Immunohistochemical markers for histopathological diagnosis and differentiation of acute cutaneous graft-versus-host disease.

Graft-versus-host disease (GvHD) is a major complication following stem-cell or solid-organ transplantation. Accurate diagnosis of cutaneous GvHD is challenging, given that drug eruptions and viral rashes may present with similar clinical/histological manifestations. Specific markers are not available. We performed the histological examination of biopsy samples from acute GvHD (aGvHD; n = 54), Stevens-Johnson syndrome/toxic epidermal necrolysis (SJS/TEN; n = 27), maculopapular drug eruption (MDE; n = 26) and healthy controls (n = 26). Samples of aGvHD showed a decrease in Langerhans cells (LC, p = 0.0001) and an increase in macrophages (MΦ, p = 0.0001) compared to healthy skin. Compared to SJS/TEN, MDE and healthy skin, aGvHD biopsies contained greater numbers of CD4+ and CD8+ T cells. The majority of CD4+ T-helper cells were localized in the upper dermis, whereas cytotoxic CD8+ T cells were found in the epidermis. Increased numbers of CD56+ natural killer (NK) cells in the upper dermis of aGvHD skin (p = 0.007) were not observed in controls or SJS/TEN and MDE. There were no differences in elafin staining between aGvHD and the latter two conditions. Acute GvHD appears to have a distinct inflammatory cell profile (T cells/NK cells) that may aid establishing in a more accurate diagnosis, especially when used to rule out differential diagnoses such as SJS/TEN or MDE.

T cell mediated hypersensitivity to previously tolerated iodinated contrast media precipitated by introduction of atezolizumab.

Many adverse reactions associated with immune checkpoint inhibitor (ICI) treatments are immunologically driven and may necessitate discontinuation of the ICI. Herein, we present a patient who had been administered the radio contrast media amidotrizoate multiple times without issue but who then developed a Stevens-Johnson syndrome reaction after coadministration of atezolizumab. Causality was confirmed by a positive re-challenge with amidotrizoate and laboratory investigations that implicated T cells. Importantly, the introduction of atezolizumab appears to have altered the immunologic response to amidotrizoate in terms of the tolerance-elicitation continuum. Proof of concept studies demonstrated enhancement of recall responses to a surrogate antigen panel following in-vitro (healthy donors) and in-vivo (ICI patients) administrations of ICIs. Our findings highlight the importance of considering all concomitant medications in patients on ICIs who develop immune-mediated adverse reactions. In the event of some immune-related adverse reactions, it may be critical to identify the culprit antigen-forming entity that the ICIs have altered the perception of rather than simply attribute causality to the ICI itself in order to optimize both patient safety and treatment of malignancies.

Carbamazepine Induces Focused T Cell Responses in Resolved Stevens-Johnson Syndrome and Toxic Epidermal Necrolysis Cases But Does Not Perturb the Immunopeptidome for T Cell Recognition.

Antiseizure medications (ASMs) are frequently implicated in T cell-mediated drug hypersensitivity reactions and cause skin tropic pathologies that range in severity from mild rashes to life-threatening systemic syndromes. During the acute stages of the more severe manifestations of these reactions, drug responsive proinflammatory CD8+ T cells display classical features of Th1 cytokine production (e.g. IFNγ) and cytolysis (e.g. granzyme B, perforin). These T cells may be found locally at the site of pathology (e.g. blister cells/fluid), as well as systemically (e.g. blood, organs). What is less understood are the long-lived immunological effects of the memory T cell pool following T cell-mediated drug hypersensitivity reactions. In this study, we examine the ASM carbamazepine (CBZ) and the CBZ-reactive memory T cell pool in patients who have a history of either Stevens-Johnson syndrome (SJS) or toxic epidermal necrolysis (TEN) from 3-to-20 years following their initial adverse reaction. We show that in vitro drug restimulation of CBZ-reactive CD8+ T cells results in a proinflammatory profile and produces a mainly focused, yet private, T cell receptor (TCR) usage amongst human leukocyte antigen (HLA)-B*15:02-positive SJS or TEN patients. Additionally, we show that expression of these CBZ-reactive TCRs in a reporter cell line, lacking endogenous αßTCR, recapitulates the features of TCR activation reported for ASM-treated T cell lines/clones, providing a useful tool for further functional validations. Finally, we conduct a comprehensive evaluation of the HLA-B*15:02 immunopeptidome following ASM (or a metabolite) treatment of a HLA-B*15:02-positive B-lymphoblastoid cell line (C1R.B*15:02) and minor perturbation of the peptide repertoire. Collectively, this study shows that the CBZ-reactive T cells characterized require both the drug and HLA-B*15:02 for activation and that reactivation of memory T cells from blood results in a focused private TCR profile in patients with resolved disease.

Human leukocyte antigen B*0702 is protective against ocular Stevens-Johnson syndrome/toxic epidermal necrolysis in the UK population.

Stevens-Johnson Syndrome and Toxic Epidermal Necrolysis (SJS/TEN) are part of a disease continuum of vesiculobullous mucocutaneous reactions affecting the skin and mucous membranes including the ocular surface. Manifestations of disease range from mild dry eye to progressive conjunctival cicatrisation, limbal epithelial stem cell failure and corneal blindness. In Far Eastern and South East Asian populations where SJS/TEN is prevalent, numerous human leukocyte antigen (HLA) gene variants at the A, B and C loci have been identified as risk factors for developing SJS/TEN with severe ocular complications (SOC). By contrast, the incidence of SJS/TEN with SOC in European countries is relatively low. To date, ocular SJS/TEN risk altering alleles have not been widely investigated in European populations. In this study, we analysed the association of HLA -A, -B and -C alleles with SJS/TEN in 33 patients residing in the UK with age matched controls. The data showed statistically significant novel negative allele association with HLA-B*0702 and a trend with HLA-C*0702 in the patient group, indicating these alleles are protective. Further characterisation of protective and risk alleles in other ethnic groups is required to fully elucidate the putative role of these alleles in the susceptibility of SJS/TEN with or without severe ocular complications in patients in the UK.

Acute pancreatic injuries: A complication of Stevens-Johnson syndrome/toxic epidermal necrolysis associated with cytotoxic immunocell activation.

BACKGROUND: Complications involving internal organs are usually present in Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN). However, pancreatic complications are rarely reported and studied. OBJECTIVE: To summarize clinical characteristics of SJS/TEN-associated acute pancreatic injuries and to investigate underlying inflammatory mechanisms. METHODS: Clinical records of 124 inpatients with SJS/TEN were reviewed. Serum levels of tumor necrosis factor α, interleukin (IL) 6, IL-18, IL-15, IL-12p70, and soluble CD56 were determined in 18 healthy donors and 17 patients with SJS/TEN, including 3 with acute pancreatic injuries. RESULTS: Acute pancreatic injury was diagnosed in 7.3% of patients (9/124) in the SJS/TEN cohort. Elevation of serum transaminase level and hypoalbuminemia occurred more frequently in patients with acute pancreatic injuries compared with those without pancreatic symptoms (P = .004 and <.001, respectively). Although acute pancreatic injury did not alter mortality rate of SJS/TEN, it was associated with longer hospitalization stays (P = .008). Within the serum cytokines whose levels were elevated in SJS/TEN, only IL-18 was found to be selectively increased in patients with acute pancreatic injuries compared with those without them (P = .03). LIMITATIONS: Cohort was small. CONCLUSION: Acute pancreatic injury is a gastrointestinal complication of SJS/TEN in which hepatotoxicity is more likely to occur. Overexpression of IL-18 might be involved in this unique entity.

Granulysin-Based Lymphocyte Activation Test for Evaluating Drug Causality in Antiepileptics-Induced Severe Cutaneous Adverse Reactions.

Aromatic antiepileptic drugs (AEDs) are common causes of cutaneous adverse drug reactions, which range from morbilliform drug eruption to life-threatening severe cutaneous adverse reactions, including drug reaction with eosinophilia and systemic symptoms, Stevens‒Johnson syndrome, and toxic epidermal necrolysis. Different in vitro methods for identifying the culprit drugs have been developed; however, it is particularly challenging for Stevens‒Johnson syndrome-toxic epidermal necrolysis. In this study, we enrolled 63 patients (39 with Stevens‒Johnson syndrome-toxic epidermal necrolysis, 13 with drug reaction with eosinophilia and systemic symptoms, and 11 with morbilliform drug eruption) and 30 tolerant controls to examine the performance of lymphocyte activation tests by measuring the expression of granulysin, granzyme B, and IFN-γ. Granulysin-based lymphocyte activation tests displayed the best sensitivity and specificity to identify the causality: 73.9% sensitivity and 96.7% specificity for carbamazepine and 68.2% sensitivity and 96.7% specificity for phenytoin. Oxcarbazepine and lamotrigine show weak antigenicity. Granulysin-based lymphocyte activation tests expanded predominantly memory cytotoxic T lymphocytes with characteristics of drug-specific T-cell receptor, major histocompatibility complex I dependence, and cross reactivity to different aromatic AEDs. Among 29 follow-up patients, 28 alternatively used nonaromatic AEDs, and none developed cutaneous adverse drug reactions. Our data suggest that granulysin-based lymphocyte activation tests represent in vitro cytotoxic T-lymphocyte memory response to offending drugs and are useful to confirm drug causality of AED-induced severe cutaneous adverse reactions. Implementing these tests will improve the AED-induced severe cutaneous adverse reactions prevention and clinical care.

Diagnosis and management of Stevens-Johnson syndrome/toxic epidermal necrolysis.

Stevens-Johnson syndrome/toxic epidermal necrolysis (SJS/TEN) is a rare, immunologically mediated cutaneous adverse reaction characterized by mucous membrane and epidermal detachment, with a mortality ranging from 15% to 25%. Risk factors for the development of SJS/TEN include immune dysregulation, active malignancy, and genetic predisposition. Medications are the most common cause, particularly antimicrobials, antiepileptics, allopurinol, and nonsteroidal anti-inflammatory medications. Drug-specific CD8 T-cells and natural killer cells are thought to be the major inducers of keratinocyte apoptosis via release of soluble cytotoxic mediators, including Fas ligand, perforin/granzyme, tumor necrosis factor, and granulysin. When SJS/TEN is suspected clinically, appropriate therapy should be instituted without delay. All patients should be managed initially in an intensive care unit or burn unit under a multidisciplinary team of physicians experienced in the care of patients with SJS/TEN. Available data support the use of various pharmacologic agents to halt disease progression and improve outcomes, but no single drug has been found to be superior or beneficial for all patients. Future research should focus on developing a better understanding of the genetic susceptibility and immunopathophysiology of the disease, as well as novel diagnostic and therapeutic targets to improve patient outcomes.

HLA genotypes and cold medicine-induced Stevens-Johnson syndrome/toxic epidermal necrolysis with severe ocular complications: a systematic review and meta-analysis.

Serious cutaneous adverse drug reactions [i.e., SJS/TEN with severe ocular complications (SOC)] associated with cold medicine (CM) were reported in several studies. To assess the risks of CM-induced SJS/TEN with SOC, systematic review and meta-analysis were employed. Studies investigating associations between HLA genotypes and CM-induced SJS/TEN with SOC were systematically searched in PubMed, Scopus and the Cochrane Library. Overall odds ratios (ORs) with 95% CIs were calculated using a random-effects model to determine these associations. An initial search of the databases identified 24,011 articles, of which 6 studies met the inclusion criteria. In total from all studies, associations between 81 different HLA genotypes and CM-induced SJS/TEN with SOC (i.e., 22 different HLA-A genotypes, 40 different HLA-B genotypes and 19 different HLA-C genotypes) were investigated. Risk factors to develop SJS/TEN with SOC in patients who used CM were identified from our meta-analysis. HLA-A*0206 (OR = 3.90; 95% CI = 1.96-7.77), HLA-A*3303 (OR = 2.28; 95% CI = 1.31-3.97), HLA-B*4403 (OR = 3.27; 95% CI = 1.52-7.03) and HLA-C*0501 (OR = 2.55; 95% CI = 1.19-5.44) were associated with CM-induced SJS/TEN with SOC. With our results demonstrating a significant association between using of CMs and the severe ADR, a genetic testing can be helpful. However, the CMs are commonly used as an over-the-counter drug in practically almost of people in populations worldwide, the genetic screening prior to use of the CMs might not be cost-effective. Nonetheless, for people with a family history of developing the ADRs with a possible involvement of CMs, a genetic screening may be beneficial.

Genetic Association of Co-Trimoxazole-Induced Severe Cutaneous Adverse Reactions Is Phenotype-Specific: HLA Class I Genotypes and Haplotypes.

Co-trimoxazole (CTX) causes various forms of severe cutaneous adverse reactions (SCARs). This case-control study was conducted to investigate the involvement between genetic variants of human leukocyte antigen (HLA) and CYP2C9 in CTX-induced SCARs, including Stevens-Johnson syndrome (SJS)/toxic epidermal necrolysis (TEN) and drug reaction with eosinophilia and systemic symptoms (DRESS) in Thai patients. Thirty cases of CTX-induced SCARs were enrolled and compared with 91 CTX-tolerant controls and 150 people from the general Thai population. Cases comprised 18 SJS/TEN and 12 DRESS patients. This study demonstrated that genetic association of CTX-induced SCARs was phenotype-specific. HLA-B*15:02 and HLA-C*08:01 alleles were significantly associated with CTX-induced SJS/TEN, whereas the HLA-B*13:01 allele was significantly associated with CTX-induced DRESS. In addition, a significant higher frequency of HLA-A*11:01-B*15:02 and HLA-B*13:01-C*03:04 haplotypes were detected in the group of CTX-induced Stevens-Johnson syndrome/toxic epidermal necrolysis (SJS/TEN) and DRESS cases, respectively. Genetic association of CTX-induced SCARs is phenotype-specific. Interestingly, these association was observed only in HIV-infected patients but not in non-HIV-infected patients.

Cancer immunotherapy and toxic epidermal necrolysis.

OBJECTIVES: Immunotherapy has come to play an increasingly important role in cancer treatment. Accordingly, immune-related adverse events (irAEs) have drawn considerable attention. In this case, a young female patient developed immune-related toxic epidermal necrolysis (TEN). The same irAEs have been rarely reported in previous studies. In this study, we describe the treatment and care methods used in this case in detail in order to provide a reference for clinical practice. METHODS: After being diagnosed with TEN, the patient accepted systemic glucocorticoid therapy, timely care of skin and mucous membranes, nutrition support, antiacid therapy, anti-inflammatory, analgesics and other supportive measures. RESULTS: The patient's skin recovered completely, and no serious adverse outcomes, such as secondary infection or multiple organ failure, occurred during treatment. CONCLUSION: Medical staff should be able to identify the performance of rare irAEs such as TENs and actively explore comprehensive treatments to ensure patient safety and avoid adverse outcomes.

Stevens-Johnson syndrome and toxic epidermal necrolysis: risk factors, causality assessment and potential prevention strategies.

Introduction: The clinical manifestations of cutaneous adverse drug reactions are variable with different severity. Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) are life-threatening severe cutaneous adverse reactions (SCARs) majorly caused by drugs and mediated by cytotoxic T cells.Areas covered: In this review, we focus on risk factors that contribute to the development of SJS/TEN and review the updated immune mechanism, preventive strategies as well as current therapeutic approaches for SJS/TEN.Expert opinion: The progress of SJS/TEN researches reveals that cytotoxic T cells majorly activated by drug interacted with the human leukocyte antigen (HLA) and T cell receptors play an important role for the immune mechanism of SJS/TEN. Several clinical assessment tools and in vitro drug-T cells activation tests have been developed to identify the causality of SJS/TEN. New therapeutic approaches and biologics such as TNF-alpha antagonist have been conducted to improve the prognosis of SJS/TEN.

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.

Pharmacogenomics in Asian Subpopulations and Impacts on Commonly Prescribed Medications.

Asians as a group comprise > 60% the world's population. There is an incredible amount of diversity in Asian and admixed populations that has not been addressed in a pharmacogenetic context. The known pharmacogenetic differences in Asian subgroups generally represent previously known variants that are present at much lower or higher frequencies in Asians compared with other populations. In this review we summarize the main drugs and known genes that appear to have differences in their pharmacogenetic properties in certain Asian populations. Evidence-based guidelines and summary statistics from the US Food and Drug Administration and the Clinical Pharmacogenetics Implementation Consortium were analyzed for ethnic differences in outcomes. Implicated drugs included commonly prescribed drugs such as warfarin, clopidogrel, carbamazepine, and allopurinol. The majority of these associations are due to Asians more commonly being poor metabolizers of cytochrome P450 (CYP) 2C19 and carriers of the human leukocyte antigen (HLA)-B*15:02 allele. The relative risk increase was shown to vary between genes and drugs, but could be > 100-fold higher in Asians. Specifically, there was a 172-fold increased risk of Stevens-Johnson syndrome and toxic epidermal necrolysis with carbamazepine use among HLA-B*15:02 carriers. The effects ranged from relatively benign reactions such as reduced drug efficacy to severe cutaneous skin reactions. These reactions are severe and prevalent enough to warrant pharmacogenetic testing and appropriate changes in dose and medication choice for at-risk populations. Further studies should be done on Asian cohorts to more fully understand pharmacogenetic variants in these populations and to clarify how such differences may influence drug response.

Altered levels of complement components associated with non-immediate drug hypersensitivity reactions.

Nonimmediate drug hypersensitivity reactions (niDHRs) range from mild-type maculopapular exanthema (MPE) to severe type Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) with unentirely clarified pathogenesis. This study sought to explore whether complement components participated in niDHRs. The participants comprised of three groups as follows: MPE (n = 65), SJS/TEN (n = 13, contains 7 SJS, 2 SJS-TEN overlap and 4 TEN), and equal healthy controls (n = 78). Skin pathological changes were confirmed by hematoxylin and eosin staining. The mRNA and protein levels of complement components were assessed. In the MPE group, there were no alterations in complement components at the protein and mRNA levels found except for a decrease in factor H mRNA. In the SJS/TEN group, up-regulated levels of C3aR and C5aR mRNA and down-regulated factor H mRNA levels in blood were noted. A lower plasma protein level of C3, Factor H and a higher level of C3a, C5, C5a, C5b-9, Factor B (p < 0.05) were found in the SJS/TEN group compared with in the control (p < 0.05). In SJS/TEN skin lesions, indirect immunofluorescence assays showed positive specific staining for C5b-9, but not C3. Both C3aR and C5aR were positive staining in the SJS/TEN samples, while staining for C1q, mannose-binding lectin (MBL), Factor B, and Factor H were only weak or negative. The findings reported here are the first to define the expression profiles/extent of the presence of various complement components at the mRNA and protein levels in niDHRs, especially in SJS/TEN. These altered complement components might, at least in part, be integral to the mechanisms underlying the pathogeneses of SJS and TEN.

Sulfonamide Hypersensitivity: Fact and Fiction.

Sulfonamide antimicrobials are commonly reported as causing drug allergy and have been implicated in a variety of hypersensitivity reactions including immediate IgE-mediated reactions, benign T-cell-mediated rashes, and severe cutaneous adverse reactions such as Stevens-Johnson syndrome, toxic epidermal necrolysis, and drug reaction with eosinophilia and systemic symptoms. Cross-reactivity is unlikely between sulfonamide antimicrobials and sulfonamide non-antimicrobials. In patients who develop reactions to a sulfonamide non-antimicrobial, there is no evidence to suggest that sulfonamide antimicrobials and other sulfonamide non-antimicrobials would cross-react. Although immediate skin testing can be performed in patients with histories of immediate reactions, they are infrequently positive and wane over time. Delayed skin testing including patch tests to sulfonamides is rarely positive. Drug challenges are a useful tool for patients with both immediate and delayed reactions to sulfonamides. The role of sulfamethoxazole desensitization is controversial as rates of hypersensitivity reactions are similar between desensitization and drug challenge.

Identification of drug-specific public TCR driving severe cutaneous adverse reactions.

Drug hypersensitivity such as severe cutaneous adverse reactions (SCAR), including Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN), could be life-threatening. Here, we enroll SCAR patients to investigate the T cell receptor (TCR) repertoire by next-generation sequencing. A public αßTCR is identified from the cytotoxic T lymphocytes of patients with carbamazepine-SJS/TEN, with its expression showing drug/phenotype-specificity and an bias for HLA-B*15:02. This public αßTCR has binding affinity for carbamazepine and its structural analogs, thereby mediating the immune response. Adoptive transfer of T cell expressing this public αßTCR to HLA-B*15:02 transgenic mice receiving oral administration of carbamazepine induces multi-organ injuries and symptoms mimicking SCAR, including hair loss, erythema, increase of inflammatory lymphocytes in the skin and blood, and liver and kidney dysfunction. Our results not only demonstrate an essential role of TCR in the immune synapse mediating SCAR, but also implicate potential clinical applications and development of therapeutics.