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Valore clinico della determinazione quantitativa delle IgE specifiche

Mario Plebani
Dipartimento Medicina di Laboratorio, Azienda Ospedaliera-Università di Padova e Centro Regionale Specializzato di Ricerca Biomedica Ospedale di Castelfranco Veneto

Biochimica Clinica: 2004; 28(3): 303-322 [Article in italian]

ABSTRACT. The diagnosis of human allergic diseases involves the combined use of a careful clinical history, physical examination, and in vitro and in vivo assay methods for the detection of IgE antibodies of defined allergen specificities. In vivo (skin testing) and in vitro (measurement of specific IgE in serum) techniques cannot be considered interchangeable, the former reflecting not only the presence of IgE but also mast cell integrity, vascular and neural responsiveness. Both techniques have similarities and differences, advantages and disadvantages. Recently introduced "second generation" immunoassays have continued to improve the analytical sensitivity and reproducibility thanks to automation and improved reagent quality. Quantitative assays may allow the use of specific clinical thresholds able to differentiate symptomatic from asymptomatic patients. False negative and false-positive results should derive from lability of some major extracts, and from possible cross-reactivities, respectively. Characterization of allergens at a molecular and submolecular level and, where necessary, the use of recombinant allergens can reduce cross-reactions and further improve the quality of immunoassays.

Problematiche nell'organizzazione e gestione dell'attivita' di laboratorio nelle allergopatie

Giulio Vignati, Dalia Griffanti, Antonietta Maronati, Emiliana Pastori
Centro Malattie Endocrine e Metaboliche, Ospedale "G.Fornaroli" Magenta (MI)

Biochimica Clinica: 2004; 28(3): 323-336 [Article in italian]

ABSTRACT. The organizing and managerial problems in laboratory diagnostics for allergometry presents many critical state, due in particular to heterogeneity of allergens typology (for the analytical aspects) and of requests (from allergists or general practitioner). In this paper we examine these aspects using, as model, the evolution of our laboratory, particularly for request management, use of methods able to give and maintain good analytical results during long time (it means perform suitable programs for QCI and VEQ), and give to clinicians correct expression of results.Using experimental data from our laboratory we evaluate and compare new possible organizing solutions for total automation of sIgE determination evaluating productivity, TAT and real time of operator job.

Valutazione del sistema UNICAP 1000 per il dosaggio in completa automazione delle IgE specifiche

Diego Faggian
Servizio di Medicina di Laboratorio Azienda Ospedaliera di Padova

Biochimica Clinica: 2004; 28(3): 337-344 [Article in italian]

ABSTRACT. Scientific Associations agree on the fact that the only rea1 weapon for contrasting allergies is prevention, consequently the best step to take is towards early diagnosis in order to avoid the development of serious symptomatology. The pathogenetic mecchanism, at the base of an allergic reaction, is mediated by IgE antibodies which appear before the symptoms and represent markers for atopy conditions, enabling differentiation between atopic and nonatopic children. It is the laboratory's role to provide constant technological development, with the task of improving the analytic quality and at the same time containing both direct and induced costs. On these bases the UniCAP 1000 system has been assessed from both the clinical and analytical point of view and interfaced on the centra1ized informative system. Therefore comparison trials have been carried out with the system previously in use, precision and manual trials which have allowed the estimation of RPI (Relative Productive Index) and the calculation of Unattended Time. UniCAP 1000 the fully automatic al1ergy diagnostic system, proved capable of operating in random conditions with priority managment of urgent exams and reduced manuality , in consequence a reduction of error possibilities, decreased working time for operators, improved analytical and clinical outcome reliability and simultaneously lower cost management.

Prevenzione primaria delle malattie allergiche: utopia o reale possibilita'?

Maria Antonella Muraro
Clinica Pediatrica, Università di Padova

Biochimica Clinica: 2004; 28(3): 345-349 [Article in italian]

ABSTRACT. The role of primary prevention measures early in life on the subsequent development of allergic diseases is controversial. Some evidence based recommendations have been recently achieved. Breastfeeding is highly recommended for all infants irrespective of atopic heredity. A dietary regimen is unequivocally effective in the prevention of allergic diseases in high-risk children. In these patients breastfeeding combined with avoidance of solid food and cow's milk for 4 months is the most effective preventive regimen. In the absence of breast milk, formulas with documented reduced allergenicity for at least 4-6 months should be used. The role of exposure to indoor allergens is debated; at present it seems cautious to keep low levels of allergens in the home of high risk children.

Diagnostica della allergia a veleno di Insetti

M.Beatrice Bilò*, Feliciana Brianzoni, Barbara Cinti, Grazia Napoli, Floriano Bonifazi
*U.O. Allergologia - Dipartimento di Malattie Respiratorie ed Allergiche- Ospedali Riuniti di Ancona

Biochimica Clinica: 2004; 28(3): 350-361 [Article in italian]

ABSTRACT. The purpose of diagnostics is to classify a sting reaction, identify the underlying pathogenetic mechanism, and to identify the offending insect. Diagnostic tests should be done in all patients with a history of a systemic sting reaction. Testing comprises skin tests with Hymenoptera venoms and analysis of the serum for Hymenoptera venom-specific IgE. Sensitivity of skin tests is higher than that of venom specific IgE serum tests. If both skin tests and specific IgE stay negative additional in-vitro tests should be carried out. Serum tryptase should be analysed in patients with a history of a severe sting reaction. Recombinant venom allergens will improve the diagnosis of venom allergy in a near future.

Cross reattività tra polline di graminacee e pomodoro in pazienti con o senza sindrome orale allergica

Franco Borghesan MD*, Ingrid Holmquist BSC*, Elisabetta Favero MD, Fulvia Chieco Bianchi MD, Lucia Billeri MD, Andrea Leonardi MD, Anita Kober PhD* e Mario Plebani MD
*Department of Laboratory Medicine, University-Hospital, Padova-Italy, *Pharmacia Diagnostic Uppsala-Svezia

Biochimica Clinica: 2004; 28(3): 362-368 [Article in italian]

ABSTRACT. Background: Aim of this study was to determine whether it is possible to identify a common antigenic determinants in patients with cross-reactivity between grass pollen and tomato. Method: We selected forty-six sensitized subjects that had consecutively referred to our allergy outpatients' clinic. Three groups of patients allergic to grass pollen were identified and then subdivided according to the presence of IgE to tomato with or without oral allergy syndrome (OAS). Radio Allergo Sorbent Test with Pharmacia-CAP techniques inhibition (RAST-CAP) was used to assess cross-reactivity and Sodium Dodecyl Sulphate Polyacrylamide Gel Electrophoreis (SDS-PAGE) immunoblotting was performed to detect specific antigenic determinants. Results: In immunoblot, the 21 patients of group 1 showed IgE against a 30-36 kD protein of g6. The same protein was shared by the patients of group 2 (who were sensitive to tomato but did not show any symptoms after ingestion of tomato), and of group 3 (who were sensitive to tomato and had OAS after ingesting tomato). The immunoblotting analysis of the tomato protein revealed that the patients from group 3 had a significantly higher prevalence of IgE against a 14-15 kD protein than groups 1 and 2. Conclusions: we have identified some allergenic proteins that define not only cross-reactivity but also co-sensitization in patients with sensitivity to grass pollen and with oral allergy syndrome to tomato.

Il laboratorio nella diagnosi delle congiuntiviti allergiche

Andrea Leonardi
Dipartimento di Neuroscienze, Clinica oculistica, Università di Padova

Biochimica Clinica: 2004; 28(3): 369-377 [Article in italian]

ABSTRACT. The diagnosis of allergic conjunctivitis is usually clinical, however, allergic tests are indicated for a more specific diagnosis and patient management. While chronic and severe ocular allergic conditions have clear diagnostic signs and symptoms, the most common diseases, seasonal and perennial allergic conjunctivitis, have no identifying patognomonic signs. Skin tests and measurement of serum specific IgE are usually sufficient for an allergic diagnosis, however, often the results of these tests are negative in the presence of a typical clinical history. In these cases, the conjunctival provocation test and the measurement of tear mediators may provide more locally spcific information. In the active form of the disease, cytological tests are indicated; the presence of tear eosinophils in particular is indicative of an allergic reaction. The specific conjunctival provocation test, performed in the non-active phase of the disease, may show local sensitivities to allergens. Low tear volume limits the potential in vitro diagnose. The measurement of tear specific IgE is not practical. An simple local test, involves the measurement of total IgE by paper strips, however, this test is not highly specific. The measurement of ECP, tryptase, IL-4, IL-5 and eotaxin tear levels may also be useful for the diagnosis of ocular allergy.

Livelli di espressione della tankirasi nel carcinoma della vescica e nelle urine*

Silvia Quattrone*, Stefania Gelmini, Cesare Selli, Donata Villari, Bruno Neri, Mario Pazzagli, Claudio Orlando
*Dipartimento di Fisiopatologia Clinica, Unità di Biochimica Clinica, Università degli Studi di Firenze

Biochimica Clinica: 2004; 28(3): 378-381 [Article in italian]

ABSTRACT. The control of human telomere length requires a telomere-specific DNA binding protein, TRF1 (telomeric repeat binding factor-1). Tankyrase (TK), a telomeric protein with homology to the catalytic domain of poly (adenosine diphosphate-ribose) polymerase, contains 24 ankyrin repeats in a domain responsible for its interaction with TRF1. ADP-ribosylation of TRF1 decreases its ability to bind to telomeric DNA and causes telomere elongation, a mechanism connected to cell immortalization and cancer development. Because of the strong tendency of bladder cancer to recur, the monitoring of asymptomatic patients has a particular importance. TK mRNA expression was measured with a quantitative method (real time RT-PCR) in bladder cancers (n=45) and in corresponding normal mucosae. In all patients, TK mRNA was also measured in exfoliated cells collected with voided urine. The expression of TK mRNA in superficial (6.2æ1.9 x 105) and infiltrating (13.0æ3.5 x 105) bladder cancer were significantly higher (p=0.016 and p=0.023, respectively) than in corresponding normal tissues (2.3æ0.3 x105). We found the highest concentrations of urinary TK mRNA in patients affected by infiltrating bladder cancer (3.7æ2.4 x 104), whereas in patients with non infiltrating superficial bladder cancers TK mRNA was lower (9.9æ8.3 x 103), but still significantly different from normal controls (1.2æ3.7 x 102, p<0.005). In conclusion TK mRNA appears a promising tool in bladder cancer diagnosis and follow-up.

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