Immediate-type Hypersensitivity Research Articles

Hair Product Allergy: A Review of Epidemiology and Management.

Allergy to hair products is an increasingly common issue among people given the exposure to these products on a daily basis. Allergic reactions could be in the form of delayed-type contact dermatitis or the form of immediate-type hypersensitivity reactions. Hair products contain many ingredients and chemicals that patients may have allergies to, but common allergens are hair dyes, fragrances, persulfate salts, ammonium thioglycolate, coconut fatty acid derivatives, and acrylates. Allergy to hair dye is the most common followed by other allergens such as fragrances and persulfate salts. We discussed testing for hair dye allergy along with suggestions for alternative hair dyes that patients may use.Allergy to topical scalp medications is also seen in patients using those products. Allergy to topical minoxidil is seen more often due to the increased use of minoxidil sprays and foams among patients to increase hair growth. We will discuss in this review the diagnosis and alternatives for patients with minoxidil allergy. Hairdressers are at higher risk of allergy to hair products compared to the general population due to prolonged exposure to allergens and specific measures should be implemented to minimize the hazards of exposure.

Etoposide hypersensitivity reactions and outcomes of desensitizations in immediate-type hypersensitivity reactions

Aims: This study aims to define characteristics of hypersensitivity reactions with etoposide, and outcomes of desensitizations in immediate-type hypersensitivity rections
 Methods: This is a retrospective observational study of patients who had hypersensitivity reactions with etoposide from January 2019 to December 2023. 
 Results: A total of 39 patients with lung cancer were included in the study. Ten (25.6%) patients had known other drug allergies and three (7.7%) patients had previous chemotherapeutic hypersensitivity two with paclitaxel and one with docetaxel. Most of the initial hypersensitivities were in the first or second cycle (n=29, 74.4%). Ten (25.4%) patients had hypersensitivity reactions at the first application of etoposide. Thirty (76.9%) patients had immediate-type hypersensitivity reactions. There was no significant difference in terms of patient and initial hypersensitivity characteristics between patients who had immediate or non-immediate type hypersensitivity reactions. Of the 30 patients with immediate-type hypersensitivity reactions, initial reaction was mild in 16 (53.3%) and moderate in 14 (46.7%) patients. Most common symptoms were erythema in 29 (96.7%), dyspnea in 13 (43.3%), chest tightness in 8 (26.7%), discomfortness in 7 (23.3%), and hypertension in 6 (20%). Skin tests were negative in five patients who underwent skin testing. A total of 98 desensitization courses were performed in 27 patients and 3 (11.1%) patients had breakthrough reactions.
 Conclusion: Most of the hypersensitivity reactions to etoposide are immediate-type and not severe. Desensitization is an effective and safe procedure to manage these reactions. Further research is needed to elucidate the mechanisms of hypersensitivity reactions.

Hypersensitivity reactions with first-line antituberculosis drugs and outcomes of rapid desensitizations

BackgroundData about drug hypersensitivity reactions with first-line antituberculosis drugs and their management is limited. Rapid drug desensitization seems to be an appropriate management. ObjectiveEvaluate the efficacy of the rapid desensitization protocols in patients who had a reaction phenotypically compatible with immediate-type drug hypersensitivity with first-line antituberculosis drugs and identify possible risk factors of breakthrough reactions during the protocols. MethodsThis is a retrospective study of active tuberculosis patients who had a reaction phenotypically compatible with immediate-type drug hypersensitivity with first-line antituberculosis drugs and underwent desensitization with the drugs used during the reaction. Characteristics of drug hypersensitivity and breakthrough reactions, and outcomes of rapid desensitizations were recorded. ResultsOne hundred and seventy-nine patients were included in the study. Most of the initial reactions (n = 132, 73.7%) occurred within the first week of treatment and were mild (n = 146, 81.6%). A total of 690 desensitizations were performed. Desensitizations were successfully completed without any breakthrough reaction in 103 (57.5%) patients and in 29 of 36 (80.6%) patients after a breakthrough reaction. The overall success of desensitizations were found to be 95% (132 of 139 patients). Most of the breakthrough reactions (84%) were mild. Sixteen patients had breakthrough reactions with multiple drugs. Although pyrazinamide was the most common culprit of breakthrough reactions and had the lowest desensitization success, it had the highest rate of a single breakthrough reaction (p < 0.001). Timing of the initial reaction and concomitant breakthrough reaction with ethambutol were found to have increased the risk for breakthrough reaction caused by rifampicin (p = 0.017 and p = 0.010 respectively). ConclusionThe rapid desensitization protocols used in this study provide a successful and effective management of the patients with a reaction phenotypically compatible with immediate-type drug hypersensitivity with first-line antituberculosis drugs.

Сучасні аспекти діагностики та лікування анафілаксії. Частина 1

Abstract. The aim of this review is to characterize the epidemiology, determine the phenotypes and endotypes of anaphylaxis, pathogenetic mechanisms of its development, systematize on their basis of clinical manifestations and degrees of severity of this condition, evaluate possible biomarkers of anaphylaxis for their wider implementation in clinical practice. Anaphylaxis is the most severe of allergic reactions, putting patients at high risk of losing their lives and requiring prompt recognition and immediate treatment. However, since its symptoms mimic the manifestations of other diseases, such as asthma and urticaria, the diagnosis of anaphylaxis is often insufficiently effective due to the very rare determination of the tryptase level, so the treatment of patients is delayed, and epinephrine (adrenaline) is used late. The main causes of anaphylaxis are poorly understood, and death due to anaphylaxis is often difficult to investigate due to misdiagnosis of the condition. Key words: anaphylaxis, phenotypes and endotypes of anaphylaxis, anaphylactic shock, immediate-type hypersensitivity reactions, IgE, monoclonal antibodies, epinephrine.

A systematic review and meta-analysis of proteomic and metabolomic alterations in anaphylaxis reactions.

Anaphylaxis manifests as a severe immediate-type hypersensitivity reaction initiated through the immunological activation of target B-cells by allergens, leading to the release of mediators. However, the well-known underlying pathological mechanisms do not fully explain the whole variety of clinical and immunological presentations. We performed a systemic review of proteomic and metabolomic studies and analyzed the extracted data to improve our understanding and identify potential new biomarkers of anaphylaxis. Proteomic and metabolomic studies in both human subjects and experimental models were extracted and selected through a systematic search conducted on databases such as PubMed, Scopus, and Web of Science, up to May 2023. Of 137 retrieved publications, we considered 12 for further analysis, including seven on proteome analysis and five on metabolome analysis. A meta-analysis of the four human studies identified 118 proteins with varying expression levels in at least two studies. Beside established pathways of mast cells and basophil activation, functional analysis of proteomic data revealed a significant enrichment of biological processes related to neutrophil activation and platelet degranulation and metabolic pathways of arachidonic acid and icosatetraenoic acid. The pathway analysis highlighted also the involvement of neutrophil degranulation, and platelet activation. Metabolome analysis across different models showed 13 common metabolites, including arachidonic acid, tryptophan and lysoPC(18:0) lysophosphatidylcholines. Our review highlights the underestimated role of neutrophils and platelets in the pathological mechanisms of anaphylactic reactions. These findings, derived from a limited number of publications, necessitate confirmation through human studies with larger sample sizes and could contribute to the development of new biomarkers for anaphylaxis. https://www.crd.york.ac.uk/PROSPERO/, identifier CRD42024506246.

Detection of Intracellular Complement Activation by Nanoparticles in Human T Lymphocytes.

The complement system is complex and includes two main components: the systemic or plasma complement and the so-called intracellular complement or complosome. The complement proteins expressed by the liver and secreted into blood plasma compose the plasma complement system, whereas complement proteins expressed by and functioning inside the cell represent the intracellular complement. The complement system plays an essential role in host defense; however, complement activation may lead to pathologies when uncontrolled. When such undesirable activation of the plasma complement occurs in response to a drug product, it leads to immediate-type hypersensitivity reactions independent of immunoglobulin E. These reactions are often called complement activation-related pseudoallergy (CARPA). In addition to the blood plasma, the complement protein C3 is found in many cells, including lymphocytes, monocytes, endothelial, and even cancer cells. The activation of the intracellular complement generates split products, which are exported from the cell onto the membrane. Since the activation of the intracellular complement in T lymphocytes was found to correlate with autoimmune disorders, and growing evidence is available for the involvement of T lymphocytes in the development of drug-induced hypersensitivity reactions, understanding the ability of nanomaterials to activate intracellular complement may aid in establishing a long-term safety profile for these materials. This chapter describes a flow cytometry-based protocol for detecting intracellular complement activation by engineered nanomaterials.

Prevalence of Type I Allergy to Latex and Type IV Allergy to Rubber Additives in Turkish Healthcare Workers.

Glove-induced dermatoses are frequently seen among healthcare workers (HCWs) and are often mistakenly defined as latex allergy. To determine the prevalences of (i) the symptoms of immediate type hypersensitivity reactions, (ii) the symptoms of hand eczema, (iii) latex sensitization detected using skin prick test (SPT), and (iv) contact hypersensitivity to rubber additives or glove pieces detected using patch test, in Turkish HCWs. Ninety-eight HCWs were included in the study. All subjects completed a questionnaire. All participants were skin prick tested for latex, and foods previously identified as concomitant allergens in latex-sensitive individuals; patch tested for 7 rubber additives, 3 additional haptens, and glove pieces. The mean age was 32.1 (± 9.4) years, and 71 (72.4%) participants were nurses. Eighty-four (85.7%) subjects had a history of mucocutaneous symptoms of immediate-type hypersensitivity occurring within the first 24 hours after latex glove contact, while 9 (9.2%) subjects demonstrated SPT positivity for latex. Eighty (81.6%) subjects had a history of glove-induced hand eczema symptoms, while patch test positivity for the rubber additives or glove pieces was in 17.3%. About one-tenth of those with a history of glove-induced type I hypersensitivity symptoms had true latex allergy, and one-quarter of those with a history of glove-related hand eczema symptoms had contact hypersensitivity to glove products. Therefore, rote avoidance of latex use is generally ineffective in the management of glove-related skin complaints. Individual measures should focus on reducing the use of soaps and disinfectants, and promoting the use of moisturizers, rather than glove choice.

Heparin-induced Anaphylaxis shock.

Introduction: Anaphylaxis is a fatal condition that can be easily managed if discovered early. Only a few examples of anaphylaxis-like reactions caused by heparin have been documented, and immediate-type hypersensitivity reactions to heparin are extremely uncommon. Case Presentation: We report a case of a 53-yearold gentleman known to have an End Stage Renal Disease (ESRD) on Hemodialysis for two years, who went to the dialysis facility in his usual state of health. After two hours of dialysis, a new lock of taurolidine/heparin was installed; one minute later, the patient started to vomit and became restless, blood pressure dropped to 60/47 mmHg, and urticarial hives and a reddish rash developed on his skin, covering his trunk and limbs. He was immediately given three doses of epinephrine intramuscularly, which he did not respond to. Therefore, an epinephrine infusion was started. IV hydrocortisone and diphenhydramine were given for symptomatic relief. The patient was shifted to the emergency department, where he became vitally stable and returned to baseline. Heparininduced anaphylaxis was assumed based on the quick response to the above medications. Conclusion: This case can be added to the growing literature regarding this rare reaction, and more studies should be done to understand the nature of the reaction better. We recommend that the healthcare team becomes vigilant of heparin as a possible cause of anaphylaxis.

Anaphylatoxin Complement 5a in Pfizer BNT162b2-Induced Immediate-Type Vaccine Hypersensitivity Reactions.

The underlying immunological mechanisms of immediate-type hypersensitivity reactions (HSR) to COVID-19 vaccines are poorly understood. We investigate the mechanisms of immediate-type hypersensitivity reactions to the Pfizer BNT162b2 vaccine and the response of antibodies to the polyethylene glycol (PEG)ylated lipid nanoparticle after two doses of vaccination. Sixty-seven participants, median age 35 and 77.3% females who tolerated two doses of the BNT162b2 vaccine (non-reactors), were subjected to various blood-sampling time points. A separate group of vaccine reactors (10 anaphylaxis and 37 anonymised tryptase samples) were recruited for blood sampling. Immunoglobulin (Ig)G, IgM and IgE antibodies to the BNT162b2 vaccine, biomarkers associated with allergic reaction, including tryptase for anaphylaxis, complement 5a(C5a), intercellular adhesion molecule 1 (ICAM-1) for endothelial activation and Interleukin (IL)-4, IL-10, IL-33, tumour necrosis factor (TNF) and monocyte chemoattractant protein (MCP-1), were measured. Basophil activation test (BAT) was performed in BNT162b2-induced anaphylaxis patients by flow cytometry. The majority of patients with immediate-type BNT162b2 vaccine HSR demonstrated raised C5a and Th2-related cytokines but normal tryptase levels during the acute reaction, together with significantly higher levels of IgM antibodies to the BNT162b2 vaccine (IgM 67.2 (median) vs. 23.9 AU/mL, p < 0.001) and ICAM-1 when compared to non-reactor controls. No detectable IgE antibodies to the BNT162b2 vaccine were found in these patients. The basophil activation tests by flow cytometry to the Pfizer vaccine, 1,2-dimyristoyl-rac-glycero-3-methoxypolyethylene glycol (DMG-PEG) and PEG-2000 were negative in four anaphylaxis patients. Acute hypersensitivity reactions post BNT162b2 vaccination suggest pseudo-allergic reactions via the activation of anaphylatoxins C5a and are independent of IgE-mechanisms. Vaccine reactors have significantly higher levels of anti-BNT162b2 IgM although its precise role remains unclear.

Can clarithromycin be used without testing in patients with penicillin allergy?

BackgroundPenicillin hypersensitivity is a common cause of suspected and proven drug allergy and drug-induced anaphylaxis in medical records and causes social and economic burdens. ObjectiveSince the rate of clarithromycin hypersensitivity is low in the general population, we aimed to investigate whether clarithromycin can be prescribed to patients with penicillin allergy without a provocation test. MethodsThe medical records of 186 patients referred to our clinic between 2015 and 2021 with a history of penicillin allergy were evaluated retrospectively. Patients having a history of at least two immediate-type hypersensitivity reactions with penicillin antibiotics or having a history of immediate-type hypersensitivity with penicillin and diagnosed by positive penicillin V/G specific IgE and/or penicillin skin tests were included in the study. Penicillin skin tests were performed according to the manufacturer's instructions. Concentrations of serum specific IgE against phenoxymethylpenicillin (penV) and benzylpenicillin (pen G) were determined using The Phadia CAP System FEIA method. An oral drug provocation test with clarithromycin was performed in all patients. ResultsThe data of 64 patients diagnosed with penicillin allergy and who underwent clarithromycin oral provocation test were analyzed. Oral provocation test with clarithromycin was positive in only two of these patients (3%). These two patients had a history of multidrug hypersensitivity, and one of them also had food and venom allergies. ConclusionWe suggest that clarithromycin can be given without an oral provocation test when an alternative antibiotic is required in patients with penicillin allergy and without multidrug hypersensitivity.

Patient Characteristics Associated With Reactions to Mrgprx2-Activating Drugs in an Electronic Health Record–Linked Biobank

Mas-related G protein-couple receptor x2 (Mrgprx2) activation underlies many common non-IgE-mediated adverse drug reactions (ADRs), yet the features of patients with reactions to Mrgprx2-activating drugs are unknown. To characterize the patient-specific comorbidities and laboratory characteristics associated with listed reactions to Mrgprx2-activating drugs, including fluoroquinolones, morphine, neuromuscular blockade agents, vancomycin, and leuprolide. We used a retrospective, observational cohort study design using electronic health record data from adults with an Mrgprx2-activating drug exposure recorded within a hospital system clinical Biobank. Odds ratios (ORs) and incidence rate ratios for clinical characteristics associated with ADRs, including immediate hypersensitivity reactions, were calculated using multivariable logistic regression. Among 59,763 patients exposed to Mrgprx2-activating drugs, 4846 had a listed ADR. Female sex, White race, asthma (OR: 1.81, 95% confidence interval [CI]: 1.68-1.94), chronic urticaria (OR: 1.73, 95% CI: 1.46-2.05), and mastocytosis (OR: 12.79, 95% CI: 5.98-27.02) were associated with increased odds of a reaction. Overall, patients with allergic disease had 1.21 times the rate of an ADR compared with patients without allergic disease. Elevated absolute eosinophil count was inversely associated with reactions, and there was no association with elevated total IgE. Observed associations were similar in a patient subgroup with immediate-type hypersensitivity reactions. Specific allergic diseases and common allergic biomarkers are differentially associated with ADRs to Mrgprx2-activating drugs. These findings from a large, "real world" drug-exposed population highlight clinical factors that may contribute to non-IgE-mediated drug allergy.

Systematic review on skin adverse effects of important hazardous hair cosmetic ingredients with a focus on hairdressers.

The burden of occupational hand eczema in hairdressers is high, and (partly strong) allergens abound in the hair cosmetic products they use. To systematically review published evidence concerning contact allergy to an indicative list of active ingredients of hair cosmetics, namely, p-phenylenediamine (PPD), toluene-2,5-diamine (PTD), persulfates, mostly ammonium persulfate (APS), glyceryl thioglycolate (GMTG), and ammonium thioglycolate (ATG), concerning the prevalence of sensitization, particularly in terms of a comparison (relative risk; RR) between hairdressers and non-hairdressers. Following a PROSPERO-registered and published protocol, eligible literature published from 2000 to February 2021 was identified, yielding 322 publications, and extracted in standardized publication record forms, also considering risk of bias. Based on 141 publications, the contact allergy prevalence to PPD was 4.3% (95% CI: 3.8-4.9%) in consecutively patch tested patients. Other ingredients were mostly tested in an aimed fashion, yielding variable, and partly high contact allergy prevalences. Where possible, the RR was calculated, yielding an average increased sensitization risk in hairdressers of between 5.4 (PPD) and 3.4 (ATG). Additional evidence related to immediate-type hypersensitivity, experimental results, exposures, and information from case reports was qualitatively synthesized. An excess risk of contact allergy is clearly evident from the pooled published evidence from the last 20 years. This should prompt an improvement in working conditions and product safety.

Intradermal testing increases the accuracy of an immediate-type cefaclor hypersensitivity diagnosis

BackgroundHypersensitivity reactions to cefaclor have increased in accordance with its frequent use. However, only limited data are available on the diagnostic value of skin tests for these conditions, particularly intradermal tests (IDTs). ObjectiveTo evaluate the clinical usefulness of IDT compared to the ImmunoCAP test in patients with cefaclor-induced immediate-type hypersensitivity. MethodsWe conducted a retrospective chart review from January 2010 to June 2020 of adult subjects from 2 tertiary hospitals in Korea with a history of suspected immediate-type hypersensitivity to cefaclor, and who had undergone ImmunoCAP and IDT. ResultsOverall, 131 subjects diagnosed with cefaclor hypersensitivity were included in the analysis. Fifty-nine patients (59/131, 45.04%) were positive in both IDT and ImmunoCAP. Fifty-four (54/131, 41.22%) and 6 (6/131, 4.58%) subjects showed positive results only with IDT or the ImmunoCAP test, respectively. Twelve subjects (12/131, 9.16%) were negative by both tests but reacted positively in a drug provocation test. The frequency of IDT positivity was similar regardless of the severity of reactions. However, positivity of ImmunoCAP was lower in subjects with mild reactions compared to those with anaphylaxis. Regarding the diagnosis of cefaclor hypersensitivity, the overall sensitivity of IDT and ImmunoCAP was 0.863 and 0.496, respectively while the specificity was 1. The combination of IDT and ImmunoCAP further increased this sensitivity to 0.908. ConclusionIDT was more sensitive than ImmunoCAP for the diagnosis of cefaclor allergy, regardless of the severity of the hypersensitivity reaction. Therefore, we recommend a combination of IDT and ImmunoCAP for the diagnosis of cefaclor hypersensitivity.

Skin tests in the work-up of cutaneous adverse drug reactions: A review and update.

Skin tests, including patch tests (PTs), prick tests, and intradermal tests (IDTs), are useful in identifying the culprits of cutaneous adverse drug reactions (CADRs), and determining safer, alternative drugs. PTs have a low sensitivity but are valuable in investigating maculopapular exanthema (MPE), as well as severe CADR, including toxic epidermal necrolysis (TEN), Stevens-Johnson syndrome (SJS), and in particular, acute generalized exanthematous pustulosis (AGEP), and drug reaction with eosinophilia and systemic symptoms (DRESS). To ensure their specificity, at least 10 control tests should be performed. Prick tests are mainly used in the evaluation of immediate-type hypersensitivity and can be performed with all drugs, except opiates. IDTs can be used to explore immediate and delayed-type hypersensitivity, if an injectable form of the drug exists. Except for SJS/TEN, IDTs should be performed by injecting 0.02 mL of the drug. We here provide a practical, up-to-date review on the use of these skin tests in the work-up of CADRs. Numerous negative controls for drug PTs, as well as criteria for the immediate and delayed positivity of prick tests and IDT, are included. It should be emphasized that a negative result never excludes the potential responsibility of a drug in a CADR.

Ceftriaxone to PRevent pneumOnia and inflammaTion aftEr Cardiac arresT (PROTECT): study protocol for a randomized, placebo-controlled trial

BackgroundPneumonia is the most common infection after out-of-hospital cardiac arrest (OHCA) occurring in up to 65% of patients who remain comatose after return of spontaneous circulation. Preventing infection after OHCA may (1) reduce exposure to broad-spectrum antibiotics, (2) prevent hemodynamic derangements due to local and systemic inflammation, and (3) prevent infection-associated morbidity and mortality.MethodsThe ceftriaxone to PRevent pneumOnia and inflammaTion aftEr Cardiac arrest (PROTECT) trial is a randomized, placebo-controlled, single-center, quadruple-blind (patient, treatment team, research team, outcome assessors), non-commercial, superiority trial to be conducted at Maine Medical Center in Portland, Maine, USA. Ceftriaxone 2 g intravenously every 12 h for 3 days will be compared with matching placebo. The primary efficacy outcome is incidence of early-onset pneumonia occurring < 4 days after mechanical ventilation initiation. Concurrently, T cell-mediated inflammation bacterial resistomes will be examined. Safety outcomes include incidence of type-one immediate-type hypersensitivity reactions, gallbladder injury, and Clostridioides difficile-associated diarrhea. The trial will enroll 120 subjects over approximately 3 to 4 years.DiscussionThe PROTECT trial is novel in its (1) inclusion of OHCA survivors regardless of initial heart rhythm, (2) use of a low-risk antibiotic available in the USA that has not previously been tested after OHCA, (3) inclusion of anti-inflammatory effects of ceftriaxone as a novel mechanism for improved clinical outcomes, and (4) complete metagenomic assessment of bacterial resistomes pre- and post-ceftriaxone prophylaxis. The long-term goal is to develop a definitive phase III trial powered for mortality or functional outcome.Trial registrationClinicalTrials.gov NCT04999592. Registered on August 10, 2021.

Successful Desensitization to mRNA COVID-19 Vaccine in a Case Series of Patients With a History of Anaphylaxis to the First Vaccine Dose.

BackgroundCoronavirus disease 2109 (COVID-19) vaccines have recently been approved to curb the global pandemic. The risk of allergic reactions to the vaccine polyethylene glycol (PEG) component has raised significant public concern. Desensitization is suggested in cases of vaccine related hypersensitivity reactions. After comprehensive literature review on the topic, our aim was to establish a safe and effective desensitization protocol for patients with suspected or confirmed immediate type hypersensitivity reactions to the COVID-19 vaccine.MethodsParticipants were referred to the McGill University Health Center (MUHC) Allergy-Immunology department for clinical evaluation following a reported reaction to their first dose of Moderna® mRNA-1273 or Pfizer-BioNTech® BNT162b2 vaccines. They underwent skin prick testing (SPT) with higher and lower molecular weight (MW) PEG and polysorbate 80, as per published protocols. Their second dose was administered following a desensitization protocol consisting of multiple dose-administration steps followed by a 60-min observation period.ResultsAmong a cohort of 142 patients with an increased risk for allergic reactions to the COVID-19 vaccines, six individuals were selected to undergo desensitization. All were female with allergic background including chronic spontaneous urticaria, anaphylaxis to medications, and/or vaccines. The main symptom after their first dose was difficulty swallowing with lightheadedness or immediate urticaria, angioedema, and/or dizziness. Two patients had positive skin testing. One patient was on chronic antihistamines which resulted in an inconclusive PEG skin test and the skin testing was negative for the three other patients. During the desensitization, two patients reported cutaneous symptoms of an immediate reaction and were managed with antihistamines. One of these patients also complained of ear pressure and had a drop in her systolic blood pressure, treated with intravenous fluids.ConclusionThis study suggests that some individuals with an immediate-type hypersensitivity reaction to their first dose of mRNA COVID-19 vaccine may safely receive their second dose using a desensitization protocol. The success of this desensitization protocol is a step forward in the fight against COVID-19, allowing more individuals to be immunized.

Review of Patients with Immediate-Type Drug Reactions and Test Results: Retrospective Study from the Malatya Province

Aim: Drug hypersensitivity is an important issue encountered by clinicians during clinical practice in Turkey and in the world. Any drug used for diagnosis or treatment has the potential to cause hypersensitivity reactions. The aim of the present study was to review the distribution of drugs reported to cause hypersensitivity reactions and to determine the distribution of tests and test results among patients that presented to the adult allergy and immunology outpatient clinic with immediate-type drug hypersensitivity in the Malatya province. Materials and Methods: The study included adult patients who were admitted with immediate-type drug hypersensitivity (allergic and/or non-allergic) between October 2017 and October 2020 and underwent testing for drugs. Age, sex, atopic diseases (asthma, allergic rhinitis, urticaria, eczema), culprit drug(s), drug reaction types, time of reaction onset, and skin and drug provocation test results were evaluated. Results: Of the 107 patients included, 83 (77.6%) were female and 24 (22.4%) were male. The mean age was 40.74 ± 11.28 years. There was a history of drug hypersensitivity to antibiotics in 44 patients (41.1%) and analgesics in 56 patients (52.3%). Urticaria and/or angioedema were the most common reactions to culprit drugs. Overall, 148 tests for drug hypersensitivity were performed, and the positivity rate was 6.1%. Conclusion: Analgesics and antibiotics were the most common causative agents in patients presenting to allergy outpatient clinics with drug allergy, and reactions occurred even with alternative agents. Thus, patients reporting drug reactions should undergo drug tests before physicians recommend drugs.

Mast cells in severe respiratory virus infections: insights for treatment and vaccine administration

&lt;abstract&gt; &lt;p&gt;Mast cells (MCs) are a part of the innate immune system and express receptors for microbial and viral pathogens characteristic of this system. The pathological role of MCs has been demonstrated for a number of highly virulent viral infections. The role of MCs and their Fc receptors for IgE in the immediate-type hypersensitivity reactions and in immunocomplex reactions is well-known, although the role of MCs and their Fc receptors for IgG (FcγR) in immunocomplex processes is much less studied. Antibody-dependent enhancement syndrome (ADE) has been observed in a number of viral infections and is associated with greater secondary infection. ADE is enhanced by virus-specific antibodies, which are not involved in the virus penetration into the cell but are capable of forming immune complexes. The role of MCs in ADE is well-established for dengue infection, RSV infection and coronavirus (CoV) infection. The involvement of IgG-mediated mast cell responses in other human viral infections including Coronavirus disease 2019 (COVID-19) is poorly understood. Recently discovered mast cell activation disease is considered one of the causes of severe post-infectious complications in COVID-19. If the role of MCs in the pathogenesis of severe viral infections, including ADE in recurrent viral infection is clarified, these cells and the products they release may serve as promising targets for such therapeutic agents as histamine receptor blockers or membrane stabilizers to prevent possible complications.&lt;/p&gt; &lt;/abstract&gt;

Immediate-Type Systemic Hypersensitivity Reactions After the Inactivated SARS-CoV-2 Vaccine in Healthcare Workers

The vaccines developed for Coronavirus disease 2019 (COVID-19) not only brought hope to the struggle against the pandemic but also raised questions about hypersensitivity reactions that might occur. Although some studies regarding these concerns with mRNA COVID-19 vaccines have been published, these data on inactivated Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) vaccine are not available. The objective of this study was to determine the safety of the inactivated SARS-CoV-2 vaccine manufactured by Sinovac by evaluating the reported systemic immediate hypersensitivity reactions (IHRs) after the administration of the vaccine to healthcare workers (HCWs). This was a retrospective analysis of inactivated SARS-CoV-2 vaccine recipients in all HCWs vaccinated at our center. Relevant data of all patients who received the vaccine were collected from the electronic medical records available at our center’s database. A statistical analysis of subjects who reported acute adverse reactions was conducted. Of the 3354 HCWs vaccinated with the first dose (female 59.9%, pre-existing allergic disorder 2.4%), four acute adverse reactions (0.12%) met the definition of a systemic IHRs were reported, and only one was confirmed to be anaphylaxis. One out of these four cases received her second dose through graded administration. For the second dose, no systemic reaction was reported in our study population. Inactivated SARS-CoV-2 vaccine appears to be well tolerated in HCWs without any pre-existing allergic disorders.

First Confirmed Case of IgE-Mediated Hypersensitivity to Evolucumab with Cross-Reactivity to Alirocumab

Proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors have become popular for aggressive lowering low-density lipoprotein cholesterol levels. Two Food and Drug Administration–approved PCSK9 inhibitors include evolucumab (Repatha) and alirocumab (Praluent), and adverse effects have reported to be rare.1 We report a case of immediate-type hypersensitivity reaction to evolucumab with cross-reactivity to alirocumab.