Recommendations for the Use of Tryptase in the Diagnosis of Anaphylaxis and Clonal Mastcell Disorders.

Summary: Tryptase is a serin-protease produced and released by mast cells after IgE-mediated or non-IgE mediated stimuli. We here review the various aspects related to the molecular characteristics of the enzyme and its biological effects, the genetic basis of its production and the release kinetics. Recommendations for the clinical use of tryptase measurement developed by a task force of Società Italiana di Patologia Clinica e Medicina di Laboratorio and Associazione Allergologi Immunologi Italiani Territoriali e Ospedalieri are given on the best procedure for a correct definition of the reference values in relation to the inter-individual variability and to the correct determination of tryptase in blood and other biological liquids, in the diagnosis of anaphylaxis (from drugs, food, insect sting, or idiophatic), death from anaphylaxis (post mortem assessment) and cutaneous or clonal mastcell disorders.

House dust mite allergy and shrimp allergy: a complex interaction.

Summary: Background and Objective. Sensitization and allergy to shrimp among Italian house dust mite allergic patients are not well defined and were investigated in a large multicenter study. Methods. Shrimp sensitization and allergy were assessed in 526 house dust mite (HDM)-allergic patients submitted to the detection of IgE to Der p 10 and 100 atopic control not sensitized to HDM. Results. Shrimp allergy occurred in 9% of patients (vs 0% of 100 atopic controls not sensitized to HDM; p minor 0.001). Shrimp-allergic patients were less frequently hypersensitive to airborne allergens other than HDM than crustacean-tolerant subjects (35% vs 58.8%; p minor 0.005). Only 51% of tropomyosin-sensitized patients had shrimp allergy, and these showed significantly higher Der p 10 IgE levels than shrimp-tolerant ones (mean 22.2 KU/l vs 6.2 KU/l; p minor 0.05). Altogether 53% of shrimp-allergic patients did not react against tropomyosin. Conclusions. Shrimp allergy seems to occur uniquely in association with hypersensitivity to HDM allergens and tropomyosin is the main shrimp allergen but not a major one, at least in Italy. Along with tropomyosin-specific IgE levels, monosensitization to HDM seems to represent a risk factor for the development of shrimp allergy among HDM allergic patients.

Recommendations for the use of molecular diagnostics in the diagnosis of allergic diseases.

Summary: The Study Group on Allergology of the Italian Society of Clinical Pathology and Laboratory Medicine (SIPMeL) and the Associazione Italiana degli Allergologi e Immunologi Territoriali e Ospedalieri (AAIITO) developed the present recommendations on the diagnosis of allergic diseases based on the use of molecular allergenic components, whose purpose is to provide the pathologists and the clinicians with information and algorithms enabling a proper use of this second-level diagnostics. Molecular diagnostics allows definition of the exact sensitization profile of the allergic patient. The methodology followed to develop these recommendations included an initial phase of discussion between all the components to integrate the knowledge derived from scientific evidence, a revision of the recommendations made by Italian and foreign experts, and the subsequent production of this document to be disseminated to all those who deal with allergy diagnostics.

Role of biomarkers in adult sepsis and their application for a good laboratory practice: a pilot study.

This study measured Procalcitonin (PCT), Presepsin (PRE-S) and pro-Adrenomedullin (pro-ADM) in intensive care unit (ICU) patient’s blood to assess their contribution to accurate diagnosis of sepsis and potential predictive impact on prognosis. The final aim was to improve the use of infection biomarkers for optimizing the impact of laboratory medicine on clinical outcomes, focusing on the good management of resources designed to produce maximum effectiveness and efficiency. Sixty-four adult patients were studied during their hospitalization in ICU; blood samples were collected and categorized according to their clinical diagnosis and illness severity, and sepsis marker levels were measured on automated immunoassay platforms. PCT, PRE-S and pro-ADM infection markers were significantly lower in controls than in sepsis or septic shock groups. The area under the curve, by ROC curve analysis, was 0.945 for PCT, 0.756 for PRE-S and 0.741 for pro-ADM. Sepsis diagnostic accuracy was not improved by combining PCT, PRE-S and pro-ADM measures. Preliminary data demonstrated that, despite PRE-S and pro-ADM being able to differentiate between septic and non-septic patients with accuracy, PCT remains the most reliable marker available. The results obtained still do not allow us to consider a combination of markers, because it would merely increase laboratory costs without improving diagnostic performance. Furthermore, the results confirm a possible prognostic role of pro-ADM in septic states, but no correlation between biomarker levels and survival at 48 h was detected. Hence PCT, PRE-S, nor pro-ADM can be used to predict short-term prognosis.

Severe anaphylaxis to sheep's milk cheese in a child desensitized to cow's milk through specific oral tolerance induction.

Specific oral tolerance induction to food (SOTI) is a new promising treatmentfor persistent IgE-mediatedfood allergy. Our paper reports a case of a 5-year-old girl with cow's milk allergy, who developed severe anaphylaxis after the ingestion of a croissant containing sheep's milk ricotta cheese, even though she had been previously desensitized to cow's milk through SOTI. The sheep's milk specific allergen causing the severe allergic reaction (a derivative of alpha-casein of 54,1kDa) was identified by SDS-PAGE and immunoblotting. We conclude that SOTI is a species-specific procedure and the induced tolerance to cow's milk doesn't necessarily provide protection against milk of other mammals. Therefore, children desensitized to cow's milk through SOTI should strictly avoid the intake of milk of other mammals, until tolerance to those kinds of milk is documented by an oral food challenge.

Assessment of NGAL as an early biomarker of acute kidney injury in adult cardiac surgery patients.

Early and predictive acute kidney injury (AKI) markers may be decisive for the clinical outcome of heart surgery. Hence, this study set out to evaluate the biological variability of urinary neutrophil gelatinase-associated lipocalin (uNGAL) levels in adult cardiac surgery patients, to test their feasibility as a biomarker of early AKI in a routine laboratory setting. uNGAL levels were measured with an automated immunoassay in urine samples from patients undergoing cardiac surgery using cardiopulmonary bypass, at the time of admission (T0) and 4 hours (T1) and 24 hours (T2) after surgery. Patients without post-operative AKI did not show significant differences in urine NGAL levels after surgery. In contrast, patients developing AKI displayed a significant increase (P=0.011) in uNGAL levels compared to T0. This increase was detectable at an earlier time point (T1, 4 hours) with respect to serum creatinine (T2, 24 hours). Confirming its utility as a biomarker, at T1 the uNGAL levels were significantly higher in AKI patients than in non-AKI patients (P=0.021). A receiver operating characteristic curve analysis of the uNGAL assay gave a sensitivity of 55.3 (95percent confidence interval, 26.59-78.73), a specificity of 72.9 (95 percent CI, 55.88-86.21), and a cut-off value for AKI prediction of 55.2. These results support the notion that urinary NGAL is an earlier marker of AKI than serum creatinine. However, the cut-off value of the assay was too low to consider it as a positive or negative diagnostic marker in AKI patients with moderate degree of severity. Likewise, its sensitivity and specificity were not high enough for it to be considered better than the others currently in use.

Automated Intelligent Microscopy for the Recognition of Decoy Cells in Urine Samples of Kidney Transplant Patients.

BACKGROUND: BK virus (BKV)-associated nephropathy is definitely involved in allograft failure after kidney transplant. Thus, the need for an early control of viral reactivation in immunocompromised patients is well established. Determination of urinary release of decoy cells (DC) and BK viral load in plasma and urine by polymerase chain reaction (PCR) usually precedes renal biopsy. The aim of the study is to assess viral reactivation by BKV-DNA PCR and DC detection in urinary sediment using automated intelligent microscopy. METHODS: Seventy-eight kidney transplant patients were analyzed for the presence of plasma BKV-DNA by quantitative TaqMan real-time PCR. Additionally, automated intelligent microscopy was used for urine sediment analysis, allowing to count cells with decoy feature, confirmed by phase contrast microscopic review. RESULTS: Plasma BKV-DNA PCR was detected in 14 (17.9%) patients. DC were identified in 19 (24.3%) urine sediments by automated analyzers and confirmed by microscopic observation. Two patients were BKV-DNA-positive/DC-negative; conversely, 7 subjects were DC-positive/BKV-DNA-negative. CONCLUSIONS: Plasma quantification of BK viral load is currently the best noninvasive method for the detection of viral reactivation. Nevertheless, automated methods to screen for the presence of DC in urine could facilitate early BK virus replication diagnosis and patient follow-up by quantitative and visual results.

Detection of interleukin-2 in addition to interferon-gamma discriminates active tuberculosis patients, latently infected individuals, and controls.

Effective control of tuberculosis (TB) includes discrimination of subjects with active TB from individuals with latent TB infection (LTBI). As distinct interferon (IFN)-gamma and interleukin (IL)-2 profiles of antigen-specific T-cells have been associated with different clinical stages and antigen loads in several viral and bacterial diseases, we analysed these cytokines in TB using a modified QuantiFERON-TB Gold In Tube test. Detection of IL-2 in addition to IFN-gamma distinguishes not only Mycobacterium tuberculosis-infected subjects from healthy controls, but also individuals with LTBI from active TB patients. This may help to improve diagnostic tests for TB.