Allergen-specific IgE: comparison between skin prick test and serum assay in real life.

BACKGROUND: The most common sensitizing allergens in in the area of Liguria region (Northwestern Italy) are pollens, mainly Parietaria and cypress, house dust mites, i.e. Dermatophagoides, and pets. IgE assessment is a crucial step in allergy diagnosis. It may be performed by skin prick test (SPT) or serum IgE (sIgE) assay. Therefore, this study compared these two methods in a real-life setting. METHODS: This retrospective study included 793 subjects, who were referred to the Allergy Department for respiratory allergy during 2014. Inclusion criteria were i) documented diagnosis of allergic rhinitis (AR), and/or allergic asthma, and/or allergic conjunctivitis. SPT and sIgE assay were performed for 5 allergens, such as Dermatophagoides pteronyssinus (D1), cat (E1), Parietaria officinalis (W19), cypress (T23), and dog (E5), as they are the most common in our geographic area. RESULTS: Using a positive SPT result as the target condition, remarkably high and statistically significant values of AUC, ranging from 0.84 to 0.94, were found. On the basis of the Youden index the following optimal classification threshold values were also computed: D1 = 0.22, E1 = 0.26, W19 = 0.61, T23 = 0.25, E5 = 0.34. These values allowed to define a set of sensitivity/specifity estimates ranging from 0.75 to 0.93 and from 0.83 to 0.93, respectively. CONCLUSIONS: The present study shows that SPT and sIgE are two tests that are rather concordant, but with different sensitivity and specificity distinct for each allergen. In clinical practice, both tests should be used depending on clinical history features and obtained findings.

Prescriptive appropriateness using inhalant and food allergen panels: a comparison between General Practitioners' and Allergists' prescription in Genoa (Italy).

SUMMARY: Background. Prescriptive appropriateness is an actual claim in healthcare, and it also concerns in vitro tests used in the allergy work-up, such as the serum allergen-specific IgE (sIgE) assay. In the Liguria Region, two panels were defined (for inhaled and food allergens) including 12 allergens. Their composition changed over time. Objectives. The aims of the present retrospective study were: i) to evaluate the percentage of positive tests, and ii) to compare the findings of sIgE assay on the basis of the general practictioners' (GPs) or specialist' prescription, considering both the old panels and the new panels. Methods. This retrospective study considered a population of adult patients, which consisted of 2368 subjects (68% females; mean age 50 years; age range: 10-103 years). Serum sIgE were measured by ImmunoCap system. Results. The percentages of positive tests were very low for food allergens and low for inhaled ones (ranging between 5% to 35%). There was change of prevalent prescriptor with new panels. Conclusions. This study underlines the relevance of prescriptive appropriateness in the allergy work-up. The sIgE assay should be limited to those allergens that have a clinical relevance, based on clinical history.

Profiles of Birch Sensitization (Bet v 1, Bet v 2, and Bet v 4) and Oral Allergy Syndrome Across Italy.

BACKGROUND: Birch allergy (BA) is a common pollinosis caused by the allergens Bet v 1, Bet v 2, and Bet v 4. Oral allergy syndrome (OAS) is frequently associated with BA. A gradient of sensitization to birch allergen across Europe has been reported. Therefore, this study aimed to investigate the birch sensitization profile, including OAS, across Italy. METHODS: We performed a retrospective study of 854 patients (391 males, mean age 35.9 years, range 18-93 years): 196 patients were recruited in Genoa, 188 in northern Italy, 359 in central Italy, and 111 in southern Italy. Serum IgE to Bet v 1, Bet v 2, and Bet v 4 was assessed, and OAS was analyzed. RESULTS: With respect to the geographical path Genoa-North-Center-South, the frequency of sensitization to Bet v 1 decreased significantly (P<.0001) from Genoa (95.41%) to southern Italy (58.56%). The frequency of sensitization to Bet v 2 increased significantly (P<.0001) from Genoa (6.12%) to southern Italy (52.25%). The frequency of Bet v 4 also increased significantly (P=.0002) from Genoa (6.12%) to southern Italy (14.41%). The distribution of patients with OAS differed significantly across the areas (P<.0001), the most marked difference ranging between 33.5% in Genoa and 76.9% in northern Italy. The frequency of birch allergens correlated with OAS in central Italy only. CONCLUSIONS: The present study demonstrated a significant difference between sensitization to birch and its clinical expression across Italy.

Serum allergen-specific IgE, allergic rhinitis severity, and age.

BACKGROUND: Allergic rhinitis (AR) is characterized by an IgE-mediated reaction. Aging usually induces a progressive decline of immune system function. There is common belief that both allergic symptoms severity and serum IgE production decline during aging. OBJECTIVE: This study aimed to evaluate the possible impact of age on: i) serum allergen-specific IgE levels in a large sample of subjects, and ii) AR symptom severity in a group of mono-allergic patients. METHODS: Serum allergen-specific IgE to birch, Bet v 1, Parietaria, and Dermatophagoides pteronyssinus were measured by immunofluorometric assay (IFMA) in a sample of 8098 subjects. AR symptom severity was assessed by visual analogue scale (VAS) in a sub-group of 531 mono-allergic patients. RESULTS: The analysis of variance showed that IgE to Bet v 1, birch, and Dermatophagoides pteronyssinus significantly decreased considering the age, whereas IgE to Parietaria did not significantly decline in respect of the age. Considering the global sample of mono-allergic patients, elderly subjects (over 65 years old) tended to have lower IgE levels, but had significantly lower VAS rating, and significantly less sensitizations than adult subjects (18-65 years old). In both adult and elderly patients VAS strongly correlated with IgE values. CONCLUSIONS: Allergen-specific IgE levels tend to reduce with aging, but with differences between types of allergy. The IgE decrease is usually associated with reduced AR symptom severity. Elderly AR patients seem to have a different phenotype/endotype in comparison with adult AR ones, characterized by milder symptoms, lower IgE production, and less sensitizations. However, a close positive relationship between IgE values and VAS scores is shared by both adult and elderly AR patients, confirming the close link between allergy and symptoms that persists also in the elderly.

Immunomodulatory properties of porcine, bone marrow-derived multipotent mesenchymal stromal cells and comparison with their human counterpart.

Thanks to their immunonodulatory properties, multipotent mesenchymal stromal cells (MSCs) are a promising strategy for preventing/reducing the risk of graft rejection after hematopoietic cell and solid organ transplantation. We have previously demonstrated that porcine MSCs (pMSCs) can be isolated from bone marrow and display similar morphology and differentiative capacity as compared to human MSC (hMSCs). In this study, we investigated the in vitro immunomodulatory properties (namely the ability to suppress lymphocyte proliferation in response to phytohemagglutinin and the cytokine production in the culture supernatants) of pMSCs from six Large White 6-month old piglets. Similarly to hMSCs, pMSCs reduced the phytohemagglutinin-induced lymphocyte proliferation. High levels of IL-6 were found in culture supernatants, whereas IL-10 and TGF-ß were not detectable. In conclusion, ex vivo expanded pMSCs share selected biological/functional properties with hMSCs. pMSCs may be used in in vivo models to investigate novel approaches of prevention of graft rejection in solid organ transplantation.

Isolation and ex vivo expansion of bone marrow-derived porcine mesenchymal stromal cells: potential for application in an experimental model of solid organ transplantation in large animals.

Pharmacological aspecific immunosuppression, despite being widely used in solid organ transplantation recipients, is unable to completely prevent allograft rejection. It promotes the occurrence of sometimes life-threatening infections. Due to their immunosuppressive and anti- inflammatory properties, there is great interest in the therapeutic use of bone marrow (BM)-derived mesenchymal stromal cells (MSC). Large animal models play a crucial role to investigate the biological and functional properties of MSCs as novel cellular therapy. In the current study we sought to isolate expand ex vivo, and phenotypically characterize MSC derived from BM of 4 Large White 6-month-old piglets. Porcine MSC (pMSC) were characterized for their in vitro differentiation capacity. pMSC were successfully isolated from all BM samples. They showed spindle-shaped morphology and a stable doubling time on culture. They were positive for CD90, CD29, CD105, and negative for CD45 and CD11b. Furthermore, they differentiated, upon specific in vitro conditions toward adipogenic and osteogenic lineages. The optimization of methods for the isolation and characterization of pMSC may be useful to elucidate their biological and functional properties. The anatomy and physiology of the pig, which is similar to humans, make this animal model more attractive than small animals to test the safety and efficacy of MSC in the context of solid organ transplantation.