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Biomedical subjects

S Bonini

Publications and source records attributed to S Bonini.

At least 91 records · Page 5Linked to original sources

Studies on the relationship between the level of specific IgE antibodies and the clinical expression of allergy: I. Definition of levels distinguishing patients with symptomatic from patients with asymptomatic allergy to common aeroallergens.

BACKGROUND: The detection of specific IgE antibodies to environmental allergens does not always coincide with a diagnosis of clinically evident allergic disease, because some patients with positive skin and/or in vitro test results have no symptoms related to the allergen or allergens that induced the antibodies. OBJECTIVE: In a multicenter study the optimal cutoff values for specific IgE antibody levels and skin test results that could discriminate between patients with symptomatic and those with asymptomatic allergy were determined. METHODS: IgE antibodies specific for a panel of common aeroallergens were assayed with the Pharmacia CAP System (Pharmacia, Uppsala, Sweden) in two groups of patients, a group of 267 patients with symptomatic allergy and a group of 232 with asymptomatic allergy--both with positive skin prick test results--and in a group of 243 healthy, nonallergic control subjects. The cutoff values were established by receiver operating characteristic analysis. RESULTS: A significantly higher mean specific IgE antibody value was found in patients with symptomatic allergy compared with patients with asymptomatic allergy (p < 0.001) and in patients with symptomatic allergy compared with healthy control subjects (p < 0.001). The optimal CAP System cutoff value between patients with symptomatic and those with asymptomatic allergy was 11.7 kU/L, and when seasonal allergens were compared with perennial allergens, the cutoffs were 10.7 kU/L and 8.4 kU/L, respectively. The optimal cutoff value for the skin prick test was a wheel area of 32 mm2 for seasonal allergens and 31 mm2 for perennial allergens. The skin test had a lower diagnostic value (sum of sensitivity and specificity) than the CAP System. CONCLUSIONS: Cutoff values for specific serum IgE antibody levels are likely to be useful in clinical practice to distinguish symptomatic from asymptomatic allergy in patients with positive skin test results.

Adolescent↗

Estrogen and progesterone receptors in vernal keratoconjunctivitis.

PURPOSE: Sex-related influences have been implicated in the pathogenesis of vernal keratoconjunctivitis (VKC), an allergic eosinophilic disease. METHODS: The authors evaluated tarsal and bulbar conjunctival biopsies from seven patients with severe and symptomatic VKC for the presence of estrogen and progesterone receptors by using monoclonal antibodies with a peroxidase-antiperoxidase technique. RESULTS: Both the epithelium and subepithelium of the tarsal and bulbar conjunctiva of patients with VKC, but not those of four nonatopic control subjects, showed intense positive staining for estrogen and progesterone receptors. Immunofluorescence colocalization of both estrogen and progesterone receptors with eosinophil cationic protein showed that approximately 70% of positive cells were eosinophils. CONCLUSIONS: Sexual hormones, through their receptors, may influence the activity of eosinophils in patients with VKC.

Adolescent↗

Increased plasma levels of nerve growth factor in vernal keratoconjunctivitis and relationship to conjunctival mast cells.

PURPOSE: To evaluate the nerve growth factor (NGF) plasma concentration in patients with vernal keratoconjunctivitis and to correlate it with the histopathology and immunopathology of the disease. METHODS: An immunoenzymatic assay was performed to measure NGF plasma levels in patients with vernal keratoconjunctivitis and in healthy matched controls. A competitive radioimmunoassay was used to detect eosinophil cationic protein (ECP) and total specific immunoglobulin E (IgE) serum levels. Histologic evaluation was performed in tarsal and bulbar conjunctival biopsies. RESULTS: Plasma levels of NGF were significantly higher (P < 0.001) in patients with vernal keratoconjunctivitis (mean = 8224.47 +/- 7802.53 pg/ml; median = 121 pg/ml) than in controls (mean = 51.68 +/- 5.94 pg/ml; median 42.5 pg/ml). Conjunctival tissue showed a significant increase of mast cells, eosinophils, and lymphocytes in vernal keratoconjunctivitis. A significant correlation was observed between plasma levels of NGF and the number of mast cells in the tarsal conjunctiva (Cc = 0.81; P < 0.005) and bulbar conjunctiva (Cc = 0.77; P < 0.01) of patients with vernal keratoconjunctivitis. No correlation was found between NGF plasma levels and total IgE serum levels in patients with vernal keratoconjunctivitis; NGF plasma levels were inversely related to the number of circulating eosinophils (Cc = -0.61; P < 0.05) and to the increased serum levels of ECP (Cc = -0.71; P < 0.02). CONCLUSIONS: These data represent the first reported evidence of increased NGF plasma levels in an allergic human disease and suggest a possible relationship between this neurotrophic polypeptide and inflammatory cells in vernal keratoconjunctivitis.

Adolescent↗

Mechanisms in adverse reactions to food. The eye.

Direct action of triggers on the target organ may cause vasodilation, exudation, hypersecretion and nerve endings stimulation without participation of mast cells and basophils. Non IgE-mediated release of mediators from mast cells and basophils may explain how triggers other than allergens can induce pseudo-allergic reactions. IgE-mediated triggering of mast cells and basophils is not confined - in the eye too - to an immediate reaction, but represents the starting point for a progression to a late-phase reaction with the participation of a network of several cells and mediators. Inflammatory changes associated with late-phase reaction in the eye represent the pathophysiological basis for a non-specific hyperreactivity to various triggers.

Conjunctivitis, Allergic↗

Increased serum levels of eosinophil cationic protein and eosinophil-derived neurotoxin (protein X) in vernal keratoconjunctivitis.

PURPOSE: To evaluate whether the eosinophil preformed mediators, eosinophil cationic protein X, and eosinophil-derived neurotoxin/eosinophil protein X (EDN/EPX) are detectable in serum and can be used as markers of eosinophilic inflammation. METHODS: A competitive radioimmunoassay was used to detect serum levels of eosinophil cationic protein and EDN/EPX in 31 patients with vernal keratoconjunctivitis (VKC) and in 15 healthy controls. RESULTS: Mean serum levels of both eosinophil cationic protein and EDN/EPX were significantly higher in patients with VKC than in controls. There was a good correlation between serum levels of eosinophil cationic protein and EDN/EPX. No significant difference in mean serum eosinophil cationic protein levels was observed between patients with positive radioallergosorbent test (RAST) results and those with negative RAST results who have VKC, whereas mean EDN/EPX and total immunoglobulin E serum levels were significantly higher in patients with positive RAST results than in those with negative RAST results who have VKC. Serum eosinophil cationic protein, but not EDN/EPX, levels were significantly related to total immunoglobulin E levels. CONCLUSION: The authors' data indicate that serum levels of eosinophil cationic protein and EDN/EPX are useful markers of eosinophilic ocular inflammation in VKC.

Adolescent↗

IgG subclass antibodies against Parietaria judaica in normal and allergic subjects.

IgG antibody response to the inhalant allergen Parietaria judaica (Pj) and IgG subclass distribution were studied in 82 normal subjects, divided into three groups according to age (0-1, 1-20, and 20-60 years) and in 32 allergic subjects aged 20-60 years. Both normal and allergic subjects showed an IgG response, and all had IgG1 antibodies specific for PjE. Serum IgG2, IgG3, and IgG4 against PjE were detectable in 36%, 46%, and 22% of normal subjects, and in 58%, 31%, and 65% of allergic subjects, respectively. A significant difference in class distribution between allergic and age-matched normal subjects was found only for IgG4 antibodies against PjE (65% and 17%; P < 0.01). The ELISA results were also analyzed quantitatively, taking into account the relative proportion of specific antibodies. Thus, in normal subjects IgG1 antibodies showed a decreasing trend as the age rose, while no differences according to the age of the subject were found for IgG2 and IgG4. When data from allergic subjects (20-60 years) and the age-matched normal group were compared, they were different for the relative percentage of IgG2 only, showing for this a significantly lower value (P < 0.001). The present data indicate that normal and allergic subjects show differences in the IgG isotype distribution depending on their sensitivity and duration of allergen exposure.

Adolescent↗

Genetic and environmental factors in the changing incidence of allergy.

Several studies have indicated that the incidence and prevalence of allergic diseases are increasing. Such data should not be regarded as mere statistical curiosities, but should be analysed to provide information on the factors contributing to allergy and its changing epidemiology. Extensive evidence has been accumulated that allergic diseases are polyfactorial. Data reported in the literature and particularly twin studies have also suggested polyfactorial control of individual allergy variables, such as total serum levels IgE and IgG4, specificity of antibody response, mediator release from inflammatory cells and target organ response. Markers of genetic susceptibility may identify individuals at risk for allergy, while identification of the environmental factors influencing the phenotypic expression of allergy can be useful in evaluating the cost-benefit ratio of taking preventive measures in such individuals.

Disease Susceptibility↗

Allergen extracts. Standardization of preparations for bronchial provocation tests. A position paper. (EAACI Sub-committee on Bronchial Provocation Tests).

Standardization of allergen provocation tests of the airways requires standardization of each of the steps involved, including standardization of the extracts used. The value of international standards is emphasized and so is the determination of a clinically relevant potency. The allergen extracts used for bronchial provocation tests must be compared with qualitatively and quantitatively clinically relevant standards using complementary immunochemical and biological methods. Ideally the same extracts should be used for diagnosis (skin test, specific IgE determinations, provocations) and treatment (immunotherapy). The importance of the biological compared with the non-biological methods is that the biological methods are established in allergenic patients in order to select a clinically relevant potency of the allergen in question, and this potency ought to be confirmed in clinical trials. Once established the biological potency of an in-house preparation can be reproduced by supplementary in vitro methods. Very few commercial allergen preparations are available which fulfil the above-mentioned criteria.

Allergens↗

Markers of eosinophilic inflammation in allergic diseases.

The paper reviews personal studies aimed at identifying clinical markers of eosinophil inflammation in allergic diseases. Preliminary data on the use of flow cytometry as a method to detect eosinophil activation through phenotypic activation markers are reported. The concept of eosinophil releasibility is introduced on the basis of in vitro eosinophil activation and mediator release by different stimuli. Data showing an increase of serum levels of ECP mainly in subjects with sensitivity to perennial allergens and related to histamine bronchial reactivity are discussed in view of their practical impact in diagnosing and monitoring of allergic diseases and asthma.

Asthma↗

Nedocromil sodium and astemizole, alone or combined, in the treatment of seasonal allergic conjunctivitis. A multicentre double blind clinical trial.

Two hundred and seven patients with active symptoms of allergic conjunctivitis were studied in a four-week multicentre double blind, double dummy, clinical trial comparing efficacy and safety of nedocromil sodium eye drops with oral astemizole, placebo, and the combined active treatments. Clinical signs were evaluated by clinicians after 1, 2 and 4 weeks, while symptoms were recorded by patients on daily diary cards. Overall opinions were recorded at the end of treatment. Nedocromil sodium eye drops and astemizole, alone or combined, significantly reduced ocular symptoms when compared to placebo (diary card total symptom score and patients' opinion). In the clinicians' opinion nedocromil sodium alone or combined (but not astemizole alone) significantly decreased ocular symptoms when compared to placebo. All treatments were safe and well tolerated, drowsiness being the most frequent side effect observed in patients treated with astemizole. These results indicate the effectiveness of nedocromil sodium eye drops in the treatment of seasonal allergic conjunctivitis.

Adolescent↗

IgE and non-IgE mechanisms in ocular allergy.

Various forms of conjunctival disease have traditionally been referred to by the umbrella term "allergic conjunctivitis," on the assumption that they are all caused by a Gell and Coombs type I hypersensitivity reaction. Recent evidence disputes this classification, however, and suggests that other mechanisms may also be responsible for the complex clinical features of conjunctival disease. Among these are non-IgE-mediated activation of mast cells, late-phase reactions, and nonspecific conjunctival hyperreactivity. The authors suggest that the pathophysiology of allergic eye disease is multifactorial, which explains the different clinical pictures seen in different patients. Both IgE-mediated and non-IgE-mediated mechanisms may cause an immediate reaction as well as allergic inflammation, and nonspecific hyperreactivity may occur both as a result of allergic inflammation and as an independent mechanism in nonallergic conjunctival disease.

Animals↗

Frequency of long-term lower limb ischemia associated with intraaortic balloon pump use.

Lower limb ischemia is a frequent complication of intraaortic balloon pump (IABP) use. The incidence and risk factors for acute ischemia have been well-defined, but little is known about long-term ischemic complications. This prospective study evaluated the incidence, nature, progression and predisposing factors for long-term lower limb ischemia in 151 patients who were previously treated with the IABP. These persons were interviewed and their lower extremities examined 12 to 20 months after undergoing IABP counterpulsation. Limb ischemia, characterized primarily by ipsilateral discomfort and diminished pulses, occurred in 18% of those evaluated. Evidence of ischemia worsened over time in 14%. Logistic regression analysis, which was based on variables found to be significant in bivariate analysis, revealed that the occurrence of limb ischemia acutely, cardiogenic shock as an indication for IABP insertion, and smoking (at the time of hospitalization or having quit < 10 years previously) were risk factors for long-term lower limb ischemia. The adjusted odds ratio for acute limb ischemia was 8.89 (95% confidence interval 2.80 to 28.21), for cardiogenic shock 3.59 (95% confidence interval 1.01 to 12.75), and for smoking 2.87 (95% confidence interval 1.10 to 7.46). Increasing numbers of patients are undergoing IABP counterpulsation and a greater proportion of these are surviving their acute event and resuming active lives. It is essential to recognize that detrimental consequences of this device can persist long after hospitalization.

Adult↗

Conjunctival hyperresponsiveness to ocular histamine challenge in patients with vernal conjunctivitis.

We compared the conjunctival responsiveness to histamine diphosphate in patients with vernal conjunctivitis and in healthy control subjects. Fourteen asymptomatic patients with vernal conjunctivitis and 10 healthy volunteers were challenged in one eye with 10 microliters of increasing doses (0.01, 0.05, 0.5, and 1 mg/ml in phosphate-buffered saline) of histamine diphosphate. The contralateral eye was challenged with the diluent only. Photographs of each eye were taken for evaluation of conjunctival redness by two masked investigators. Both patients with vernal conjunctivitis and control subjects reacted to histamine with a dose-dependent conjunctival redness 2 to 5 minutes after ocular challenge. Conjunctival redness was more intense in patients with vernal conjunctivitis than in control subjects after ocular challenge with 0.01 and 0.05 mg/ml of histamine diphosphate solution (p less than 0.05). Moreover, the threshold concentration of histamine diphosphate, extrapolated from each individual dose-response curve, was significantly (p less than 0.02) lower in patients with vernal conjunctivitis than in control subjects. Our findings suggest that patients with vernal conjunctivitis demonstrate conjunctival hyperresponsiveness to a nonspecific challenging agent. Nonspecific conjunctival hyperreactivity, a novel concept in allergic eye disease, may be relevant for a better understanding of the pathogenesis and clinical variability of vernal conjunctivitis.

Adolescent↗

Effectiveness of nedocromil sodium 2% eyedrops on clinical symptoms and tear fluid cytology of patients with vernal conjunctivitis.

A double-masked, randomised, placebo-controlled study was conducted to evaluate the effectiveness of nedocromil 2% eyedrops, a mast cell stabilizer, in 20 symptomatic patients with vernal conjunctivitis. A 1-week baseline period was followed by 6 weeks of treatment. Clinical examination and cytological evaluation of tear fluid were performed weekly, and the patients recorded their subjective assessment on a daily diary card. The nedocromil group showed significantly less hyperaemia in the course of treatment than did the placebo group, and significantly less itching at all visits compared with baseline itching. In the nedocromil-treated group, but not in the placebo group, the number of neutrophils, eosinophils and lymphocytes in tears decreased significantly during some treatment weeks when compared with baseline. The overall assessment of treatment efficacy by both clinician and patient was significantly in favour of nedocromil treatment over placebo.

Adolescent↗

Parietaria pollinosis: a review.

Species of the genus Parietaria (pellitory) are a prevalent cause of allergy in the Mediterranean area and the most important in some European regions such as southern Italy and coastal Spain (14, 26, 27, 29, 30, 31, 36, 59, 69). Up to now, however, Parietaria has received little attention in northern Europe and the US because of its limited regional distribution. Therefore, less is known about Parietaria allergy than about other inhalant allergens such as those of grasses, ragweed, and mites. During the last 5 years, only 31 reports on Parietaria allergy have appeared in the literature, as compared with 37 papers on birch pollen. This ratio may appear unbalanced, considering that millions of people suffer from pollinosis caused by Parietaria, while a much smaller number have rhinitis and/or asthma caused by birch pollen. The increasing movement of people throughout Europe and to and from the US is reason to broaden our knowledge of patterns of inhalant allergy in each geographic area, especially where tourism and immigration are high. This paper briefly reviews available data and personal studies on the botanical, aerobiological, immunochemical, and clinical features of Parietaria allergy.

Allergens↗

Pollen-related allergy in Italy.

Pollen-related allergies are very common in Italy and pollinosis is the commonest allergic disease. The type of allergenic plants and the prevalence of hay fever varies among regions. In the Mediterranean area there are characteristic climatic conditions (mildness of winter, summer dryness) that facilitate the growth of a typical vegetation with its associated various types of allergenic pollen grains, some of them very different from those of central and northern Europe. Italy has a central position in the Mediterranean basin, but because of its geographic characteristics, there are different climatic aspects with different vegetation between northern, central, and southern areas. Gramineae are the most common allergenic plants in northern and central Italy, where more than 60% of patients with pollinosis are grass-pollen sensitive. Parietaria is the most important pollinating plant in southern Italy and Liguria. Olea europaea, the olive tree with cultivation widespread in the whole Mediterranean basin, is responsible for frequently severe pollinosis, particularly in some regions of the southern Italy.

Allergens↗