Eosinophilic Drug Allergy

Peripheral eosinophil trends and clinical outcomes after non-traumatic subarachnoid hemorrhage

Background/objective

Uncontrolled systemic inflammation after non-traumatic subarachnoid hemorrhage (SAH) is associated with worse outcomes. Changes in the peripheral eosinophil count have been linked to worse clinical outcomes after ischemic stroke, intracerebral hemorrhage, and traumatic brain injury. We aimed to investigate the association of eosinophil counts with clinical outcomes after SAH.

Methods

This retrospective observational study included patients with SAH admitted from January 2009 to July 2016. Variables included demographics, modified Fisher scale (mFS), Hunt-Hess Scale (HHS), global cerebral edema (GCE), and the presence of any infection. Peripheral eosinophil counts were examined as part of routine clinical care on admission and daily for 10 days after aneurysmal rupture. Outcome measures included dichotomized discharge mortality, modified Ranked Scale (mRS) score, delayed cerebral ischemia (DCI), vasospasm, and need for ventriculoperitoneal shunt (VPS). Statistical tests included the chi-square test, Student's t-test, and multivariable logistic regression (MLR) model.

Results

A total of 451 patients were included. The median age was 54 (IQR 45, 63) years, and 295 (65.4%) were female patients. On admission, 95 patients (21.1%) had a high HHS (>4), and 54 (12.0%) had GCE. A total of 110 (24.4%) patients had angiographic vasospasm, 88 (19.5%) developed DCI, 126 (27.9%) had an infection during hospitalization, and 56 (12.4%) required VPS. Eosinophil counts increased and peaked on days 8-10. Higher eosinophil counts on days 3-5 and day 8 were seen in patients with GCE (p < 0.05). Higher eosinophil counts on days 7-9 (p < 0.05) occurred in patients with poor discharge functional outcomes. In multivariable logistic regression models, higher day 8 eosinophil count was independently associated with worse discharge mRS (OR 6.72 [95% CI 1.27, 40.4], p = 0.03).

Conclusion

This study demonstrated that a delayed increase in eosinophils after SAH occurs and may contribute to functional outcomes. The mechanism of this effect and the relationship with SAH pathophysiology merit further investigation.

Delayed Drug Hypersensitivity Reactions: Molecular Recognition, Genetic Susceptibility, and Immune Mediators

Drug hypersensitivity reactions are classified into immediate and delayed types, according to the onset time. In contrast to the immediate type, delayed drug hypersensitivity mainly involves T lymphocyte recognition of the drug antigens and cell activation. The clinical presentations of such hypersensitivity are various and range from mild reactions (e.g., maculopapular exanthema (MPE) and fixed drug eruption (FDE)), to drug-induced liver injury (DILI) and severe cutaneous adverse reactions (SCARs) (e.g., Stevens-Johnson syndrome (SJS), toxic epidermal necrolysis (TEN), drug reaction with eosinophilia and systemic symptoms (DRESS), and acute generalized exanthematous pustulosis (AGEP)). The common culprits of delayed drug hypersensitivity include anti-epileptics, antibiotics, anti-gout agents, anti-viral drugs, etc. Delayed drug hypersensitivity is proposed to be initiated by different models of molecular recognition, composed of drug/metabolite antigen and endogenous peptide, HLA presentation, and T cell receptor (TCR) interaction. Increasing the genetic variants of HLA loci and drug metabolic enzymes has been identified to be responsible for delayed drug hypersensitivity. Furthermore, preferential TCR clonotypes, and the activation of cytotoxic proteins/cytokines/chemokines, are also involved in the pathogenesis of delayed drug hypersensitivity. This review provides a summary of the current understanding of the molecular recognition, genetic susceptibility, and immune mediators of delayed drug hypersensitivity.

Eosinophilia in Amoxicillin-Induced Rash in Infectious Mononucleosis

A link between amoxicillin-induced rash in infectious mononucleosis and allergy has been previously reported. However, the pathophysiological cause and aspects are unclear. Additionally, the complex immunological interaction between the host and Epstein-Barr virus needs to be studied. This article reports a case of amoxicillin-induced rash in infectious mononucleosis resulting in an exuberant rash, facial edema, and marked eosinophilia, which prompted additional workup. Both the eosinophilia and the rash brought to light a possible association with a persistent delayed-type hypersensitivity. Further scientific discussion and investigation can identify predictive indicators that can portend clinical outcome.

Eosinophilic esophagitis induced by sublingual immunotherapy with cedar pollen: a case report

Eosinophilic esophagitis (EoE) is a chronic inflammatory disease associated with eosinophilic infiltration of the esophageal mucosa mostly due to exposure to allergens. However, the causes and pathogenesis of EoE are not fully understood. We encountered a case of EoE that was triggered by sublingual immunotherapy (SLIT) for cedar pollen allergy. A 40-year-old man who was treated with Japanese cedar pollen tablet SLIT for cedar pollen allergy developed heartburn 3 weeks after the initiation of the treatment. He took vonoprazan for the heartburn, but the heartburn did not improve. Then, esophagogastroduodenoscopy was performed; it revealed longitudinal furrows and white spots on the esophageal mucosa, decreased vascular permeability, and erosions. Consequently, the patient was diagnosed with EoE. Heartburn and chest discomfort disappeared 1 week after the discontinuation of Japanese cedar pollen tablet SLIT, and the patient tested positive for drug allergy to Japanese cedar pollen tablet SLIT. In this study, we found that if heartburn persists during SLIT for cedar pollen allergy, and does not improve on administration of vonoprazan or proton pump inhibitors, EoE should be suspected. In addition, the occurrence of EoE due to drug allergy is indicated.

Current Perspectives on Severe Drug Eruption

Adverse drug reactions involving the skin are commonly known as drug eruptions. Severe drug eruption may cause severe cutaneous adverse drug reactions (SCARs), which are considered to be fatal and life-threatening, including Stevens-Johnson syndrome (SJS), toxic epidermal necrolysis (TEN), acute generalized exanthematous pustulosis (AGEP), and drug reaction with eosinophilia and systemic symptoms (DRESS). Although cases are relatively rare, approximately 2% of hospitalized patients are affected by SCARs. There is an incidence of 2 to 7 cases/million per year of SJS/TEN and 1/1000 to 1/10,000 exposures to offending agents result in DRESS. However, the mortality rate of severe drug eruptions can reach up to 50%. SCARs represent a real medical emergency, and early identification and proper management are critical to survival. The common pathogenesis of severe drug eruptions includes genetic linkage with HLA- and non-HLA-genes, drug-specific T cell-mediated cytotoxicity, T cell receptor restriction, and cytotoxicity mechanisms. A multidisciplinary approach is required for acute management. Immediate withdrawal of potentially causative drugs and specific supportive treatment is of great importance. Immunoglobulins, systemic corticosteroids, and cyclosporine A are the most frequently used treatments for SCARs; additionally, new biologics and plasma exchange are reasonable strategies to reduce mortality. Although there are many treatment methods for severe drug eruption, controversies remain regarding the timing and dosage of drug eruption. Types, dosages, and indications of new biological agents, such as tumor necrosis factor antagonists, mepolizumab, and omalizumab, are still under exploration. This review summarizes the clinical characteristics, risk factors, pathogenesis, and treatment strategies of severe drug eruption to guide clinical management.

Systemic Steroid Treatment for Imatinib-Associated Severe Skin Rash in Patients with Gastrointestinal Stromal Tumor: A Phase II Study

BACKGROUND

To achieve optimal clinical outcomes in patients with gastrointestinal stromal tumor (GIST), it is crucial to maintain sufficient dosing of imatinib. Skin rash is a common imatinib-associated adverse event and may affect compliance. This phase II study was conducted to evaluate whether imatinib-associated severe skin rash can be managed with systemic steroids without dose reduction or interruption of imatinib. This study is registered at ClinicalTrials.gov, number NCT03440515.

PATIENTS AND METHODS

Between 2014 and 2016, 29 patients with imatinib-associated severe skin rash were enrolled. Skin rash of grade 2 with grade ≥2 pruritus or of grade 3 was considered severe. Oral prednisolone was administered 30 mg/day for 3 weeks, then tapered off over 12 weeks. The primary endpoint was treatment success rate (TSR). Treatment success was defined as maintaining imatinib for more than 15 weeks after completion of the steroid administration schedule without skin rash that led to additional steroid treatment or dose reduction or interruption of imatinib.

RESULTS

Of the 29 patients enrolled, 22 patients with skin rash were treated successfully (TSR, 75.8%), 2 (6.9%) were evaluated as treatment failures, and 5 (17.2%) were not evaluable. The 2-year rash-free and imatinib reduction-free interval rate was 67.2% with median follow-up of 22.0 months (range, 0.4-30.3). Recurrence of severe skin rash occurred in seven patients (24.1%). Systemic steroids were well tolerated except in one patient who experienced pneumocystis pneumonia.

CONCLUSION

This study demonstrated that imatinib-associated severe skin rash can be effectively controlled by systemic steroid treatment without interruption or dose reduction of imatinib in patients with GIST.

IMPLICATIONS FOR PRACTICE

Imatinib has been the standard treatment of gastrointestinal stromal tumor in both adjuvant and palliative settings. It is crucial to maintain sufficient dosing of imatinib to achieve optimal clinical outcomes. Imatinib commonly causes imatinib-associated skin rash, which may worsen drug compliance. This phase II study demonstrated that systemic steroids could help maintaining the efficacy of imatinib by preventing interruption or dose reduction of imatinib. The present study provides a new administration strategy of systemic steroids and its efficacy and safety data. Thus, this study can be a cornerstone to establish treatment guidelines for imatinib-associated skin rash.

Approach to Patients with Eosinophilia

Physicians may encounter blood or tissue eosinophilia through a routine complete blood count with differential or a tissue pathology report. In this article, the basic biology of eosinophils is reviewed and definitions of blood eosinophilia, as well as the challenges of defining tissue eosinophilia, are discussed. Conditions associated with eosinophilia are briefly discussed as well as a general approach to evaluating eosinophilia. Future challenges include determining which eosinophil-associated diseases benefit from eosinophil-targeted therapy and identifying biomarkers for disease activity and diagnosis.

[Vasculitides and eosinophilic pulmonary diseases]

Eosinophilic granulocytes form peripheral effector cells controlled by Th2 lymphocytes, which cause local cell, tissue, and functional disorders of infiltrated organs via the release of cytotoxic basic proteins and oxygen radicals. Diseases associated with eosinophilia include systemic and organ-related forms. The lungs are involved in eosinophilic granulomatosis with polyangiitis (EGPA, formerly known as Churg-Strauss syndrome), acute and chronic eosinophilic pneumonia, as well as in an organ manifestation in hypereosinophilic syndrome and certain parasitic diseases. In particular, the lungs are frequently affected in vasculitis of small vessels, including EGPA, granulomatosis with polyangiitis (GPA), and microscopic polyangiitis (MPA). Among these, EGPA is the most frequent pulmonary eosinophil vasculitis representative. In addition, there are various overlap syndromes in which characteristic features of EGPA can be detected in the context of other anti-neutrophil cytoplasmic antibody (ANCA-)associated vasculitides. Occasionally, non-ANCA-associated pulmonary vasculitides occur with eosinophilia (e.g., Schönlein-Henoch purpura, Kawasaki disease, drug-induced hypersensitivity, and paraneoplastic syndrome). Herein, the pulmonary vasculitides accompanying eosinophilia are presented with respect to both the lung manifestations and pulmonary eosinophilia.

Severe meningo-/encephalitis after daclizumab therapy for multiple sclerosis

Background:

Daclizumab is a monoclonal antibody that binds the high-affinity interleukin-2 receptor and was approved for the treatment of relapsing multiple sclerosis. Due to severe inflammatory brain disorders, the approval was suspended in March 2018.

Objective and Methods:

This retrospective cohort study summarizes clinical, laboratory, radiological, and histological findings of seven patients who developed meningo-/encephalitis after daclizumab therapy.

Results:

Patients presented with encephalitis and/or meningitis and suffered from systemic symptoms such as fever (5/7), exanthema (5/7), or gastrointestinal symptoms (4/7). Secondary autoimmune diseases developed. Blood analysis revealed an increase in eosinophils (5/7). Six patients fulfilled the diagnostic criteria for a drug reaction with eosinophilia and systemic symptoms (DRESS). Magnetic resonance imaging (MRI) showed multiple contrast-enhancing lesions, and enhancement of the ependyma (6/7), meninges (5/7), cranial or spinal nerves (2/7), and a vasculitic pattern (3/7). Histology revealed a pronounced inflammatory infiltrate consisting of lymphocytes, plasma cells and eosinophils, and densely infiltrated vessels. Most patients showed an insufficient therapeutic response and a high disability at last follow-up (median Expanded Disability Status Scale (EDSS) 8). Two patients died.

Conclusion:

Meningoencephalitis and DRESS may occur with daclizumab therapy. This potential lethal side effect is characterized by a dysregulated immune response. Our findings underline the importance of postmarketing drug surveillance.

[Vasculitides and eosinophilic pulmonary diseases]

Eosinophilic granulocytes form peripheral effector cells controlled by Th2 lymphocytes, which cause local cell, tissue, and functional disorders of infiltrated organs via the release of cytotoxic basic proteins and oxygen radicals. Diseases associated with eosinophilia include systemic and organ-related forms. The lungs are involved in eosinophilic granulomatosis with polyangiitis (EGPA, formerly known as Churg-Strauss syndrome), acute and chronic eosinophilic pneumonia, as well as in an organ manifestation in hypereosinophilic syndrome and certain parasitic diseases. In particular, the lungs are frequently affected in vasculitis of small vessels, including EGPA, granulomatosis with polyangiitis (GPA), and microscopic polyangiitis (MPA). Among these, EGPA is the most frequent pulmonary eosinophil vasculitis representative. In addition, there are various overlap syndromes in which characteristic features of EGPA can be detected in the context of other anti-neutrophil cytoplasmic antibody (ANCA-)associated vasculitides. Occasionally, non-ANCA-associated pulmonary vasculitides occur with eosinophilia (e.g., Schönlein-Henoch purpura, Kawasaki disease, drug-induced hypersensitivity, and paraneoplastic syndrome). Herein, the pulmonary vasculitides accompanying eosinophilia are presented with respect to both the lung manifestations and pulmonary eosinophilia.

Drug reaction with eosinophilia and systemic symptoms after daclizumab therapy

Objective

To report on 2 women with multiple sclerosis (MS) who developed severe neurologic deterioration and a drug reaction with eosinophilia and systemic symptoms (DRESS) after treatment with 2 and 4 subcutaneous injections of daclizumab, respectively.

Methods

This report includes clinical, MRI, and histopathologic data.

Results

Daclizumab is a humanized monoclonal antibody that binds the interleukin-2 receptor. It was approved for the treatment of relapsing MS. DRESS is an immunologic reaction to various medications that is characterized by eosinophilia as well as cutaneous and visceral manifestations. Following daclizumab treatment, both patients showed fulminant neurologic deterioration along with blood eosinophilia and skin changes, and both fulfilled the clinical criteria for the diagnosis of DRESS. They presented with multiple gadolinium-enhancing supra- and infratentorial lesions, with lesions in the basal ganglia, mesencephalon, and cerebellum. Brain biopsies revealed a pronounced inflammatory infiltrate including numerous eosinophils infiltrating demyelinating lesions, a feature that is atypical for MS but compatible with DRESS. In addition, numerous plasma cells and changes reminiscent of vasculitis were evident.

Conclusions

Neurologic deterioration and DRESS occurred as severe adverse drug effects of daclizumab treatment. Early diagnosis and treatment of DRESS are essential because it is associated with complications such as new autoimmune diseases and liver failure, and may even be lethal. Because of its potential serious side effects, daclizumab was recently suspended for use in the European Union.

Eosinophils from Physiology to Disease: A Comprehensive Review

Despite being the second least represented granulocyte subpopulation in the circulating blood, eosinophils are receiving a growing interest from the scientific community, due to their complex pathophysiological role in a broad range of local and systemic inflammatory diseases as well as in cancer and thrombosis. Eosinophils are crucial for the control of parasitic infections, but increasing evidence suggests that they are also involved in vital defensive tasks against bacterial and viral pathogens including HIV. On the other side of the coin, eosinophil potential to provide a strong defensive response against invading microbes through the release of a large array of compounds can prove toxic to the host tissues and dysregulate haemostasis. Increasing knowledge of eosinophil biological behaviour is leading to major changes in established paradigms for the classification and diagnosis of several allergic and autoimmune diseases and has paved the way to a "golden age" of eosinophil-targeted agents. In this review, we provide a comprehensive update on the pathophysiological role of eosinophils in host defence, inflammation, and cancer and discuss potential clinical implications in light of recent therapeutic advances.

Rash diagnostics: an update on the diagnosis of allergic rashes

PURPOSE OF REVIEW

The purpose of this review is to summarize recent research regarding the diagnosis of allergic rashes and to suggest future directions for the promotion of accurate diagnosis and endotype specification.

RECENT FINDINGS

Multiple cohort studies demonstrate that with appropriate clinical evaluation, drug allergy labels can be removed in up to 90% of cases. Genetic tests can predict severe adverse cutaneous drug reactions in some cases and in vitro tests are being sought to identify causative drugs in others. Biomarkers to define endotypes of atopic dermatitis are needed to predict which patients will benefit from evolving targeted therapies. Hyperspectral imaging is a rapidly evolving technology in medical diagnostics; additional research is needed to demonstrate whether this promising technology can be used to distinguish allergic rashes and/or endotypes in atopic dermatitis.

SUMMARY

Diagnostic tools for the assessment of allergic rashes are primitive in that they frequently rely on challenges to ascertain whether suspected allergens were causative. Validated in vitro tests with high sensitivity and specificity for drug allergies would benefit the field, particularly in delayed type reactions, as would identification of any hyperspectral signatures that could identify endotypes in atopic dermatitis.