Utilizing Biologics in Drug Desensitization

Basophil activation test is a complementary tool in the diagnosis of immediate reactions to platinum salts and taxanes

BACKGROUND

Delabelling pathways offer confirmatory diagnosis and can prevent unnecessary second-line therapies or drug desensitization procedures after chemotherapeutic hypersensitivity reactions (CHT-HSRs). However, these pathways rely on risky in vivo tests. Data on whether in vitro tests could be helpful are scarce. We assessed the role of basophil activation test (BAT) in the diagnosis of HSRs to platin salts (PSs) and taxanes (TXs) in a well-defined population featuring varied endophenotypes and severities of HSRs.

METHODS

We conducted a 3-year-long multicentric, prospective study with 121 suspected-immediate CHT-HSR patients. The allergy workup included clinical history (initial reaction based on Type I, cytokine release syndrome, and mixed phenotype's symptoms and if unable to fit in any of these, as "indeterminate"), skin testing (ST), and drug provocation testing (DPT), provided risk assessment was favorable. Final diagnosis classified patients as "hypersensitive," "non-hypersensitive," or "inconclusive." We performed BAT using CD63 and CD203c as activation markers in patients and controls. Patients underwent DPT regardless of BAT results to prevent bias.

RESULTS

ST positivity significantly correlated with skin involvement, Type I phenotype, cancer recurrence, and lifetime exposures before reactions. DPTs were negative in all indeterminate phenotype patients (p = .02) and those considered low-risk, whereas they were negative in 62% moderate-risk patients. 55% were confirmed as hypersensitive (mainly Type I reactions, p < .0001), 24% as non-hypersensitive (mainly TXs and indeterminate phenotypes), and 21% as inconclusive. BAT showed 79% sensitivity in Type I IgE-mediated reactions to PSs with a high correlation to ST.

CONCLUSIONS

BAT is a promising tool for delabelling and endotyping CHT-HSRs, especially Type I reactions to PSs, possibly identifying patients at risk of positive DPT. ST seems useful in confirming CHT-HSRs, especially PS-induced reactions, and DPT remains the gold standard, being essential even in moderate-risk patients.

Myocarditis Associated with COVID-19 Vaccination

Myocarditis after the COVID-19 vaccine is one of the important adverse events following immunization, observed mainly after mRNA-based vaccines. Importantly, post-vaccination myocarditis was less common than myocarditis after SARS-CoV-2 infection, as it was scored at 19.7 per 1,000,000 doses and 2.76 per 1000 infections. Predominantly, its course was benign and, compared with the myocarditis after COVID-19 infection, significantly fewer patients developed heart failure or died among patients with post-vaccination myocarditis. The group at highest risk of myocarditis related to COVID-19 vaccination were young males who received a second dose of an mRNA vaccine. It was observed that, among mRNA vaccines, specifically mRNA-1273 was associated with a higher risk of myocarditis. The mechanism underlying myocarditis after COVID-19 vaccination is still under investigation and certain processes are being considered. Currently, some follow-up assessments of patients who developed vaccine-induced myocarditis are available and suggest a favorable prognosis. The aim of this review is to discuss the most recent data on myocarditis after COVID-19 vaccination considering its epidemiology, clinical presentation, diagnosis, management, relative risk of myocarditis compared with SARS-CoV-2 infection, potential underlying mechanism, and follow-up data of patients who developed post-vaccination myocarditis.

Tryptase in drug-induced anaphylaxis: the need for acute and baseline values

PURPOSE OF REVIEW

The purpose of this narrative review was to summarize data and official recommendations purporting to paired tryptase determination in patients experiencing drug-induced anaphylaxis, published between January 1, 2023 and June 1, 2024.

RECENT FINDINGS

Three main lines of evidence obtained through paired acute and baseline tryptase determination were identified: diagnostic criterion for hypersensitivity reactions involving systemic mast cell activation; differential diagnostic criterion for hypersensitivity reactions involving other mechanisms of immediate reactions; and added value of acute and baseline tryptase levels for personalized management following drug-induced anaphylaxis: cause, risk of recurrence, underlying mast cell conditions including hereditary α-tryptasemia, familial clusters.

SUMMARY

The implementation of existing guidelines which consensually recommend paired tryptase measurement is a persistent unmet need hampering optimal diagnosis of drug-induced anaphylaxis and patient management. Another major unmet need is the lack of standardized recommendations for hereditary α-tryptasemia testing and counselling. Progress in this field is seen at a rapid pace, requiring significant efforts of continued medical education for practicing clinicians and laboratory specialists worldwide.

Prescribing Practices and Barriers of Biologics for Chronic Rhinosinusitis Amongst Otolaryngologists

OBJECTIVE(S)

Biologics for chronic rhinosinusitis with nasal polyposis (CRSwNP) are an evolving therapeutic option, but there are limited data on physician experiences in prescribing them. The goal of this study was to gain a better understanding of these experiences including prescribing practices, patient factors which guide prescriber decision, and physician and patient-reported issues which might limit cost-effectiveness of these therapies.

METHODS

A survey was distributed to attending otolaryngologists using the Canadian Society of Otolaryngology (CSOHNS) email distribution and eSurvey program. Responses were tabulated for the entire cohort and compared between rhinologists and non-rhinologists where appropriate. Frequencies and proportions were expressed as a percentage of total respondents. Fisher's exact test was used for statistical analysis between groups.

RESULTS

Seventy-nine total survey responses were recorded representing a response rate of 43%. Significantly more rhinologists reported prescribing biologic medications on their own (100% vs. 50%; p < 0.001) and a higher proportion (1 to 10% vs. <1%) of their patients were on biologics compared with non-rhinologists (p = 0.023). Rhinologists were more likely to consider poor response to medical therapies, need for rescue steroids, and comorbid type 2 conditions in their decision to pursue biologics than non-rhinologists, but they also experienced poorer assistance from patient support programs and less availability to medications.

CONCLUSION

Rhinologists are more comfortable with prescribing and managing biologics for CRSwNP compared with non-rhinologist colleagues. Clinicians prescribing biologic medications for CRSwNP should be familiar with guidelines, indications, and potential adverse events.

LEVEL OF EVIDENCE

N/A Laryngoscope, 134:3493-3498, 2024.

Ofatumumab Desensitization Protocol: A Case of Refractory Immune Thrombocytopenic Purpura

Chronic immune thrombocytopenic purpura (ITP) is an acquired hematologic condition that involves immune-mediated platelet destruction with resultant bleeding of variable severity. Refractory ITP occurs when patients fail to tolerate and/or respond to multiple treatment modalities. In this case, we examine the clinical course of a 39-year-old female with refractory ITP and discuss how we navigated a multitude of challenges by adapting an established desensitization protocol to meet our patient's needs. To our knowledge, we describe the first successful desensitization to ofatumumab for use in ITP in the current literature.

Serum tryptase and drug hypersensitivity: why, how and what? A systematic review

PURPOSE OF REVIEW

Serum tryptase, a mast cell marker, provides clues for the mechanism, severity, and management of drug hypersensitivity induced by immunoglobulin E dependent or independent mast cell activation.

RECENT FINDINGS

The interpretation of serum tryptase levels has been challenged during the last 2 years by major advances in tryptase genetics and their rapid incorporation into clinical practice. On the contrary, new pathophysiological insight into nonmast cell-dependent immediate hypersensitivity has been gained.

SUMMARY

This review provides up-to-date information on the pathophysiology and recommended use and interpretation of tryptase in the context of drug hypersensitivity reactions as a function of their endotype.

Desensitization in children allergic to drugs: Indications, protocols, and limits

Any drug can potentially induce a hypersensitivity reaction. If after the allergological work-up the drug hypersensitivity reaction is confirmed, in most cases, the simple avoidance of the culprit drug and a suggestion of an unrelated alternative is enough. However, there are circumstances where the choice to stop the treatment affects the survival, the safety and/or the quality of life of the patient and the global outcome of the disease in question. When this occurs, drug desensitization can be the answer and should not be viewed as an extravagance, nor the pediatric age should be considered a contraindication. Drug desensitization in children can be safely and successfully performed, having a positive impact on the survival and overall prognosis. In general, the indications for DDS are the same in adults as in children. However, in this age group there are specificities that this paper aimed to describe, reviewing the mechanisms behind drug hypersensitivity and rapid drug desensitization, types of protocols, indications, and contraindications, as well as several technical aspects that are specific to the pediatric age.