Salmonella Paratyphi A Outer Membrane Vesicles Displaying Vi Polysaccharide as a Multivalent Vaccine against Enteric Fever.

Typhoid and paratyphoid fevers have a high incidence worldwide and coexist in many geographical areas, especially in low-middle-income countries (LMIC) in South and Southeast Asia. There is extensive consensus on the urgent need for better and affordable vaccines against systemic Salmonella infections. Generalized modules for membrane antigens (GMMA), outer membrane exosomes shed by Salmonella bacteria genetically manipulated to increase blebbing, resemble the bacterial surface where protective antigens are displayed in their native environment. Here, we engineered S Paratyphi A using the pDC5-viaB plasmid to generate GMMA displaying the heterologous S Typhi Vi antigen together with the homologous O:2 O antigen. The presence of both Vi and O:2 was confirmed by flow cytometry on bacterial cells, and their amount was quantified on the resulting vesicles through a panel of analytical methods. When tested in mice, such GMMA induced a strong antibody response against both Vi and O:2, and these antibodies were functional in a serum bactericidal assay. Our approach yielded a bivalent vaccine candidate able to induce immune responses against different Salmonella serovars, which could benefit LMIC residents and travelers.

Management of patients with severe asthma: results from a survey among allergists and clinical immunologists of the Central Italy Inter-Regional Section of SIAAIC.

BACKGROUND: Asthma, and severe asthma in particular, is often managed within a specialized field with allergists and clinical immunologists playing a leading role. In this respect, the National Scientific Society SIAAIC (Società Italiana di Allergologia, Asma ed Immunologia Clinica), structured in Regional and Inter-Regional sections, interviewed a large number of specialists involved in the management of this respiratory disease. METHODS: A survey entitled "Management of patients with asthma and severe asthma" based on 17 questions was conducted through the SIAAIC newsletter in 2019 thanks to the collaboration between GlaxoSmithKline S.p.A. and the Inter-Regional Section of SIAAIC of Central Italy. RESULTS: Fifty-nine allergists and clinical immunologists participated to the survey, and 40 of them completed the entire questionnaire. Almost all of the specialists (88%) reported that asthma control was achieved in above 50% of their patients, even if only one third (32%) actually used validated clinical tools such as asthma control test (ACT). Poor adherence to inhaled therapy was recognized as the main cause of asthma control failure by 60% of respondents, and 2-5 min on average is dedicated to the patient inhaler technique training by two-thirds of the experts (65%). Maintenance and as-needed therapy (SMART/MART) is considered an appropriate approach in only a minority of the patients (25%) by one half of the respondents (52%). A high number of exacerbations despite the maximum inhalation therapy were recognized as highly suspicious of severe asthma. Patients eligible for biological therapies are 3-5% of the patients, and almost all the responders (95%) agreed that patients affected by severe asthma need to be managed in specialized centers with dedicated settings. Biological drugs are generally prescribed after 3-6 months from the initial access to the center, and once started, the follow-up is initially programmed monthly, and then every 3-6 months after the first year of treatment (96% of responders). After phenotyping and severity assessment, comorbidities (urticaria, chronic rhinosinusitis with or without nasal polyps, vasculitis, etc.) are the drivers of choice among the different biological drugs. In the management of severe asthma, general practitioners (GPs) should play a central role in selecting patients and referring them to specialized centers while Scientific Societies should train GPs to appropriately recognize difficult asthma and promote public disease awareness campaigns. CONCLUSIONS: This survey which collects the point of view of allergists and clinical immunologists from Central Italy highlights that asthma control is still not measured with validated instruments. There is a general consensus that severe asthma should be managed only in dedicated centers and to this aim it is essential to encourage patient selection from a primary care setting and develop disease awareness campaigns for patients.

Dual role of splenic mononuclear and polymorphonuclear cells in the outcome of ciprofloxacin treatment of Salmonella enterica infections.

OBJECTIVES: To determine the immune cell populations associated with Salmonella enterica serovar Typhimurium before and after ciprofloxacin treatment using a murine model of systemic infection. The effect of depletion of immune cells associating with Salmonella on treatment outcome was also determined. METHODS: We infected mice with a Salmonella enterica serovar Typhimurium strain expressing GFP and used multicolour flow cytometry to identify splenic immune cell populations associating with GFP-positive Salmonella before and after treatment with ciprofloxacin. This was followed by depletion of different immune cell populations using antibodies and liposomes. RESULTS: Our results identified CD11b+CD11chi/lo (dendritic cells/macrophages) and Ly6G+CD11b+ (neutrophils) leucocytes as the main host cell populations that are associated with Salmonella after ciprofloxacin treatment. We therefore proceeded to test the effects of depletion of such populations during treatment. We show that depletion of Ly6G+CD11b+ populations resulted in an increase in the number of viable bacterial cells in the spleen at the end of ciprofloxacin treatment. Conversely, treatment with clodronate liposomes during antimicrobial treatment, which depleted the CD11b+CD11chi/lo populations, resulted in lower numbers of viable bacteria in the tissues. CONCLUSIONS: Our study identified host cells where Salmonella bacteria persist during ciprofloxacin treatment and revealed a dual and opposing effect of removal of Ly6G+CD11b+ and CD11b+CD11chi/lo host cells on the efficacy of antimicrobial treatment. This suggests a dichotomy in the role of these populations in clearance/persistence of Salmonella during antimicrobial treatment.

Omalizumab retreatment in patients with chronic spontaneous urticaria: a systematic review of published evidence.

Summary: A systematic review of the current literature on retreatment with omalizumab of patients with relapsing chronic spontaneous urticaria was performed. Published evidence shows that retreatment is safe and clinically effective, and that time to complete clinical response reduces as the number of retreatments increases.

Migrants and allergy: a new view of the atopic march.

Summary: Atopy is the result of the influence of environmental factors on genetically predisposed individuals. Migration flows represent an interesting model to study the possible reciprocal roles of genes and environment. In this review the following issues influencing the development of allergic sensitization and/or atopic disorders in migrants will be rooted out: 1) ethnicity, genetic polymorphisms and risk of atopy; 2) double faceted effects of parasitic infestations; 3) biodiversity loss and industrial progress. Moreover, an extensive revision of the literature about the relationship between the migratory status and allergy development is provided.

Within-host spatiotemporal dynamics of systemic Salmonella infection during and after antimicrobial treatment.

OBJECTIVES: We determined the interactions between efficacy of antibiotic treatment, pathogen growth rates and between-organ spread during systemic Salmonella infections. METHODS: We infected mice with isogenic molecularly tagged subpopulations of either a fast-growing WT or a slow-growing ΔaroC Salmonella strain. We monitored viable bacterial numbers and fluctuations in the proportions of each bacterial subpopulation in spleen, liver, blood and mesenteric lymph nodes (MLNs) before, during and after the cessation of treatment with ampicillin and ciprofloxacin. RESULTS: Both antimicrobials induced a reduction in viable bacterial numbers in the spleen, liver and blood. This reduction was biphasic in infections with fast-growing bacteria, with a rapid initial reduction followed by a phase of lower effect. Conversely, a slow and gradual reduction of the bacterial load was seen in infections with the slow-growing strain, indicating a positive correlation between bacterial net growth rates and the efficacy of ampicillin and ciprofloxacin. The viable numbers of either bacterial strain remained constant in MLNs throughout the treatment with a relapse of the infection with WT bacteria occurring after cessation of the treatment. The frequency of each tagged bacterial subpopulation was similar in the spleen and liver, but different from that of the MLNs before, during and after treatment. CONCLUSIONS: In Salmonella infections, bacterial growth rates correlate with treatment efficacy. MLNs are a site with a bacterial population structure different to those of the spleen and liver and where the total viable bacterial load remains largely unaffected by antimicrobials, but can resume growth after cessation of treatment.

Multilocular sinonasal malignant melanoma: a poor prognostic subgroup?

Clinical observations show that two subtypes of sinonasal malignant melanoma exist: uni- and multilocular melanoma. The aim of this retrospective study was to determine the prevalence and outcome of multilocular sinonasal malignant melanoma. All patients with sinonasal malignant melanoma treated at our institution between 1992 and 2011 were included. Survival and recurrence data were analyzed related to the distribution pattern of the tumors and other factors. Twenty-five patients were identified and included in the analysis. Seven patients (28 %) suffered from multilocular, the remaining 18 patients (72 %) from unilocular sinonasal malignant melanoma. The first group showed a significantly worse disease-free survival, whereas disease-specific and overall survival did not differ between the two subtypes. Multilocular sinonasal malignant melanoma is associated with an unfavorable disease-free survival compared to its unilocular counterpart.

Management of chronic spontaneous urticaria: practical parameters.

Chronic urticaria (CU) is a skin disorder characterized by transient, pruritic wheals persisting for longer than 6 weeks. According to the European Academy of Allergy and Clinical Immunology (EAACI) guidelines, CU can be categorized into two main types: chronic spontaneous urticaria (CSU), in which the wheals appear spontaneously, and inducible urticaria, that is triggered by physical agents. CSU may be due to triggering factors such as food allergens or infections, but in at least 40% of cases it is autoimmune in origin, caused by circulating autoantibodies anti-FcεR1 or anti-IgE, or autoreactive. In the present paper, re-evaluating the EAACI guidelines, we have developed a document containing some practical indications which are useful for diagnosis and management of CSU in the context of the Italian situation. Concerning CSU treatment, second generation antihistamines are the first-line treatment; these drugs can be used, as second-line treatment, at a higher than licensed dose in patients who do not respond adequately at licensed doses. The third-line treatment includes leukotriene receptor antagonists which, however, do not have a specific indication for the treatment of CSU, cyclosporine, whose use in this disease is still off-label, and omalizumab. The latter is a recombinant monoclonal IgG antibody that binds free IgE, down regulates mast cell function and induces eosinophil apoptosis. Recently, it has emerged as an effective and safe treatment for antihistamine-unresponsive CSU of both autoimmune/autoreactive and non-autoimmune/non-autoreactive, and has been officially approved for use against this disease.

Illness perception, mood and coping strategies in allergic rhinitis: are there differences among ARIA classes of severity?

BACKGROUND: This study was designed to assess if illness perception, mood state and coping strategies differ according to allergic rhinitis (AR) persistence and severity. METHODS: Illness perception, mood profiles, coping behaviors and rhinitis symptoms were assessed by means of validated tools inpatients classified according to the Allergic Rhinitis and Its Impact on Asthma (ARIA) guidelines. RESULTS: Two hundred and thirty-one patients underwent data analysis. No difference in age, sex, socio-economic status, smoking habits was detected comparing patients according to AR severity, duration or 4 ARIA classes. Patients with intermittent AR reported higher scores than those with persistent AR in confusion-bewilderment of Profile of Mood States (POMS); patients with moderate/severe rhinitis had significantly higher scores than those with mild rhinitis in TSSS, Identity and Consequences. No differences were detected in all assessed outcomes in the 4 ARIA classes. CONCLUSIONS: The patient's perspective about AR is independent of persistence and severity of symptoms. This may explain why AR remains under-diagnosed and under-treated, even in its most severe forms. Self-management plans should consider the patient's perspective.

Practical approach to self-administration of intravenous C1-INH concentrate: a nursing perspective.

At an international hereditary angioedema (HAE) expert meeting, results from a survey were used to guide discussion on how best to advise patients on self-administering intravenous C1 esterase inhibitor therapy. Treatment differences across Europe were highlighted, together with the practicalities of self-administration and useful resources for patients in the future. The international HAE experts noted an increase in the uptake of self-administration, with patients being trained by nursing staff. All patients who are willing and able to self-administer should be offered this treatment option and patients should be encouraged to treat attacks early. Several initiatives were suggested regarding support for patients who self-administer therapy, including a 24-hour helpline and home care agencies.

Factors influencing the prescription of allergen immunotherapy: the allergen immunotherapy decision analysis (AIDA) study.

The evidence of efficacy of allergen immunotherapy (AIT) for respiratory allergy has been demonstrated by a number of meta-analyses. However, the daily practice of AIT is quite different from controlled trials, facing challenges in terms of selection of patients, practical performance, and, of particular importance, use of allergen extracts of inadequate quality. We here performed a survey, named the Allergen Immunotherapy Decision Analysis (AIDA), to evaluate which criteria are used by specialists to choose a product for sublingual immunotherapy (SLIT) in patients with respiratory allergy. A questionnaire composed of 14 items to be ranked by each participant according to the importance attributed when choosing SLIT products was submitted to 444 Italian specialists. The responses of the 169 (38.1%) physicians, who answered all questions, were analysed. Most of the respondents were allergists (79%), followed by pulmonologists (10.8%), both allergists and pulmonologists (4.8%), and otorhinolaryngologists (3%); 59.8% of the respondents were males and 40.2% were females. The age distribution showed that 89.9% of the respondents were aged between 35 and 64 years. All respondents usually prescribed AIT products in their clinical practice: 31.4% used only SLIT, whereas 69.2% used both subcutaneous and sublingual administration. The rankings, expressed as means, attributed by physicians for each of the 14 items were as follows: level of evidence-based medicine (EBM ) validation of efficacy (3.44), level of EBM validation of safety (4.30), standardization of the product (5.37), efficacy based on personal experience (5.82), defined content(s) of the major allergen(s) in micrograms (5.96), scientific evidence for each single allergen (6.17), safety based on personal experience (6.32), ease of administration protocol (8.08), cost and terms of payment (e.g. instalments) (9.17), dose personalization (9.24), patient preference (9.25), ease of product storage (9.93), reimbursement (10.12), and availability of a helpline or on-line assistance from the manufacturer (11.89). These attitudes need to be taken into consideration by regulatory agencies as well as by producers.

Comparison of cephalometric changes in Class II growing patients with increased vertical dimension after high-pull and cervical headgear treatment.

AIM: The aim of the present study was to evaluate the cephalometric changes in growing Class II patients with increased vertical dimension treated with cervical or high-pull headgear, by using an untreated control group with similar skeletal characteristics. MATERIALS: From the initial sample, 56 patients satisfied the inclusion and exclusion criteria; 20 patients were treated with cervical headgear (CHG), 15 with high-pull headgear (HHG), and 21 were not treated (CG). Cephalograms were available for each subject at baseline (T1) and after treatment/observation time (T2) for the three groups. A total of 17 measurements were taken on the lateral head films. Group comparison among CHG, HHG and CG was done using ANOVA test. CONCLUSION: In Class II high-angle growing patients, cervical headgear seems to be preferred in the correction of maxillary protrusion, molar relationship and increased anterior facial height. Extrusion of the upper molar may favour forward repositioning of the mandible and clockwise rotation in Class II patients with increased vertical dimension.

3D Computed Tomography vs. 2D radiography: comparison of 3D direct anthropometry with 2D norm calculations and analysis of differences in soft tissue measurements.

OBJECTIVE: The aim of this study was twofold: (1) to compare soft tissue measurements of the same distances obtained from 3D computed tomography reconstructions with 2D cephalometric radiograms, (2) to compare data from 3D measurements from direct anthropometry and 2D "norms" for the facial measurements. PATIENTS AND METHODS: A total of 40 Caucasian patients that had their CBCT scans for various dental and dentoskeletal reasons were enrolled in this study. All the patients had large field of view (from the forehead to the chin). The data were stored in DICOM format and imported into a software for 3D reconstructions. After 3D facial soft tissue model generation, the distances between 18 soft tissue points were measured. The 3D soft tissue analysis was performed, and the facial indices were calculated. The mean 3D values were compared with 2D measurements performed on lateral cephalograms and Arnett's and Farkas' norms. The measurements were statistically compared using Student's t-test. RESULTS: Assessments from 2D and 3D measurements showed no statistical difference except for the distance Pogonion (for both male and female) and Labial superius prominence (females) to the True Vertical Line in 2D /Plane in case of 3D measurements. There was a significant difference between all 3D measurements and Arnett's and anthropometric Farkas' "norms". The mean difference between Farkas' "norms" and 3D measurements was within 3 mm for 70% of measurements. CONCLUSIONS: According to the results, 3D soft tissue analysis allows for complete diagnostic determination. The 3D "norms" are to be verified on a greater sample.

RhinAsthma patient perspective: a short daily asthma and rhinitis QoL assessment.

BACKGROUND: The present study aimed to develop a short validated patient-completed questionnaire, the RhinAsthma Patient Perspective (RAPP), to assess the health-related quality of life (HRQoL) in patients with asthma and comorbid allergic rhinitis in clinical practice. METHODS: A provisional RAPP questionnaire was formed from candidate items identified through retrospective analysis of 333 RHINASTHMA questionnaires. This was then tested on 150 asthma patients with allergic rhinitis. RESULTS: Psychometric analyses identified eight items fitting a unidimensional model to form RAPP. Internal consistency (Cronbach's alpha coefficient > 0.8) and agreement with RHINASTHMA (r = -0.31, P = 0.0001) were excellent. Criterion, discriminant, and convergent validity were good. Reliability in 47 stable patients was very good (intra-class and concordance correlation coefficients were 0.90 and 0.89, respectively). Responsiveness in 103 patients with health improvement or deterioration was significantly associated with changes in Global Rating Scale (r = -0.4965, P < 0.01), Rhinitis Visual Analogue Scale (r = 0.5722, P < 0.01) and asthma control test (r = -0.6483, P < 0.01). Minimal clinical difference in the analyzed population was 2. CONCLUSION: RhinAsthma Patient Perspective is a simple eight-question questionnaire with good measurement properties and sensitivity to health changes, which will provide a valid, reliable and standardized HRQoL measurement in patients with asthma and comorbid allergic rhinitis in clinical practice.

Satisfaction with allergy treatments depends on symptom severity but not on allergen specificity in patients with allergic rhinitis.

Allergic rhinitis is characterized by troublesome symptoms that may be particularly severe. Most of rhinitics are dissatisfied with drug treatments. The dissatisfaction level depends on symptoms severity, but not on the type of causal allergen.

Pregnancy in women with Hereditary Angioedema due to C1-inhibitor deficiency: Results from the ITACA cohort study on outcome of mothers and children with in utero exposure to plasma-derived C1-inhibitor.

Background: In women with Hereditary Angioedema (HAE) due to C1-inhibitor (C1INH) deficiency (C1INH-HAE), pregnancy counseling and treatment can be challenging. Despite the evidence of the immediate favorable outcome and safety of plasma-derived (pd)C1INH concentrate, there are no data regarding any difference among women who underwent or not pdC1INH during pregnancy or on children with in utero exposure to pdC1INH. The present interview study aimed at analyzing outcome of C1INH-HAE mothers and children according to pdC1INH-exposure during pregnancies. Methods: C1INH-HAE women who experienced at least 1 pregnancy were included from seven centers of the Italian Network for Hereditary and Acquired Angioedema (ITACA). The interview study retrospectively analyzed pregnancies who underwent (group 1) or not (group 2) pdC1INH. The overall goals of the study included immediate and long-term outcomes, in terms of outcomes in the time interval between pregnancy and survey. Results: A total of 168 pregnancies from 87 included women were analyzed. At term delivery (>37 gestation-week, GW) has been registered in 73.8% of cases, while spontaneous abortion (SA) occurred in 14.2% of cases with a mean GW 7 ± 2. The group 1 including pdC1INH-treated pregnancies comprised a third of the cohort (51/168, time interval 1.5 ± 10.4 yrs), while the group 2 represented 69.6% (117/168, time interval 32.8 ± 14 yrs). The same prevalence of SA occurred when comparing group 1 (11.7%) with group 2 (15.4%) with a similar GW at SA. The group 1 was older at the pregnancy time and younger at the interview than the group 2 (P < 0.01 for both); moreover, the group 1 showed a higher prevalence of cesarean delivery (P < 0.0001). The overall prevalence of obstetrical syndromes was similar between two groups: however, gestational diabetes was described only in pdC1INH-untreated pregnancies. In utero pdC1INH-exposed children (n = 45) did not show differences compared with unexposed ones (n = 99) in neonatal short-term outcomes. Conclusion: Through appropriate management and counseling, most of C1INH-HAE women undergo successful pregnancy and delivery. For pregnant C1INH-HAE women being treated with pdC1INH, our findings are reassuring and might lead to an improvement of both the knowledge about treatments and the experience of HAE itself.

Gas1 Regulates Patterning of the Murine and Human Dentitions through Sonic Hedgehog.

The mammalian dentition is a serially homogeneous structure that exhibits wide numerical and morphological variation among multiple different species. Patterning of the dentition is achieved through complex reiterative molecular signaling interactions that occur throughout the process of odontogenesis. The secreted signaling molecule Sonic hedgehog (Shh) plays a key role in this process, and the Shh coreceptor growth arrest-specific 1 (Gas1) is expressed in odontogenic mesenchyme and epithelium during multiple stages of tooth development. We show that mice engineered with Gas1 loss-of-function mutation have variation in number, morphology, and size of teeth within their molar dentition. Specifically, supernumerary teeth with variable morphology are present mesial to the first molar with high penetrance, while molar teeth are characterized by the presence of both additional and absent cusps, combined with reduced dimensions and exacerbated by the presence of a supernumerary tooth. We demonstrate that the supernumerary tooth in Gas1 mutant mice arises through proliferation and survival of vestigial tooth germs and that Gas1 function in cranial neural crest cells is essential for the regulation of tooth number, acting to restrict Wnt and downstream FGF signaling in odontogenic epithelium through facilitation of Shh signal transduction. Moreover, regulation of tooth number is independent of the additional Hedgehog coreceptors Cdon and Boc, which are also expressed in multiple regions of the developing tooth germ. Interestingly, further reduction of Hedgehog pathway activity in Shhtm6Amc hypomorphic mice leads to fusion of the molar field and reduced prevalence of supernumerary teeth in a Gas1 mutant background. Finally, we demonstrate defective coronal morphology and reduced coronal dimensions in the molar dentition of human subjects identified with pathogenic mutations in GAS1 and SHH/GAS1, suggesting that regulation of Hedgehog signaling through GAS1 is also essential for normal patterning of the human dentition.

Nitrogen dioxide pollution increases vulnerability to COVID-19 through altered immune function.

Previous ecological studies suggest the existence of possible interplays between the exposure to air pollutants and SARS-CoV-2 infection. Confirmations at individual level, however, are lacking. To explore the relationships between previous exposure to particulate matter < 10 µm (PM10) and nitrogen dioxide (NO2), the clinical outcome following hospital admittance, and lymphocyte subsets in COVID-19 patients with pneumonia. In 147 geocoded patients, we assessed the individual exposure to PM10 and NO2 in the 2 weeks before hospital admittance. We divided subjects according to the clinical outcome (i.e., discharge at home vs in-hospital death), and explored the lymphocyte-related immune function as an index possibly affecting individual vulnerability to the infection. As compared with discharged subjects, patients who underwent in-hospital death presented neutrophilia, lymphopenia, lower number of T CD45, CD3, CD4, CD16/56 + CD3 + , and B CD19 + cells, and higher previous exposure to NO2, but not PM10. Age and previous NO2 exposure were independent predictors for mortality. NO2 concentrations were also negatively related with the number of CD45, CD3, and CD4 cells. Previous NO2 exposure is a co-factor independently affecting the mortality risk in infected individuals, through negative immune effects. Lymphopenia and altered lymphocyte subsets might precede viral infection due to nonmodifiable (i.e., age) and external (i.e., air pollution) factors. Thus, decreasing the burden of air pollutants should be a valuable primary prevention measure to reduce individual susceptibility to SARS-CoV-2 infection and mortality.

Anti-infliximab IgE and non-IgE antibodies and induction of infusion-related severe anaphylactic reactions.

BACKGROUND: Infliximab is a chimeric monoclonal antibody against TNF-alpha useful in the treatment of many chronic inflammatory diseases. Severe anaphylaxis has been reported during therapy, although the exact mechanism has not been fully defined. The reactions have been related to the infliximab immunogenicity and development of specific antibodies. AIMS OF THE STUDY: Evaluation of the development of IgE and non-IgE antibodies to infliximab and their relationship with infusion reaction. METHODS: Seventy-one patients (11 reactives, 11 therapeutically nonresponders, and 49 unreactive therapeutically responders) and 20 non-infliximab-exposed control subjects (ten rheumatoid arthritis, five spondyloarthropathies, five vasculitis) were evaluated for the presence of IgE (ImmunoCAP assay), IgM, and non-isotype-specific (ELISA assays) anti-infliximab antibodies. Sera were obtained at baseline and during the course of treatment, before each infliximab infusion. RESULTS: Eleven out of 71 patients had a hypersensitivity reaction to infliximab. Non-isotype-specific anti-infliximab antibodies were detected in eight reactive and two nonresponder patients. Three patients with severe reactions displayed anti-infliximab IgE antibodies and positive skin testing. Detectable levels of anti-infliximab IgM antibodies were shown in three additional IgE- and skin testing-negative patients. IgE and IgM antibodies to infliximab were not detectable in the two nonresponder patients. Antibodies developed before the 2nd and the 3rd infusion, and their appearance was strictly related to the timing of the reaction. CONCLUSIONS: This report indicates that in some patients with infliximab-related severe reactions, IgE or IgM antibodies against infliximab were detectable. The majority of reactions could be predicted by the appearance of anti-infliximab antibodies.

Influence of total serum IgE levels on the in vitro detection of beta-lactams-specific IgE antibodies.

BACKGROUND: Allergic reactions to beta-lactams are a frequent cause of adverse drug reactions; the diagnosis is based on history, clinical examination, skin testing (prick and intradermal) and demonstration of serum-specific IgE antibodies (Abs). OBJECTIVE: We compared the diagnostic performance of the Phadia CAP system for the detection of IgE to beta-lactams carried out using the new test with cut-off limits of 0.10 kUA/L and the old test with cut-off limits of 0.35 kUA/L for positive results; subsequently, we analysed the effect of total serum IgE values and of atopic phenotype on the diagnostic performance of the tests. METHODS: The study comprised a total of 34 patients with a history of immediate adverse reactions to beta-lactams, which were confirmed by positive skin testing, and 115 control subjects with tolerance to beta-lactams over the last year. The Phadia CAP System was used for the determination of serum total and specific IgE Abs towards penicilloyl G (c1), penicilloyl V (c2), ampicilloyl (c5) and amoxicilloyl (c6). The overall diagnostic performance was assessed as a diagnostic odds ratio (DOR). RESULTS: The new test showed a higher sensitivity (85% vs. 44%) than the old test and a lower specificity (54% vs. 80%) but the overall diagnostic performance was poor (DOR 6.78 vs. 3.16, P = 0.333) in both tests. The total IgE value influences the DOR of both tests; DOR was better for values under 200 kU/L [DOR = 66; 95% confidence interval (CI): 11.3-384.1] or 500 kU/L (DOR = 45.7; 95% CI: 5.3-394.4) for the new and old tests, respectively. CONCLUSIONS: The reduction in the positive cut off value has not significantly improved the overall diagnostic performance of the beta-lactams-specific IgE assay. Because of the influence of serum total IgE on the detection of beta-lactam-specific IgE Abs, the combination of both tests is mandatory in the in vitro diagnostic approach of beta-lactam allergy.