histamine-rich food is part of the investigation. Analysis of the enzyme diamine oxidase (DAO) is sometimes used as an additional tool for diagnosis. This study aimed to describe the distribution of DAO in a large representative cohort of adults and to determine the association between DAO activity and possible associated factors. The study is based on the population-based West Sweden Asthma Study and includes 1051 subjects. Subjects underwent structured interviews including questions on demography, asthma, allergy symptoms, and lifestyle factors. Subjects were assessed for specific-IgE-antibodies and measurement of DAO activity in serum. Previously suggested cut-off levels for low values (10 U/mL), and median levels of DAO were used. In the group of 1051 subjects, only a few presented reactions upon histamine intake, whereas 44% presented DAO levels below the suggested normal cut-off levels. BMI and age were shown to have an impact on DAO activity among women with increasing activity of DAO with increasing BMI and age. Among men, only increasing age was seen to have an impact on DAO levels. There was no difference in DAO levels with different sensitization status to common foods or airborne allergens. No association between DAO levels and reported symptoms to histamine-rich foods could be found. In conclusion, the determination of the DAO enzyme needs to be re-evaluated and may not be used as a valuable tool for histamine intolerance using current cut-off values. Further studies are needed to improve the use of DAO as a biomarker for histamine intolerance.

Allergic rhinitis is characterized by a chronic inflammation of nasal mucosa and represents a risk factor for asthma occurrence. H1 antihistamines reduce the symptoms of rhinitis, but some compounds may have anti-inflammatory properties. We evaluated the plasma level of some cytokines in patients with persistent allergic rhinitis (PAR) and their evolution after a 4-week treatment with H1 anti-histamines, as well as the risk of asthma after 1.5 years. Randomized clinical trial. Eighty-five patients with PAR and 30 healthy volunteers were included in the study. The patients with PAR were randomly divided into 2 groups: 41 patients treated with 5 mg/day desloratadine and 44 patients under 5 mg/day levocetirizine for 4 weeks. The clinical and biological evaluations were performed before and after treatment and included rhinitis symptoms and total symptoms score, type of sensitization, and plasmatic levels of total IgE, IL-1β, IL-6, IL-8 and TNF-α. IL-8 and TNF-α were significantly increased in patients with PAR compared to healthy volunteers (5.85 vs 3.12, p<0.001 and 2.32 vs 1.06, p<0.001, respectively). Both H1 antihistamines reduce all symptoms of allergic rhinitis, including nasal congestion and the plasmatic level of IL-1β, IL-6, IL-8 and TNF-α, after 4 weeks of treatment. The reduction of cytokine levels was not influenced by patients' age, sex, duration or severity of rhinitis, or type of sensitization. Levocetirizine has a superior effect compared to desloratadine in reducing the rhinitis symptoms and cytokines' level. Twenty eight (32.9%) of the patients presented asthma symptoms after 1.5 years. The occurrence of asthma was influenced by house dust sensitization (OR-14.6; CI 95% 1.8-116.3; p=0.01), but baseline values of cytokines were not predictive factors for its appearance. Levocetirizine and desloratadine as a prolonged therapy reduce plasmatic levels of some pro-inflammatory cytokines in patients with PAR. Levocetirizine has a better effect on decreasing the symptoms and plasmatic levels of IL-1β and IL-8. (ClinicalTrials. gov Identifier: NCT02507635). POSDRU and University of Medicine and Pharmacy, Iuliu Haţieganu, Cluj Napoca.

Background and Objectives: The evolution of allergic rhinitis to asthma is a part of “atopic march”. The aim of this study was to analyze possible predictive markers for asthma occurrence in patients with allergic rhinitis to house dust mites (HDM). Materials and Methods: Fifty-eight patients with persistent allergic rhinitis (PAR) were included. The clinical, biological evaluation and fractionated exhaled nitric oxide (FeNO) measurement were performed at enrolment. The patients were clinically evaluated after one year to determine asthma occurrence. Results: The severity of rhinitis symptoms, levels of total immunoglobulin E (IgE), ICAM-1, VCAM-1, E-selectin and IL-6, but not IL-8 and TNF-α were higher in patients with allergic rhinitis who developed asthma compared to non-asthmatics, but the differences were not significant to considered them as predictive factors for asthma occurrence. The risk of asthma was independently influenced by patients aged over 30 years ((OR-3.74; CI95% 0.86–16.31; p = 0.07), a duration of allergic rhinitis over 12 months ((OR-4.20; CI95% 0.88–20; p = 0.07) and a basal FeNO over 28 parts per billion (pbb) ((OR-18.68; CI95% 3.79–92.05; p < 0.001). Conclusion: Clinical and biological parameters may predict asthma occurrence in patients with persistent allergic rhinitis to HDM. Adult patients with a longer duration of rhinitis symptoms and a high level of FeNO have a greater risk to develop asthma.

Objectives: Biomarker research is an important area of investigation in Gaucher disease, caused by an inherited deficiency of a lysosomal enzyme, glucocerebrosidase. We evaluated the usefulness of neopterin, as a novel biomarker reflecting chronic inflammation and immune system activation in Gaucher disease and analysed its evolution in response to enzyme replacement therapy (ERT). Methods: Circulating plasma neopterin levels in 31 patients with non-neuronopathic Gaucher disease were measured before and after the onset of ERT and were compared with those of 18 healthy controls. Plasma chitotriosidase activity was also monitored, as a reference biomarker, against which we evaluated the evolution of neopterin. Results: Neopterin levels were significantly increased in treatment-naïve patients (mean 11.90 ± 5.82 nM) compared with controls (6.63 ± 5.59 nM, Mann–Whitney U test P = 0.001), but returned to normal levels (6.92 ± 4.66 nM) following ERT. Investigating the diagnostic value of neopterin by receiver operating characteristic analysis, we found a cut-off value of 7.613 nM that corresponds to an area under the curve of 0.780 and indicates a good discrimination capacity, with a sensitivity of 0.774 and a specificity of 0.778. Discussion: Our results suggest that measurement of circulating neopterin may be considered as a novel test for the confirmation of diagnosis and monitoring of the efficacy of therapeutic intervention in Gaucher disease. Plasma neopterin levels reflect the global accumulation and activation of Gaucher cells and the extent of chronic immune activation in this disorder. Conclusion: Neopterin may be an alternative storage cell biomarker in Gaucher disease, especially in chitotriosidase-deficient patients.