Basophil Activation Test in the Diagnosis of Anisakis Allergy: An Observational Study from an Area of High Seafood Consumption in Italy.

The rising popularity of undercooked or raw seafood containing larvae of the Anisakis parasite has led to issues of public health concern due to allergic manifestations. We conducted an observational study on the use of an innovative Anisakis allergy diagnostic algorithm in a convenience sample of 53 allergic outpatients recruited in Western Sicily, between April 2021 and March 2022. We included individuals with an anamnesis suggestive of IgE sensitization to Anisakis reporting clinical manifestation in the last month due to allergic reactions after eating fresh fish, or in subjects at high exposure risk with sea products while abstaining from fish ingestion, excluding those with documented fish sensitization. Outpatients were tested via Skin Prick Test, IgE-specific dosage and Basophil Activation Test (BAT). Twenty-six outpatients were diagnosed with Anisakis, while 27 with Chronic Urticaria (CU). We found a seven-fold excess risk for Anisakis (p4) positivity in the Anisakis allergic outpatients, as compared to the CU ones. BAT showed the best diagnostic accuracy (92.45%) and specificity (100%), while specific IgE to Ascaris (p1) documented the best sensitivity (92.31%) but a very low specificity (37.04%). In conclusion, our findings may represent a potentially useful contribution to the future development of updated clinical guidelines.

Allergy to Polyethilenglicole of Anti-SARS CoV2 Vaccine Recipient: A Case Report of Young Adult Recipient and the Management of Future Exposure to SARS-CoV2.

The main contraindication to the anti-SARS CoV2 vaccine is an anaphylactic reaction to a vaccine component. The need to vaccinate allergic people who are at higher risk can be of public health interest and this report shows a case of an allergic reaction to PEG of a HCW who had received the first dose of anti-SARS CoV2 vaccine. For 5 h after the administration of the vaccine, she had the appearance of erythematous spots on the face and neck, and a feeling of a slurred mouth and hoarseness. In order to treat the event, she was administered 8 mg intravenous dexamethasone, 1 vial intravenous chlorphenamine maleate, 250 mL intravenous 0.9% NaCl, and conventional oxygen therapy (2 L/min) with complete resolution of the suspected adverse drug reaction. According to the contraindication to the cutaneous test for this patient, BAT was used for further investigations. The patient who suffered the adverse reaction to the COVID-19 vaccine and other five allergic patients who did not report any adverse reaction after the vaccination were tested. There was a significant activation of the vaccine-reactive patient's basophils with 14.79 CD203chigh% at the concentration of 0.2 mg/mL, while other patients were negative. People who have a confirmed reaction to a vaccine component should undergo further investigation to discover other possible cross-reactions and select the right vaccine to immunize them.

The extract, the molecular allergen or both for the in vitro diagnosis of peach and peanut sensitization?

INTRODUCTION: Identifying the target molecule in food allergies, helps to assess the risk of anaphylaxis in a patient. Lipid Transfer Protein is the most frequent cause of food allergies in the Mediterranean area. The diagnosis based on allergenic extracts, suffers from a high variability in the results because some important allergenic molecules are lacking. This study was disegned to assess whether Pru p 3 and Ara h 9 molecules are quantitative and qualitative enough present in their whole allergenic extracts. METHODS: 943 patients with a clinical history of suspected peach and/or peanut food allergies were recruited and underwent measurement of a specific serum IgE (ImmunoCAP system (Thermofisher/Phadia Diagnostics, Uppsala, Sweden) to the following allergens and molecules: peach (f95) and/or peanut (f13), Pru p 3 (f420), Pru p 1 (f419), Pru p 4 (f421), Ara h 1 (f422), Ara h 2 (f423) Ara h 3 (f424) and Ara h 9 (f427). RESULTS: Out of the 943 patients included in this study, 122 were positive to sIgE to peanut extract. At a cut-off point of 0.35 kIU/L, 62 patients were positive to sIgE to Ara h 9 but negative to peanut extract. Increasing the cut-off point of Ara h 9 at 10 kIU/L, 15 patients were only positive to sIgE to Ara h 9. 244 out of the 943 patients were positive to sIgE to peach extract. At a cut-off point of 0.35 kIU/L, 27 patients were negative to sIgE to Pru p 3 and positive to sIgE to peach extract, whilst 11 patients were peach extract sIgE positive and sIgE negative to Pru p 1, Pru p 3 and Pru p 4. Only 12 patients resulted positive to Pru p1 and/or Pru p 4. CONCLUSION: Our data strongly suggests to include the measurement of sIgE to Ara h 9 into the diagnostic algorithm of peanut sensitization. 4.5% of the sicilian population suspected of peach sensitization were positive to peach extract and negative to all the available molecules.

Different co-sensitizations could determine different risk assessment in peach allergy? Evaluation of an anaphylactic biomarker in Pru p 3 positive patients.

BACKGROUND: In Italy, the nsLTP (Pru p 3) has been identified as the most frequent cause of food allergy and anaphylaxis. In order to estimate the risk assessment in peach allergy, we investigated the presence of correlations between the levels of sIgE to Pru p 3 with the severity of the clinical symptoms in two Pru p 3 positive populations from two different areas of Italy. METHODS: 133 consecutively Pru p 3 positive patients were recruited from South Italy, where the prevalence of PR-10 and profilin sensitization is low, and from North-East Italy, where the sensitization to pathogenesis related protein -10 (PR-10) and profilin is higher. Skin prick test (SPT) to peach extract and sIgE to peach panallergens were performed. RESULTS: All 133 patients were positive to SPT to peach extract and to sIgE to Pru p 3. The North-East population was simultaneously positive to Pru p 1 (42.8 %) and Pru p 4 (12.7 %), while no Southern patients were positive to PR-10 or to profilin. A significant difference in the levels of sIgE to Pru p 3 was found only in South Italy Pru p 3 + patients vs. asymptomatic patients (p = 0.01) and in mild reactions vs. severe reactions (p = 0.0008). In South Italy patients, it was also found a significant correlation between the severity of the clinical reaction and the levels of sIgE to Pru p 3 (p = 0.001). CONCLUSION: Level of sIgE to Pru p 3 indicates the possibility of development a severe food allergic reaction. Pru p 3 positive patients from different geographical areas and with different co-sensitizations to Pru p 1 and/or Pru p 4 could have a different risk assessment in peach allergy.

Allergen component specific ige measurement with the Immulite™ 2000 system: diagnostic accuracy and intermethod comparison.

BACKGROUND: The identification of the allergenic molecules, associated to the advances in the field of recombinant allergens, led to the development of a new concept in allergy diagnosis called component-resolved diagnosis. The aim of our study was to evaluate the diagnostic accuracy of different allergen components using the full automatic singleplex quantitative platform Immulite™ 2000. METHODS: One hundred ninety-five allergic outpatients (35 to olive pollen, 35 to birch pollen, 35 to profilin, 35 to house dust mites, 35 to peach, and 20 to shrimp) and 20 negative controls were enrolled for the study. Bet v 1, Bet v 2, Ole e 1, Der p 1, Der p 2, Der f 1, Der f 2, Pru p 3, tropomyosin were tested both with Immulite™ 2000 and ImmunoCAP™ (Thermo Fisher Scientific, Uppsala, Sweden). RESULTS: Sensitivity of allergen-specific Immunoglobulin E (sIgE) to Ole e 1, Bet v 1, Der p 1, Der p 2, Der f 1, Der f 2, Pen m 1, and Pru p 3 with Immulite™ 2000 was 100%, 100%, 77.1%, 94.3%, 71.4%, 94%, 75%, and 97.1%, respectively, and the specificity was 100% for all the allergens. The overall agreement between Immulite™ 2000 and ImmunoCAP™ (Thermo Fisher Scientific) platforms was 98.6% (Cohen's kappa = 0.979; confidence interval [CI] 95%: 0.960-0.997). From moderate to strong, positive linear correlations between the assays (r(2) from 0.322 to 0.860, and Spearman's rho from 0.824 to 0.971) were showed. CONCLUSIONS: A high diagnostic accuracy of the sIgE to allergen components measurement with Immulite™ 2000 and a high agreement with ImmunoCAP™ platforms were shown in this study.

A comparison between two different in vitro basophil activation tests for gluten- and cow's milk protein sensitivity in irritable bowel syndrome (IBS)-like patients.

BACKGROUND: The diagnosis of food hypersensitivity (FH) in adult patients with gastrointestinal symptoms, beyond the immediate IgE-mediated clinical manifestations, is very often difficult. The aims of our study were to: 1) evaluate the frequency of FH in patients with irritable bowel syndrome (IBS)-like clinical presentation; and 2) compare the diagnostic accuracy of two different methods of in vitro basophil activation tests. METHODS: Three hundred and five patients (235 females, age range 18-66 years) were included and underwent a diagnostic elimination diet and successive double-blind placebo-controlled (DBPC) challenges. Two different methods of in vitro basophil activation tests (BAT) (CD63 expression after in vitro wheat or cow's milk proteins stimulation) were evaluated: one was performed on separated leukocytes, and the other on whole blood. RESULTS: Ninety patients of the 305 studied (29.5%) were positive to the challenges and were diagnosed as suffering from FH. BAT on separate leukocytes showed a sensitivity of 86% and a specificity of 91% in FH diagnosis. BAT on whole blood showed a sensitivity of 15%-20% and a specificity of 73% in FH diagnosis (p<0.0001 compared to the other method). CONCLUSIONS: About one third of the IBS patients included in the study were suffering from FH and were cured on the elimination diet. The BAT based on CD63 detection on whole blood samples did not work in FH diagnosis and showed a significantly lower sensitivity, specificity and diagnostic accuracy than the assay based on separated leukocytes.

The old and new tests for celiac disease: which is the best test combination to diagnose celiac disease in pediatric patients?

BACKGROUND: In the diagnosis of celiac disease (CD), serum assays for anti-endomysium (EMA) and anti-transglutaminase (anti-tTG) antibodies have excellent diagnostic accuracy. However, these assays are less sensitive in young pediatric patients. Recently, a new ELISA test using deamidated gliadin peptides (DGP) as antigen has proved to be very sensitive and specific even in pediatric patients. In addition, anti-actin IgA antibodies (AAA) is another test that can be used in CD patients because antibody concentrations correlate with the degree of villous atrophy. This study evaluated the clinical accuracy of anti-tTG, EMA, AGA, anti-DGP and AAA and the effectiveness of these in different combinations for diagnosing CD in a large cohort of pediatric patients. METHODS: Sera of 150 children under 6 years of age were tested: 95 patients had a diagnosis of CD, while 55 patients who did not suffer from CD were used as controls. Anti-DGP IgA/IgG and AAA were assayed with ELISA kits, while anti-tTG IgA/IgG and AGA IgG/IgA were assayed using a quantitative fluoroimmunoassay. The EMA test was conducted by indirect immunofluorescence. RESULTS: Seventy-six of 95 (80%) CD patients were positive for DGP IgA and/or tTG IgA. Eighty of 95 (84.2%) patients were positive for DGP IgG and/or tTG IgA. None of the controls were positive for these antibodies. Eighty-four of 95 (88.4%) patients and 8/55 (14.5%) controls were positive for AAA and/or anti-tTG IgA. CONCLUSIONS: In very young children, association of anti-tTG IgA with anti-DGP IgG is the best test combination for diagnosing CD, yielding a cumulative sensitivity of 84.2% and a specificity of 100%.

A cytologic assay for diagnosis of food hypersensitivity in patients with irritable bowel syndrome.

BACKGROUND & AIMS: A percentage of patients with symptoms of irritable bowel syndrome (IBS) suffer from food hypersensitivity (FH) and improve on a food-elimination diet. No assays have satisfactory levels of sensitivity for identifying patients with FH. We evaluated the efficacy of an in vitro basophil activation assay in the diagnosis of FH in IBS-like patients. METHODS: Blood samples were collected from 120 consecutive patients diagnosed with IBS according to Rome II criteria. We analyzed in vitro activation of basophils by food allergens (based on levels of CD63 expression), as well as total and food-specific immunoglobulin (Ig)E levels in serum. Effects of elimination diets and double-blind food challenges were used as standards for FH diagnosis. RESULTS: Twenty-four of the patients (20%) had FH (cow's milk and/or wheat hypersensitivity); their symptom scores improved significantly when they were placed on an elimination diet. Patients with FH differed from other IBS patients in that they had a longer duration of clinical history, a history of FH as children, and an increased frequency of self-reported FH; they also had hypersensitivities to other antigens (eg, egg or soy). The basophil activation assay diagnosed FH with 86% sensitivity, 88% specificity, and 87% accuracy; this level of sensitivity was significantly higher than that of serum total IgE or food-specific IgE assays. CONCLUSIONS: A cytometric assay that quantifies basophils after stimulation with food antigens based on cell-surface expression of CD63 had high levels of sensitivity, specificity, and accuracy in diagnosing FH. This assay might be used to diagnose FH in patients with IBS-like symptoms.