Skin Test Results Research Articles

Tuberculosis in the US Kidney Failure Population.

People with chronic kidney disease (CKD) have a higher risk for progression to tuberculosis disease following infection with Mycobacterium tuberculosis. We produced a nationwide incidence estimate and description of tuberculosis among people with kidney failure. We completed a cross-sectional descriptive analysis of people with a reported case of tuberculosis in the United States between 2010 and 2021. We stratified all people with tuberculosis by reported kidney failure status. The primary outcome was tuberculosis incidence among people with kidney failure. We also compared characteristics of people with tuberculosis by reported kidney failure status. Approximately 3% of people (2,892 of 111,155) diagnosed with tuberculosis between 2010 and 2021 also had kidney failure. Annual tuberculosis incidence ranged from 26.1 to 45.4 per 100,000 people with kidney failure and 2.1 to 3.5 per 100,000 people without kidney failure. Among people with kidney failure, 924 (32%) had extrapulmonary tuberculosis only, and nearly 40% died: 286 were diagnosed with tuberculosis after death, and 792 died during treatment. People with tuberculosis and kidney failure had approximately twice the prevalence of a false-negative tuberculin skin test result (39%) compared to people with tuberculosis alone (20%). Tuberculosis incidence among people with kidney failure between 2010 and 2021 in the United States was 10-fold that among people without kidney failure.

Determining the role of basophil activation testing in reported type 1 allergy to beta-lactam antibiotics.

Allergy to beta-lactam antibiotics (BLA), especially to penicillin, is the most commonly reported drug allergy by patients. Alternative antibiotics can yield negative consequences, such as extended hospitalization days due to less efficacy and overall higher costs. The basophil activation test (BAT) is an in vitro assay, in which activation of an individual's own basophils is quantified by flow cytometry. It is an increasingly applied in vitro method in allergy testing that is also gaining traction in drug allergies. We correlated 37 BAT results with skin test results. The cohort exclusively included patients with suspected type I BLA allergy. In addition, we examined the concordance of these results with clinical symptoms reported in the BLA patients' medical histories. BLA-BAT revealed a high specificity of 92.3% [95% confidence interval (CI) 66.7-98.6] but a low sensitivity of only 20.8% (95% CI 9.24-40.47) using BLA-skin tests as a comparator. Negative BLA-BAT in patients with a history of grade I anaphylaxis yielded doubt on the assumption of grading. The exclusion of grade I BLA anaphylaxis increased the sensitivity to 29.4% (95% CI 13.28-53.13) with a still high specificity of 85.7% (95% CI 48.69-97.43). When ImmunoCAP was available, we compared specific IgE and BAT results by using Cohens' kappa (κ) and revealed a moderate level of agreement (κ = 0.538, p = 0.029). BAT reveals specific positive results exclusively in patients with cephalosporin anaphylaxis. However, these findings could not be generally confirmed in the heterogeneous group of BLA.

Successful Desensitization to Irinotecan in a Patient with Metastatic Esophageal Squamous Cell Carcinoma and a History of Anaphylaxis in Response to Irinotecan-Case Report and Literature Review.

Background:Irinotecan is a topoisomerase I inhibitor used for the treatment of various cancers, such as gastrointestinal, pancreatic, pulmonary, ovarian, and cervical cancers. Among chemotherapy agents, it represents a rare trigger of drug hypersensitivity reactions, with few cases being reported until today. Methods: We present the case of a patient with metastatic esophageal cancer and a history of irinotecan-induced grade IV (WAO classification) anaphylaxis. An IgE-mediated reaction was confirmed in our case, as evidenced by a positive intradermal skin test result, and we carried out a successful desensitization protocol, given irinotecan's indispensability in the treatment regimen. Our case underscores the fact that in such situations where the culprit drug is also the only therapeutic option available for such a patient, implementing a desensitization protocol may represent the only viable approach to ensure safe and successful dosing. Results: A comprehensive review of the literature was also conducted to assess previously reported irinotecan-induced hypersensitivity reactions, the utility of skin tests in identifying sensitisation to irinotecan, and the existing desensitization protocols. We found a total of seventeen cases of hypersensitivity reactions to irinotecan in the literature, out of which four provided the skin test results obtained and six performed desensitization protocols for irinotecan. Conclusions: Our literature review highlights that skin testing and desensitization protocols can provide suitable solutions for managing hypersensitivity reactions to irinotecan.

Bacillus Calmette-Guérin (BCG) Vaccine in America and Overseas: A Narrative Review.

This narrative review examines the role of the Bacillus Calmette-Guérin (BCG) vaccine in global tuberculosis (TB) control efforts, with particular emphasis on the differences in vaccination policies between countries, such as the US, where routine BCG administration is not practiced. A significant complication of the BCG vaccine is false positive results in the tuberculin skin test (TST), often leading to misdiagnoses and unnecessary treatments. To address these issues, interferon-gamma release assays (IGRAs) have emerged as a more specific diagnostic tool that reduces false positives associated with prior BCG vaccination. However, despite advancements, public health challenges persist in accurately detecting latent and active TB, particularly in populations previously vaccinated with BCG. This review synthesizes existing literature to assess these challenges, emphasizing the need for updated policies and improved diagnostic tools for BCG-vaccinated populations in the USand globally. Recommendations include integrating IGRAs into routine practice and tailoring TB control strategies to mitigate the diagnostic complications of BCG.

Latent tubercolosis infection in the migrant population: an Italian surveillance experience

Abstract Background The Special Reception Center (“Centro Accoglienza Straordinario” or CAS in Italian) concept was born in Italy in 2014 to receive the large number of migrants arriving in Italy. There are around 3100 centres are in Italy, of which 200+ in Tuscany. Each Center’s objective is to support migrants’ social integration through Italian language and job orientation courses. On arrival at a facility, migrants undergo diagnostic and lab tests to highlight potentially infectious diseases; among these, tuberculosis is one of the most frequently encountered. Therefore, the objective of the study is to estimate the prevalence of Latent Tuberculosis Infections (LTBIs) among migrants hosted in CAS centers. Methods From May-December 2023, Amiata Senese, Val d’Orcia and Valdichiana Senese Public Health Unit staff, according to national and departmental guidelines, implemented a number of health surveillance protocols, with close attention to latent tuberculosis infection. This protocol includes the Mantoux TB skin test at the CAS: in case of positivity, subjects are directed to further exams (chest X-ray, TB-IGRA blood test, infectious disease specialist consultation) in order to implement a therapy. Results From May-December 2023, 259 migrants (241 males and 18 females) received the TB skin tests. Average subject age was 26. Pakistan was the most represented nation of origin with 130 migrants (50%), followed by Bangladesh (9.7%) and Ivory Coast (7.3%). 77 migrants showed a positive TB skin test result (29.7%): of these 56 (i.e. 21.6% of the migrants screened) were also positive to the TB-IGRA blood test and treated for LTBI. Conclusions The high prevalence of LTBIs found in the referenced CAS indicates the need to continue/extend these surveillance protocols. Implementing successfully this procedure requires the involvement of a range of professionals from the socio-health sector within a process necessarily coordinated by the Disease Prevention Department. Key messages • Screening and surveillance of infectious diseases among migrant population represent a major public health issue for European health systems. • Detection and treatment of Latent Tubercolosis Infections require a multiprofessional and integrated approach, coordinated by the Disease Prevention Department.

Allergic reactions to enzyme replacement therapy in children with lysosomal storage diseases and their management.

Human recombinant enzyme replacement therapy, given to compensate for genetic enzyme deficiency in lysosomal storage diseases, delays the progression of the disease and improves the quality of life. However, enzyme replacement therapy may cause hypersensitivity reactions. Within the scope of this research, we aimed to elucidate the frequency and clinical features of hypersensitivity reactions against enzyme replacement therapy in children with lysosomal storage diseases and clarify the management of these reactions. Medical records of pediatric patients with lysosomal storage disease and receiving enzyme replacement therapy were retrospectively reviewed, and patients who experienced allergic reactions were included in the study. The demographic characteristics of the patients, their diagnosis, the responsible enzyme, the time at which the reaction started and at what dose, the signs and symptoms associated with the reaction, diagnostic tests, the management of the reaction, and the protocol applied for the maintenance of enzyme replacement therapy after the reaction were recorded. Hypersensitivity reactions developed in 18 of 71 patients (25.3 %) who received enzyme replacement therapy. The most common cutaneous findings were observed. Anaphylaxis developed in 6 of 18 patients. Patients who experienced recurrent hypersensitivity reactions with premedication or a slower infusion rate, those with positive skin test results, and patients who developed anaphylaxis were given enzyme replacement therapy with desensitization. HSR may develop during enzyme replacement therapy, which are vital in lysosomal storage diseases, and discontinuation of enzyme replacement therapy is a significant loss for patients with metabolic disorders. These reactions can be treated with premedication and long-term infusions, but some patients may require desensitization protocols for continued treatment.

Fish and shellfish allergy: Presentation and management differences in the UK and US—analysis of 945 patients

Seafood allergy (SA), including allergy to shellfish (crustacean and mollusks) and fish, is among the 4 most common food allergies causing anaphylaxis, but there are limited data showing SA clinical management in different countries. We sought to characterize a large cohort of patients with fish and shellfish allergy and to facilitate standardization of future care for this increasingly common allergic disease. We performed a retrospective, observational, noninterventional study from 945 patients from 2015 to 2019 in 7 hospitals in the United States and the United Kingdom to evaluate SA. Achi-square test was used to detect differences in family history, medical history, and current symptoms between patients in 2 countries. Underdiagnosed anaphylaxis in patients with SA was associated with underuse of epinephrine (adrenaline) autoinjectors in both countries. Oral food challenge was used only when skin or serologic test results were negative. Asthma and allergic rhinitis were more common in the US patients withSA, but eczema was more common in UK patients with SA (P< .001). Respiratory, gastrointestinal, and neurological symptoms were higher in UK patients with SA than in US patients with SA (P< .001). In international multicenter cohorts of patients with fish and shellfish allergy, there are opportunities for improvement in management. Physician identification of anaphylaxis, use of diagnostic oral food challenges, and anaphylaxis treatment with epinephrine are areas with significant knowledge gaps in need of improvement in the United Kingdom and the United States. There is an opportunityfor the development of unified, standardized diagnostic protocols for SA with distribution for allergists and trainees.

True Rate of Allergy among Pediatric Inpatients with Penicillin Allergy Labels (TRIAL).

Penicillin allergy is a common drug allergy diagnosis in pediatric patients; however, upon appropriate allergy testing, many of these patients are found not to have a true allergy. For patients with a reported allergy, alternative antibiotics are prescribed, which are less effective, more toxic, or more expensive. There is a lack of data evaluating allergies in hospitalized children and comparing allergy assessments conducted by pediatric allergists and pharmacists. To estimate the percentage of pediatric patients admitted with reported penicillin allergy who did not have a true penicillin allergy. This single-centre prospective cohort study included inpatients between 6 months and 17 years of age, with a documented penicillin allergy, who were admitted to the general pediatric and oncology units of a tertiary care children's hospital between November 2019 and March 2023. The allergy history, evaluation, and risk categorization were performed by pharmacists. The history was reviewed with the allergist, and the patient was then referred, underwent skin testing, or received oral amoxicillin challenge with monitoring for 1 hour. Thirty patients were included, of whom 29 (97%) had delabelling of their penicillin allergy. Four patients (13%) had delabelling on the basis of history alone, without risk assessment. Twenty-five (83%) of the patients were assessed as having low risk; 24 of these had delabelling following oral challenge, and 1 did not complete the oral challenge because of transfer to another hospital. One patient (3%) was assessed as having moderate risk, with delabelling on the basis of results of skin testing and oral challenge. The pharmacist's and allergist's risk assessments were in agreement in 29 (97%) of the 30 cases. Pediatric patients, including those with oncologic malignancies, are often mislabelled as having a penicillin allergy. Pharmacists are able to accurately determine true allergy risk and delabel penicillin allergies for pediatric patients in the hospital setting.

Is Component-Specific Antibody Testing Sufficient to Replace the Oral Food Challenge in the Diagnostics of Peanut-Sensitized Children? A Proof-of-Concept Study.

(1) Peanut allergy is associated with high risk of anaphylaxis which could be prevented by oral immunotherapy. Patients eligible for immunotherapy are selected on the basis of a food challenge, although currently the assessment of antibodies against main peanut molecules (Ara h 1, 2, 3 and 6) is thought to be another option. (2) The current study assessed the relationship between the mentioned antibodies, challenge outcomes, skin tests and some other parameters in peanut-sensitized children. It involved 74 children, divided into two groups, based on their response to a food challenge. (3) Both groups differed in results of skin tests, levels of component-specific antibodies and peanut exposure history. The antibody levels were then used to calculate thresholds for prediction of challenge results or symptom severity. While the antibody-based challenge prediction revealed statistical significance, it failed in cases of severe symptoms. Furthermore, no significant correlation was observed between antibody levels, symptom-eliciting doses and the risk of severe anaphylaxis. Although in some patients it could result from interference with IgG4, the latter would not be a universal explanation of this phenomenon. (4) Despite some limitations, antibody-based screening may be an alternative to the food challenge, although its clinical relevance still requires further studies.

Differentiation of Bovine Tuberculosis and Paratuberculosis Infections with Antemortem Diagnostic Methods

In this study, based on the results of tuberculin skin tests (Bovine and Avian PPD) used in the antemortem diagnosis and differentiation of Bovine Tuberculosis, the animals in the farms with suspected Tuberculosis were serologically examined to diagnose Paratuberculosis infection and fecal bacterioscopy was performed. In addition, it was aimed to obtain data that will contribute to the eradication studies of Bovine Tuberculosis disease by comparing the antemortem diagnostic methods of Bovine Tuberculosis disease, which is endemic in Türkiye and by determining the sensitivity and specificity values of the interferon gamma (IFN-γ) test. In this context, intradermal tuberculin test was applied to 423 cattle with suspected Tuberculosis in a total of 5 dairy cattle farms, one each from Çankırı, Çorum, Ankara, Eskişehir and Konya regions, and this test was determined as the gold standard method and the sensitivity and specificity of the IFN-γ test were determined as 86% and 97%, respectively. For the diagnosis of Paratuberculosis infection, antibody ELISA, fecal bacterioscopy and IFN-γ ELISA were performed on these animals and the prevalence of these tests were 10.4%, 5.44% and 4.96% respectively and 4 (0.95%) of the cattle were positive for each of the diagnostic methods for Map infection. As a result, it was concluded that IFN-γ test, which gives similar results to intradermal tuberculin test results, can also be used in the antemortem diagnosis of Bovine Tuberculosis. Also, in the comparative intradermal tuberculin test for the diagnosis of Tuberculosis infection, avian PPD positive animals were found to play a decisive role in the detection of nonspecific reactions or Paratuberculosis infected animals, supported by other tests used for the diagnosis of Paratuberculosis.

Overlooked, dismissed, and downplayed: reversion of Mycobacterium tuberculosis immunoreactivity.

Tuberculosis (TB) is caused by Mycobacterium tuberculosis (Mtb). Following infection, immune responses to Mtb antigens can be measured using the tuberculin skin test or an interferon-γ release assay. The gain of Mtb immunoreactivity, a change from a negative to a positive tuberculin skin test or interferon-γ release assay result, is called conversion and has long been used as a measure of Mtb exposure. However, the loss of immunoreactivity (reversion; a positive followed by a negative result) has often been overlooked. Instead, in clinical and epidemiological circles, Mtb immunoreactivity is commonly considered to persist lifelong and confer a lifetime of disease risk. We present a critical review, describing the evidence for reversion from cohort studies, ecological studies and studies of TB progression risk. We outline the inconsistent reasons why reversion has been dismissed from common understanding and present evidence demonstrating that, just as conversion predominantly indicates prior exposure to Mtb antigens, so its opposite, reversion, suggests the reduction or absence of exposure (endogenous or exogenous). Mtb immunoreactivity is dynamic in both individuals and populations and this is why it is useful for stratifying short-term TB progression risk. The neglect of reversion has shaped TB research and policy at all levels, influencing clinical management and skewing Mtb infection risk estimation and transmission modelling, leading to an underestimation of the contribution of re-exposure to the burden of TB, a serious oversight for an infectious disease. More than a century after it was first demonstrated, it is time to incorporate reversion into our understanding of the natural history of TB.

Polyethylene glycol hypersensitivity, patient outcomes in a 7-year retrospective study

BackgroundImmediate IgE-mediated hypersensitivity reactions to polyethylene glycol (PEG) are rare. Our understanding of PEG hypersensitivity is limited. ObjectiveTo evaluate the clinical characteristics and investigation outcomes of the largest cohort of patients with PEG allergy reported. MethodsA total of 44 patients investigated for suspected PEG allergy across 4 United Kingdom tertiary allergy centers between October 2013 and December 2020 were studied. Clinical characteristics, index reaction, and approaches to and outcomes of allergy investigations were analyzed. ResultsPEG hypersensitivity was confirmed in 42 of 44 cases. Macrogol laxatives were the most common index drugs reported (23%), followed by depo-medroxyprogesterone (19%), oral penicillin V (10%), and depo-methylprednisolone (10%). In general, 61% experienced grade III anaphylaxis. Intradermal testing (IDT) increased the diagnostic sensitivity from 51% to 85%. Five patients experienced systemic reactions during IDT. Of the 5 patients, 2 were skin prick test positive to a high molecular weight PEG. Three patients with negative skin test results had positive drug provocation test results. Seven patients with PEG allergy reported tolerance to H1-antihistamines containing PEG. Administration of messenger RNA COVID-19 or Oxford/AstraZeneca COVID-19 vaccines was tolerated in all 16 patients to whom they were administered. ConclusionPEG hypersensitivity is an uncommon cause of drug-induced anaphylaxis. Four index drugs accounted for two-thirds of the cases, and reactions to these drugs should prompt PEG hypersensitivity investigations. PEG IDT increases diagnostic yield. The role of skin prick test with higher molecular weight PEGs requires further attention. Further studies are required to understand PEG thresholds and PEG equivalent doses of various administration routes. COVID-19 vaccines were tolerated by all exposed.

Epidemiology of perioperative anaphylaxis in France in 2017–2018: the 11th GERAP survey

BackgroundPerioperative anaphylaxis is rare but is associated with significant morbidity. This complication has been well described in France by the GERAP (Groupe d'Etude des Réactions Anaphylactiques Périopératoires), a network focused on its study. The epidemiology of perioperative anaphylaxis is evolving, influenced by environmental factors and clinical practice. The aim of this study was to update the epidemiology of perioperative anaphylaxis in France. MethodsThis multicentre retrospective study was performed in 26 allergy clinics of the GERAP network in 2017–8. ResultsThere were 765 patients with perioperative anaphylaxis included. Most cases were severe, with 428 (56%) reactions graded as 3 or 4 according to the Ring and Messmer classification. Skin test results were available for 676 patients, with a culprit agent identified in 471 cases (70%). Neuromuscular blocking agents were the main cause of perioperative anaphylaxis (n=281; 60%), followed by antibiotics (n=118; 25%) and patent blue dye (n=11; 2%). Cefazolin was the main antibiotic responsible for perioperative anaphylaxis (52% of antibiotic-related reactions). Suxamethonium and rocuronium were the main neuromuscular blocking agents responsible for perioperative anaphylaxis with 7.1 (6.1–8.4) and 5.6 (4.2–7.4) reactions per 100,000 vials sold, respectively, whereas cefazolin-related cases were estimated at 0.7 (0.5–0.9) reactions per 100,000 vials sold. ConclusionsOur results confirm that most commonly identified triggering agents remain neuromuscular blocking agents. Reactions to antibiotics, particularly cefazolin, are becoming increasingly frequent. The origin of sensitisation to cefazolin is unknown, as no cross-sensitisation has been described, and it should be the subject of further study. Perioperative anaphylaxis should be followed over the years and understood given the changing triggers. Clinical trial registrationClinicalTrials.gov (NCT 04654923).

One-Bag 8-Step Ferric Carboxymaltose Desensitization Protocol for Patients with a History of Hypersensitivity Reactions to Iron Preparations

Introduction: Iron deficiency is the most common cause of anemia in both sexes, although it is more common in women. Intravenous (IV) iron replacement is preferred in patients who cannot tolerate oral treatment or when iron stores need to be replenished rapidly. In this study, we wanted to share the ferric carboxymaltose (FCM) desensitization protocol that we self-created and successfully applied. Methods: This retrospective cross-sectional study included patients with a history of hypersensitivity reactions (HSRs) to IV or oral iron replacement and patients who were planned to receive IV iron replacement but were referred to the allergy clinic because of have risk factors (atopic diseases, history of HSR to other drugs, high serum tryptase levels, etc.) for HSRs. Before desensitization, some of the patients underwent skin tests (skin prick test and intradermal test) with FCM, and the results were recorded. Skin tests were not performed in patients with a history of drug use (antihistamine, systemic steroid, omalizumab, etc.) that affected the results of skin tests. All patients underwent a one-bag 8-step desensitization protocol with 500 mg FCM and were observed for 2 h after desensitization. Results: A total of 15 patients (14 females and 1 male) with a mean age of 41.13 ± 11.18 years were included in the study. When the patients were evaluated in terms of the risk of allergic reactions according to their clinical history, 8 patients had a history of anaphylaxis with iron preparations (FCM, n = 4; ferric hydroxide sucrose, n = 2; iron [II] glycine sulfate, n = 1; and iron [III] hydroxide polymaltose, n = 1), and 7 patients had a history of HSR other than anaphylaxis with iron preparations (urticaria, n = 6 [FCM, n = 2; iron (II) glycine sulfate, n = 2; and iron (III) hydroxide polymaltose, n = 2] and urticaria + angioedema [ferric hydroxide sucrose, n = 1]). Desensitization was successfully completed in all patients. No HSR was observed during or after the procedure in any of the patients. Conclusion: IV iron replacement is a very effective method, especially in cases where iron stores need to be replenished more rapidly. In patients with a history of iron HSR or at risk of developing HSR, replacement can be safely performed without an allergic reaction with successful desensitization protocols.

Pilot study on the use of basophil activation tests and skin tests for the prevention of allergic transfusion reactions.

Management of severe allergic transfusion reactions (ATR) is challenging. In this study, we investigate the usefulness of skin tests and basophil activation tests (BAT) in chronically transfused patients for the prevention of future ATR. BAT and skin tests were carried with the supernatant of red blood cell (RBC) units for a sickle-cell disease patient under chronic exchange transfusion who has presented a severe ATR, in order to prevent potential future ATR. If the results for both BAT and skin tests were negative, the RBC units could be transfused to the patient. If either one of the results was positive, the tested RBC unit was discarded for the patient. 192 RBC units were tested with both tests. The level of results concordance between the two tests was 95%. Out of the 169 negative units with both tests, 118 units were transfused to the patient for which he presented no ATR. In our study, combining both BAT and skin tests was associated with a good negative predictive value since we were able to safely transfuse our patient. Further studies are still necessary to confirm this result but this pilot study indicates that skin tests and BAT might help prevent ATR. When BAT is not available, skin tests may also be useful in preventing ATR.

Standardized diagnosis results of suspected local anesthetics allergy

To review and investigate the diagnosis results of local anesthetics (LA) allergy and improve the understanding of LA allergy in clinician. From March 2017 to February 2022, a total of 24 patients were investigated in Allergy Center of West China Hospital,Sichuan University on suspicion of LA allergy. Clinical data and results of skin tests and drug provocation tests (DPT) with the suspected drugs were retrospectively evaluated. The value of standardized diagnostic protocol in the LA allergy were analyzed. The results showed that 24 patients (3 men/21 women) were included with age range from 20 to 74 years. Three cases (12.5%) were positive in previous LA skin tests and proved to be tolerated through standardized tests. Twenty-one patients were initially diagnosed as "LA allergy" because of adverse reactions after previous use of LA, including 20 cases of immediate-type reaction and 1 case of delayed-type reaction. Three cases were considered LA allergy through standardized diagnosis approaches, including skin tests and DPT. One patient was diagnosed with anaphylaxis caused by chlorhexidine. Of the remaining 17 patients, 7 were considered as psychosomatic reactions (29.1%), 3 of sympathetic nervous system conditions (12.5%), 1 of spontaneous urticaria (4.2%), 2 of vasovagal syncope (8.3%), drug side effects (8.3%), skin irritation (8.3%), respectively. In conclusion, true allergic reactions to LA are rare. Through standardized skin tests and DPT, allergy can be ruled out in the vast majority of patients who complain of "LA allergy". For patients who are highly suspected of LA inducing anaphylaxis, other local anesthetics that can be used as safe alternatives should be determined by diagnostic tests according to future needs.

Identification of New Mycobacterium bovis antigens and development of a multiplexed serological bead-immunoassay for the diagnosis of bovine tuberculosis in cattle.

Serological assays for bovine tuberculosis diagnosis require the use of multiple Mycobacterium bovis specific antigens to ensure the detection of infected animals. In the present study, identification and selection process of antigens, based on data from published proteomic studies and involving the use of bioinformatics tools and an immuno-screening step, was firstly performed for identifying novel antigens that elicit an antibody response in M. bovis infection. Based on this approach, a panel of 10 M. bovis antigens [with known relevance (MPB70, MPB83, MPB70/83, and ESAT6/CFP10) and novel (Mb1961c, Mb1301c, Mb3871, Mb1403, Mb0592, and PE25/PPE41)] were constructed and thenused to develop a new multiplexed serological assay based on Luminex technology. The performance of the Luminex-bTB immunoassay was evaluated using sera from cattle with known tuberculosis status. Among the proteins whose ability to detect bovine tuberculosis was evaluated for the first time, PE25/PPE41 and Mb1403, but not Mb3871, showed good detection capacity. Following multiple antigen combination, the final Luminex-bTB immunoassay included seven antigens (MPB70, MPB83, MPB70/83, ESAT6/CFP10, PE25/PPE41, Mb1403, and Mb0592) and showed better global performance than the immunoassay using the four usual antigens (MPB70, MPB70/83, MPB83 and ESAT6/CFP10). The specificity and sensitivity values were, respectively, of 97.6% and 42.8% when the cut-off of two-positive antigens was used to classify samples as positive. With the use of the more-restrictive criterion of three-positive antigens, the specificity increased to 99.2% but the sensitivity decreased to 23.9%. The analysis of antigen profiles generated with the Luminex-bTB immunoassay showed that mainly serodominant proteins were recognized in samples from infected cattle. The detection of Mb1961c and Mb1301c appeared to be associated with presumed false-positive results. Moreover, sera from cattle originating from bTB-outbreaks but having inconclusive or negative skin test results were identified as positive by the Luminex-bTB immunoassay and showed an antigen pattern associated with M. bovis infection. The Luminex-bTB immunoassay including seven antigens may be useful as adjunct test for the detection of M. bovis-infected herds, and different cut-offs could be applied according to the bovine tuberculosis epidemiological context.

History and Utility of Specific IgE Cutoff levels: What is the Relevance for Allergy Diagnosis?

Allergy is defined clinically, by symptoms on allergen exposure. A patient is considered sensitized when allergen-specific IgE (sIgE) antibody can be detected in serum or plasma or a skin test result is positive, even if no clinical reaction has been experienced. Sensitization should be regarded as a requisite and risk factor for allergy but is not synonymous with an allergy diagnosis. To provide a correct allergy diagnosis, test results regarding allergen-sIgE must always be considered in view of the patient's case history and clinical observations. Correct assessment of a patient's sensitization to specific allergens relies on the use of accurate and quantitative methods for detection of sIgE antibodies. The evolution of sIgE immunoassays toward higher analytical performance and the use of different cutoff levels in the interpretation of test results sometimes cause confusion. Earlier versions of sIgE assays offered a limit of quantitation of 0.35 kilounits of sIgE per liter (kUA/L), which also became an established cutoff level for a positive test result in the clinical use of the assays. Current sIgE assays are capable of reliably measuring sIgE levels as low as 0.1 kUA/L and can thereby demonstrate sensitization in cases in which previous assays could not. When the outcome of sIgE test results is evaluated, it is critically important to distinguish between the analytical data as such and their clinical interpretation. Even though sIgE may be present in the absence of symptoms of allergy, available information suggests that sIgE concentrations between 0.1 kUA/L and 0.35 kUA/L may be clinically relevant in some individuals, not least among children, although this should be further evaluated for various allergies. Moreover, it is becoming widely adopted that nondichotomous interpretation of sIgE levels may offer a diagnostic benefit compared with using a predefined cutoff level.

Autoimmune Diseases and Low Baseline IgE in Chronic Spontaneous Urticaria: A Clinical and Therapeutic Prospective Analysis in Real-Life Clinical Practice

Autoimmunity contributes to the pathogenesis of chronic spontaneous urticaria (CSU). The subtyping of CSU has revealed an autoimmune form of CSU. Despite autoimmune diseases having been associated with CSU, there are few prospective studies that have evaluated the characteristics and biomarkers of patients with CSU and autoimmune disease in a real-life practice setting. To evaluate the presence of specific biomarkers for the presence of autoimmune disease in CSU and to analyze the clinical and therapeutic features of patients with CSU and autoimmune disease. The clinical, laboratory, and therapeutic features of patients with CSU at a tertiary-level center were prospectively collected. Data obtained were compared in function of the presence/absence of autoimmune disease and typified according to IgE levels. Patients with CSU who had associated autoimmune disease corresponded to middle-aged women with a common pattern of blood test findings: both low baseline IgE and high-affinity receptor of IgE expression, basopenia, eosinopenia, higher baseline erythrocyte sedimentation rate and D-dimer, increased presence of antinuclear antibodies, IgG against thyroid peroxidase, and positive autologous serum skin test result. Total baseline IgE less than or equal to 43.8 IU/mL was both the optimal cutoff to predict autoimmune disease in the CSU cohort and a significant risk factor for the presence of autoimmune disease in the regression analysis. In real-life clinical practice, characteristics of patients with CSU and autoimmune disease share common features with type IIb autoimmune CSU. Total baseline IgE less than or equal to 43.8 IU/mL has been detected as a possible biomarker of autoimmune disease in patients with CSU.

Taxanes Hypersensitivity is not a risk factor for severe reactions to SARS-Cov-2 Vaccines.

Introduction. The main mechanism involved in hypersensitivity reactions (HSR) to Taxanes (primarily Paclitaxel and Docetaxel) seems to be a complement activation by their excipients: polyoxyethylated castor oil (Paclitaxel) and Polysorbate 80 (Docetaxel). SARS-CoV-2 vaccines contains Polysorbate 80 or polyethylene glycol (PEG) as excipients, which are structurally correlated to polyoxyethylated castor oil. The aim of this study was to verify the presence of a higher risk of HSR to SARS-CoV-2 vaccines in patients with history of HSR to taxanes. Methods. Patients with history of HSR to taxanes were evaluated before the vaccination in our center and underwent skin tests for PEG and Polysorbate 80 (P and P). Some patients completed the vaccination course in other centers without prior P and P skin tests because they had not manifested taxanes hypersensitivity before vaccination, or because those tests were not available. Results. A total of 50 patients were evaluated. 100% of patients with history of hypersensitivity to taxanes completed the vaccine course with no cases of anaphylaxis. 33 patients underwent skin tests for P and P before the vaccination and no correlation was found between P and P skin tests positivity and taxanes skin tests positivity (p = 0.538). 7 patients developed mild symptoms during skin tests and vaccination, similar but weaker than those suffered at the time of the taxane infusion, and independently from the results of skin tests (2/7 positive patients). Conclusions. In our cohort Patients with history of reaction to taxanes were not at higher risk to develop anaphylaxis to SARS-CoV-2 vaccines. However, a common non-IgE mediated mechanism behind those HSRs cannot be completely excluded. This can only account for mild and harmless symptoms in case of SARS-CoV-2 vaccines. Antihistamine premedication and longer observation after the vaccination are still prudent in these patients.