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.

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.

Impact of traditional practices on food safety: a case of acute toxoplasmosis related to the consumption of contaminated raw pork sausage in Italy.

A case of acute toxoplasmosis in an adolescent girl, almost certainly related to the consumption of raw sausage, is described. The girl suffered of fever and weakness and presented a swollen lymph node in the submandibular region. Serology analysis was positive for Toxoplasma gondii and excluded other infections. Further analysis, with avidity test and immunoblot, confirmed the acute toxoplasmosis. She reported that about a month before the appearance of the symptoms, she had eaten a piece of raw sausage while it was being prepared by her father. We analyzed sausage samples prepared from this same batch that had been frozen for later consumption, and they demonstrated evidence of T. gondii DNA when using a specific nested PCR assay. The sausage was prepared from the meat of a pig that had been backyard raised and slaughtered at home, a traditional practice in rural communities in many countries. The tasting of fresh prepared raw sausage is a common practice throughout Italy, and it could be a major cause for toxoplasmosis as suggested by the results of a questionnaire administered in the province of Palermo, Sicily. Contact with cats and, to a lesser extent, raw salad consumption were also referred to as presumptive causes for the symptomatic cases. Two additional cases of acute toxoplasmosis reported during questionnaire administration were alleged to have been caused by the consumption of fresh sausage made with the meat of a pig raised in the yard. Traditional practices in animal farming, and the processing of meat from animals raised in the backyard or meat from wild game animals, might have a big impact on food safety.

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.

Fecal assays detect hypersensitivity to cow's milk protein and gluten in adults with irritable bowel syndrome.

BACKGROUND & AIMS: Some patients with irritable bowel syndrome (IBS)-like symptoms suffer from food hypersensitivity (FH); their symptoms improve when they are placed on elimination diets. No assays identify patients with FH with satisfactory levels of sensitivity. We determined the frequency of FH among patients with symptoms of IBS and the ability of fecal assays for tryptase, eosinophil cationic protein (ECP), or calprotectin to diagnose FH. METHODS: The study included 160 patients with IBS, 40 patients with other gastrointestinal diseases, and 50 healthy individuals (controls). At the start of the study, patients completed a symptom severity questionnaire, fecal samples were assayed, and levels of specific immunoglobulin E were measured. Patients were observed for 4 weeks, placed on an elimination diet (without cow's milk and derivatives, wheat, egg, tomato, and chocolate) for 4 weeks, and kept a diet diary. Those who reported improvements after the elimination diet period were then diagnosed with FH, based on the results of a double-blind, placebo-controlled, oral food challenge (with cow's milk proteins and then with wheat proteins). RESULTS: Forty of the patients with IBS (25%) were found to have FH. Levels of fecal ECP and tryptase were significantly higher among patients with IBS and FH than those without FH. The ECP assay was the most accurate assay for diagnosis of FH, showing 65% sensitivity and 91% specificity. CONCLUSIONS: Twenty-five percent of patients with IBS have FH. These patients had increased levels of fecal ECP and tryptase, indicating that they might cause inflammation in patients with IBS. Fecal assays for ECP could be used to identify FH in patients with IBS.

Investigation and management of Toxoplasma gondii infection in pregnancy and infancy: a prospective study.

AIM: Toxoplasma gondii infection during pregnancy poses a serious risk to the fetus, therefore timely and accurate diagnosis is essential. The aim of this study was to estimate the frequency of congenital infection via evaluating mother's immunological status and the possibility to improving the diagnostic and therapeutic approaches. METHODS: Eighty five mothers with Toxoplasma seroconversion and their offspring were enrolled (among them, 2 spontaneous abortions were documented in the first trimester). Prenatal PCR diagnosis was carried out on 50 patients (60%), with 7 positive cases (14%). Morphological ultrasound scanning revealed anomalies in one fetus. Long-term follow-up included general physical examinations, serological status tested using Western blot, neuro-radiological, ophthalmologic and neurologic examinations, psychological and developmental tests, visual evoked potential tests and audiology tests, as well as anti-Toxoplasma treatment regimes. RESULTS: Fourteen (17%) of the infants were infected at one-year serological follow-up. Chi-square for linear trend of vertical transmission from the first to the third trimester was significant (P=0.009). Western blot analysis showed IgM and IgA in half of the infected infants. In 69 uninfected infants, anti-Toxoplasma IgG immunoblot analysis excluded infection within the 3 months in 18 infants (26%) and in the others within 6 months of life. The most relevant instrumental findings are described. CONCLUSION: Western blot analysis may help to evaluate infection within the 6 months of life. The accuracy of ultrasound imaging to determine the brain damage in the fetus and newborns is doubtful, and should be combined with MR imaging. Multistep approaches can improve the timing of postnatal follow-up.

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.

Diagnostic efficacy of the ELISA test for the detection of deamidated anti-gliadin peptide antibodies in the diagnosis and monitoring of celiac disease.

BACKGROUND AND AIM: We evaluated the diagnostic performance of an ELISA test for anti-gliadin IgA and IgG antibodies, which uses synthetic deamidated gliadin peptides (anti-gliadin antibodies, AGAs) as coating; the results were compared with a test that uses extracted gliadin (AGAe). METHODS: The study was conducted on the sera of 144 patients suffering from celiac disease (CD), including 20 patients with IgA deficiency and 9 who were following a gluten-free diet (GFD), and 129 controls. RESULTS: In the 115 CD patients (without IgA deficiency), the sensitivity of AGAe IgA and IgG was 32.2 and 60.9%, whereas that of AGAs IgA and IgG was 59.1 and 72.2%. The specificity for AGAe IgA and IgG, and AGAs IgA and IgG was 93.8 and 89.9%, and 96.9% and 99.2%, respectively. Of the 20 patients with CD and IgA deficiency, 7 tested positive for AGAe IgG and 14 for AGAs IgG. The test using deamidated gliadin peptides performed better in terms of sensitivity and specificity than the AGA tests with extracted antigen. CONCLUSIONS: The very high specificity of the AGAs IgG test (99.2%) also suggests that patients who test positive with this assay require a thorough followup, even if the anti-tissue transglutaminase antibodies (anti-tTG) and anti-endomysial autoantibodies (EMA) assays are negative.

Effect of physical training on exercise capacity, gas exchange and N-terminal pro-brain natriuretic peptide levels in patients with chronic heart failure.

BACKGROUND: Decreased exercise capacity is the main factor restricting the daily life of patients with chronic heart failure. N-terminal pro-brain natriuretic peptide (NT pro-BNP) is strongly related to the severity of and is an independent predictor of outcome in chronic heart failure. DESIGN: The study aimed to evaluate the effect of exercise training on functional capacity and on changes in NT pro-BNP levels and to assess the effect of exercise training on quality of life. MATERIALS AND METHODS: Sixty patients (45 men/15 women, mean age 52.7 years; +/-5.3 SD), with stable heart failure (45 ischaemic/hypertensive and 15 idiopathic patients), in New York Heart Association (NYHA) functional class II (n=35) to III (n=25), with an ejection fraction less than 40%, were randomly assigned to a training (n=30) and a control group (n=30). The training group (30 patients) performed 3 months of supervised physical training programme using a bicycle ergometer for 30 min three times a week at a load corresponding to 60-70% of their oxygen consumption (VO2) peak. The control group did not change their previous physical activity. A graded maximal exercise test with respiratory gas analysis and an endurance test with constant workload corresponding to 85% of the peak oxygen load at the baseline and after 3 months were performed, and at the same times NT pro-BNP levels were measured. RESULTS: The exercise capacity increased from 15.8 (+/-2.3 SD) to 29.9 (+/-2.1 SD) min (P<0.0001) and the peak VO2 tended to improve from 14.5 (+/-1.4 SD) to 17.7 (+/-2.6 SD) ml/kg per min (P<0.0001) during the supervised training period. VO2 at the anaerobic threshold increased from 12.9 (+/-1.0 SD) to 15.5 (+/-1.7 SD) ml/kg per min (P<0.0001). NT pro-BNP levels decreased from 3376 (+/-3133 SD) to 1434 (+/-1673 SD) pg/ml (P=0.043). The positive training effects were associated with an improvement in the NYHA functional class. CONCLUSION: Physical training of moderate intensity significantly improves the exercise capacity and neurohormonal modulation in patients with chronic heart failure. This is associated with an alleviation of symptoms and improvement in quality of life.

[Systemic lupus erythematosus between clinical practice and the laboratory: state of the art and new findings on anti-DNA autoantibodies]. / Il lupus eritematoso sistemico tra clinica e laboratorio: stato dell'arte e nuove acquisizioni sugli autoanticorpi anti DNA.

Identification of autoantibodies directed against nuclear antigens is a very important finding in the assessment of autoimmune rheumatic diseases. In particular, the anti-DNA autoantibodies have assumed a fundamental importance, both speculative and clinical, in the study of the systemic lupus erythemathous. The aim of the present review is to focalize on anti-DNA the mechanisms of both induction and production of anti-DNA autoantibodies, pathophysiologic and diagnostic and clinical aspects. For this purpose, forty years of studies on this topic have been reviewed. Aspects on different conformational shapes of double-stranded DNA have been discussed such as related pathogenetic and diagnostic ones. Finally, the review has dealt with experimental therapies, focusing on both animal models and the most recent clinical trials according to Evidence Based Medicine.