Allopurinol is the most common cause of Stevens-Johnson syndrome and toxic epidermal necrolysis in Europe and Israel

Anticancer Agent-Induced Life-Threatening Skin Toxicities: A Database Study of Spontaneous Reporting Data

Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) are potentially life-threatening cutaneous and mucosal adverse reactions to drugs. Nevertheless, the connection to anticancer agents remains unclear. To provide insight into the association of such adverse reactions with anticancer agents, we analyzed the profile of anticancer agent-induced SJS and TEN in the Japanese population. Of the 9,738 SJS/TEN events recorded in a database of spontaneous reporting data, 485 (5%, further categorized as SJS, 384 events, 79%; TEN, 101 events, 21%) were identified as anticancer agent-induced, and 53 of these (11%) were fatal. Multivariate logistic regression analyses indicated that, compared with patients using other drugs, those using anticancer drugs had lower incident risk of death (hazard ratio [HR], 0.592; p = .0006), longer median time to onset of SJS/TEN (18 vs. 11 days; p < .0001; multivariate Cox regression: HR, 0.66; p < .0001), and a higher likelihood of developing SJS/TEN later than 70 days after initiation of the suspected causal agent (15% vs. 7%; p < .0001), highlighting the need for vigilance and continuous monitoring for SJS/TEN in patients treated with anticancer agents. IMPLICATIONS FOR PRACTICE: Life-threatening skin toxicities induced by anti-cancer agents indicated significantly lower incident risk of death and longer time to onset of symptoms than for those induced by other drugs.

Genetic Basis of Delayed Hypersensitivity Reactions to Drugs in Jewish and Arab Populations

Genetic variation can affect drug pharmacokinetics and pharmacodynamics and contribute to variability between individuals in response to medications. Specifically, differences in allele frequencies among individuals and ethnic groups have been associated with variation in their propensity to develop drug hypersensitivity reactions (HSRs). This article reviews the current knowledge on the genetic background of HSRs and its relevance to Jewish and Arab populations. The focus is on human leukocyte antigen (HLA) alleles and haplotypes as predictive markers of HSRs ("immunopharmacogenetics"), but other genes and alleles are described as well. Also discussed is the translation of the pharmacogenetic information to practice recommendations.

Drug-induced Stevens-Johnson syndrome and toxic epidermal necrolysis in vietnamese spontaneous adverse drug reaction database: A subgroup approach to disproportionality analysis

WHAT IS KNOWN AND OBJECTIVE

Despite the numerous studies investigating drug-induced Stevens-Johnson syndrome/toxic epidermal necrolysis (SJS/TEN), the understanding and quantitative data in developing countries remain limited. The study aimed to describe and quantify the drug-related risk of SJS/TEN in a resource-limited context using the Vietnamese spontaneous reporting database (VSRD) of adverse drug reactions.

METHODS

Spontaneous reports relating to medium- and late-onset severe cutaneous adverse reactions (MLOSCAR) and SJS/TEN recorded in the VSRD from 2010 to 2015 were retrospectively analysed. The demographic characteristics and drug information were described and compared between SJS/TEN and other MLOSCAR reports. The drug-induced SJS/TEN signals were estimated using subgrouped disproportionality analysis with calculation of the reporting odds ratio (ROR) and the respective 95% confidence interval (CI).

RESULTS

The VSRD received 2,849 MLOSCAR reports, 136 of which focus on SJS/TEN over a 6-year period. About 60% of SJS/TEN patients were male, and the majority of them were adults (mean age 42.5 ± 22.9). Up to 91.8% of drugs induced SJS/TEN within 1-28 days, and 45% SJS/TEN cases were evaluated as life-threatening. Positive signals were generated with carbamazepine (n = 25, ROR [95% CI] = 11.99 [7.07-19.92]), allopurinol (n = 15, ROR [95% CI] = 4.2 [2.20-7.59]), traditional/herbal medicines (n = 7, ROR [95% CI] = 2.76 [1.12-5.86]), colchicine (n = 4, ROR [95% CI] = 6.22 [1.69-18.72]), valproic acid (n = 3, ROR [95% CI] = 8.71 [1.89-30.19]) and meloxicam (n = 3, ROR [95% CI] = 7.09 [1.55-24.29]), which are well known for SJS/TEN. Cefixime (n = 5, ROR [95% CI] = 3.34 [1.13-8.00]) and paracetamol (n = 22, ROR [95% CI] = 5.23 [3.10-8.49]) also generated positive signals despite their popularity in Vietnam.

WHAT IS NEW AND CONCLUSION

This first Vietnamese population-based study has highlighted original characteristics and signals of drug-induced SJS/TEN, which are relatively consistent with other worldwide data and typical for a developing country.

Current Perspectives on Stevens-Johnson Syndrome and Toxic Epidermal Necrolysis

Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) are considered a delayed-type hypersensitivity reaction to drugs. They represent true medical emergencies and an early recognition and appropriate management is decisive for the survival. SJS/TEN manifest with an "influenza-like" prodromal phase (malaise, fever), followed by painful cutaneous and mucous membrane (ocular, oral, and genital) lesions, and other systemic symptoms. The difference between SJS, SJS/TEN overlap, and TEN is defined by the degree of skin detachment: SJS is defined as skin involvement of < 10%, TEN is defined as skin involvement of > 30%, and SJS/TEN overlap as 10-30% skin involvement. The diagnosis of different degrees of epidermal necrolysis is based on the clinical assessment in conjunction with the corresponding histopathology. The mortality rates for SJS and TEN have decreased in the last decades. Today, the severity-of-illness score for toxic epidermal necrolysis (SCORTEN) is available for SJS/TEN severity assessment. Drugs with a high risk of causing SJS/TEN are anti-infective sulfonamides, anti-epileptic drugs, non-steroidal anti-inflammatory drugs of the oxicam type, allopurinol, nevirapine, and chlormezanone. Besides conventional drugs, herbal remedies and new biologicals should be considered as causative agents. The increased risk of hypersensitivity reactions to certain drugs may be linked to specific HLA antigens. Our understanding of the pathogenesis of SJS/TEN has improved: drug-specific T cell-mediated cytotoxicity, genetic linkage with HLA- and non-HLA-genes, TCR restriction, and cytotoxicity mechanisms were clarified. However, many factors contributing to epidermal necrolysis still have to be identified, especially in virus-induced and autoimmune forms of epidermal necrolysis not related to drugs. In SJS/TEN, the most common complications are ocular, cutaneous, or renal. Nasopharyngeal, esophageal, and genital mucosal involvement with blisters, erosions as well as secondary development of strictures also play a role. However, in the acute phase, septicemia is a leading cause of morbidity and fatality. Pulmonary and hepatic involvement is frequent. The acute management of SJS/TEN requires a multidisciplinary approach. Immediate withdrawal of potentially causative drugs is mandatory. Prompt referral to an appropriate medical center for specific supportive treatment is of utmost importance. The most frequently used treatments for SJS/TEN are systemic corticosteroids, immunoglobulins, and cyclosporine A.

Active surveillance of severe cutaneous adverse reactions: A case-population approach using a registry and a health care database

PURPOSE

The "case-population" design has been proposed for the surveillance of rare events like Stevens-Johnson syndrome/toxic epidermal necrolysis (SJS/TEN), wherein a registry of cases is combined with sales data from the source population in order to estimate crude odds ratios (ORs). A major drawback of this method is the inability to distinguish between new and non-new users of drugs, which for the study of hypersensitivity reactions is of utmost importance.

METHODS

We have explored an approach in which the exposure to the drugs of interest in the source population is inferred from a primary health care database (BIFAP), which helped us to identify drug initiators among all users and additionally adjust for potential confounders. A total of 44 SJS/TEN cases from the Registry and 44 000 controls randomly sampled from BIFAP and matched with cases for index date were included. We estimated the adjusted ORs (AORs) and 95% confidence intervals (CI) of SJS/TEN associated with the new use of 13 drugs (for which we had at least two exposed cases) through a conditional logistic regression model.

RESULTS

AORs (95% CI) were estimated for phenytoin, 4618 (434-49112); cotrimoxazole, 1142 (163-8015); allopurinol, 160 (36-709); dexamethasone, 38 (1.33-1077); ibuprofen, 33 (8.6-124); lorazepam, 27 (5.8-124); paracetamol, 13 (2.8-62); levofloxacine, 12 (1.24-120); amoxicillin, 6.9 (1.39-35); pantoprazole, 6.5 (0.10-420); metamizole, 6.3 (0.69-57); amoxicillin clavulanic acid, 4.2 (0.53-34); and omeprazole, 1.34 (0.06-31). The inclusion of non-new users dramatically decreased the AORs for all drugs.

CONCLUSIONS

The case-population approach using a registry of cases and a primary health care database proved feasible and efficient for the active surveillance of SJS/TEN.

Stevens-Johnson Syndrome/Toxic Epidermal Necrolysis: A Multicenter Retrospective Study of 377 Adult Patients from the United States

Stevens-Johnson syndrome/toxic epidermal necrolysis (SJS/TEN) is a rare, severe mucocutaneous reaction with few large cohorts reported. This multicenter retrospective study included patients with SJS/TEN seen by inpatient consultative dermatologists at 18 academic medical centers in the United States. A total of 377 adult patients with SJS/TEN between January 1, 2000 and June 1, 2015 were entered, including 260 of 377 (69%) from 2010 onward. The most frequent cause of SJS/TEN was medication reaction in 338 of 377 (89.7%), most often to trimethoprim/sulfamethoxazole (89/338; 26.3%). Most patients were managed in an intensive care (100/368; 27.2%) or burn unit (151/368; 41.0%). Most received pharmacologic therapy (266/376; 70.7%) versus supportive care alone (110/376; 29.3%)-typically corticosteroids (113/266; 42.5%), intravenous immunoglobulin (94/266; 35.3%), or both therapies (54/266; 20.3%). Based on day 1 SCORTEN predicted mortality, approximately 78 in-hospital deaths were expected (77.7/368; 21%), but the observed mortality of 54 patients (54/368; 14.7%) was significantly lower (standardized mortality ratio = 0.70; 95% confidence interval = 0.58-0.79). Stratified by therapy received, the standardized mortality ratio was lowest among those receiving both steroids and intravenous immunoglobulin (standardized mortality ratio = 0.52; 95% confidence interval 0.21-0.79). This large cohort provides contemporary information regarding US patients with SJS/TEN. Mortality, although substantial, was significantly lower than predicted. Although the precise role of pharmacotherapy remains unclear, co-administration of corticosteroids and intravenous immunoglobulin, among other therapies, may warrant further study.

Physiology of Hyperuricemia and Urate-Lowering Treatments

Gout is the most common form of inflammatory arthritis and is a multifactorial disease typically characterized by hyperuricemia and monosodium urate crystal deposition predominantly in, but not limited to, the joints and the urinary tract. The prevalence of gout and hyperuricemia has increased in developed countries over the past two decades and research into the area has become progressively more active. We review the current field of knowledge with emphasis on active areas of hyperuricemia research including the underlying physiology, genetics and epidemiology, with a focus on studies which suggest association of hyperuricemia with common comorbidities including cardiovascular disease, renal insufficiency, metabolic syndrome and diabetes. Finally, we discuss current therapies and emerging drug discovery efforts aimed at delivering an optimized clinical treatment strategy.

Hypouricemic Effects of Extracts From Agrocybe aegerita on Hyperuricemia Mice and Virtual Prediction of Bioactives by Molecular Docking

Agrocybe aegerita has long been utilized for promoting diuresis in traditional Chinese medicine (TCM) with a close correlation to hypouricemia. Ethanol (AAE) and water (AAW) extracts of the compound led to a remarkable decrease in serum uric acid levels (SUA) in hyperuricemia mice, approaching that of the normal control. Both AAE and AAW exhibited suppression effects on hepatic xanthine oxidase (XOD) activities and elevation effects on renal OAT1 (organic anion transporter 1). However, only little negative impact was observed on the inner organ functions. The molecular docking was used to screen our in-home compound database for A. aegerita, and four compounds including 2-formyl-3,5-dihydroxybenzyl acetate, 2,4-dihydroxy-6-methylbenzaldehyde, 2-(6-hydroxy-1H-indol-3-yl)acetamide, and 6-hydroxy-1H-indole-3-carbaldehyde (HHC) were identified as potential active compounds. Their inhibitory mechanism on XOD might be attributed to their localization in the tunnel for the entrance of substrates to XOD active site, preventing the entrance of the substrates. To confirm the activity of the screened compounds experimentally, HHC was selected due to its high ranking and availability. The assaying result suggested the significant inhibitory activity of HHC on XOD. Also, these compounds were predicted to carry good ADME (absorption, distribution, metabolism, and excretion) properties, thereby necessitating further investigation. The current results provided an insight into the hypouricemic effects of macrofungi and their bioactives, which might provide the significant theoretical foundation for identifying and designing novel hypouricemia compounds.

Severe cutaneous adverse reactions due to inappropriate medication use

BACKGROUND

The proportion of severe cutaneous adverse reactions (SCARs) that could be avoided if medication use was consistent with good medical practice is unknown.

OBJECTIVES

To estimate the proportion of SCARs related to inappropriate medication use.

METHODS

We carried out a retrospective study of all validated SCARs collected in a French registry between 2003 and 2016. For each case, all plausible drugs suspected of inducing SCARs (i.e. not just the drug regarded as 'the most probable') were considered with regard to (i) prescription for an inappropriate indication, (ii) unintentional rechallenge despite a previous allergy to the drug or (iii) self-medication with prescription medicines.

RESULTS

In total, 602 cases were included in the analyses. Antibiotics, anticonvulsants and allopurinol were the drugs most frequently involved, accounting for more than 50% of all cases. All suspected medications were considered to have been appropriately used for 417 of the 602 individuals included in the study population [69·3%, 95% confidence interval (CI) 65·6-73·0] and inappropriately used for 144 individuals (23·9%, 95% CI 20·5-27·3). These inappropriate uses were due mainly to prescriptions for an inappropriate indication (65·8%, 95% CI 58·4-73·2) or unintentional rechallenge (20·9%, 95% CI 14·6-27·2). Allopurinol and co-trimoxazole were the drugs most frequently involved in inappropriate indications. Antibiotics were the largest group involved in unintentional rechallenge. Nonsteroidal anti-inflammatory drugs, available on prescription, were most frequently involved in inappropriate self-medication.

CONCLUSIONS

Our results underline the need for respecting the appropriate indication for drugs in order to reduce the incidence of SCARs. Reducing unintentional rechallenge also seems to be a necessary preventive measure.

Racial/ethnic variation and risk factors for allopurinol-associated severe cutaneous adverse reactions: a cohort study

OBJECTIVES

To examine associations of race/ethnicity and purported risk factors with hospitalised allopurinol-associated severe cutaneous adverse reactions (AASCARs).

METHODS

We used US Medicaid data to identify incident allopurinol users between 1999 and 2012. We examined the risk of hospitalised AASCARs according to race/ethnicity and purported key risk factors and calculated relative risks (RR).

RESULTS

Among 400 401 allopurinol initiators, we documented 203 hospitalised AASCAR cases (1 in 1972 initiators). The average AASCAR hospitalisation was 9.6 days and 43 individuals (21%) died. The multivariable-adjusted RRs for AASCARs among blacks, Asians and Native Hawaiians/Pacific Islanders compared with whites or Hispanics were 3.00 (95% CI 2.18 to 4.14), 3.03 (95% CI 1.72 to 5.34) and 6.68 (95% CI 4.37 to 10.22), respectively. Female sex, older age (≥60 years), chronic kidney disease and initial allopurinol dose (>100 mg/day) were independently associated with a 2.5-fold, 1.7-fold, 2.3-fold and 1.9-fold higher risk of AASCAR, respectively. In our combined demographic analysis, older women (≥60 years) of a high-risk race/ethnicity (blacks, Asians or Native Hawaiians/Pacific Islanders) had over a 12-fold higher risk of hospitalised AASCARs than younger men of a low-risk race/ethnicity (whites or Hispanics) (multivariable-adjusted RR, 12.25; 95% CI 6.46 to 23.25).

CONCLUSIONS

This racially diverse (yet mostly white) cohort study indicates that the risk of hospitalised AASCAR is rare overall, although blacks, Asians and Native Hawaiians/Pacific-Islanders have a substantially higher risk of hospitalised AASCARs, particularly among older women. These data also support the practice of initiating allopurinol at a low dose (eg, ≤100 mg/day).

Drug-Induced Stevens-Johnson Syndrome and Toxic Epidermal Necrolysis Call for Optimum Patient Stratification and Theranostics via Pharmacogenomics

The Global Genomic Medicine Collaborative, a multinational coalition of genomic and policy experts working to implement genomics in clinical care, considers pharmacogenomics to be among the first areas in genomic medicine that can provide guidance in routine clinical practice, by linking genetic variation and drug response. Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) are severe life-threatening reactions to medications with a high incidence worldwide. Genomic screening prior to drug administration is a key opportunity and potential paradigm for using genomic medicine to reduce morbidity and mortality and ultimately eliminate one of the most devastating adverse drug reactions. This review focuses on the current understanding of the surveillance, pathogenesis, and treatment of SJS/TEN, including the role of genomics and pharmacogenomics in the etiology, treatment, and eradication of preventable causes of drug-induced SJS/TEN. Gaps, unmet needs, and priorities for future research have been identified for the optimal management of drug-induced SJS/TEN in various ethnic populations. Pharmacogenomics holds great promise for optimal patient stratification and theranostics, yet its clinical implementation needs to be cost-effective and sustainable.

Randomised clinical trial: efficacy, safety and dosage of adjunctive allopurinol in azathioprine/mercaptopurine nonresponders (AAA Study)

BACKGROUND

Thiopurine hypermethylation towards 6-methylmercaptopurine (6MMP) instead of 6-thioguanine nucleotides (6TGN) is associated with inefficacy in patients with IBD. Allopurinol reverses such hypermethylation.

AIMS

To prospectively determine efficacy of allopurinol-thiopurine combination and to compare 2 doses of allopurinol.

DESIGN

In a multicentre, double-blind trial, patients with clinically active or steroid-dependent IBD and thiopurine shunting were randomised to 50 or 100 mg/d allopurinol and 25% of their screening thiopurine dose, which was subsequently optimised, aiming for 6TGN of 260-500 pmol/8x10⁸ RBCs. The primary endpoint was steroid-free clinical remission at 24 weeks.

RESULTS

Of 73 patients, 39 (53% [95% CI 42-65]) achieved steroid-free remission, (54% with 50 mg/d and 53% with 100 mg/d). 81% were able to discontinue steroids. Therapeutic 6TGN levels were achieved in both groups. Final thiopurine doses were lower with 100 mg/d allopurinol (P < 0.005). 6MMP: 6TGN ratio decreased from mean 64 to 4 (P < 0.001), being higher with 50 mg/d (6 ± 1.83) than for 100 mg/d ([1 ± 0.16], P = 0.003). Three patients on 50 mg/d failed to sustain low ratios at 24 weeks. Toxicity was minimal; three patients on 50 mg/d allopurinol developed transient leukopenia. Alanine aminotransferase concentrations decreased (P < 0.001) similarly in both arms. Faecal calprotectin levels at study end were lower in patients who achieved the primary endpoint (median 171 [85-541] vs 821[110-5892] ug/g, P = 0.03).

CONCLUSIONS

Low-dose allopurinol-thiopurine combination safely reverses shunting and optimises 6TGN with associated improvement in disease activity. 100 mg/d allopurinol is preferable due to greater metabolite profile stability and lower thiopurine dose without additional toxicity.

Effect and mechanism of dioscin from Dioscorea spongiosa on uric acid excretion in animal model of hyperuricemia

ETHNOPHARMACOLOGY RELEVANCE

Dioscin, a spirostane glycoside, the rhizoma of Dioscorea septemloba (Diocoreacea) is used for diuresis, rheumatism, and joints pain. Given the poor solubility and stability of Dioscin, we proposed a hypothesis that Dioscin's metabolite(s) are the active substance(s) in vivo to contribute to the reducing effects on serum uric acid levels.

AIM OF THE STUDY

The aim of this study is to identify the active metabolite(s) of Dioscin in vivo and to explore the mechanism of its antihyperuricemic activity.

MATERIALS AND METHODS

After oral administration of Dioscin in potassium oxonate (PO) induced hyperuricemia rats and adenine-PO induced hyperuricemia mice models, serum uric acid and creatinine levels, clearance of uric acid and creatinine, fractional excretion of uric acid, and renal pathological lesions were determined were used to evaluate the antihyperuricemic effects. Renal glucose transporter-9 (GLUT-9) and organic anion transporter-1 (OAT-1) expressions were analyzed by western blotting method. Renal uric acid excretion was evaluated using stably urate transporter-1 (URAT-1) transfected human epithelial kidney cell line. Intestinal uric acid excretion was evaluated by measuring the transcellular transport of uric acid in HCT116 cells.

RESULTS

In hyperuricemia rats, both 25 and 50mg/kg of oral Dioscin decreased serum uric acid levels over 4h. In the hyperuricemia mice, two weeks treatment of Dioscin significantly decreased serum uric acid and creatinine levels, increased clearance of uric acid and creatinine, increased fractional excretion of uric acid, and reduced renal pathological lesions caused by hyperuricemia. In addition, renal GLUT -9 was significantly down-regulated and OAT-1 was up-regulated in Dioscin treated hyperuricemia mice. Dioscin's metabolite Tigogenin significantly inhibited uric acid re-absorption via URAT1 from 10 to 100μM. Diosgenin and Tigogenin increased uric acid excretion via ATP binding cassette subfamily G member 2 (ABCG2).

CONCLUSION

Decreasing effect of Dioscin on serum uric acid level and enhancing effect on urate excretion were confirmed in hyperuricemia animal models. Tigogenin, a metabolite of Dioscin, was identified as an active substance with antihyperuricemic activity in vivo, through inhibition of URAT1 and promotion of ABCG2.

Severe Cutaneous Adverse Drug Reactions: Presentation, Risk Factors, and Management

PURPOSE OF STUDY

Immune-mediated adverse drug reactions occur commonly in clinical practice and include mild, self-limited cutaneous eruptions, IgE-mediated hypersensitivity, and severe cutaneous adverse drug reactions (SCAR). SCARs represent an uncommon but potentially life-threatening form of delayed T cell-mediated reaction. The spectrum of illness ranges from acute generalized exanthematous pustulosis (AGEP) to drug reaction with eosinophilia with systemic symptoms (DRESS), to the most severe form of illness, Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN).

RECENT FINDINGS

There is emerging literature on the efficacy of cyclosporine in decreasing mortality in SJS/TEN. The purpose of our review is to discuss the typical presentations of these conditions, with a special focus on identifying the culprit medication. We review risk factors for developing SCAR, including HLA alleles strongly associated with drug hypersensitivity. We conclude by discussing current strategies for the management of these conditions.

[Severe skin reactions due to new medications]

Stevens-Johnson syndrome (SJS), toxic epidermal necrolysis (TEN) and a specific form of hypersensitivity syndrome which is nowadays called "drug reaction with eosinophilia and systemic symptoms" (DRESS) are severe, mainly drug-induced skin reactions. Whereas SJS/TEN is considered one reaction entity of different severity, DRESS has to be distinguished from SJS/TEN but also from other severe exanthems due to multiorgan involvement. Although SJS/TEN is generally referred to as drug reaction, in total only about three quarters of the cases are actually caused by drugs. After the clinical diagnosis is made, identification of the potential inducing factor is most important. In case medications are considered as causal, their withdrawal plays a key role in management. In order to identify and withdraw the inducing agent, a detailed and thorough medication history must be obtained. Agents identified or confirmed as inducers of SJS/TEN by pharmacoepidemiological studies are allopurinol, antibacterial sulfonamides, various antiepileptics, nevirapine and nonsteroidal anti-inflammatory drugs of the oxicam-type. Among drugs inducing DRESS are also various antiepileptics, but in addition allopurinol, sulfonamides and minocycline. Some cases of SJS/TEN and DRESS associated with the use of new medication, including targeted therapies and biologicals, have been observed.

Randomized, controlled trial of TNF-α antagonist in CTL-mediated severe cutaneous adverse reactions

BACKGROUND

Cytotoxic T lymphocyte-mediated (CTL-mediated) severe cutaneous adverse reactions (SCARs), including Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN), are rare but life-threatening adverse reactions commonly induced by drugs. Although high levels of CTL-associated cytokines, chemokines, or cytotoxic proteins, including TNF-α and granulysin, were observed in SJS-TEN patients in recent studies, the optimal treatment for these diseases remains controversial. We aimed to evaluate the efficacy, safety, and therapeutic mechanism of a TNF-α antagonist in CTL-mediated SCARs.

METHODS

We enrolled 96 patients with SJS-TEN in a randomized trial to compare the effects of the TNF-α antagonist etanercept versus traditional corticosteroids.

RESULTS

Etanercept improved clinical outcomes in patients with SJS-TEN. Etanercept decreased the SCORTEN-based predicted mortality rate (predicted and observed rates, 17.7% and 8.3%, respectively). Compared with corticosteroids, etanercept further reduced the skin-healing time in moderate-to-severe SJS-TEN patients (median time for skin healing was 14 and 19 days for etanercept and corticosteroids, respectively; P = 0.010), with a lower incidence of gastrointestinal hemorrhage in all SJS-TEN patients (2.6% for etanercept and 18.2% for corticosteroids; P = 0.03). In the therapeutic mechanism study, etanercept decreased the TNF-α and granulysin secretions in blister fluids and plasma (45.7%-62.5% decrease after treatment; all P < 0.05) and increased the Treg population (2-fold percentage increase after treatment; P = 0.002), which was related to mortality in severe SJS-TEN.

CONCLUSIONS

The anti-TNF-α biologic agent etanercept serves as an effective alternative for the treatment of CTL-mediated SCARs.

TRIAL REGISTRATION

ClinicalTrials.gov NCT01276314.

FUNDING

Ministry of Science and Technology of Taiwan.

Cordycepin, a Characteristic Bioactive Constituent in Cordyceps militaris, Ameliorates Hyperuricemia through URAT1 in Hyperuricemic Mice

Recently, we've reported the anti-hyperuricemic effects of Cordyceps militaris. As a characteristic compound of C. militaris, we hypothesized that cordycepin may play a role in preventing hyperurecimia. Remarkably, cordycepin produced important anti-hyperuricemic actions, decreasing SUA (serum uric acid) to 216, 210, and 203 μmol/L (P < 0.01) at 15, 30, and 60 mg/kg in comparison of hyperuricemic control (337 μmol/L), closing to normal control (202 μmol/L). Elisa, RT-PCR and western blot analysis demonstrated that the actions may be attributed to its downregulation of uric acid transporter 1 (URAT1) in kidney. Serum creatinine levels and blood urine nitrogen and liver, kidney, and spleen coefficients demonstrated that cordycepin may not impact liver, renal, and spleen functions. In addition, we used computational molecular simulation to investigate the binding mechanism of cordycepin. Of which, van der Waals interaction dominated the binding. Residues TRP290, ARG17, ALA408, GLY411, and MET147 contributed mainly on nonpolar energy. This provided the theoretical guidance to rationally design and synthesis novel URAT1 inhibitors.

PSORS1C1 Hypomethylation Is Associated with Allopurinol-Induced Severe Cutaneous Adverse Reactions during Disease Onset Period: A Multicenter Retrospective Case-Control Clinical Study in Han Chinese

Background: Allopurinol-induced severe cutaneous adverse reactions (SCARs), including drug rash with eosinophilia and systemic symptoms (DRESS), Stevens-Johnson syndrome (SJS) and toxic epidermal necrosis (TEN), are life-threatening autoimmune reactions. Evidence is growing that epigenetic variation, particularly DNA methylation, is associated with autoimmune diseases. However, the potential role of aberrant DNA methylation in allopurinol-SCARs is largely unknown.

Objective: To address the knowledge gap between allopurinol-SCARs and DNA methylation, we studied the DNA methylation profiles in peripheral blood cells from allopurinol-SCARs and allopurinol-tolerant subjects.

Methods: A genome-scale DNA methylation profiling was conducted using the Illumina Infinium HumanMethylation450 (HM450) platform on 15 patients with allopurinol-SCARs (3 TEN, 2 SJS/TEN overlap and 10 SJS) and 20 age- and gender-matched allopurinol-tolerant controls at disease onset. Pyrosequencing was used to validate the candidate CpG (cytosine-guanine dinucleotide) sites in an independent cohort of 40 allopurinol-SCARs and 48 allopurinol-tolerants.

Results: After bioinformatics analysis of methylation data obtained from HM450 BeadChip, we identified 41 differentially methylated CpG loci (P < 0.05) annotated to 26 genes showing altered DNA methylation between allopurinol-SCARs and allopurinol-tolerants. Among these genes, significant hypomethylation of PSORS1C1 (cg24926791) was further validated in a larger sample cohort, showing significant difference between DRESS and controls (P = 0.00127), ST (SJS and TEN) and controls (P = 3.75 × 10⁻¹³), and SCARs and controls (P = 5.93 × 10⁻¹⁵).

Conclusions: Our data identified differentially methylated genes between allopurinol-SCARs and allopurinol-tolerant controls and showed that PSORS1C1 hypomethylation was associated with allopurinol-SCARs (OR = 30.22, 95%CI = 4.73–192.96) during disease onset, suggesting that aberrant DNA methylation may be a mechanism of allopurinol-SCARs.

Limitations: Firstly, the data come from whole blood samples known to possess epigenetic heterogeneity, i. e., blood samples comprise a heterogeneous cell population with varying proportions of distinct cell-types with different DNA methylation patterns. Consequently, the interpretation of DNA methylation results should be performed with great caution due to the heterogeneous nature of the sample. Secondly, whether the identified disease-associated changes of epigenome precede disease onset, or result from the disease progression, needs further investigation. Comparing the methylation status before patients develop allopurinol-SCARs and after may help examine methylation levels from disease onset to disease progression.

Phosphorescent inner filter effect-based sensing of xanthine oxidase and its inhibitors with Mn-doped ZnS quantum dots

Large bandgap semiconductor ZnS QDs (Mn-doped) were explored for inner filter effect-based sensing of xanthine oxidase and its inhibitors, due to the maximum spectral overlap between the absorption of uric acid (the enzymatic product of xanthine oxidase) and the excitation of Mn-doped ZnS QDs.

A practical guide to thiopurine prescribing and monitoring in IBD

Thiopurines are often the mainstay of treatment for many patients with inflammatory bowel disease. As such, a general understanding of the evidence behind their use and of their metabolism is extremely useful in clinical practice. This review gives a practical overview of thiopurine metabolism, the importance of thiopurine S-methyltransferase testing prior to the start of therapy and the monitoring of thioguanine nucleotide levels while on treatment, guiding a personalised approach to optimising thiopurine therapy.

Occurrence of Dermatomyositis Immediately after Mastectomy Subsequent to Severe Chemotherapeutic Drug Eruption

We herein report a patient with breast cancer who developed dermatomyositis (DM) immediately after mastectomy. She had a history of severe drug eruption during neoadjuvant chemotherapy six months previously. Within a month after the operation, myalgia and rash, including Gottron's papules, developed, and skeletal-muscle enzymes elevated, so she was diagnosed with probable DM according to the Bohan and Peter criteria. In many neoplastic DM cases, the course of the disease parallels the course of the malignancy. Possible mechanisms were suggested to explain the development of DM in the present case and offer new insight into autoimmune diseases.

Correlation Between Serum Concentrations of N-Desmethylclozapine and Granulocyte Levels in Patients with Schizophrenia: A Retrospective Observational Study

BACKGROUND

Clozapine is restricted to use in patients with treatment-refractory schizophrenia due to the risk of a serious drop in absolute neutrophil granulocyte count (ANC). The formation of reactive, unstable metabolites (adducts) has been suggested as a mechanism of clozapine-induced granulocyte decline. These adducts are not detectable in vivo, but stable clozapine metabolites could potentially be indirect pharmacokinetic measures of adduct formation.

OBJECTIVE

The present retrospective observational study investigated the correlation between concentrations of N-desmethylclozapine, the major stable clozapine metabolite, and ANC in a real-life population of clozapine-treated patients.

METHODS

Patients were included from a therapeutic drug monitoring service at the Center for Psychopharmacology, Diakonhjemmet Hospital, Oslo, Norway, between March 2005 and December 2015. Information about clozapine and N-desmethylclozapine steady-state trough concentrations, as well as accompanying measurements of ANC, were collected from the laboratory database. Correlations of serum concentrations of N-desmethylclozapine and clozapine (and their respective ratios) with ANC were investigated by linear mixed-model analysis.

RESULTS

Overall, 129 patients with 855 measurements of clozapine/N-desmethylclozapine concentrations and ANC (range 0.9-19 × 10⁹ cells/L, median 4.6) were included. Concentrations of N-desmethylclozapine, but not clozapine, correlated significantly and positively with ANC (estimated model slope 0.0011 × 10⁹ cells/L/nM; p = 0.002), and the N-desmethylclozapine/clozapine ratio also positively correlated with ANC (p = 0.040).

CONCLUSIONS

N-Desmethylclozapine level and ANC significantly correlated in this real-life population of schizophrenia patients. The positive correlation, which was also present for the metabolic ratio, might reflect reduced clozapine availability for the formation of reactive metabolites potentially affecting granulocyte level. However, as our findings were based on ANC mainly within the reference range, this hypothesis should be studied further in clozapine-treated patients with neutropenia or agranulocytosis.

Delayed-type hypersensitivity to oral and parenteral drugs

Adverse drug reactions of the delayed type rank among the most common dermatoses and are predominantly characterized by exanthematous macular or maculopapular eruptions. However, approximately 2 % of affected individuals develop severe or even life-threatening systemic immune reactions associated with organ involvement, requiring immediate diagnosis and treatment. Numerous drugs are capable of eliciting delayed-type hypersensitivity reactions, with antibiotics, anticonvulsant drugs, and the xanthine oxidase inhibitor allopurinol being the most common. Apart from genetic susceptibility, predisposing factors for the development of drug hypersensitivity reactions include high drug doses, polypharmacy, long treatment duration, female gender, as well as acute or chronic infections.

Allopurinol suppresses expression of the regulatory T-cell migration factors TARC/CCL17 and MDC/CCL22 in HaCaT keratinocytes via restriction of nuclear factor-κB activation

Recent studies have shown that sparse distribution of regulatory T cells (Tregs) in the skin might be involved in the onset of severe cutaneous adverse drug reactions such as Stevens-Johnson syndrome and toxic epidermal necrolysis. Treg migration toward epithelial cells is regulated by certain chemokines, including TARC/CCL17 and MDC/CCL22. In this study, we analyzed the effect of allopurinol (APN), a drug known to cause severe adverse reactions, on the expression of factors affecting Treg migration and the mechanisms involved. APN inhibited the tumor necrosis factor (TNF)-α- and interferon (IFN)-γ-associated expression of TARC/CCL17 and MDC/CCL22 mRNA in HaCaT cells in a dose-dependent manner. Consistent with this, APN also suppressed TNF-α- and IFN-γ-induced production of TARC/CCL17 and MDC/CCL22 proteins and the migration of C-C chemokine receptor type 4-positive cells. Activity of the transcription factors NF-κB and STAT1, which are involved in TARC/CCL17 and MDC/CCL22 expression, was also investigated. APN inhibited activation of NF-κB, but not that of STAT1. Furthermore, it restricted p38 MAPK phosphorylation. These results suggest that APN inhibits TNF-α- and IFN-γ-induced TARC/CCL17 and MDC/CCL22 production through downregulation of p38 MAPK and NF-κB signaling, resulting in the sparse distribution of Tregs in the skin of patients with APN-associated Stevens-Johnson syndrome/toxic epidermal necrolysis.

Incidence, causative drugs, and economic consequences of drug-induced SJS, TEN, and SJS-TEN overlap and potential drug-drug interactions during treatment: a retrospective analysis at an Indonesian referral hospital

Background

Stevens–Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) are acute life-threatening adverse drug reactions (ADRs) that are commonly caused by medications. Apart from their contribution to morbidity and mortality, these diseases may also present substantial consequences on health care resources. In this study, we aimed to identify the incidence, causative drugs, and economic consequences of these serious ADRs and potential drug–drug interactions (DDIs) during treatment.

Methods

A retrospective study that included 150 patients diagnosed with drug-induced SJS, SJS–TEN overlap, and TEN, from 2009 to 2013 in a referral hospital in West Java Province, Indonesia, was conducted to analyze the causative drugs, cost of illness (COI) as a representation of economic consequences, and potential DDIs during treatment.

Results

The results showed that analgesic–antipyretic drugs were the most frequently implicated drugs. The COIs for SJS, SJS–TEN overlap, and TEN patients were 119.49, 139.21, and 162.08 US dollars per day, respectively. Furthermore, potential DDIs with several therapeutic medications and corticosteroids used to treat SJS, SJS–TEN overlap, and TEN were also identified.

Conclusion

This study showed that analgesic–antipyretic was the major causative drug which contributed to SJS, SJS–TEN overlap, and TEN. Furthermore, our results also showed that SJS, SJS–TEN overlap, and TEN may cause considerable financial consequences to patients.

Collaboration in pharmacovigilance: lamotrigine and fatal severe cutaneous adverse reactions - a review of spontaneous reports

Pharmacovigilance presents many challenges, particularly when managing unpredictable, rare conditions, eg, severe cutaneous adverse reactions (SCARs). Such rare events are often only detected from spontaneous reports, which present their own limitations, particularly during a prolonged global launch schedule. GlaxoSmithKline’s routine pharmacovigilance includes regular reviews of global adverse event (AE) reports and aggregate data from a central safety database. Lamotrigine is one of the several antiepileptic drugs associated with SCARs. After identification of increased rates of fatal SCAR cases with lamotrigine in Japan between September and December 2014, this analysis investigated the global incidence of fatal SCARs with lamotrigine and explored whether known risk factors may have contributed to these cases. Global fatal SCAR cases reported with lamotrigine administration from launch until January 2015 were reviewed for evidence of temporal association with dosing and the presence of risk factors, including comorbidities, concomitant medications, and noncompliance with the prescribing information (PI). Worldwide, the estimated cumulative exposure to lamotrigine was >8.4 million patient-years. Globally, there were 54,513 AE reports for lamotrigine, of which 3,454 (6.3%) concerned SCARs. Of these, 122 (3.5%) had a fatal outcome (attributable and nonattributable to lamotrigine), equating to 0.01 fatal SCARs per 1,000 patient-years. In Japan (estimated cumulative exposure 141,000 patient-years), 17 fatal SCARs were reported (attributable and nonattributable), equating to 0.12 per 1,000 patient-years. Seventy-one percent of fatal SCAR cases in Japan showed evidence of noncompliance with the recommended dosing regimen; in 65% of the cases, a delay in discontinuation of lamotrigine after early signs of hypersensitivity was reported. Despite a number of limitations inherent in comparing spontaneous report data, this analysis highlights the need for adherence to the lamotrigine PI and emphasizes the importance of collaboration between global and local pharmacovigilance departments, to promptly identify and reduce the risk of rare and serious events, such as SCARs.

Polypharmacy and sun exposure: Implications for mitochondrial DNA deletions in skin

Most somatic cells contain many copies of mitochondrial DNA (mtDNA). Because of both the high copy number and the lack of repair mechanisms available to mtDNA, damage to it largely goes unrepaired, and can accumulate over time. Large scale deletions are a recognised type of damage sustained by mtDNA as a consequence of exposure to the ultraviolet light in sunlight. A group of patients were identified as having abnormally high levels of either a 4977 base pair deletion (mtDNA⁴⁹⁷⁷) or 3895 base pair deletion (mtDNA³⁸⁹⁵), in mtDNA from sun exposed skin or skin suspected to be a non-melanoma skin cancer, but not in their non-sun exposed skin biopsies. In three of the four cases, skin cancer was ruled out due to histological testing. Additional factors from these patients' medical histories were studied, and it was noted that they shared diagnoses for multiple pathologies common to an older population, and that they were being treated with the same or related pharmaceuticals, including some that had been known to cause dermal side effects. Investigation into the biochemistry underlying the symptoms, the effects of sun exposure and side effects of the prescribed pharmaceuticals revealed a possible synergistic relationship leading to the localised high levels of mtDNA deletions.

Exacerbation of allopurinol-induced drug reaction with eosinophilia and systemic symptoms by teicoplanin: A case report

WHAT IS KNOWN AND OBJECTIVE

Drug reaction with eosinophilia and systemic symptoms (DRESS) syndrome is a rare and potentially life-threatening drug reaction. Allopurinol is one of the most frequently reported drugs accounting for DRESS syndrome development. In contrast to allopurinol, DRESS syndrome induced by teicoplanin has not been reported frequently.

CASE DESCRIPTION

A 50-year-old woman was admitted to receive FLAG chemotherapy regimen (fludarabine, cytarabine (high-dose Ara-C), granulocyte colony-stimulating factor) for relapsed acute lymphoblastic leukaemia (ALL) treatment. Allopurinol was initiated at a dose of 300 mg per day 48 hours before chemotherapy regimen initiation, for tumour lysis syndrome prophylaxis. Seven days after allopurinol initiation, the patient presented with fever, dyspnoea, shortening of breath, facial oedema, generalized pruritus, erythema and macular rash affecting the face, abdomen, trunk, upper and lower limbs and an elevation in hepatic enzymes. Allopurinol was immediately discontinued and intravenous hydrocortisone was started concomitantly alongside other supportive measures. About 72 hours later, pruritus, erythema and rash were ameliorated and abnormalities in liver tests were improved. Afterwards, teicoplanin administration led to severe deterioration of pruritus, erythema and rash; subsequently, serum alanine aminotransferase increased again and episodes of worsening dyspnea occurred. Signs of hypersensitivity reaction were reduced by discontinuation of teicoplanin and supportive care.

WHAT IS NEW AND CONCLUSION

We report a case of allopurinol-induced DRESS syndrome, which was exacerbated by administration of teicoplanin. It can be suggested that the administration of drugs with high possibility of hypersensitivity reactions should be avoided during the acute phase of DRESS syndrome.

Overlapping DRESS and Stevens-Johnson Syndrome: Case Report and Review of the Literature

Drug-induced severe cutaneous adverse reactions (SCARs) include acute generalized exanthematous pustulosis, drug reaction with eosinophilia and systemic symptoms (DRESS), and epidermal necrolysis (Stevens-Johnson syndrome [SJS], toxic epidermal necrolysis). The identification of the causal drug is crucial in order to avoid further exposure, but making the right differential diagnosis of the type of SCAR is equally important since treatment, follow-up, and prognosis of different SCARs are not the same. These syndromes are distinct entities with different clinical, biological, and histological patterns, but sometimes the early distinction between 2 SCARs can be extremely challenging, and overlapping conditions could therefore be taken into consideration, although true overlapping SCARs are very rare when using strict diagnostic criteria (described by the RegiSCAR group). Only a better understanding of the physiopathology of the SCARs could possibly explain these ambiguities and overlaps. We report a case of SCAR in an 86-year-old patient probably induced by allopurinol and simultaneously fulfilling the diagnostic criteria for DRESS and SJS, thus considered as an overlapping case of SCARs.

Severe Delayed Cutaneous and Systemic Reactions to Drugs: A Global Perspective on the Science and Art of Current Practice

Most immune-mediated adverse drug reactions (IM-ADRs) involve the skin, and many have additional systemic features. Severe cutaneous adverse drug reactions (SCARs) are an uncommon, potentially life-threatening, and challenging subgroup of IM-ADRs with diverse clinical phenotypes, mechanisms, and offending drugs. T-cell-mediated immunopathology is central to these severe delayed reactions, but effector cells and cytokines differ by clinical phenotype. Strong HLA-gene associations have been elucidated for specific drug-SCAR IM-ADRs such as Stevens-Johnson syndrome/toxic epidermal necrolysis, although the mechanisms by which carriage of a specific HLA allele is necessary but not sufficient for the development of many IM-ADRs is still being defined. SCAR management is complicated by substantial short- and long-term morbidity/mortality and the potential need to treat ongoing comorbid disease with related medications. Multidisciplinary specialist teams at experienced units should care for patients. In the setting of SCAR, patient outcomes as well as preventive, diagnostic, treatment, and management approaches are often not generalizable, but rather context specific, driven by population HLA-genetics, the pharmacology and genetic risk factors of the implicated drug, severity of underlying comorbid disease necessitating ongoing treatments, and cost considerations. In this review, we update the basic and clinical science of SCAR diagnosis and management.

Protective role of α-lipoic acid in hyperuricemia-induced endothelial dysfunction

The aim of the current study was to determine the effects of α-lipoic acid (LA) on hyperuricemia and endothelial dysfunction, and to uncover the underlying mechanism of its action. A hyperuricemic rat model was established by administration of uric acid (UA) and the rats were orally fed with 2 g/kg/day LA or phosphate-buffered saline. Primary rat aortic endothelial cells were subsequently isolated, and a cell viability assay, apoptosis assay, enzyme nitric oxide synthase (eNOS) activity assay and mitochondrial function assay were all performed. For the in vitro study, human umbilical vein endothelial cells were used and western blotting was performed to assess Akt signaling activity. The results of the current study indicated that LA inhibited apoptosis, enhanced eNOS activity and production of nitric oxide (NO), and rescued mitochondrial mass and function in uric acid (UA)-treated endothelial cells. LA activated Akt signaling and inhibition of Akt signaling abolished the effects of LA on cell viability, NO production, ROS production and ATP levels in UA-treated endothelial cells. Therefore, the current study demonstrated that LA attenuated oxidant stress and inhibited apoptosis in UA-treated endothelial cells by activating Akt signaling. The results indicate that LA may serve as a therapeutic approach to treat hyperuricemia-induced endothelial dysfunction.

Bibliometric analysis of literature on toxic epidermal necrolysis and Stevens-Johnson syndrome: 1940 - 2015

Background

Stevens Johnson Syndrome (SJS) and toxic epidermal necrolysis (TEN) are rare but fatal adverse skin reactions that affect all age groups. In order to better understand literature on this topic, we conducted a bibliometric study using Scopus database to shed light on number and growth of publications, most active countries, institutions, journals and authors involved in publishing articles in this field, citation analysis, top cited articles, international collaboration, role of medications and genetic association. Bibliometric analysis will enrich the literature on these rare conditions and will provide baseline data for future comparison.

Results

Three thousand eight hundred fifty-six journal articles were retrieved. The h-index of retrieved documents was 95. Growth rates of publications were highest from 1966 to 1975 and from 2006 to 2015. The United States of America (n = 640; 16.57%) was the leading country in number of publications. However, French and Japanese researchers and institutions were most active in publishing articles on SJS and TEN. International collaboration among active countries was relatively low and ranges from 32.5% for Swiss researchers and 1.47% for Spanish researchers. The most frequently mentioned medication in retrieved articles was carbamazepine (n = 146) followed by phenytoin (n = 114) and allopurinol (n = 112). Mycoplasma infection was mentioned in 111 articles. Most documents on SJS and TEN were published in dermatology journals, specifically Archives of Dermatology. However, in the last decade, top cited articles appeared in dermatology and pharmacogenetic journals. Carbamazepine was frequently encountered with Han Chinese and HLA-B 1502 terms while allopurinol was frequently encountered with HLA-B 5801 and Japanese terms.

Conclusion

Bibliometric analysis reveals that research publications on SJS and TEN have been increasing since the l940s, with relatively low international collaboration. Documents are being published, not only in dermatology journals, but also in genetic, public health and general medicine journals. Research on SJS and TEN can be helpful to clinicians and researchers not only to document complications and fatal outcomes, but also to identify potential causative agents and potential ethnic variations to note gaps in research.

Validation of a Rapid, Robust, Inexpensive Screening Method for Detecting the HLA-B*58:01 Allele in the Prevention of Allopurinol-Induced Severe Cutaneous Adverse Reactions

The HLA B^*58:01 allele has been worldwide reported as a pharmacogenetic susceptibility to allopurinol-induced severe cutaneous adverse reactions (SCARs). To prevent these life-threatening conditions, the American College of Rheumatology hingly recommended that the HLA-B^*58:01 be screened prior to the initiation of allopurinol therapy. Therefore, we developed a rapid, robust, inexpensive screening method using SYBR® Green real time PCR to detect the HLA-B^*58:01 allele. A total of 119 samples were tested. The assay has a sensitivity of 100% (95% CI: 69.15%-100%), a specificity of 100% (95% CI: 96.67%-100%), a positive predictive value of 100% (95% CI: 69.15%-100%) and a negative predictive value of 100% (95% CI: 96.67%-100%). HLA-B^*58:01 genotyping results showed 100% agreement with those obtained from Luminex SSO/SBT/SSP. The lowest limit of detection of this method is 0.8 ng/µL of DNA. The unit cost of the test is only $3.8 USD. This novel screening test using SYBR® real time PCR would be appropriate to identify individuals with the HLA-B^*58:01 allele for the prevention of allopurinol-induced SCARs.

Measuring High-Risk Patients' Preferences for Pharmacogenetic Testing to Reduce Severe Adverse Drug Reaction: A Discrete Choice Experiment

OBJECTIVES

To investigate patient preferences and willingness to pay (WTP) for a genetic test that can reduce the risk of life-threatening adverse drug reactions (ADRs). We hypothesize that test features (risk of developing the adverse reaction with and without testing, test cost, and treatment cost) and the choice context (physician recommendation and the most common choice made by peer patients) will influence choices.

METHODS

A discrete choice experiment was conducted in which 189 patients at high risk for gout were asked to choose between treatment options that varied along key attributes. A latent class logit model was used to analyze the choice data and test the hypotheses.

RESULTS

We identified two classes of patients: the risk-averse class and the cost-conscious class. The WTP to reduce the risk of life-threatening ADRs from 1 out of 600 to 1 out of 1 million was SGD1215 in the risk-averse class. In contrast, in the cost-conscious class, the WTP was insensitive to the extent of risk reduction. Overall, the predicted take-up rate for the test is 65% at a price of SGD400. If the test was recommended by a physician or was chosen by most of the patients, the take-up rate for the test would increase by 8.5 and 1.5 percentage points, respectively.

CONCLUSIONS

There is a potentially large demand for genetic tests that could reduce the risk of life-threatening ADRs. Physician recommendations and providing information on the choices of others are powerful influences on demand, even more so than moderate price reductions.

In vitro test to confirm diagnosis of allopurinol-induced severe cutaneous adverse reactions

BACKGROUND

Allopurinol is a frequent cause of severe cutaneous adverse reactions (SCARs), such as drug reaction with eosinophilia and systemic symptoms (DRESS), Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN). The reactions can potentially be fatal. As drug rechallenge in patients with a history of drug-induced SCARs is contraindicated, in vitro testing may have a diagnostic role as a confirmation test.

OBJECTIVES

To study the diagnostic value of interferon (IFN)-γ enzyme-linked immunospot (ELISpot) assay as a confirmatory test in patients with a history of allopurinol-induced SCARs.

METHODS

Peripheral blood mononuclear cells (PBMCs) from 24 patients with a history of allopurinol-induced SCAR (13 DRESS, 11 SJS/TEN) and 21 control subjects were incubated with allopurinol or oxypurinol in the presence or absence of antiprogrammed death ligand 1 antibody (anti-PD-L1). The numbers of IFN-γ-releasing cells after stimulation in each group were subsequently measured with ELISpot.

RESULTS

The numbers of IFN-γ-releasing cells in allopurinol-allergic subjects were significantly higher than in control subjects when stimulating PBMCs with oxypurinol 100 μg mL^-1 , especially when adding anti-PD-L1 supplementation. According to the receiver operating characteristic curve results, the optimal discriminatory power of IFN-γ ELISpot in confirming diagnosis of allopurinol-induced SCARs can be obtained using 16 spot-forming cells per 10⁶ PBMCs as a cut-off value upon oxypurinol/anti-PD-L1 stimulation (79·2% sensitivity and 95·2% specificity).

CONCLUSIONS

The measurement of oxypurinol/anti-PD-L1-inducing IFN-γ-releasing cells yields a high diagnostic value in distinguishing between allopurinol-allergic and control subjects. This technique is beneficial in confirming diagnosis of allopurinol-induced SCARs in patients whose reaction develops while taking multiple drugs.

2016 updated EULAR evidence-based recommendations for the management of gout

Background

New drugs and new evidence concerning the use of established treatments have become available since the publication of the first European League Against Rheumatism (EULAR) recommendations for the management of gout, in 2006. This situation has prompted a systematic review and update of the 2006 recommendations.

Methods

The EULAR task force consisted of 15 rheumatologists, 1 radiologist, 2 general practitioners, 1 research fellow, 2 patients and 3 experts in epidemiology/methodology from 12 European countries. A systematic review of the literature concerning all aspects of gout treatments was performed. Subsequently, recommendations were formulated by use of a Delphi consensus approach.

Results

Three overarching principles and 11 key recommendations were generated. For the treatment of flare, colchicine, non-steroidal anti-inflammatory drugs (NSAIDs), oral or intra-articular steroids or a combination are recommended. In patients with frequent flare and contraindications to colchicine, NSAIDs and corticosteroids, an interleukin-1 blocker should be considered. In addition to education and a non-pharmacological management approach, urate-lowering therapy (ULT) should be considered from the first presentation of the disease, and serum uric acid (SUA) levels should be maintained at<6 mg/dL (360 µmol/L) and <5 mg/dL (300 µmol/L) in those with severe gout. Allopurinol is recommended as first-line ULT and its dosage should be adjusted according to renal function. If the SUA target cannot be achieved with allopurinol, then febuxostat, a uricosuric or combining a xanthine oxidase inhibitor with a uricosuric should be considered. For patients with refractory gout, pegloticase is recommended.

Conclusions

These recommendations aim to inform physicians and patients about the non-pharmacological and pharmacological treatments for gout and to provide the best strategies to achieve the predefined urate target to cure the disease.

Stevens-Johnson Syndrome and Toxic Epidermal Necrolysis in the Pediatric Population: A Review

Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) are severe dermatologic reactions with mucocutaneous involvement that carry elevated mortality rates. They differ along a spectrum of severity based upon body surface area affected. These conditions, usually caused by a drug or infection, are believed to result from cell-mediated and often drug-specific cytotoxic reactions against keratinocytes, leading to widespread dermal-epidermal detachment. Studies attempting to identify potential curative therapies such as intravenous immune globulin (IVIG) and corticosteroids remain inconclusive. However, improved outcomes have been demonstrated by early withdrawal of offending medications, early transfer to an intensive care unit or burn unit, and aggressive supportive care. Due to the rare incidence of SJS and TEN, its recurrence among survivors hints at future vulnerability for these patients, and notorious offending medications should thus be avoided. This clinical review will highlight the diagnostic and therapeutic challenges posed by SJS and TEN, while emphasizing the need to maintain them high on the emergency medicine physician's differential. The review will also detail the supportive measures to take for preventing the rapid progression of mucocutaneous complications and subsequent sepsis-related mortality.

Hypouricemic effect of allopurinol are improved by Pallidifloside D based on the uric acid metabolism enzymes PRPS, HGPRT and PRPPAT

Allopurinol is a commonly used medication to treat hyperuricemia and its complications. Pallidifloside D, a saponin glycoside constituent from the total saponins of Smilax riparia, had been proved to enhanced hypouricemic effect of allopurinol based on uric acid metabolism enzyme XOD. In this study, we evaluated whether Pallidifloside D (5mg/kg) enhanced hypouricemic effect of allopurinol (5mg/kg) related to others uric acid metabolism enzymes such as PRPS, HGPRT and PRPPAT. We found that, compared with allopurinol alone, the combination of allopurinol and Pallidifloside D significantly up-regulated HGPRT mRNA expression and down-regulated the mRNA expression of PRPS and PRPPAT in PC12 cells (all P<0.01). These results strongly suggest that hypouricemic effect of allopurinol are improved by Pallidifloside D via numerous mechanisms and our data may have a potential value in clinical practice in the treatment of gout and other hyperuricemic conditions.