Weak complex formation of adverse drug reaction-associated HLAB57, B58, and B15 molecules

The combination of certain human leukocyte antigen (HLA) polymorphisms with administration of certain drugs shows a strong correlation with developing drug hypersensitivity. Examples of typical combinations are HLA-B*57:01 with abacavir and HLA-B*15:02 with carbamazepine. However, despite belonging to the same serotype, HLA-B*57:03 and HLA-B*15:01 are not associated with drug hypersensitivity. Recent studies have shown that several HLA polymorphisms are associated with multiple drugs rather than a single drug, all resulting in drug hypersensitivity. In this study, we compared the molecular structures and intracellular localization of HLA-B*57:01, HLA-B*58:01, and HLA-B*15:02, which pose risks for developing drug hypersensitivity, as well as HLA-B*57:03 and HLA-B*15:01 that do not present such risks. We found that HLA molecules posing risks have a low affinity for the subunit β₂-microglobulin; notably, the weak hydrogen bond formed via Gln96 of the HLA molecule contributes to this behavior. We also clarified that these HLA molecules are easily accumulated in the endoplasmic reticulum, exhibiting a low expression on the cell surface. Considering that these hypersensitivity risk-associated HLA molecules form complexes with β₂-microglobulin and peptides in the endoplasmic reticulum, we assumed that their low complex formation ability in the endoplasmic reticulum facilitates the interaction with multiple drugs.

Outcome of a de-labelling algorithm compared with results of penicillin (β-lactam) allergy testing

Background

Penicillin allergy labels frequently impede guideline-directed treatment with a penicillin or other β-lactam antibiotics. Despite presumed allergy, targeted questioning may indicate a low probability of sensitization and permit reasonably safe administration of the antibiotic in question. In this study, we evaluated a standardized algorithm aiming to differentiate non-allergic patients from those with true allergic β-lactam hypersensitivity.

Methods

We retrospectively applied a de-labelling algorithm in 800 consecutive patients with suspected β-lactam hypersensitivity. All had undergone complete allergy work-up permitting to definitely exclude or diagnose β-lactam allergy between 2009 and 2019.

Results

In 595 (74.4%) out of 800 cases evaluated, β-lactam allergy could be excluded by negative challenge testing. IgE-mediated anaphylaxis was diagnosed in 70 (8.7%) patients, delayed-type hypersensitivity in 135 (16.9%). In 62 (88.6%) anaphylaxis cases, the algorithm correctly advised to use an alternative antibiotic. Accuracy was higher in patients with moderate to severe anaphylaxis (97.7%) compared to those with a history of mild reactions (73.1%). The algorithm correctly identified 122 (90.4%) patients with proven delayed-type hypersensitivity. It permitted de-labelling in 330 (55.5%) out of 595 patients with diagnostic exclusion of penicillin hypersensitivity, but failed to identify the remaining 265 (44.5%) as low-risk cases.

Conclusions

The algorithm detected 89.8% of cases with penicillin (β-lactam) allergy, sensitivity was optimal for moderate to severe anaphylaxis. Study data justify the implementation of a standardized de-labelling algorithm under close supervision in order to permit guideline-directed treatment and reduce the use of broad-spectrum antibiotics as part of an antibiotic stewardship program.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13223-022-00659-1.

A systematic review of drug allergy alert systems

BACKGROUND AND OBJECTIVE

Drug allergy alert systems (DAAS), have been considered an effective strategy to reduce preventable adverse drug events (ADEs), improving patient's safety. To date, no review has been conducted analyzing characteristics of DAAS in the hospital setting. Therefore, the aim of this study is to identify, describe and summarize the DAAS used in hospitals. The secondary objectives are to analyse drug allergy alerts (DAA) characteristics, the override rate (OvR) and the clinical consequences of alert overrides.

METHODS

Searches were conducted in Medline and Cochrane Library to identify studies describing DAAS. Systems characteristics, generated alerts, DAA, OvR, and its clinical consequences were extracted and analyzed.

RESULTS

Twenty-eight articles were included in the review. Seventeen different electronic DAAS were identified, of which 53% were commercially available. Systems differed in drug allergy information and rules for generating alerts. DAA were generally interruptive, triggered by non-exact match at drug prescribing and when ignored, an override reason was mandatory. The OvR ranged from 43.7% to 97%. The main override reason given by providers was that 'patient had previously tolerated or had taken the drug without allergic reaction'. Clinical consequences of overriding DAA were only analyzed in four studies, with an ADE incidence between 0% and 6%.

CONCLUSIONS

Different DAAS are used in hospitals with some degree of heterogeneity. Accurate and updated drug allergy information is important to generate only high value alerts. A regular review of DAAS and a standardization of alert rules, alert information and override reasons are necessary to optimize systems. Future studies should evaluate the impact of the DAAS aspects on preventing ADEs.

Desensitization for the prevention of drug hypersensitivity reactions

Drug desensitization is the temporary induction of tolerance to a sensitized drug by administering slow increments of the drug, starting from a very small amount to a full therapeutic dose. It can be used as a therapeutic strategy for patients with drug hypersensitivity when no comparable alternatives are available. Desensitization has been recommended for immunoglobulin E (IgE)-mediated immediate hypersensitivity; however, its indications have recently been expanded to include non-IgE-mediated, non-immunological, or delayed T cell-mediated reactions. Currently, the mechanism of desensitization is not fully understood. However, the attenuation of various intracellular signals in target cells is an area of active research, such as high-affinity IgE receptor (FcεRI) internalization, anti-drug IgG4 blocking antibody, altered signaling pathways in mast cells and basophils, and reduced Ca2+ influx. Agents commonly requiring desensitization include antineoplastic agents, antibiotics, antituberculous agents, and aspirin/nonsteroidal antiinflammatory drugs. Various desensitization protocols (rapid or slow, multi-bag or one-bag, with different target doses) have been proposed for each drug. An appropriate protocol should be selected with the appropriate concentration, dosage, dosing interval, and route of administration. In addition, the protocol should be adjusted with consideration of the severity of the initial reaction, the characteristics of the drug itself, as well as the frequency, pattern, and degree of breakthrough reactions.

A randomized double-blind feasibility study comparing cetirizine and diphenhydramine in the prevention of paclitaxel-associated infusion-related reactions: the PREMED-F1 study

Purpose

Cetirizine is a less sedative alternative to diphenhydramine for the prevention of infusion-related reactions (IRR) to paclitaxel. However, its use remains controversial. In this study, we assessed feasibility for a future definitive non-inferiority trial comparing cetirizine to diphenhydramine as premedication to prevent paclitaxel-related IRR.

Methods

This was a single-center randomized prospective feasibility study. Participants were paclitaxel-naive cancer patients scheduled to start paclitaxel chemotherapy. They were randomly assigned to receive either intravenous diphenhydramine 50 mg + oral placebo (control) or intravenous placebo + oral cetirizine 10 mg (intervention) for their first two paclitaxel treatments. The percentage of eligible patients completing a first paclitaxel treatment and the recruitment rate were assessed (feasibility outcomes). Drowsiness was measured at baseline and at selected time points using the Stanford Sleepiness Scale (SSS) (safety outcome). IRR events were also documented (efficacy outcome).

Results

Among 37 eligible patients, 27 were recruited and randomized (control 13; intervention 14) and 25 completed the study. The recruitment rate was 4.8 participants/month, meeting the primary feasibility target. Drowsiness was the main adverse effect associated with the premedication. The increase in drowsiness compared to baseline (ΔSSS) was greater in the diphenhydramine group compared to the cetirizine group (median ΔSSS 2 (IQR 3.25) vs median ΔSSS 0 (IQR 1), p < 0.01) when measured one hour after the premedication administration. One participant had an IRR and no unexpected serious adverse event occurred.

Conclusion

The trial methods were feasible in terms of recruitment, retention, and safety. Cetirizine was significantly less sedating than diphenhydramine. IRR were infrequent and a larger trial is warranted to confirm non-inferiority for IRR prevention.

Trial registration

ClinicalTrials.gov, NCT04237090 (22.01.2020).

Supplementary Information

The online version contains supplementary material available at 10.1007/s00520-021-06734-4.

Diagnosis of non-immediate hypersensitivity to amoxicillin in children by skin test and drug provocation tests: A retrospective case-series study

BACKGROUND

Skin rash often occurs upon oral administration of amoxicillin in children, due to non-immediate hypersensitivity. However, information on delayed hypersensitivity to amoxicillin is scarce. Moreover, the appropriate diagnostic method and actual diagnostic rate of delayed hypersensitivity to amoxicillin among Japanese children are unclear. We conducted intradermal tests (IDTs) and drug provocation tests (DPTs) and retrospectively investigated the proportion of children with a definitive diagnosis of non-immediate hypersensitivity to amoxicillin. We then evaluated the characteristics of patients with a positive allergic workup.

METHODS

We enrolled children referred for suspected findings of mild or moderate non-immediate hypersensitivity to amoxicillin between August 2018 and March 2020. If the IDT in the delayed phase was negative, DPT with amoxicillin (60-90 mg/kg/day) was performed for 7 days. Non-immediate hypersensitivity to amoxicillin was defined when IDT or DPT was positive. We evaluated the potential of the drug-induced lymphocyte stimulation test (DLST) to reveal hypersensitivity to amoxicillin.

RESULTS

This study enrolled 27 children. Fourteen children (52%) had hypersensitivity to amoxicillin, of whom 12 had positive IDTs and two had positive DPTs. No differences in age, sex, history of allergic disease, days from oral use to symptom onset, type of rash at symptom onset, generalized rash, and DLST results were observed between the hypersensitivity and non-hypersensitivity groups.

CONCLUSIONS

Examination should be performed for children with mild or moderate reactions because positive cases have no significant features and half of the suspected cases are negative.

Drug reaction with eosinophilia and systemic symptoms (DRESS) syndrome in liver transplantation

Drug reaction with eosinophilia and systemic symptoms (DRESS) syndrome is a rare delayed-type hypersensitivity reaction that causes skin abnormalities and mucosal involvement of the entire body. This is a case report of DRESS occurring in a liver transplantation recipient after taking drugs. A 57-year-old female patient with hepatocellular carcinoma underwent living donor liver transplantation in April 2019. She had no previous medical histories relevant to allergic diseases. There were no adverse events during hospitalization. She was admitted to evaluate and treat a headache occurring at one month after transplantation. However, she suffered from adverse drug reactions after taking anticonvulsants, showing skin rash, itching sense, and fever with eosinophilia. Piperacillin/Tazoperan was administered for ten days as an empirical antibiotic. Skin biopsy was performed on postoperative day 106 for erythematous maculopapular rash in the arms, legs, and torso. Her symptoms improved after discontinuation of the suspected medication with conservative skin treatment and high-dose steroid treatment. This case suggests that suspicion of drug history is essential for early diagnosis and management of DRESS.

75% negative skin test results in patients with suspected hypersensitivity to beta-lactam antibiotics: Influencing factors and interpretation of test results

Background

The diagnostic approach for beta-lactam (BL) drug hypersensitivity reactions (DHR) is based on the history, clinical signs, skin tests (ST), in vitro tests, and drug provocation tests (DPT). The aim of this study was to assess the performance of an allergy workup with ST in a real-world use.

Methods

In this cross-sectional study the rate of positive ST in subjects with suspected DHR to penicillins and cephalosporins was investigated. Of special interest were correlations of ST positivity: 1) to the time intervals between index reaction and the allergic work-up, 2) time interval from drug exposure to the onset of signs, 3) pattern of manifestation in delayed DHR and involvement of test area in the index reaction, and 4) potential advantage of patch testing in delayed DHR.

Results

175 patients were included between January 2018 and April 2019 (63.4% female), 45 (25.7%) with immediate DHR manifestation and 130 with delayed DHR manifestation (74.3%). A total of 44 patients (25.1%) had a positive ST (immediate DHR 37.8% versus 20.0% in delayed DHR). ST positivity decreased in both groups after 3 years from 47.8% [95%CI 29.2-67] to 23.5% [95%CI 9.6-47.3] in immediate DHR and 23.0% [95%CI 15-4-32.9] to 12.9% [95%CI 5.1-28.9] in delayed DHR. The proportion of positive ST was higher in patients with more severe forms of delayed DHR, and in subjects with a shorter latency period of onset of symptoms after drug exposure: 0-3d: 29.5% [95%CI 19.6-41.9] vs. >3d: 11.6% [95%CI 6.0-21.2]). No sensitization was shown in delayed urticaria or angioedema. ST done outside the skin area involved during the index reaction were negative in all cases (0/38 vs. 26/84 in cases with involved area). The combination of patch test and intradermal test (IDT) revealed an additional positive result in 2/77 cases. Additional in vitro testing reduced the proportion of negative test results to 72%.

Conclusion

In most patients with negative test results, we could not clarify the cause of the BL-associated adverse events even with further investigations (including DPT). How to prevent new drug-induced adverse events in such patients has hardly been investigated yet. Corresponding cohort studies could improve the data situation.

Drug Hypersensitivity Reactions

Drug hypersensitivity reactions are a diverse group of reactions mediated by the immune system after exposure to a drug. The Gell and Coombs classification divides immunologic DHRs into 4 major pathophysiologic categories based on immunologic mechanism. Anaphylaxis is a Type I hypersensitivity reaction that requires immediate recognition and treatment. Severe cutaneous adverse reactions (SCARs) are a group of dermatologic diseases that result from a Type IV hypersensitivity process and include drug reaction with eosinophilia and systemic symptom (DRESS) syndrome, Stevens-Johnson Syndrome (SJS), toxic epidermal necrolysis (TEN), and acute generalized exanthematous pustulosis (AGEP). Other types of reactions are slow to develop and do not always require rapid treatment. Emergency physicians should have a good understanding of these various types of drug hypersensitivity reactions and how to approach the patient regarding evaluation and treatment.

Clozapine-induced myocarditis and patient outcomes after drug rechallenge following myocarditis: A systematic case review

Clozapine is underutilized due, in part, to concerns about rare but severe adverse drug reactions, including cardiac inflammation and injury (myocarditis). Risk factors for clozapine-induced myocarditis are limited and predictors for the successful rechallenge of clozapine after an episode of myocarditis are even more poorly understood. We conducted a systematic review, in accordance with the PRISMA recommendation, of published case reports to describe demographic and clinical characteristics of patients with clozapine-induced myocarditis and identify potential markers of clozapine rechallenge success. A total of 180 cases from 88 articles were evaluated. Male cases of clozapine-associated myocarditis were more frequently reported than female cases by a ratio of 6:1. Less than half of patients reported the presence of chest pain (35%) or flu-like symptoms (43%) but increases in troponin or C-reactive protein were present in 87% of cases. Clozapine rechallenge was carried out in 34 (2 female) cases, with successful reintroduction in 22 (2 female) cases (64.7%) and one fatality (2.9%). No demographic or clinical markers were significantly associated with rechallenge success after correction for multiple testing. Standardized reporting of clozapine-induced myocarditis cases is needed to facilitate the identification of factors associated with successful rechallenge.

Risk factors of beta-lactam anaphylaxis in Korea: A 6-year multicenter retrospective adult case-control study

Background

Beta-lactams (BLs) are commonly used antibiotics and leading causative agents of drug-induced anaphylaxis. Few studies on the culprit drugs and risk factors of BL-induced anaphylaxis are available. Our goal was to evaluate the culprit drugs and compare the risk factors in patients with BL-induced anaphylaxis to matched tolerant controls in a hospital setting.

Methods

We retrospectively enrolled all patients who developed anaphylaxis from intravenous BL during hospitalization from 9 Korean hospitals. We compared clinical parameters between patients with BL-induced anaphylaxis and 4-fold BL-tolerant controls matched by age, sex, BL use, and the purpose of BL administration.

Results

Seventy-four cases of BL-induced anaphylaxis and 296 BL-tolerant controls were enrolled. Cephalosporin accounted for 77% of total BL-induced anaphylaxis, and the top derivatives were ceftriaxone (23.0%), cefazedone (10.8%), and cefbuperazone (9.5%). Among penicillin derivatives, piperacillin (16.2%) was the most common, followed by ampicillin (2.7%). History of drug allergy (odds ratio [OR], 19.91; 95% confidence interval [CI] 5.33–74.44), previous exposure to the causative BL (OR, 7.71; 95% CI, 1.62–36.76), and concurrent administration of angiotensin-converting enzyme inhibitors (ACEIs) (OR, 5.97; 95% CI, 1.28–27.91) were independent risk factors associated with BL-induced anaphylaxis. Food allergy (OR, 13.93; 95% CI 1.31–148.9) and previous exposure to BL (OR, 6.59; 95% CI, 1.30–33.31) were identified as risk factors for cephalosporin-induced anaphylaxis.

Conclusions

To prevent BL-induced anaphylaxis, attention should be paid to histories of drug or food allergy, previous exposure to BLs, and ACEI use. The risk factors and clinical outcomes might vary according to the BL classes.

High occurrence of simultaneous multiple-drug hypersensitivity syndrome induced by first-line anti-tuberculosis drugs

Background

Multiple drug hypersensitivity syndrome (MDHS) results in treatment delay or failure and often results in severe drug hypersensitivity reactions. There are few reports of MDHS in response to anti-tuberculosis drugs; however, clinical information is scarce. Understanding the frequency and clinical characteristics of simultaneous MDHS against first-line anti-tuberculosis drugs in patients with non-severe drug hypersensitivity reactions is necessary.

Methods

We reviewed 27 patients with drug fever or maculopapular exanthem in response to first-line anti-tuberculosis drugs between January 2010 and June 2019. Drug fever or maculopapular exanthem occurred when isoniazid, rifampin, ethambutol, and pyrazinamide were administered simultaneously. Drug provocation tests for the 4 drugs were performed to identify the culprit drugs.

Results

All patients showed positive reactions to 1 or more drugs. MDHS was diagnosed in 13 (48%) patients, of whom 11 and 2 patients reacted to 2 and 3 drugs, respectively. In comparison to the patients with single-drug hypersensitivity, the patients with MDHS did not exhibit any differences in characteristics. Ethambutol and rifampin were the common drugs that induced a reaction, and the combination of these 2 drugs induced MDHS most frequently. Among the patients with MDHS, there were no differences between the drugs that caused drug fever and maculopapular exanthem. All patients with MDHS were successfully treated with alternative drugs.

Conclusions

Simultaneous MDHS may occur frequently in patients with drug fever or maculopapular exanthem caused by first-line anti-tuberculosis drugs, indicating the need to evaluate the allergy responses for all 4 drugs, even in patients without severe drug hypersensitivity. The combination of ethambutol and rifampin was the most common trigger that induced MDHS.

Evaluation of skin test indications for general anesthetics in real life: a prospective cohort study

BACKGROUND

In daily practice, atopic patients and those who have other drug allergies are referred to allergy clinics for evaluation of possible general anesthetic allergy despite the fact that it is not recommended in recent guidelines.

OBJECTIVE

The aim of this prospective study is to determine the negative predictive value of skin tests for common general anesthetic drugs prior to general anesthesia in atopic patients and in patients who had drug allergies by including the data of those who had previously tolerated or reacted to general anesthesia.

METHODS

A database program was constituted to collect the preoperative skin test data of patients referred to our clinic between 2013 and 2018. Demographic and clinical history, medications implemented during perioperative period, reactions, and results of skin tests performed with anesthetic drugs and latex were evaluated.

RESULTS

Four hundred fifty-nine out of the total 1167 patients referred fulfilled the inclusion criteria for further evaluation. Nearly 75% of the patients were female and mean age was 46.3 ± 14.3 years. History of hypersensitivity reactions (HRs) due to NSAIDs and/or antibiotics, radiocontrast agents, local anesthetics, and food were present in the 53.1%, 4.1%, 1.5%, and 2.0%, respectively. The negative predictive values of skin tests for general anesthetics were in the range of 80-100%. Only 4 patients (0,87%) experienced HRs during operation.

CONCLUSION

These real-life data reveal high rates of negative predictive value of skin tests with general anesthetic drugs and a low reaction rate in atopic patients and in patients with allergy to other drugs.

Detection of drug-specific immunoglobulin E (IgE) and acute mediator release for the diagnosis of immediate drug hypersensitivity reactions

The diagnosis of a drug hypersensitivity reaction (DHR) is complex. The first step after taking the clinical history is to look for a sensitization to confirm or exclude the diagnosis and to identify the culprit drug. Skin tests are the primary means of detecting sensitization in DHR, but are associated with a risk for a severe reaction and may be contraindicated. In vitro tests offer the potential to support or confirm a diagnosis of DHR and influence medical decision making. For immediate-type DHR, a few validated assays for measurement of specific IgE (sIgE) are commercially available to a limited number of drugs. In addition, several home-made sIgE radioimmunoassays have been used in other studies. The sensitivity of the sIgE assay is drug-dependant and generally low (0-85%) for betalactams and reported heterogeneous for other drugs ranging from 26% for chlorhexidine and 44% for suxamethonium to 92% for chlorhexidine. However, as all these studies included patients, in whom DHR was confirmed only by skin tests and not by provocation, the results have to be interpreted carefully and may be unreliable. Determination of mediators during an acute phase of a reaction may indirectly support the diagnosis of a DHR by demonstrating mast cell and basophil mediator release. Negative in vitro tests do not exclude a DHR or imputability of a drug, but a positive result may support causality and eliminate the necessity for a drug provocation test. Unfortunately, evidence is limited with a lack of well-controlled studies in larger numbers of well-phenotyped patients, which results in susceptibility for bias and a need for future multicenter studies.

Epidemiology and outcomes of geriatric and non-geriatric patients with drug allergy labels in Hong Kong

INTRODUCTION

Adverse drug reactions are more common in geriatric patients than in younger patients, but there have been insufficient studies concerning the epidemiology or burden of drug allergy labels in geriatric patients. We prospectively investigated the prevalence and outcomes of geriatric patients with drug allergy labels in a cohort of hospitalised patients.

METHODS

Patients admitted to a regional hospital over a 6-month period were recruited for this study. All patients with drug allergy labels were prospectively followed until discharge; clinical data were anonymously extracted for analyses. Patients were categorised into either geriatric (aged ≥65 years) or non-geriatric (aged <65 years) groups. Demographic characteristics, clinical outcomes, and prevalences of drug allergy labels were compared between groups.

RESULTS

There were 4361 admissions involving 3641 patients during the 6-month study period. Overall, 492 patients (13.5%) had drug allergy labels, consisting of 151 non-geriatric patients (30.7%) and 341 geriatric patients (69.3%). The prevalence of drug allergy labels did not significantly differ between geriatric and non-geriatric patients (13.5% vs 13.5%, P=0.976). Significantly more patients in the geriatric group had drug allergy labels to cardiovascular system drugs (15.5% vs 4.6%, P=0.001). Geriatric patients had a significantly lower rate of direct discharge from the hospital (73.0% vs 88.1%, P<0.001) and required transfers to convalescent or rehabilitation care for further management.

CONCLUSIONS

More than 13% of hospitalised geriatric patients had drug allergy labels. The leading causes of drug allergy labels were similar between geriatric and non-geriatric patients. Geriatric patients with drug allergy labels had significantly more labelled allergies to cardiovascular system drugs and adverse clinical outcomes.

Portuguese version of Parent-reported Drug Hypersensitivity Quality of Life Questionnaire (P-DrHy-Q): assessment of reliability and validity

Summary

Background. Drug hypersensitivity in children impacts the quality of life of the patients and their caregivers. The parent-reported drug hypersensitivity quality of life questionnaire (P-DrHy-Q), the first disease-specific quality-of-life questionnaire for caregivers who have children with drug hypersensitivity, was recently developed. The aim of this study was to assess the validity and reliability of the portuguese version of the P-DrHy-Q. Methods. A translation of the Parent-reported Drug Hypersensitivity Quality of Life Questionnaire (P-DrHy-Q) to the Portuguese population was performed, assessing its applicability in 74 caregivers from two allergy departments. The analyses included internal consistency (Cronbach's alpha) and test-retest reliability: 14 caregivers completed the P-DrHy-Q without any intervention one week after answering the first questionnaire. Results. The 12-item scale assessed the mental health and social activity. The internal consistency of the scale was good (Cronbach's alpha = 0.884) and the test-retest associations were excelent (Intra-class correlation coefficient = 0.985; p less than 0.001). The mean value of the questionnaire was (37.01 SD; 18.57) with Mental Health being more affected than Social Activity. Employed caregivers had a significant higher score (p less than 0.001). No other factor was statistically significant. Conclusions. The Portuguese version of the P-DrHy-Q is valid for evaluating quality of life impairment in Portuguese caregivers of children with drug hypersensitivity. Its application might be relevant for future research and provide clinicians and researchers with a tool to define which psychosocial support is required to provide more comprehensive care in drug hypersensitivity.

A case of bortezomib (Velcade)-induced Stevens-Johnson syndrome confirmed by patch test

Bortezomib, a highly selective reversible inhibitor of the proteasome complex, is used to the current standard of care in the treatment of multiple myeloma. Although its most commonly reported side effects are gastrointestinal symptoms, peripheral neuropathy, neuropathic pain, and thrombocytopenia, cutaneous adverse reactions are also frequently seen. However, severe cutaneous adverse reactions (SCAR) such as Stevens-Johnson syndrome (SJS) occur very rarely. Here we report the first case of bortezomib-induced SJS with confirmed by patch test. In this case, we performed a patch test that proved bortezomib was the offensive drug in this patient, who had been treated with multiple drugs including antibiotics, allopurinol, and anticancer drugs. Although bortezomib-induced SCARs are generally very rare, we suggest that clinicians be aware of potential adverse reactions including SJS.

Tackling the Patient with Multiple Drug "Allergies": Multiple Drug Intolerance Syndrome

As populations age, the prevalence of reported drug "allergy" increases, often leading to suboptimal care and increased morbidity because of unnecessary avoidance of safe and effective medications. Evaluation by a drug allergy specialist is often warranted when a patient has more than 2 unrelated drug "allergies" listed in the medical record. In this commentary, we clarify and propose standard terminology to use when evaluating patients with multiple drug allergy labels including and more specifically when diagnosing multiple drug intolerance syndrome and the much rarer multiple drug hypersensitivity syndrome. We review epidemiology and key features of multiple drug intolerance syndrome and multiple drug hypersensitivity syndrome. We summarize the methodologic and practical diagnostic workup and management of individuals with MDIS to assist with the accurate delabeling of drug "allergies" in the electronic health record.

ELISpot assay as a diagnostic tool in drug hypersensitivity reactions

In patients with drug hypersensitivity reactions, confirmation of causality frequently facilitates decision on a continuation or withdrawal of a given treatment. Unfortunately, identification of the culprit drug often proves difficult. In vivo methods possess well-known disadvantages like low sensitivity of skin tests or the risk of relapse during drug provocation tests. Therefore, laboratory assays are of great interest as they may improve causal diagnosis without putting patients at risk. In this article, the mechanistic principles and methodological issues of the enzyme-linked immunospot (ELISpot) assay were recapped the context of drug hypersensitivity reactions. A review of ELISpot application in causal diagnosis of drug hypersensitivity was based on literature search. The main findings are: (i) ELISpot assay has a good performance in the detection of drug-specific response. (ii) ELISpot results seem to be not substantially impacted by the type of drug or phenotype of the reaction. (iii) Testing within 30 days since the episode of drug hypersensitivity reaction shows a better performance than in later recovery phase. (iv) Data from pediatric population are too scarce to draw any conclusions. (v) Differences in laboratory protocols and in criteria used in the assessment of ELISpot plates along with the issue of the technical feasibility and reproducibility may limit the use of this assay in the routine diagnostic of drug hypersensitivity reactions.

Reintroduction of Antituberculous Drugs in Patients with Antituberculous Drug-Related Drug Reaction with Eosinophilia and Systemic Symptoms

BACKGROUND

Patients who suffered drug reaction with eosinophilia and systemic symptom (DRESS) during the treatment of tuberculosis (TB) commonly experience multidrug hypersensitivity reactions resulting in limited anti-TB drug choices. Therefore, reintroduction based on a desensitization protocol may be an option to resume anti-TB medication.

OBJECTIVE

To evaluate the outcomes and safety of resuming anti-TB drugs according to reintroduction methods in patients with anti-TB drug-related DRESS.

METHODS

A retrospective cohort of patients who had experienced anti-TB drug-related severe cutaneous adverse reactions from 2011 to 2017 was established from separate 5 institutions.

RESULTS

Anti-TB medication was resumed in 27 of 29 patients with anti-TB drug-related DRESS through complete changing regimen (n = 9), reintroduction by a graded challenge (n = 5), or reintroduction using a desensitization protocol (n = 13). Nine patients completely changed their anti-TB regimen to second-line TB drugs, but only 1 (11.1%) succeeded in maintaining new anti-TB drugs. The other 8 failed to take drugs due to the occurrence of hypersensitivity reactions to the newly introduced anti-TB drugs. Two (40.0%) of 5 patients who underwent graded rechallenges successfully completed anti-TB drugs, whereas 3 (60%) failed to resume anti-TB drugs due to the recurrence of hypersensitivity reactions. In 13 patients who resumed anti-TB drugs using a desensitization protocol, no one who underwent desensitization developed recurrence of DRESS; 11 (84.6%) eventually completed anti-TB treatment and 2 eventually failed to complete anti-TB treatment due to late-onset itching and drug-induced liver injury.

CONCLUSIONS

Resuming anti-TB medication based on desensitization protocols may be a safe and effective option for those with anti-TB drug-related DRESS.