A comparison of different allergometric tests, skin prick test, Pharmacia UniCAP and ADVIA Centaur, for diagnosis of allergic diseases in children.

BACKGROUND: The diagnosis of allergic disease is performed by skin prick tests (SPT) or through the demonstration of specific IgE in a blood sample via an in vitro test. The measurement of IgE concentration against allergens provides critical information in clinical allergy. Standardized and reproducible methods contribute to the quality of diagnosis and treatment of allergic disease. METHODS: In this study we evaluated the performance of a new specific IgE method, developed by ALK-Abellò for Bayer Diagnostics to run on their ADVIA Centaur immunoassay system. One hundred and fifty-one children with allergic diseases (both food and inhalant allergies) were tested for specific IgE (sIgE) via SPT and in vitro tests (UniCAP system, Pharmacia, and ADVIA Centaur immunoassay system, Bayer Diagnostics) and the test results were correlated with the clinical data. RESULTS: Statistical analysis revealed no significant difference between the two in vitro tests compared with clinical history. The sensitivities and specificities are similar, but the UniCAP system method has higher sensitivity. In the children with cow's milk allergy, the UniCAP system has sensitivity of 91% and specificity of 70%; the ADVIA Centaur immunoassay has sensitivity of 82% and specificity of 74%. In hen's egg allergy, UniCAP system has 94% sensitivity and 64% specificity, and the ADVIA Centaur system has 88% sensitivity and 52% specificity. In inhalant allergies, the two methods show statistically similar performances for both grass pollen allergies (UniCAP sensitivity 100%, specificity 73%; ADVIA Centaur sensitivity 95%, specificity 79%) and in the dust mites allergies (UniCAP sensitivity 91%, specificity 62%; ADVIA Centaur sensitivity 86%, specificity 64%). In cat allergies, the systems showed equivalent results (UniCAP sensitivity 100%, specificity 71%; ADVIA Centaur sensitivity 100%, specificity 70%). Using the UniCAP system, the geometric mean of sIgE values in children with clinical allergy is significantly higher than in sensitized ones. The ADVIA Centaur system shows a similar trend with the exclusion of cow's milk and Dermatophagoides farinae allergens. With this last method the mean value of sIgE is higher in sensitized than in symptomatic children. CONCLUSION: The new ADVIA Centaur method compares favorably with the results obtained on the UniCAP system. If other studies continue to confirm this data, then the advantages are numerous: the use of only a small quantity of serum (25 micro l per allergen), rapid turnaround time, minimal hands-on time, and no interference from IgG.

Effects of acute cold pressor test on vagally stimulated gastric acid secretion and circulating levels of human pancreatic polypeptide and gastrin.

The aims of our study were 3-fold: (1) to determine the effect of an acute cold pressor test on vagally stimulated gastric acid secretion, (2) to evaluate whether adrenergic blockers are able to prevent the stress-induced alterations of vagally stimulated gastric acid secretion, and (3) to assess the effect of stress and adrenergic blockers on serum levels of vagally stimulated pancreatic polypeptide and gastrin. Twenty-eight studies were carried out on 7 healthy subjects, each one of them being evaluated on four separate occasions. Active (4 degrees C) or control (37 degrees C) cold pressor tests were applied in random order after an interval of 15 min following completion of a vagal stimulation represented by modified sham feeding. Each stressful stimulus was preceded by an intravenous bolus plus an infusion of either adrenergic blockers (propranolol and phentolamine) or placebo. Modified sham feeding significantly stimulated gastric acid secretion and circulating hormonal levels, compared to basal values. Cold pressor test significantly stimulated gastric acid secretion 30 min after the beginning of the stressful stimulus. This stress-induced secretory response was completely prevented by infusions of adrenergic blockers. No effect was induced by stressful stimuli or by adrenergic blockers on human pancreatic polypeptide and gastrin circulating levels. The present study demonstrates that the cold pressor test induces a late increase of vagally stimulated gastric acid secretion suggesting a possible role mediated by adrenergic neural pathways.

Insulin and androgen relationships with abdominal body fat distribution in women with and without hyperandrogenism.

This retrospective study was carried out to investigate, in a large group of hyperandrogenized women with polycystic ovary syndrome (PCOS) and nonhyperandrogenized control women, the interrelationships between sex steroids and indices of body fat distribution. Moreover, we investigated the relationships between these parameters and insulin blood levels, since obese women with abdominal pattern of fat distribution (A-BFD), as well as those with PCOS (either obese and nonobese) are characterized by moderate to severe hyperinsulinemia. A sample of 100 women with PCOS and that of 138 women without clinical signs of hyperandrogenism, who served as a control group, were investigated. The waist to hip circumference ratio (WHR) which was used to define different patterns of fat topography was significantly (p < 0.05) higher in PCOS (0.84 +/- 0.10) than in control women (0.81 +/- 0.08). In both groups, women with WHR values lower than or equal to 0.85 were considered as having a peripheral pattern of body fat distribution (P-BFD) whereas those having WHR values higher than 0.85 had A-BFD. Compared to controls, women with PCOS had higher LH, androgen and estrogen concentrations. In both PCOS and controls there were no differences in sex hormone levels between women with different patterns of fat distribution, except androstenedione, which levels were significantly higher in women with A-BFD than with P-BFD. Women with PCOS showed significantly higher insulin levels than controls. Moreover, in both groups fasting and stimulated insulin were significantly higher in women with A-BFD than in those with P-BFD.(ABSTRACT TRUNCATED AT 250 WORDS)

Benfluorex action on metabolic control and insulin sensitivity in type 2 non-insulin dependent diabetics.

In this study, 16 overweight or obese NIDDM patients with a long period of stable weight and dietary surveillance were treated with 150 mg t.i.d. of Benfluorex per os for 3 months. A significant improvement occurred in the fasting and post-meal glucose levels and in the HbA1C values, regardless of weight changes that occurred throughout the study. No significant changes were found in the fasting or meal-stimulated insulin (IRI) levels and in the glucose:IRI molar ratios. On the contrary, there were no significant variations in C-peptide levels while the glucose:CPR ratio appeared to decrease while on Benfluorex. In basal conditions, 11 patients presented insulin insensitivity (as measured by the glucose-insulin-somatostatin technique) which was unaffected by the pharmacological treatment. Benfluorex may therefore ameliorate metabolic control in overweight or obese NIDDM patients, but our data do not clarify whether its effects are mediated by an improvement in the action of insulin in peripheral tissues.