Desensitization for drug allergy

Changing patterns in the epidemiology of drug allergy

Drug allergy (DA) remains a complex and unaddressed problem worldwide that often deprives patients of optimal medication choices and places them at risk for life-threatening reactions. Underdiagnosis and overdiagnosis are common and due to the lack of standardized definitions and biomarkers. The true burden of DA is unknown, and recent efforts in data gathering through electronic medical records are starting to provide emerging patterns around the world. Ten percent of the general population engaged in health care claim to have a DA, and the most common label is penicillin allergy. Up to 20% of emergency room visits for anaphylaxis are due to DA and 15%-20% of hospitalized patients report DA. It is estimated that DA will increase based on the availability and use of new and targeted antibiotics, vaccines, chemotherapies, biologicals, and small molecules, which are aimed at improving patient's options and quality of life. Global and regional variations in the prevalence of diseases such as human immunodeficiency virus and mycobacterial diseases, and the drugs used to treat these infections have an impact on DA. The aim of this review is to provide an update on the global impact of DA by presenting emerging data on drug epidemiology in adult and pediatric populations.

Desensitization Protocol for Cemiplimab-Related Infusion Reaction in Cutaneous Squamous Cell Carcinoma: A Case Report and Literature Review

BACKGROUND

The landscape of systemic therapies for advanced non-melanoma skin cancers has been revolutionized by the advent of immunotherapy. Cemiplimab is the only immune checkpoint inhibitor (ICI) approved by the European Medicine Agency for recurrent/metastatic cutaneous squamous cell carcinoma (cSCC). Its excellent efficacy outcomes are achieved due to its good tolerability profile. The drug-related hypersensitivity reaction (HSR) is a well-known issue in oncology, but it is rarely reported in respect to immune checkpoint inhibitors. Cemiplimab is among the agents with the best infusion tolerability profiles. Clinical practice guidelines in this field are lacking.

RESULTS

We report on the successful management of a severe infusion reaction induced by Cemiplimab in a patient with cSCC based on a desensitization protocol, which led to adequate treatment delivery and prolonged clinical benefit. A review of the available literature on HSR rates and its management with ICIs, and on drug desensitization (DD) protocols and their efficacy, was conducted to highlight the limited knowledge on this topic and its importance.

CONCLUSION

Our experience highlights the need for a DD protocol in order to improve the treatment of HSRs, particularly when elicited by an immunotherapy agent, preventing treatment discontinuation and preserving its efficacy.

Interleukin-6 and cytokine release syndrome: A new understanding in drug hypersensitivity reactions

Immediate drug hypersensitivity reactions (DHRs) are historically thought to be because of immunoglobulin E (IgE) cross-linking, causing mast cell degranulation and release of mediators like tryptase and histamine. With the increasing use of monoclonal antibodies, it has become apparent that some patients present atypical features during immediate DHRs, including occurrence in initial exposure, a lack of urticaria and angioedema, and the presence of fever, chills, rigors and musculoskeletal pain as the predominant symptoms. This observation led to the recognition of a novel phenotype of immediate DHRs called cytokine release syndrome (CRS). Other types of immediate DHRs include infusion-related reactions (which present similarly to CRS), and mixed reactions (which share overlapping features of both type 1 reactions and CRS). Desensitization to culprit drugs can be a lifesaving option in patients who develop immediate DHRs to first-line treatment. Whereas robust data are supporting the safety and efficacy of drug desensitization, breakthrough reactions can still occur and CRS seems to be a more common cause than type 1 reactions. Tryptase has been the only available biomarker for immediate DHRs and is associated with type 1 reactions. Emerging evidence consistently found the association between increased serum interleukin 6 level and DHR-related CRS, suggesting that interleukin 6 can be a novel biomarker, in addition to tryptase, to distinguish various types of DHRs. In the era of precision medicine, phenotyping and endotyping hypersensitivity reactions to chemotherapy and monoclonal antibodies using validated biomarkers should be part of routine drug allergy care.

The first successful desensitization protocol in exenatide allergy: a case report

BACKGROUND

Glucagon-like peptide-1 (GLP-1) receptor agonists are important treatment options in obese patients with type 2 diabetes. To date, few immediate allergic reactions due to GLP-1 receptor agonists were reported. One report revealed that a patient with a level 1 anaphylaxis according to Brighton Criteria due to an exendin based GLP-1 receptor agonist was able to tolerate liraglutide (Human GLP-1 analogue), the alternative GLP-1 receptor agonist. Since exenatide is the only available GLP-1 receptor agonist covered by insurance in Turkey, a drug desensitization protocol, the only therapeutic method in hypersensitivity reactions used in case of absence of an alternative drug, was considered. Here, we report a successful desensitization protocol for the first time in two obese diabetic patients with an immediate hypersensitivity to exenatide.

CASE PRESENTATION

The first patient was a 47 year-old female. She was referred to our outpatient allergy clinic because of a generalized urticaria developed within minutes after the last dose, following a week of an exenatide BID 5 mcg/20 mcl treatment. Although the reaction was sudden onset, it did not meet the Brighton Criteria of anaphylaxis. The second patient was a 46 year-old female. She had a large local immediate injection site reaction that appeared 15 min following an exenatide BID 5 mcg/20 mcl injection. The injection site reaction was not accompanied by a systemic allergic reaction. We performed desensitization with exenatide to two patients who need GLP-1 receptor agonist treatment. Protocol was completed in 7 steps in approximately 3 h, with the aim of reaching the daily dosage of exenatide. Throughout this process, we observed that both cases tolerated the protocol without any complaints or complications. Following the protocol, the patients safely tolerated the treatment for 3 months.

CONCLUSIONS

We present the first successful desensitization protocol to exenatide in both local and/or systemic immediate hypersensitivity reactions and indicate the importance of desensitization in patients who do not have alternative therapies.

Safety and efficacy of rapid drug desensitization in children

BACKGROUND

Any drug taken at the recommended dosage may cause hypersensitivity reactions (DHR). Rapid drug desensitization (RDD) protocols have been developed in the case of a confirmed or highly suspected HSR to allow safe administration of the medicine when there is no alternative drug or in the presence of a less effective or more toxic alternative. The aim of this study was to evaluate the characteristics of children who underwent desensitization, the safety and efficacy of RDD in children, as well as, the characteristics and management of breakthrough reactions.

METHOD

This retrospective study concerned children who underwent RDD due to physician-diagnosed HSRs during or up to 48 hours after the infusion of various drugs between February 2010-February 2021. Patients with a chronic disease needing chronic drug usage and acute infections seen in patients with chronic diseases were included. The results of RDD were documented.

RESULTS

The study included 48 patients [8.1(IQR = 3.32-13.4) years, 60.4% male] with 58 HSRs of which 62.1% were classified as moderate and 5.2% as severe. Most of the patients were being treated for leukemia (41.7%), solid tumors (29.2%), and infections (6.3%). Skin tests were done for 41 out of 58 HSRs in 35 patients, and twenty of them were positive. A total of 269 RDDs were performed for 18 different drugs. Ninety percent of desensitizations were achieved with no reaction, and 3.7% and 5.6% with mild and moderate reactions, respectively. In multivariate analysis, skin test positivity was the only risk factor for breakthrough reactions (OR = 8.5, CI = 1.72-42.15, p = .009).

CONCLUSION

We demonstrated the safety and efficacy of RDD in childhood, thereby offered the first line treatment options to children with chronic diseases with hypersensitivity reactions (HSRs).

Evaluation of desensitization protocols to betalactam antibiotics

WHAT IS KNOWN AND OBJECTIVE

Betalactam antibiotics are the most frequent cause of hypersensitivity reactions. Rapid drug desensitization (RDD) is a technique that induces temporary tolerance to a drug allowing a patient to receive the optimal agent. The increased use of RDD and the lack of standardization among available protocols in terms of formulation, starting dose, number of steps and dosing frequency make it essential to determine the safety and appropriate management of these protocols, especially regarding reconstitution, diluents, stability and drug administration in order to guarantee reproducibility. We reviewed betalactam desensitization protocols in a tertiary hospital, in accordance with currently published practices and evaluated its use on patients over a period of three years.

METHODS

(a) We performed a literature search in PubMed, MEDLINE and Google Scholar databases for case reports and/or systematic reviews describing desensitization protocols for betalactam antibiotics. Pharmacokinetic parameters and physicochemical stability were checked for each antibiotic. (b) We retrospectively reviewed inpatients undergoing our antibiotic desensitization protocols from February 2018 to January 2021. Data and outcomes of desensitization procedures were analysed.

RESULTS

We developed nine RDD protocols: meropenem, ceftriaxone, ceftazidime, ampicillin, ceftolozane/tazobactam, cloxacillin, piperacillin/tazobactam, amoxicillin/clavulanate and penicillin G sodium. Five antibiotics have RDD protocols for two different doses, adjusted to patients with impaired renal function. Detailed data (diluent, total dose, volume, concentrations, duration and stability) of the protocol of each antibiotic used are provided. 28 desensitizations were performed in 17 patients, three of them with confirmed allergies by skin test. 26 out of 28 (92.9%) of them were successfully completed, including those three with positive skin results. The pathogens most frequently involved were E. faecalis and P. aeruginosa; both frequently associated with bacterial resistance. Meropenem, ceftriaxone and ceftazidime were the antibiotics most desensitized. 25 out of 26 (96.1%) procedures were successful in resolving the infection.

WHAT IS NEW AND CONCLUSIONS

Detailed information about compounding, dilution and stability is crucial to ensure safe and successful desensitization processes, as well as good coordination between the Allergy and Pharmacy departments. The increase in bacterial resistance to many of the commercially available antibiotics limits the therapeutic options for treating multidrug-resistant infections; in those situations, antibiotic desensitization may be a key therapeutic option. Although there is a broad consensus in limiting the use of RDD to patients with confirmed allergy, in usual clinical practice its application in those strongly suspected of having type I hypersensitivity is still observed. Our betalactam desensitization protocols have shown themselves to be safe and effective, as evidenced by data from the 17 patients on whom they have been tested.

A new rapid titration protocol for lamotrigine that reduces the risk of skin rash

Objective

Lamotrigine is one of the most widely used antiepileptic drugs, but it has a critical issue of a skin rash if the starting dose is too high or the escalation rate is too rapid. We investigated the efficacy and safety of a novel and rapid titration protocol for lamotrigine that takes only 11 days to reach a daily dose of 200 mg.

Methods

We prospectively enrolled 33 adult patients (age 18‐85) who were diagnosed with epilepsy and started lamotrigine administration for the first time at a single tertiary hospital. Our new protocol starts with a subthreshold dose of the drug and then administers a stepwise‐incremental dose until reaching the full therapeutic dose within 11 days.

Results

Of 29 patients analyzed, only two (6.9%) experienced idiosyncratic skin rash before the first follow‐up visit at 2 weeks (±3 days). In addition, a therapeutic concentration was reached in more than 75% of studied patients after 2 weeks of lamotrigine administration.

Significance

These findings demonstrate the value of the novel tolerance induction protocol for lamotrigine, which could widen the available application of lamotrigine in various situations. However, this study is a preliminary study limited by a small number of patients and its nonrandomized and open‐label design, so the current protocol needs more rigorous clinical evaluations before the application to the real clinical setting.

Patient characterization and predictors of aspirin desensitization response

Background

Hypersensitivity to nonsteroidal anti-inflammatory drugs (NSAIDs) may limit the use of aspirin in patients with cardiovascular diseases. Aspirin desensitization, which is a resource-intensive process, can offer such patients access to aspirin through the induction of temporary tolerance to aspirin. However, there is limited information on aspirin desensitization response in patients undergoing aspirin desensitization for cardiac indications in Asia.

Objective

To characterize patients who have undergone aspirin desensitization, evaluate their responses to the procedure, and identify risk factor(s) associated with failure of aspirin desensitization.

Methods

We conducted a retrospective review of medical records of patients who underwent aspirin desensitization in Singapore General Hospital between 1 June 2014 and 31 October 2017. Chi-square or Fisher exact test were used to analyze categorical data while independent samples t test or Wilcoxon rank-sum test were used for continuous data where appropriate. Multivariate logistic regression was used to identify predictors of aspirin desensitization failure.

Results

All 214 patients in our study had cardiovascular indications for aspirin, with angioedema being the most common type of index reaction experienced with NSAIDs (n = 104, 48.6%). One hundred sixty-five patients (77.1%) achieved successful aspirin desensitization. In the selected sample analysis of patients with true NSAID hypersensitivity (n = 163), an index reaction of angioedema to NSAIDs was found to be significantly associated with a higher risk of failing aspirin desensitization (odds ratio, 7.21; 95% confidence interval, 1.94–26.71).

Conclusion

Majority of the patients who underwent aspirin desensitization in our institution were able to achieve tolerance to aspirin. An index reaction of angioedema to NSAIDs was identified as a risk factor for aspirin desensitization failure. This information can aid in the risk stratification of patients undergoing aspirin desensitization and ensure efficient resource allocation for this procedure.

Aspirin Desensitization: Implications for Acetylsalicylic Acid-Sensitive Pregnant Women

Low-dose acetylsalicylic acid (ASA) is widely used during pregnancy to prevent obstetric complications of placental dysfunction, such as preeclampsia, stillbirth and fetal growth restriction, and obstetric complications in pregnant women with antiphospholipid syndrome. ASA-sensitive pregnant women cannot benefit from the effects of ASA due to the possibility of severe or potentially life-threatening hypersensitivity reactions to ASA. ASA desensitization is a valuable and safe therapeutic option for these women, allowing them to start daily prophylaxis with ASA and prevent pregnancy complications. The authors discuss the recent advances in obstetric conditions preventable by ASA and the management of ASA hypersensitivity in pregnancy, including ASA desensitization. To encourage the implementation of ASA desensitization protocols in ASA-sensitive pregnant women, they also propose a practical approach for use in daily clinical practice.

Implementation of EMR-based standardized antibiotic desensitization protocols and its impact on providers

Background: As desensitization protocols become more readily available and published, more institutions are implementing them and searching for ways to streamline the process. There have been no published studies to date on the effect that electronic medical record systems (EMR) have on the safety and efficiency of β-lactam antibiotic desensitization. Objective: The purpose of this study was to evaluate the changes in workflow, efficiency, and medical errors after implementation of β-lactam antibiotic desensitization. Methods: A collaborative effort between the Allergy/Immunology Division and the Pharmacy Department led to the creation and implementation of antibiotic desensitization order sets. Pre- and postimplementation of β-lactam antibiotic surveys were sent to pharmacists and allergy/immunology fellows and attendings at a single-center tertiary care center. Results: There were only 26 valid respondents (12.3%) to both the pre- and postimplementation surveys. The percentage of respondents who thought that the time needed to prepare desensitization materials was < 4 hours increased from 23% to 77% (p < 0.001). The percentage of respondents who thought that the time needed to input electronic desensitization orders was < 1 hour increased from 19% to 54% (p = 0.002). The percentage of respondents who identified zero errors increased from 42% to 92% (p = 0.001). The perception of the overall desensitization process efficiency significantly increased (p < 0.001). Conclusion: Creation of standardized electronic β-lactam antibiotic desensitization order sets significantly decreased the time taken to order and prepare materials and increased overall efficiency.

Successful Desensitization Protocol in an Infant Following Anaphylaxis Secondary to Recombinant Factor VIIa

Background: Recombinant factor VIIa (rFVIIa) is a highly purified recombinant protein. It is approved for the treatment and prevention of bleeding episodes associated with congenital factor VII deficiency, congenital hemophilia with inhibitors, and Glanzmann's thrombasthenia. The most commonly reported adverse events are thrombolytic in nature. In this report, we present a successful desensitization protocol administered to an infant with a history of anaphylaxis to rFVIIa. Case: A male infant with a history of gingival bleeding at the age of 6 months was diagnosed with factor VII deficiency with a factor VII level of 1%. His sister also had diagnosis of factor VII deficiency. Our patient was hospitalized at 10 months of age with generalized petechiae and bloody stools. Twenty minutes after administration of rFVIIa, he developed anaphylaxis that responded to epinephrine and supportive care. Subsequently he was evaluated at the allergy clinic, where a skin prick test with rFVIIa was negative. However, the intradermal skin test, applied with 1/1,000 (1 μg/1 mL, 0.1 mL) dilution of rFVIIa, showed induration of 8 mm (positive reaction). Because there is no alternative treatment for factor VII deficiency, we developed a successful 13-step desensitization protocol with rFVIIa (NovoSeven^®). Desensitization was performed an additional 2 times using the same protocol, one of which was for a head injury and the other for a swollen knee since the period between the doses was ∼3 months. Conclusion: Allergic reactions, such as anaphylaxis can occur without prior exposure. This can be due to the high molecular weight and structural property of the biological agent. In this report, we present an effective desensitization protocol for an infant with a history of anaphylaxis to rFVIIa. Desensitization protocols in this age group should be carried out in a medical facility and with specialized staff and equipment prepared to care for anaphylaxis.

A Unique Case of Acquired Hemophilia A Presenting with Transient Ischemic Attack

Acquired hemophilia A (AHA) is a rare but serious condition, usually associated with significant spontaneous or traumatic bleeding and a high mortality rate. In this report, we describe the case of an elderly patient presenting a transient ischemic attack concurrently with AHA. A thrombotic event in AHA is occasionally associated with the use of bypassing agents for treatment, but a spontaneous thrombotic event has not ever been described.

Hypersensitivity Reactions to Biologicals: from Bench to Bedside

Purpose of Review

Biologic agents are new treatment options for chronic inflammatory diseases and cancers. As a result of their unique mechanism of action, they are more effective and less toxic treatment option and their clinical usage is increasing. While they are more commonly used, various adverse effects have been observed including life-threatening ones, including anaphylaxis. The aim of this review is to distinguish the anaphylaxis from other hypersensitivity reactions (HSR) and provide a management algorithm for the anaphylactic reactions induced by biological agents.

Recent Findings

Many case reports and series have been published regarding anaphylaxis and other hypersensitivity reactions (concerning cytokine release syndrome, acute infusion–related reactions) due to biologic agents. Although acute treatment of HSR varies according to the clinical presentation, desensitization with the drug is the major management option for subsequent administrations in the case of anaphylactic reactions.

Summary

Anaphylaxis and other immediate onset hypersensitivity reactions are occasionally difficult to differentiate from each other, and mixed-type reactions may be observed. Immediate management of anaphylaxis includes discontinuation of infusion, immediate administration of adrenaline, antihistamines, corticosteroids, and other treatment options depending on the symptoms. After 30–120 min of the reaction, a blood sample for serum tryptase levels should be obtained and after 4–6 weeks skin testing with the culprit drug should be performed for decision of long-term management via either graded challenge or desensitization.

Rapid Desensitization for Hypersensitivity Reactions to Chemotherapeutic Drugs; A Case Series

Usage of cancer chemotherapeutics drugs can be associated with adverse drug reactions. When IgE-mediated drug reactions are formed following administration of a chemotherapeutics drug that is a drug of choice, drug desensitization protocols can be helpful. HSR can be allergic or nonallergic, but the clinical manifestations are similar. RDD is effective when used appropriately, however it is often over utilized instead of performing a drug challenge. RDD is both an acceptable approach and a high-risk treatment modality in patients, in whom the offending agent is the first choice in chemotherapy. The safety of this modality has been acceptable in large studies. The side effects are often less frequent and less severe by repeating the protocol. We present 4 cases of successful desensitization in cancer patients, who have developed IgE- mediated reactions to their major chemotherapy drug.

Desensitization therapy using 'Mariana Castells' protocol in a patient with multiple autoimmune disorders- does it work?

Clinical use of antibiotics is becoming more widespread with each passing day for various infectious diseases. This has caused an abrupt increase in hypersensitivity reactions linked to these drugs, sometimes preventing the use of first-line therapies. In these patients, clinical presentation may vary from mild skin infections to life-threatening anaphylactic reactions. Our patient is a 30 year old female with past medical history significant for mast cell activation syndrome and multiple autoimmune diseases who presented with chief complaint of fever. Patient was diagnosed with MSSA bacteremia requiring the start of an antibiotic regimen. Mariana castells protocol was used for desensitizing the patient before starting her on antibiotic regimen. Patient was desensitized in 2 days using the standard 12-step protocol and started on cefazolin for her long-term treatment of the infection. No acute episodes of drug hypersensitivity were reported. During the course of her hospital admission, she improved significantly with no complications. Our patient having a history of both multiple autoimmune diseases and mast-cell activation syndrome tolerated the protocol well with no complications. Appropriate treatment of the reactions including epinephrine use and management with personalized desensitization protocols can enhance the quality of life, life expectancy, and safety of an increasing at risk population of patients with infectious diseases allergic to their best medications. Protocols, such as mariana castells, are completely safe in autoimmune disorders and should be utilized as the standard of care in appropriate patient population.

Interleukin-10 is increased in successful drug desensitization regardless of the hypersensitivity reaction type

Background

Little is known about the mechanism of desensitization in hypersensitivity drug reactions.

Objective

The aim of this study was to evaluate the effects of drug desensitization on some cytokine levels in patients desensitized for drug hypersensitivity reactions.

Methods

Patients with a hypersensitivity reaction to any drug for whom desensitization was planned with the culprit drug, patients who could tolerate the same drugs and healthy subjects who were not exposed to these drugs were enrolled. Bead-based Milliplex MAP multiplex technology was used to determine interleukin (IL)-4, IL-5, interferon-γ and IL-10 levels in the sera of the subjects as a baseline and 24 hours after desensitization had been completed in the patients.

Results

A total of 26 patients (16 female [61.5%]; mean age 48.46 ± 15.97 years old), 10 control patients (5 female [50%]; mean age 47.4 ± 15.4 years old) and 5 healthy subjects (3 female [60%]; mean age 34.2 ± 5.6 years old) were enrolled. Four of the 26 patients did not tolerate the procedure and were grouped as the 'unsuccessful desensitization group' whereas 22 patients successfully completed the procedure and formed the 'successful desensitization group.' Baseline cytokine levels in the 3 groups were not statistically different. Postdesensitization IL-10 levels in the successful desensitization group were significantly higher than their initial levels (p = 0.005) whereas none of the cytokine levels significantly changed in the unsuccessful desensitization group. The rise in IL-10 levels was greater in chemotherapeutic desensitizations when compared to other drugs (p = 0.006).

Conclusion

Successful desensitization independent of the hypersensitivity reaction type seems to be related to the increase of IL-10.

Basophil Activation Test: Old and New Applications in Allergy

PURPOSE OF REVIEW

The basophil activation test (BAT) using flow cytometry has supplanted traditional methods of measuring basophil degranulation using histamine and other mediator release, and can be used for clinical applications as well as to explore the immune mechanisms of effector cell response to allergen. This review discusses the advancements made in clinical, diagnostic and laboratory research of allergy utilizing an ever-evolving BAT.

RECENT FINDINGS

Being an in vitro surrogate of the allergic reaction that happens in vivo in the sick patient, the BAT can be used to support the diagnosis of various allergic conditions, such as food, drug, respiratory and insect venom allergies, and the assessment of clinical response to allergen-specific immunotherapy and other immunomodulatory treatments. The BAT can also be used for research purposes to explore the mechanisms of allergy and tolerance at the level of the basophil, for instance by manipulating IgE and IgG and their receptors and by studying intracellular signalling cascade in response to allergen. This review covers the applications of the BAT to the clinical management of allergic patients and the increased understanding of the mechanisms of immune response to allergens as well as technological advancements made in recent years.

Bypassing adverse injection reactions to nanoparticles through shape modification and attachment to erythrocytes

Intravenously injected nanopharmaceuticals, including PEGylated nanoparticles, induce adverse cardiopulmonary reactions in sensitive human subjects, and these reactions are highly reproducible in pigs. Although the underlying mechanisms are poorly understood, roles for both the complement system and reactive macrophages have been implicated. Here, we show the dominance and importance of robust pulmonary intravascular macrophage clearance of nanoparticles in mediating adverse cardiopulmonary distress in pigs irrespective of complement activation. Specifically, we show that delaying particle recognition by macrophages within the first few minutes of injection overcomes adverse reactions in pigs using two independent approaches. First, we changed the particle geometry from a spherical shape (which triggers cardiopulmonary distress) to either rod- or disk-shape morphology. Second, we physically adhered spheres to the surface of erythrocytes. These strategies, which are distinct from commonly leveraged stealth engineering approaches such as nanoparticle surface functionalization with poly(ethylene glycol) and/or immunological modulators, prevent robust macrophage recognition, resulting in the reduction or mitigation of adverse cardiopulmonary distress associated with nanopharmaceutical administration.

Drug Hypersensitivity and Desensitizations: Mechanisms and New Approaches

Drug hypersensitivity reactions (HSRs) are increasing in the 21st Century with the ever expanding availability of new therapeutic agents. Patients with cancer, chronic inflammatory diseases, cystic fibrosis, or diabetes can become allergic to their first line therapy after repeated exposures or through cross reactivity with environmental allergens. Avoidance of the offending allergenic drug may impact disease management, quality of life, and life expectancy. Precision medicine provides new tools for the understanding and management of hypersensitivity reactions (HSRs), as well as a personalized treatment approach for IgE (Immunoglobuline E) and non-IgE mediated HSRs with drug desensitization (DS). DS induces a temporary hyporesponsive state by incremental escalation of sub-optimal doses of the offending drug. In vitro models have shown evidence that IgE desensitization is an antigen-specific process which blocks calcium flux, impacts antigen/IgE/FcεRI complex internalization and prevents the acute and late phase reactions as well as mast cell mediator release. Through a "bench to bedside" approach, in vitro desensitization models help elucidate the molecular pathways involved in DS, providing new insights to improved desensitization protocols for all patients. The aim of this review is to summarize up to date information on the drug HSRs, the IgE mediated mechanisms of desensitization, and their clinical applications.

Desensitization to Oxcarbazepine: Long-Term Efficacy and Tolerability

BACKGROUND AND PURPOSE

Antiepileptic drug (AED)-associated cutaneous adverse drug reactions can lead to the discontinuation of medications. The aim of this study was to determine the long-term efficacy and safety of performing desensitization to oxcarbazepine.

METHODS

This study involved 20 patients who exhibited cutaneous adverse drug reactions associated with oxcarbazepine use between July 2009 and March 2016 at Samsung Medical Center. All of the participants had to discontinue oxcarbazepine despite presenting initially positive responses. Human leukocyte antigen genotyping was performed to detect the genetic predisposition to Stevens-Johnson syndrome. The desensitization to oxcarbazepine was performed with a starting dosage of 0.1 mg/day. Efficacy was evaluated by comparing the frequency of seizures before and at 1 and 3 years after desensitization. Adverse events occurring during desensitization and the retention rate after desensitization were also investigated.

RESULTS

Nineteen patients (95%) safely completed the desensitization protocol. One withdrew owing to emotional problems that appeared to be associated with oxcarbazepine. The follow-up period was 4.6±1.2 years (mean±SD), and oxcarbazepine was maintained for more than 3 years after desensitization in 15 patients (83.3%). The response rates were 84.2% and 77.8% at 1 and 3 years after desensitization, respectively. Eight patients remained seizure-free for 3 years, and two discontinued all AEDs. Transient adverse reactions such as mild rash and itching were reported by five patients during desensitization.

CONCLUSIONS

This study has demonstrated the long-term efficacy and safety of desensitization to oxcarbazepine in patients exhibiting cutaneous adverse drug reactions. This favorable outcome should encourage the implementation of desensitization in patients presenting with hypersensitivity to oxcarbazepine as an alternative strategy in clinical practice.

Rapid Desensitization for Immediate Hypersensitivity to Galsulfase Therapy in Patients with MPS VI

Mucopolysaccharidosis type VI (MPS VI) is a progressive, chronic, and multisystem lysosomal storage disease. Enzyme replacement therapy (ERT) with the recombinant human arylsulfatase B enzyme (galsulfase [Naglazyme]) is recommended as first-line therapy. It is generally reported as safe and well tolerated. Frequently observed mild to moderate infusion-related reactions which can be easily handled by reducing or interrupting the infusion and/or administering additional antihistamines, antipyretics, and corticosteroids are mostly mediated by non-IgE mechanisms. Here we report two children with MPS VI who experienced IgE-mediated reactions with galsulfase at the second year of the therapy. One child had anaphylaxis and the other had urticarial eruptions. They could receive ERT after successful rapid desensitization. To our knowledge, this is the second report on galsulfase allergy with IgE-mediated reaction. It is important to recognize IgE-mediated reactions since they can be life-threatening and do not respond to the standard therapies. We recommend allergy skin tests in the evaluation of infusion-related reactions unresponsive to standard therapies, so that continuation of ERT will be feasible after successful desensitization.

Anaphylaxis to chemotherapy and monoclonal antibodies

Hypersensitivity reactions are increasingly prevalent, although underrecognized and underreported. Platins induce immunoglobulin E-mediated sensitization; taxenes and some monoclonal antibodies can induce reactions at first exposure. Severe hypersensitivity can preclude first-line therapy. Tryptase level at the time of a reaction is a useful diagnostic tool. Skin testing provides a specific diagnosis. Newer tests are promising diagnostic tools to help identify patients at risk before first exposure. Safe management includes rapid drug desensitization. This review provides information regarding the scope of hypersensitivity and anaphylactic reactions induced by chemotherapy and biological drugs, as well as diagnosis, management, and treatment options.

Desensitization to ceftaroline in a patient with multiple medication hypersensitivity reactions

PURPOSE

The case of a patient with multiple medication hypersensitivity reactions and a methicillin-resistant Staphylococcus aureus (MRSA) infection who underwent desensitization to ceftaroline is reported.

SUMMARY

A 32-year-old Caucasian woman with asthma, gastroesophageal reflux disease, heart murmur, and major depression was admitted for MRSA cellulitis with a subcutaneous abscess along the left sternomanubrial joint and clavicular osteomyelitis secondary to port placement after gastric bypass surgery. The patient had an extensive history of hypersensitivity reactions. Pertinent documented allergies were as follows: penicillin (anaphylaxis), daptomycin (anaphylaxis), vancomycin (hives), linezolid (hives), ertapenem (rash), ciprofloxacin (rash), and tigecycline (rash). The patient also reported previous reactions to aztreonam (unknown) and gentamicin (hives). The pharmacy was consulted to develop a desensitization protocol for ceftaroline. The desensitization protocol used three serial dilutions of ceftaroline to make 14 sequential infusions with escalating doses. Intramuscular epinephrine, i.v. diphenhydramine, and i.v. methylprednisolone were ordered as needed for the development of immediate hypersensitivity reactions during or after administration of ceftaroline. The cumulative dose (574.94 mg) was administered intravenously over 225 minutes with no breakthrough symptoms reported during or after the desensitization protocol. Ceftaroline fosamil 600 mg i.v. every 12 hours was continued for six weeks.

CONCLUSION

Desensitization to ceftaroline was conducted for a patient with extensive history of hypersensitivity reactions to other drugs, including penicillin-induced anaphylaxis. Desensitization and subsequent treatment with full doses of ceftaroline were accomplished without apparent adverse effects.

Management of hypersensitivity to platinum- and taxane-based chemotherapy: cepo review and clinical recommendations

BACKGROUND

Although antineoplastic agents are critical in the treatment of cancer, they can potentially cause hypersensitivity reactions that can have serious consequences. When such a reaction occurs, clinicians can either continue the treatment, at the risk of causing a severe or a potentially fatal anaphylactic reaction, or stop the treatment, although it might be the only one available. The objective of the present work was to evaluate the effectiveness of methods used to prevent and treat hypersensitivity reactions to platinum- or taxane-based chemotherapy and to develop evidence-based recommendations.

METHODS

The scientific literature published to December 2013, inclusive, was reviewed.

RESULTS

Premedication with antihistamines, H2 blockers, and corticosteroids is not effective in preventing hypersensitivity reactions to platinum salts. However, premedication significantly reduces the incidence of hypersensitivity to taxanes. A skin test can generally be performed to screen for patients at risk of developing a severe reaction to platinum salts in the presence of grade 1 or 2 reactions, but skin testing does not appear to be useful for taxanes. A desensitization protocol allows for re-administration of either platinum- or taxane-based chemotherapy to some patients without causing severe hypersensitivity reactions.

CONCLUSIONS

Several strategies such as premedication, skin testing, and desensitization protocols are available to potentially allow for administration of platinum- or taxane-based chemotherapy to patients who have had a hypersensitivity reaction and for whom no other treatment options are available. Considering the available evidence, the Comité de l'évolution des pratiques en oncologie made recommendations for clinical practice in Quebec.

Aspirin hypersensitivity and desensitization protocols: implications for cardiac patients

Aspirin or acetylsalicylic acid is an important therapy for many cardiology patients but hypersensitivity to this drug affects around 1% of the population and intolerance may affect up to 20%. While alternative medications to aspirin are available, in many cases there is a compelling need for aspirin therapy. In these patients, aspirin desensitization may be considered. However, this is a complex issue with a lack of international standardization. This article reviews the available evidence for aspirin desensitization and provides practical advice for the management of these patients.

Human leukocyte antigen genotypes and trial of desensitization in patients with oxcarbazepine-induced skin rash: a pilot study

BACKGROUND

Skin rash associated with specific antiepileptic drugs occurs not infrequently and it usually necessitates discontinuation of the causative drugs. An alternative strategy is to desensitize the individual to the offending drug. We checked the human leukocyte antigen genotypes and conducted a pilot study to investigate the usefulness and safety of desensitization in pediatric patients with skin rash associated with oxcarbazepine.

METHODS

We enrolled 19 patients with epilepsy who had discontinued oxcarbazepine because of skin rash despite an initial good response and then became refractory to other antiepileptic drugs along with an individual with paroxysmal kinesigenic dyskinesia with a similar situation. High-resolution HLA-A and -B genotyping was performed to investigate the genetic risk. The desensitization began with 0.1 mg daily reaching 120 mg on the thirty-first day. Thereafter, the dose was increased at a rate of 12 mg/day.

RESULTS

Nineteen patients completed the desensitization protocol to a target dosage over 2-5 months. Five patients developed itching and erythema during desensitization, but the symptoms disappeared after withholding a dose increment transiently. There were no human leukocyte antigen genotypes relevant to aromatic antiepileptic drug-induced severe hypersensitivity reactions. The seizure frequency was reduced to less than at baseline in 18 individuals.

CONCLUSION

This study demonstrated 95% efficacy, including 42% seizure-free patients and the favorable tolerability of desensitization to oxcarbazepine in patients with intractable epilepsy and one patient with paroxysmal kinesigenic dyskinesia. Screening for sensitive human leukocyte antigen types and exclusion of severe hypersensitivity reactions should precede desensitization.

Oral vancomycin desensitisation to treat Clostridium difficile infection in a vancomycin allergic patient

The prevalence of Clostridium difficile infection (CDI) is increasing worldwide. Oral vancomycin is an effective and frequently used treatment. However, patients with CDI who are allergic to intravenous vancomycin cannot receive oral vancomycin due to the risk of anaphylaxis if given the oral form.

We present a case where oral vancomycin desensitisation was used to successfully treat a vancomycin allergic patient with recurrent CDI.

Overview of penicillin allergy

Allergy to penicillin is the most commonly reported antibiotic allergy. However, most patients who report a positive history of a prior reaction to penicillin are not found to be allergic to penicillin upon skin testing. Often, this history is vague or based on a parent's recollection of an event that occurred in the distant past. Avoidance of penicillin based on self-reported allergic history alone often leads to the use of an alternate antibiotic with greater cost or side effect profile. Patients with a negative skin test to both major and minor determinants may generally be given penicillin, with a statistical risk of developing an allergic reaction similar to that observed in the general population. A more cautious approach in these cases where the degree of suspicion is low, an allergic etiology is unproven, or there is a negative skin test, is to do a graded challenge. If the skin test is positive, an alternate antibiotic should be used. If, however, an alternate antibiotic is not available, then desensitization may be performed, but there are limitations to desensitization as well, and tolerance is not permanent. Avoidance of cephalosporins may be recommended in cases of penicillin allergy, but newer generation cephalosporins have demonstrate less cross-reactivity to penicillin than earlier generation ones. Desensitization protocols for cephalosporins are available but not standardized. The mechanisms of antibiotic sensitization are not clearly understood.

Review of hypersensitivity reactions to antineoplastic agents

OBJECTIVE

To review the characteristics and management of hypersensitivity reactions caused by antineoplastic agents.

METHOD

We conducted a search in the Pubmed and EMBASE databases for the last 10 years.

RESULTS

Almost all chemotherapeutic agents have the potential to cause hypersensitivity reactions, but some groups have been associated with increased risk, such as platinum compounds, taxanes, asparaginase, monoclonal antibodies and epipodophyllotoxins. The clinical manifestations of these reactions are variable and unpredictable, including symptoms affecting the skin and the pulmonary, cardiac and gastrointestinal systems. The mechanism associated with their development is not yet fully understood. Diagnosis is based on patients' signs and symptoms and skin testing. The management of patients who suffer a hypersensitivity reaction to a chemotherapeutic agent varies with the severity of the reaction, the need to continue treatment, and the availability of alternative therapies.

CONCLUSIONS

Due to a progressive increase in the use of chemotherapeutic agents an increased incidence of hypersensitivity reactions is to be expected. Desensitisation protocols are a noteworthy alternative that make it possible to re-initiate patients' therapy with the causative agent of the hypersensitivity reaction. Their use should be assessed individually, weighing risks and benefits.

Desensitization regimens for drug allergy: state of the art in the 21st century

Adverse reactions to drugs are increasingly being recognized as important contributions to disease in their own right as well as impediments to the best treatment of various conditions, including infectious, autoimmune, and neoplastic maladies. Rapid drug desensitization (RDD) is an effective mechanism for safely administering important medications while minimizing or entirely circumventing such adverse reactions in sensitized patients. We reviewed the literature on RDD in the last 10 years, including our experience from the Brigham and Women's Hospital Desensitization Program with hundreds of patients desensitized to a broad variety of drugs. RDD in our programme has been uniformly successful in patients with hypersensitivity reactions to antibiotics, chemotherapeutics, and monoclonal antibodies. Any reactions that occur during desensitization are generally much less severe than the initial hypersensitivity reaction to the drug, and patients have received the full dose of the desired medication 99.9% of the time out of (796) desensitizations. To date, there have been no fatalities. RDD is a safe and highly effective method for treating sensitized patients with the optimal pharmacologic agents. Its use should be expanded, but because patient safety is paramount, protocols must be created, reviewed, and overseen by allergist-immunologists with special training and experience in modern techniques of desensitization.

Clinical applications of drug desensitization in the Asia-Pacific region

Drug desensitization is the induction, within hours to days, of a temporary state of tolerance to a drug which the patient has developed a hypersensitivity reaction to. It may be used for IgE and non-IgE mediated allergic reactions, and certain non-allergic reactions. The indication for desensitization is where no alternative medications are available for the treatment of that condition, and where the benefits of desensitization outweigh the risks. Desensitization is a therapeutic modality for drug allergy (similar to allergen specific immunotherapy for allergic rhinitis and insect venom anaphylaxis). In contrast, the drug provocation test is a diagnostic modality used to confirm or refute the diagnosis of drug allergy. This review discusses the clinical applications of desensitization for the treatment of common infectious, metabolic and cardiovascular diseases, and oncological conditions in the Asia-Pacific region.

A paragonimiasis patient with allergic reaction to praziquantel and resistance to triclabendazole: successful treatment after desensitization to praziquantel

Paragonimiasis is an infectious disease caused by trematodes of the genus Paragonimus. This trematode can be treated successfully with praziquantel in more than 90% of the cases. Although praziquantel is generally well tolerated, anaphylactic reactions to this drug have been reported in a few cases. We report here a 46-year-old Korean female with paragonimiasis, presumed to be due to Paragonimus westermani, who displayed an allergic reaction to praziquantel and resistance to triclabendazole treatment. The patient was successfully treated with praziquantel following a rapid desensitization procedure. Desensitization to praziquantel could be considered when no alternative drugs are available.

Rapid IgE desensitization is antigen specific and impairs early and late mast cell responses targeting FcεRI internalization

Rapid IgE desensitization provides temporary tolerization for patients who have presented severe hypersensitivity reactions to food and drugs, protecting them from anaphylaxis, but the underlying mechanisms are still incompletely understood. Thus, here we develop an effective and reproducible in vitro model of rapid IgE desensitization for mouse BM-derived mast cells (BMMCs) under physiologic calcium conditions, and we characterize its antigen specificity and primary events. BMMCs were challenged with DNP-human serum albumin conjugated (DNP-HSA) and/or OVA antigens, delivered either as a single dose (activation) or as increasing sequential doses (desensitization). Compared to activated cells, desensitized BMMCs had impaired degranulation, calcium flux, secretion of arachidonic acid products, early and late TNF-α production, IL-6 production, and phosphorylation of STAT6 and p38 mitogen-activated protein kinase (p38 MAPK). OVA-desensitized cells responded to DNP and DNP-desensitized cells responded to OVA, proving specificity. Internalization of specific antigen, IgE and high-affinity receptor for IgE (FcεRI) were impaired in desensitized BMMCs. Our results demonstrate that rapid IgE desensitization is antigen specific and inhibits early and late mast cell activation responses and internalization of the antigen/IgE/FcεRI complexes.

General considerations on rapid desensitization for drug hypersensitivity - a consensus statement

Drug hypersensitivity reactions can occur with most drugs, are unpredictable, may affect any organ or system, and range widely in clinical severity from mild pruritus to anaphylaxis. In most cases, the suspected drug is avoided in the future. However, for certain patients, the particular drug may be essential for optimal therapy. Under these circumstances, desensitization may be performed. Drug desensitization is defined as the induction of a temporary state of tolerance of a compound responsible for a hypersensitivity reaction. It is performed by administering increasing doses of the medication concerned over a short period of time (from several hours to a few days) until the total cumulative therapeutic dose is achieved and tolerated. It is a high-risk procedure used only in patients in whom alternatives are less effective or not available after a positive risk/benefit analysis. Desensitization protocols have been developed and are used in patients with allergic reactions to antibiotics (mainly penicillin), insulins, sulfonamides, chemotherapeutic and biologic agents, and many other drugs. Desensitization is mainly performed in IgE-mediated reactions, but also in reactions where drug-specific IgE have not been demonstrated. Desensitization induces a temporary tolerant state, which can only be maintained by continuous administration of the medication. Thus, for treatments like chemotherapy, which have an average interval of 4 weeks between cycles, the procedure must be repeated for every new course. In this paper, some background information on rapid desensitization procedures is provided. We define the drugs and drug reactions indicated for such procedures, describe the possible mechanism of action, and discuss the indications and contraindications. The data should serve as background information for a database (accessible via the EAACI-homepage) with standardized protocols for rapid desensitization for antibiotics, chemotherapeutic agents, monoclonal antibodies/fusion proteins, and other drugs.