Drug allergy: causes and desensitization

Two cases of childhood absence epilepsy who showed seizure disappearance after ethosuximide drug eruption

Background

Recent studies suggest potential roles of immune response in the pathophysiology of epilepsy. Anti-seizure medications (ASMs) are known to have side effects of drug eruption caused by immune responses. A few reports in adults have demonstrated disappearance of seizures after an ASM drug eruption episode. In this paper, we described 2 cases of childhood absence epilepsy (CAE) who showed seizure disappearance after ethosuximide (ESM) drug eruption, suggesting the possibility that the epilepsy disappears due to immune responses to ASM.

Case presentation

Case 1 was an 8-year-old girl diagnosed with CAE. She was treated with valproate acid (VPA) initially, and then ESM was administered as an additional treatment. Her epileptic seizure disappeared 4 days after initiation of ESM. However, drug eruption appeared 1 week after the administration of ESM. Even after discontinuation of ESM administration, she maintains no seizure after the drug eruption. Case 2 was a 5-year-old boy diagnosed as CAE. He was treated with VPA initially, and ESM was administered additionally. Drug eruption appeared 1 month after the administration of ESM. Even after ESM was terminated, he maintained seizure freedom after the appearance of eruption.

Conclusions

Epileptic seizures may have been suppressed due to the immune responses caused by ASM eruption. Further studies are needed to elucidate the pathophysiologic effects of drug eruption on epilepsy through immune responses.

Recurrent Drug-Induced Hypersensitivity Syndrome Following Bortezomib for Multiple Myeloma

Drug-induced hypersensitivity syndrome is a rare, severe, and delayed hypersensitivity reaction that may occur with exposure to a number of medications. Typical implicated medications include aromatic anticonvulsants, sulfonamides, minocycline, dapsone, and allopurinol. Bortezomib is a proteasome inhibitor and has rarely been associated with cutaneous hypersensitivity reactions. We report a case of recurrent drug-induced hypersensitivity syndrome secondary to bortezomib in a patient with multiple myeloma. The aim of this article is to highlight a unique mediation that may cause drug-induced hypersensitivity syndrome and to emphasize the challenge of managing these patients long-term to prevent relapse of the syndrome.

Drug-induced hypersensitivity syndrome following temozolimide for glioblastoma multiforme and the role of desensitization therapy

INTRODUCTION

Temozolomide is an oral alkylating agent used as first line treatment of glioblastoma multiforme (GBM). It has also been used in the treatment of certain solid tumors such as metastatic melanoma. Commonly reported adverse effects include nausea and vomiting, constipation, headache, fatigue and myelosuppression. Cutaneous hypersensitivity reactions are rare and include an urticarial hypersensitivity reaction, alopecia, and Stevens-Johnson syndrome. To our knowledge, there are minimal reports of temozolomide-induced DRESS syndrome.

CASE REPORT

We present a 54-year-old man with glioblastoma multiforme who presented with a fever, diarrhea and progressively worsening rash 6 weeks after starting temozolomide.

MANAGEMENT & OUTCOME

The patient was diagnosed recurrent DRESS syndrome and restarted on a gradual prednisone taper with resolution over the following weeks. Unfortunately, the patient was unable to be followed long-term due to relocation to a different state.

DISCUSSION

To our knowledge, there are minimal reports of temozolomide-induced DRESS syndrome. The diagnosis can be life-threatening, which makes management of patients with GBM and no alternative treatment option challenging. The use of de-sensitization therapy to temozolomide has been proposed for the management of severe adverse cutaneous reactions.

Adaptive Immune Responses Associated with the Central Nervous System Pathology of Gulf War Illness

Gulf War Illness is a multisymptomatic condition which affects 30% of veterans from the 1991 Gulf War. While there is evidence for a role of peripheral cellular and humoral adaptive immune responses in Gulf War Illness, a potential role of the adaptive immune system in the central nervous system pathology of this condition remains unknown. Furthermore, many of the clinical features of Gulf War Illness resembles those of autoimmune diseases, but the biological processes are likely different as the etiology of Gulf War Illness is linked to hazardous chemical exposures specific to the Gulf War theatre. This review discusses Gulf War chemical–induced maladaptive immune responses and a potential role of cellular and humoral immune responses that may be relevant to the central nervous system symptoms and pathology of Gulf War Illness. The discussion may stimulate investigations into adaptive immunity for developing novel therapies for Gulf War Illness.

Cytokines/Chemokines: Novel Biomarkers Associated with Severe Cutaneous Adverse Reactions

Although the incidence of severe cutaneous adverse reactions (SCARs) is very low, if it is not diagnosed and treated in time, it can not only cause skin and mucous membrane involvement, but can also cause multiple organ failure and even death. The diagnostic criteria and treatment guidelines for severe drug eruptions have not been unified. Many medical centers have used human leukocyte antigen alleles to diagnose SCARs. Some prospective studies have shown that susceptibility gene testing can prevent SCARs as early as possible, but the widespread implementation of its technology is limited by being ethnically specific. With the unique advantages of cytokine detection technology, cytokines are increasingly important for the diagnosis and treatment of SCARs. Related cytokines/chemokines involved in the pathogenesis, adjuvant diagnosis, and treatment of SCARs are discussed.

A permethrin metabolite is associated with adaptive immune responses in Gulf War Illness

Gulf War Illness (GWI), affecting 30% of veterans from the 1991 Gulf War (GW), is a multi-symptom illness with features similar to those of patients with autoimmune diseases. The objective of the current work is to determine if exposure to GW-related pesticides, such as permethrin (PER), activates peripheral and central nervous system (CNS) adaptive immune responses. In the current study, we focused on a PER metabolite, 3-phenoxybenzoic acid (3-PBA), as this is a common metabolite previously shown to form adducts with endogenous proteins. We observed the presence of 3-PBA and 3-PBA modified lysine of protein peptides in the brain, blood and liver of pyridostigmine bromide (PB) and  PER (PB+PER) exposed mice at acute and chronic post-exposure timepoints. We tested whether 3-PBA-haptenated albumin (3-PBA-albumin) can activate immune cells since it is known that chemically haptenated proteins can stimulate immune responses. We detected autoantibodies against 3-PBA-albumin in plasma from PB + PER exposed mice and veterans with GWI at chronic post-exposure timepoints. We also observed that in vitro treatment of blood with 3-PBA-albumin resulted in the activation of B- and T-helper lymphocytes and that these immune cells were also increased in blood of PB + PER exposed mice and veterans with GWI. These immune changes corresponded with elevated levels of infiltrating monocytes in the brain and blood of PB + PER exposed mice which coincided with alterations in the markers of blood-brain barrier disruption, brain macrophages and neuroinflammation. These studies suggest that pesticide exposure associated with GWI may have resulted in the activation of the peripheral and CNS adaptive immune responses, possibly contributing to an autoimmune-type phenotype in veterans with GWI.

Mechanisms of hypersensitivity reactions induced by drugs

Adverse drug reactions include drug hypersensitivity reactions (DHRs), which can be immunologically mediated or non-immunologically mediated. The high number of DHRs unconfirmed and/or self-reported is a frequent problem in daily clinical practice, with considerable impact on future prescription choices and patient health. It is important to distinguish between hypersensitivity and non-hypersensitivity reactions by adopting a structured diagnostic approach to confirm or discard the suspected drug, not only to avoid life-threatening reactions, but also to reduce the frequent over-diagnosis of DHRs. (www.actabiomedica.it)

Clinical Role of Human Leukocyte Antigen in Health and Disease

Most of the genes in the major histocompatibility complex (MHC) region express high polymorphism that is fundamental for their function. The most important function of human leukocyte antigen (HLA) molecule is in the induction, regulation of immune responses and the selection of the T cell repertoire. A clinician's attention is normally drawn to a system only when it malfunctions. The HLA system is no exception in this regard, but in contrast to other systems, it also arouses interest when it functions well - too well, in fact. Population studies carried out over the last several decades have identified a long list of human diseases that are significantly more common among individuals that carry particular HLA alleles including inflammatory, autoimmune and malignant disorders. HLA-disease association is the name of this phenomenon, and the mechanism underlying is still a subject of hot debate. Social behaviours are affected by HLA genes and preference for HLA disparate mates may provide 'good genes' for an individual's offspring. Also, certain HLA genes may be associated with shorter life and others with longer lifespan, but the effects depend both on the genetic background and on the environmental conditions. The following is a general overview of the important functional aspects of HLA in health and diseases.