Recommendations for HLA-B*15:02 and HLA-A*31:01 genetic testing to reduce the risk of carbamazepine-induced hypersensitivity reactions

Epilepsia (Impact Factor: 4.57). 02/2014; 55(4). DOI: 10.1111/epi.12564


To systematically review evidence on genetic risk factors for carbamazepine (CBZ)–induced hypersensitivity reactions (HSRs) and provide practice recommendations addressing the key questions: (1) Should genetic testing for HLA-B*15:02 and HLA-A*31:01 be performed in patients with an indication for CBZ therapy to reduce the occurrence of CBZ-induced HSRs? (2) Are there subgroups of patients who may benefit more from genetic testing for HLA-B*15:02 or HLA-A*31:01 compared to others? (3) How should patients with an indication for CBZ therapy be managed based on their genetic test results? MethodsA systematic literature search was performed for HLA-B*15:02 and HLA-A*31:01 and their association with CBZ-induced HSRs. Evidence was critically appraised and clinical practice recommendations were developed based on expert group consensus. ResultsPatients carrying HLA-B*15:02 are at strongly increased risk for CBZ-induced Stevens-Johnson syndrome/toxic epidermal necrolysis (SJS/TEN) in populations where HLA-B*15:02 is common, but not CBZ-induced hypersensitivity syndrome (HSS) or maculopapular exanthema (MPE). HLA-B*15:02–positive patients with CBZ-SJS/TEN have been reported from Asian countries only, including China, Thailand, Malaysia, and India. HLA-B*15:02 is rare among Caucasians or Japanese; no HLA-B*15:02-positive patients with CBZ-SJS/TEN have been reported so far in these groups. HLA-A*31:01–positive patients are at increased risk for CBZ-induced HSS and MPE, and possibly SJS/TEN and acute generalized exanthematous pustulosis (AGEP). This association has been shown in Caucasian, Japanese, Korean, Chinese, and patients of mixed origin; however, HLA-A*31:01 is common in most ethnic groups. Not all patients carrying either risk variant develop an HSR, resulting in a relatively low positive predictive value of the genetic tests. SignificanceThis review provides the latest update on genetic markers for CBZ HSRs, clinical practice recommendations as a basis for informed decision making regarding the use of HLA-B*15:02 and HLA-A*31:01 genetic testing in patients with an indication for CBZ therapy, and identifies knowledge gaps to guide future research.A PowerPoint slide summarizing this article is available for download in the Supporting Information section here.

34 Reads
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The vast range of genetic diversity contributes to a wonderful array of human traits and characteristics. Unfortunately, a consequence of this genetic diversity is large variability in drug response between people, meaning that no single medication is safe and effective in everyone. The debilitating and sometimes deadly consequences of adverse drug reactions (ADRs) are a major and unmet problem of modern medicine. Pharmacogenomics can uncover associations between genetic variation and drug safety and has the potential to predict ADRs in individual patients. Here we review pharmacogenomic successes leading to changes in clinical practice, as well as clinical areas likely to be impacted by pharmacogenomics in the near future. We also discuss some of the challenges, and potential solutions, that remain for the implementation of pharmacogenomic testing into clinical practice for the significant improvement of drug safety.
    Clinical Genetics 03/2014; 86(1). DOI:10.1111/cge.12392 · 3.93 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Drug Reaction with Eosinophilia and Systemic Symptoms (DRESS) is characterized by an heterogeneous group of severe dermatologic manifestations and systemic involvement, due to several groups of medicaments. A series of 9 consecutive cases, observed from 2008 to 2013 in the Department of Dermatology, University of Pavia, is reported, all satisfying the clinical, hematological and systemic diagnostic criteria of DRESS. Clinically, 4 out of 9 patients had an urticarial and papular eruption, 2 an erythema-multiforme-like (EM-like) pattern, 2 erythroderma and 1 had an erythematous and macular reaction. Aim of the study was to describe the histopathologic features of DRESS and to trace a possible correlation between the four clinical recognized types of the syndrome and the histopathological patterns. Predominantly, a superficial perivascular lymphocytic infiltrate, extravasation of erythrocytes, and focal interface changes characterized DRESS cases. Less frequently, histopathology revealed the presence of necrotic keratinocytes; surprisingly, only in 2 cases the presence of rare dermal eosinophils was detected, even if all the patients had significant peripheral eosinophilia. A histopathological diagnosis of DRESS seems per se, according to our data, not feasible, since the main histopathological changes (interface changes, superficial perivascular dermatitis, focal spongiosis, lichenoid infiltrate, rare presence of necrotic keratinocytes) can be interpreted generically as a drug induced dermatitis. The above mentioned histopathological changes, however, when associated with clinical information on cutaneous and systemic involvement of the patient, allow the pathologist or the dermatopathologist to make a diagnosis of DRESS with a reliable margin of certainty.
    Giornale Italiano di Dermatologia e Venereologia 06/2014; 149(3):291-300. · 0.68 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Epilepsy affects 50 million persons worldwide, a third of whom continue to experience debilitating seizures despite optimum anti-epileptic drug (AED) treatment. Twelve-month remission from seizures is less likely in female patients, individuals aged 11–36 years and those with neurological insults and shorter time between first seizure and starting treatment. It has been found that the presence of multiple seizures prior to diagnosis is a risk factor for pharmacoresistance and is correlated with epilepsy type as well as intrinsic severity. The key role of neuroinflammation in the pathophysiology of resistant epilepsy is becoming clear. Our work in this area suggests that high-mobility group box 1 isoforms may be candidate biomarkers for treatment stratification and novel drug targets in epilepsy. Furthermore, transporter polymorphisms contributing to the intrinsic severity of epilepsy are providing robust neurobiological evidence on an emerging theory of drug resistance, which may also provide new insights into disease stratification. Some of the rare genetic epilepsies enable treatment stratification through testing for the causal mutation, for example SCN1A mutations in patients with Dravet's syndrome. Up to 50% of patients develop adverse reactions to AEDs which in turn affects tolerability and compliance. Immune-mediated hypersensitivity reactions to AED therapy, such as toxic epidermal necrolysis, are the most serious adverse reactions and have been associated with polymorphisms in the human leucocyte antigen (HLA) complex. Pharmacogenetic screening for HLA-B*15:02 in Asian populations can prevent carbamazepine-induced Stevens–Johnson syndrome. We have identified HLA-A*31:01 as a potential risk marker for all phenotypes of carbamazepine-induced hypersensitivity with applicability in European and other populations. In this review, we explore the currently available key stratification approaches to address the therapeutic challenges in epilepsy.
    Journal of Internal Medicine 10/2014; 277(2). DOI:10.1111/joim.12322 · 6.06 Impact Factor
Show more