Rituximab Desensitization in Pediatric Patients: Results of a Case Series

Hypersensitivity reactions to biologics in children

INTRODUCTION

Hypersensitivity reactions (HSRs) have been observed with the use of biologics in children. The management of HSRs in children is mainly based on experiences from the adult population. Recently, data from different centers experienced in managing these reactions, including desensitization in children, have been published, allowing clinicians to have an appropriate global overview and compare results.

AREAS COVERED

This review highlights the published data on hypersensitivity reactions to biologics in children and drug desensitization protocols adapted to the pediatric population.

EXPERT OPINION

With regard to HSRs to biologics in children, few data are available. Compared with the adult population, there is a lack of knowledge in the endophenotypes, management and the standardization of protocols including premedication regimens in children. An international consensus is needed to provide clinicians with new insight on how to apply personalized management and to perform tailored desensitization protocols in pediatric populations. Various specialists including allergists, pediatricians, oncologists, hematologists, rheumatologists, and pharmacists, should build a multidisciplinary management team to keep pediatric patients on their best treatment options in the safest manner.

Standards for practical intravenous rapid drug desensitization & delabeling: A WAO committee statement

Drug hypersensitivity reactions (DHRs) to intravenous drugs can be severe and might leave patients and doctors in a difficult position where an essential treatment or intervention has to be suspended. Even if virtually any intravenous medication can potentially trigger a life-threatening DHR, chemotherapeutics, biologics, and antibiotics are amongst the intravenous drugs most frequently involved in these reactions. Admittedly, suspending such treatments may negatively impact the survival outcomes or the quality of life of affected patients.

Delabeling pathways and rapid drug desensitization (RDD) can help reactive patients stay on first-choice therapies instead of turning to less efficacious, less cost-effective, or more toxic alternatives. However, these are high-complexity and high-risk techniques, which usually need expert teams and allergy-specific techniques (skin testing, in vitro testing, drug provocation testing) to ensure safety, an accurate diagnosis, and personalized management. Unfortunately, there are significant inequalities within and among countries in access to allergy departments with the necessary expertise and resources to offer these techniques and tackle these DHRs optimally.

The main objective of this consensus document is to create a great benefit for patients worldwide by aiding allergists to expand the scope of their practice and support them with evidence, data, and experience from leading groups from around the globe.

This statement of the Drug Hypersensitivity Committee of the World Allergy Organization (WAO) aims to be a comprehensive practical guide on the technical aspects of implementing acute-onset intravenous hypersensitivity delabeling and RDD for a wide range of drugs. Thus, the manuscript does not only focus on clinical pathways. Instead, it also provides guidance on topics usually left unaddressed, namely, internal validation, continuous quality improvement, creating a healthy multidisciplinary environment, and redesigning care (including a specific supplemental section on a real-life example of how to design a dedicated space that can combine basic and complex diagnostic and therapeutic techniques in allergy).

Successful desensitization to high dose rituximab for a child with nephrotic syndrome - The first report in the literature

Rituximab is a chimeric monoclonal antibody, which is mainly used in the treatment of lymphoma and autoimmune disorders, but also has been recently approved for the treatment of nephrotic syndrome. The treatment dose is between 375 mg/m² and 750 mg/m². Rituximab has been associated with hypersensitivity reactions, which can be classified either into early and late infusion-associated adverse reactions. Different desensitization protocols have been described in adult patients who require rituximab, however, there is a limited experience in children and in patients with nephrotic syndrome. Additionally, all the published protocols for adults and children are based on the low-dose rituximab desensitization. We report the first case in the literature of desensitization to high-dose rituximab in a child with nephrotic syndrome, suggesting a well-tolerated protocol adjusted on the high dose and the clinical reaction to the drug. This protocol can be used for children with nephrotic syndrome and severe reaction that require 750 mg/m² of rituximab.

Hypersensitivity and Immune-related Adverse Events in Biologic Therapy

Biologic medications are an expanding field of therapeutics for various medical conditions including cancer and inflammatory diseases. Due to their targeted approach to therapy, biologics can be less toxic than traditional systemic medications. However, as use becomes more widespread, adverse effects from biologic administration have also become apparent. Immune-related adverse events are a common mechanism by which biologics can cause on-target immune-related toxicities and both immediate and delayed-type hypersensitivity reactions. Immediate hypersensitivity reactions can be mediated by cytokine release or antibody mediated reactions, while delayed-type hypersensitivity is most often caused by serum sickness-like reactions. Additionally, biologics used for treatment of cancer using checkpoint blockade and rheumatologic disease using cytokine blockade can result in autoimmunity. Finally, when inflammatory cytokines are targeted for treatment of autoimmune or autoinflammatory disease, the host immune defense can be compromised predisposing to secondary immunodeficiency. This review will discuss the mechanisms of these reactions and discuss examples of biologics implicated in each of these adverse events.

Rituximab desensitization in pediatric acute lymphoblastic leukemia with severe anaphylaxis

INTRODUCTION

Hypersensitivity reactions (HSRs) to rituximab occur during the first infusion in 29% to 40% of patients. Commonly, these hypersensitivity reactions are the result of a release of cytokines, although IgE mediated reactions have also been reported.

CASE REPORT

A 7-year-old female patient with diagnosis of CD-20 positive acute lymphoblastic B-cell leukemia was included in a pilot study that consisted of two doses of rituximab treatment in the induction to remission phase by the pediatric hematology service; 30 minutes after the first administration of 300 mg of rituximab the patient started with generalized rash, nausea, vomiting, tachycardia, dyspnea, foreign body sensation in throat, oxygen desaturation until 89% and hypotension; therefore, the infusion of rituximab was suspended, and intramuscular epinephrine was administered as well as intravenous hydrocortisone and chlorphenamine and supplemental oxygen supply with adequate resolution of symptoms.

MANAGEMENT & OUTCOME

Intradermal skin testing with rituximab at the concentration 1 mg/ml (dilution 1:10), was positive. Desensitization to rituximab was indicated by our service with 4 bags - 16 steps protocol with an initial concentration dose of 1/1,000 of the total dose. The patient was premedicated 1 hour prior with intravenous chlorphenamine, methylprednisolone and ondansetron. Intravenous prophylactic fluids with normal saline solution were administered during the infusion. The procedure was carried out with close monitoring of vital signs in a course of 6.67 hours, without presenting hypersensitivity reactions.

DISCUSSION

HSR to rituximab may be induced by the activation of mast cells and basophils. Desensitization protocols are developed when there is no alternative drug for the underlying condition.

Hypersensitivity Reactions to Monoclonal Antibodies in Children

Biologic drugs are widely used in pediatric medicine. Monoclonal antibodies (mAbs) in particular are a therapeutic option for rheumatic, autoinflammatory and oncologic diseases. Adverse drug reactions and hypersensitivity reactions (HSR) to mAbs may occur in children. Clinical presentation of HSRs to mAbs can be classified according to phenotypes in infusion-related reactions, cytokine release syndrome, both alpha type reactions and type I (IgE/non-IgE), type III, and type IV reactions, all beta-type reactions. The aim of this review is to focus on HSRs associated with the most frequent mAbs in childhood, with particular attention to beta-type reactions. When a reaction to mAbs is suspected a diagnostic work-up including in-vivo and in-vitro testing should be performed. A drug provocation test is recommended only when no alternative drugs are available. In selected patients with immediate IgE-mediated drug allergy a desensitization protocol is indicated. Despite the heavy use of mAbs in childhood, studies evaluating the reliability of diagnostic test are lacking. Although desensitization may be effective in reducing the risk of reactions in children, standardized pediatric protocols are still not available.

Desensitization to biological agents used in rheumatology

Biological agents such as monoclonal antibodies and fusion proteins are widely used for the treatment of patients with various rheumatic disorders, influencing the quality of life, disability and even mortality in patients. However, biological agents can evoke adverse reactions of different grades of severity. Although drug avoidance remains a gold standard in the care of patients hypersensitive to medication, in certain clinical situations the culprit drug is the drug of choice and cannot be replaced by another equally effective compound. In such cases, desensitization can allow the patient to be treated within current guidelines and with the most effective treatment. The authors searched Medline and Scopus databases for English-language sources using the following key words: hypersensitivity, desensitization, biologicals, adalimumab, etanercept, adalimumab, certolizumab, golimumab, rituximab, infliximab, ixekizumab, tocilizumab, anakinra and canakinumab. The aim of our review is to present the current knowledge about desensitization to biological agents and some guidelines according to patient inclusion, contraindications, procedures, and safety requirements. Drug desensitization is a new issue in rheumatology, and the solution to the problem of allergic reactions to biological drugs, which gives patients with rheumatic diseases the opportunity to extend and prolong their therapy. The present article is one of the first widely discussing this topic in the biological treatment of rheumatic diseases.

Protocols for drug allergy desensitization in children

Introduction: When a drug hypersensitivity reaction is proven, desensitization protocols allow the reintroduction of the molecule in patients for whom such therapy is essential. Through drug desensitization (DDS), a temporary immune tolerance is maintained for the single course of a specific therapy. In pediatrics, indications for such a procedure include children with chronic diseases, severe infectious diseases and/or malignancies, who have a proven drug hypersensitivity.Areas covered: We ran a search on PubMed and Web of Science for papers on DDS and on DDS in children. Most protocols and recommendations on DDS focus on adults and have been adapted for children. The best candidates for desensitization are children with a history of immediate, IgE-mediated drug allergy, but this therapy may be applied also in nonallergic hypersensitivities and in non-immediate reactions. Most protocols in literature focus on antibiotics, especially beta-lactams, on chemotherapeutic agents, and on monoclonal antibodies.Expert opinion: Pediatric allergists should cooperate with specialists in infectious diseases and onco-hematology to provide DDS to children in need. Standardized protocols and international guidelines are still needed to optimize such treatment and to implement it in clinical daily practice.

Recent developments in drug hypersensitivity in children

Introduction: Drug allergy is an important public health problem that causes 0.4-10.3% of hospital admissions in children. The epidemiology, clinical spectrum, diagnosis, and management of drug hypersensitivity reactions (DHRs) differ in pediatric and adult patients. However, the same algorithms used in adults have often been applied in the pediatric population due to a lack of evidence in the literature. Areas covered: In this review, we aimed to discuss recent developments in the area of pediatric DHRs based on the growing body of literature advancing our understanding of the epidemiology, clinical aspects, and diagnostic approaches to DHRs in children. Expert opinion: Misdiagnosis, under-diagnosis, and self-diagnosis are common problems related to drug allergies in children. Viral infections are particularly frequent in children and make diagnosis difficult. Identifying true DHR is a key step in the management of drug allergy in children. Therefore, a complete allergy work-up with standardized drug allergy tests is necessary. In order to eliminate non-standardized tests, future studies including larger numbers of children should be conducted to determine more accurate standardized tests for diagnosing DHRs in the pediatric population.

Pediatric Drug Hypersensitivity

PURPOSE OF REVIEW

Pediatric drug hypersensitivity is a rapidly evolving field. The purpose of this paper is to review the current state of pediatric drug hypersensitivity and highlight new developments in diagnosis and management.

RECENT FINDINGS

This paper will discuss the safety and use of risk stratification to proceed directly to oral challenge without prior skin testing for β-lactam reactions. We review unique aspects of pediatric drug challenges and desensitizations. It is important to accurately diagnose pediatric drug hypersensitivity reactions through a detailed history, physical examination, and available diagnostic testing. Understanding of the underlying mechanism leads to appropriate classification which is necessary to direct management. The decision to perform drug challenge, desensitization, or recommend avoidance of a medication can have a significant impact on a patient's treatment. Utilization of weight-based dose and infusion rate adjustments for current drug challenge and desensitization protocols optimize success.

Antibiotic Allergy in Pediatrics

The overlabeling of pediatric antibiotic allergy represents a huge burden in society. Given that up to 10% of the US population is labeled as penicillin allergic, it can be estimated that at least 5 million children in this country are labeled with penicillin allergy. We now understand that most of the cutaneous symptoms that are interpreted as drug allergy are likely viral induced or due to a drug-virus interaction, and they usually do not represent a long-lasting, drug-specific, adaptive immune response to the antibiotic that a child received. Because most antibiotic allergy labels acquired in childhood are carried into adulthood, the overlabeling of antibiotic allergy is a liability that leads to unnecessary long-term health care risks, costs, and antibiotic resistance. Fortunately, awareness of this growing burden is increasing and leading to more emphasis on antibiotic allergy delabeling strategies in the adult population. There is growing literature that is used to support the safe and efficacious use of tools such as skin testing and drug challenge to evaluate and manage children with antibiotic allergy labels. In addition, there is an increasing understanding of antibiotic reactivity within classes and side-chain reactions. In summary, a better overall understanding of the current tools available for the diagnosis and management of adverse drug reactions is likely to change how pediatric primary care providers evaluate and treat patients with such diagnoses and prevent the unnecessary avoidance of antibiotics, particularly penicillins.

Management of Children with Hypersensitivity to Antibiotics and Monoclonal Antibodies

Proper management of drug allergy in children is based on a thorough history, in vitro testing (if available), in vivo testing, and drug challenge. This approach has been well developed with beta-lactam drugs but not with non-beta-lactam drugs and monoclonal antibodies. Children commonly develop rashes during an antibiotic course, which can lead to misdiagnosis of drug allergy. Clinical reactions to monoclonal antibodies vary and are managed depending on the type. A better knowledge of drug reactions that can occur in antibiotic allergy and monoclonal allergy can aid a provider in better management of their drug-allergic pediatric patients.