Unique Clinical Characteristics and Prognosis of Allopurinol-Induced Severe Cutaneous Adverse Reactions

Ameliorative action of "daitongxiao" against hyperuricemia includes the "uric acid transporter group"

This study aimed to investigate the potential mechanisms involved in the therapeutic effects of daitongxiao (DTX) on hyperuricemia (HUA). DTX was administered to two animal models of HUA via gavage feeding: HUA quail model (a uricotelic animal with urate oxidase deficiency), treated continuously for 35 days post-HUA induction, and HUA rats (an animal with active urate oxidase), treated continuously for 28 days post-HUA induction. HUA was induced in quail by administering a solution of sterile dry yeast powder via gavage feeding, while in rats, it was induced by intragastric gavage feeding of a solution of adenine and ethambutol hydrochloride. DTX improved overall health; increased bodyweight; reduced renal index, serum urate levels, serum xanthine oxidase activity, blood urea nitrogen, and creatinine; and enhanced urinary and fecal uric acid (UA) excretion in these two animal models. The results of hematoxylin and eosin and hexamine silver staining of kidney sections revealed that DTX significantly mitigated HUA-induced renal structural damage and inflammatory response. The results of quantitative real-time polymerase chain reaction, Western blotting, and immunofluorescence analyses revealed that DTX downregulated the renal expression levels of glucose transporter 9 (GLUT9) and upregulated the renal expression levels of organic anion transporters (OAT1 and OAT3) in both HUA models. Thus, the findings of this study suggest that DTX suppresses the progression of HUA by modulating the expression of the UA transporter group members.

Drug-induced hypersensitivity syndrome/drug reaction with eosinophilia and systemic symptoms. Part I. Epidemiology, pathogenesis, clinicopathological features, and prognosis

Drug-induced hypersensitivity syndrome (DiHS), also known as drug reaction with eosinophilia and systemic symptoms (DRESS), is a severe cutaneous adverse reaction (SCAR) characterized by an exanthem, fever, and hematologic and visceral organ involvement. Anticonvulsants, antibiotics, and allopurinol are the most common triggers. The pathogenesis involves a complex interplay between drugs, viruses, and the immune system primarily mediated by T-cells. DiHS/DRESS typically presents with a morbilliform eruption 2-6 weeks after drug exposure, and is associated with significant morbidity, mortality, and risk of relapse. Long-term sequelae primarily relate to organ dysfunction and autoimmune diseases. Part I of this continuing medical education activity on DiHS/DRESS provides an update on epidemiology, novel insights into pathogenesis, and a description of clinicopathological features and prognosis.

Renal herb formula protects against hyperuricemic nephropathy by inhibiting apoptosis and inflammation

BACKGROUND

Hyperuricemic nephropathy may be induced by the elevation and accumulation of uric acid in kidney after hyperuricemia, which leads to kidney residential cells apoptosis and inflammation. Renal herb formula (RHF) is a self-designed formula based on traditional Chinese medicine theory and clinical practice in kidney disease treatment. In the literature available currently, there is not yet research article reporting the reno-protective effect of RHF against hyperuricemic nephropathy.

PURPOSE

This study was performed to analyze the bioactive compound profiles of RHF, evaluate its protective effects against hyperuricemic nephropathy, and investigate the mechanisms of actions regarding apoptosis and inflammation.

METHODS

Ultra-performance liquid chromatography with a diode-array detector was applied to establish fingerprint and chemical composition of RHF. Potassium oxonate was used to induce hyperuricemic nephropathy in mice, and uric acid was used to stimulate apoptosis and inflammatory response in HK-2 cells, while the mice and cells were treated with RHF to explore its reno-protective effects and mechanisms.

RESULTS

It was found that chlorogenic acid, neochlorogenic acid, cryptochlorogenic acid, and isochlorogenic acid A-C may be the characteristic components of RHF. RHF treatment could improve kidney functions in mice with hyperuricemic nephropathies, such as decreasing urine protein, uric acid, and creatinine and serum uric acid, creatinine, and urea nitrogen. Histopathological observations showed that RHF treatment ameliorated kidney glomerular hypotrophy, tubular damage, and inflammatory infiltration. Mechanism studies revealed that RHF inhibited kidney residential cell apoptosis and inflammatory response by targeting the p53-associated intrinsic apoptosis pathway and NF-κB-mediated inflammatory pathway.

CONCLUSION

Taken together, it could be concluded that RHF exerted reno-protective effects against hyperuricemic nephropathy through reducing apoptosis and inflammation. RHF and the bioactive compounds chlorogenic acid analogs as promising candidates may be developed into novel and effective drugs for hyperuricemic nephropathy treatment and management.

A lifetime economic research of universal HLA-B*58:01 genotyping or febuxostat initiation therapy in Chinese gout patients with mild to moderate chronic kidney disease

OBJECTIVE

To evaluate Chinese long-term economic impact of universal human leukocyte antigen B (HLA-B)*58:01 genotyping-guided urate-lowering therapy or febuxostat initiation therapy for gout patients with mild to moderate chronic kidney disease (CKD) from perspective of healthcare system.

METHODS

A Markov model embedded in a decision tree was structured including four mutually exclusive health states (uncontrolled-on-therapy, controlled-on-therapy, uncontrolled-off-therapy, and death). Mainly based on Chinese real-world data, the incremental costs per quality-adjusted life years (QALYs) gained were evaluated from three groups (universal HLA-B*58:01 testing strategy, and no genotyping prior to allopurinol or febuxostat initiation therapy) at 25-year time horizon. All costs were adjusted to 2021 levels based on Chinese Consumer Price Index and were discounted by 5% annually. One-way and probability sensitivity analysis were performed.

RESULTS

Among these three groups, universal HLA-B*58:01 genotyping was the most cost-effective strategy in base-case analysis according to Chinese average willingness-to-pay threshold of $37 654.50 per QALY. The based incremental cost-effectiveness ratio was $31784.55 per QALY, associated with 0.046 additional QALYs and $1463.81 increment costs per patient at a 25-year time horizon compared with no genotyping prior to allopurinol initiation strategy. Sensitivity analysis showed 64.3% robustness of these results.

CONCLUSION

From Chinese perspective of healthcare system, HLA-B*58:01 genotyping strategy was cost-effective for gout patients with mild to moderate CKD in mainland China, especially in the most developed area, such as Beijing and Shanghai. Therefore, we suggest China's health authorities choose the genotyping strategy and make different recommendations according to the differences of local conditions.

Treating Preeclampsia in the COVID-19 Era: Is Allopurinol Useful as an Adjuvant Therapy? A Case Report and Review of the Literature

Acute respiratory syndrome-related coronavirus 2, or SARS-CoV-2, mainly affects the vulnerable population, especially those with comorbidities, such as pregnant women. SARS-CoV-2 has been found to cause multiple manifestations, one of which is preeclampsia. In preeclampsia, uric acid is excessively produced in the ischemic placenta and is released into circulation by placental reperfusion. Another effect of uric acid is oxidative stress with the production of oxygen free radicals associated with severe preeclampsia and fetal hypoxia. In our case report, we present the situation of a 38-year-old pregnant woman who developed preeclampsia after infection with SARS-CoV-2 with rapid evolution and an increased level of uric acid. We discuss the option of Allopurinol treatment in the third trimester of pregnancy instead of premature birth, with excellent benefits for both the mother and newborn. Additional clinical correlations between antioxidant treatment with Allopurinol and placental findings are needed.

The mechanism study of Miao medicine Tongfengting decoction in the treatment of gout based on network pharmacology and molecular docking

AIM

This study sought to clarify the mechanism of action of Miao medicine Tongfengting decoction in the treatment of gout through network pharmacology and molecular docking by searching for its key targets and related pathways.

METHODS

The active ingredients of Miao medicine Tongfengting Decoction were obtained from the TCMSP data platform, searched the relevant databases for gout-related targets,using String and Cytoscape 3.9 to build a "compound-cross-target-disease" network diagram,performed gene ontology (GO) and Kyoto encyclopedia of genes and genomes (KEGG) enrichment analysis in the DAVID database, and performed the docking analysis using PyMoL 2.3.0 and AutoDock.

RESULTS

After screening, 298 main targets of the Miao medicine Tongfengting decoction for gout were identified. The target network is established, and the topology of protein-protein interaction (PPI) network is analyzed. The enrichment analysis of KEGG pathway showed that these targets were related to Pathways in cancer, PI3K Akt signaling pathway, MAPK signaling pathway and other pathways. Molecular docking showed that the target protein had good binding power with the main active components of the compound of Miao medicine Tongfengting Decoction.

CONCLUSION

Miao medicine Tongfengting decoction probably regulates immune mechanism using a multi-component, multi-target, and multi-pathway strategy to reduce inflammatory response and exert its therapeutic effect on gout.

Design, synthesis and activity evaluation of novel lesinurad analogues containing thienopyrimidinone or pyridine substructure as human urate transporter 1 inhibitors

Urate Transporter 1 (URAT1) plays a crucial role in uric acid transport, making it an attractive target for the treatment of gout and hyperuricemia. As a representative URAT1 inhibitor, Lesinurad treat gout by promoting the uric acid excretion. However, its lower in vitro and in vivo activity should be highly attracted attention. Herein, the bioisosterism, molecular hybridization and scaffold hopping strategies were exploited to modify all the structural components of Lesinurad and finally thirty novel compounds bearing thienopyrimidinone or pyridine core were obtained. Most of the compounds displayed certain URAT1 inhibitory activity in vitro. Among them, thienopyrimidinones 6 (IC50 = 7.68 μM), 10 (IC50 = 7.56 μM), 14 (IC50 = 7.31 μM) and 15 (IC50 = 7.90 μM) showed slightly better potency than positive control Lesinurad (IC50 = 9.38 μM). Notably, 10 also displayed inhibitory activity (IC50 = 55.96 μM) against GLUT9. Additionally, in vivo serum uric acid (SUA)-lowering experiments were performed on some representative compounds and it was revealed that all the selected compounds could decrease the SUA level in mice, of which the decrease rate of SUA was 73.29% for the most promising compound 10, significantly greater than that of Lesinurad (26.89%). Meanwhile, the preliminary SARs based on the URAT1 inhibitory activity were discussed in detail, which pointed out the direction for further structural optimization. Overall, the thienopyrimidinone and pyridine are prospective skeletons for the developing novel URAT1 inhibitors with considerable potential for optimization.

Potential molecular mechanisms of Ermiao san in the treatment of hyperuricemia and gout based on network pharmacology with molecular docking

A network pharmacology integrated molecular docking strategy was used to predict the underlying molecular mechanism of Ermiao san in the treatment of hyperuricemia and gout. Traditional Chinese medicine systems pharmacology (TCMSP) database and analysis platform were used to screen out the active compounds and their targets of Ermiao san. The disease target genes related to hyperuricemia (HUA) and gout were obtained by searching CTD, DisGeNET, DrugBank, GeneCards, OMIM, TTD, and PharmGKB databases with "Hyperuricemia" and "Gout" as keywords, respectively. The potential targets of Ermiao san in the treatment of HUA and gout were screened through a Venn diagram. The protein-protein interaction network was constructed using Cytoscape software. Gene ontology and Kyoto Encyclopedia of Genes and Genomes enrichment analyses were then conducted. Finally, some compounds and core targets were selected for molecular docking verification by Autodock Vina and Pymol software. Forty-six active compounds, such as quercetin, wogonin and beta-sitosterol, etc were identified. Ermiao san plays a therapeutic role in HUA and gout regulating various biological processes, cellular compounds, and molecular functions. The core targets of Ermiao san for treating HUA and gout are AT1 (namely Protein Kinase Bα), interleukin-1 beta, prostaglandin-endoperoxide synthase 2, JUN, etc. And the key pathways are nuclear factor-κB, interleukin-17 and tumor necrosis factor. The results of molecular docking analyses suggested that active compounds of Ermiao san could bind well to the core protein receptors. Ermiao san has a synergistic mechanism of multiple compounds, multiple targets, and multiple pathways in the treatment of HUA and gout, which provides a good theoretical basis for the clinical application.

Disease severity and status in Stevens–Johnson syndrome and toxic epidermal necrolysis: Key knowledge gaps and research needs

Stevens–Johnson syndrome and toxic epidermal necrolysis (SJS/TEN) are on a spectrum of cutaneous drug reactions characterized by pan-epidermal necrosis with SJS affecting < 10% of body surface area (BSA), TEN > 30%, and SJS/TEN overlap between 10 and 30%. Severity-of-illness score for toxic epidermal necrolysis (SCORTEN) is a validated tool to predict mortality rates based on age, heart rate, BSA, malignancy and serum urea, bicarbonate, and glucose. Despite improved understanding, SJS/TEN mortality remains constant and therapeutic interventions are not universally accepted for a number of reasons, including rarity of SJS/TEN; inconsistent definition of cases, disease severity, and endpoints in studies; low efficacy of interventions; and variations in treatment protocols. Apart from mortality, none of the other endpoints used to evaluate interventions, including duration of hospitalization, is sufficiently standardized to be reproducible across cases and treatment centers. Some of the gaps in SJS/TEN research can be narrowed through international collaboration to harmonize research endpoints. A case is made for an urgent international collaborative effort to develop consensus on definitions of endpoints such as disease status, progression, cessation, and complete re-epithelialization in interventional studies. The deficiencies of using BSA as the sole determinant of SJS/TEN severity, excluding internal organ involvement and extension of skin necrosis beyond the epidermis, are discussed and the role these factors play on time to healing and mortality beyond the acute stage is highlighted. The potential role of artificial intelligence, biomarkers, and PET/CT scan with radiolabeled glucose as markers of disease status, activity, and therapeutic response is also discussed.

Current state and prospects of gout treatment in Korea

Effective management of gout includes the following: appropriate control of gout flares; lifestyle modifications; management of comorbidities; and long-term urate-lowering therapy (ULT) to prevent subsequent gout flares, structural joint damage, and shortening of life expectancy. In addition to traditional treatments for gout, novel therapies have been introduced in recent years. Indeed, new recommendations for the management of gout have been proposed by various international societies. Although effective and safe medications to treat gout have been available, management of the disease has continued to be suboptimal, with poor patient adherence to ULT and failure to reach serum urate target. This review outlines recent progress in gout management, mainly based on the latest published guidelines, and specifically provides an update on efficient strategies for implementing treatment, efficacy and safety of specific medications for gout, and cardiovascular outcomes of ULT. In particular, we reviewed gout management approaches that can be applied to a Korean population.

The Use of Electronic Health Records to Study Drug-Induced Hypersensitivity Reactions from 2000 to 2021: A Systematic Review

Electronic health records (EHRs) have revolutionized the field of drug hypersensitivity reaction (DHR) research. In this systematic review, we assessed 140 articles from 2000-2021, classifying them under six themes: observational studies (n=61), clinical documentation (n=27), case management (n=22), clinical decision support (CDS) (n=18), case identification (n=9), and genetic studies (n=3). EHRs provide convenient access to millions of medical records, facilitating epidemiological studies of DHRs. Though the goal of CDS is to promote safe drug prescribing, allergy alerts must be designed and used in a way that supports this effort. Ultimately, accurate allergy documentation is essential for DHR prevention.

The Roles of Immunoregulatory Networks in Severe Drug Hypersensitivity

The immunomodulatory effects of regulatory T cells (Tregs) and co-signaling receptors have gained much attention, as they help balance immunogenic and immunotolerant responses that may be disrupted in autoimmune and infectious diseases. Drug hypersensitivity has a myriad of manifestations, which ranges from the mild maculopapular exanthema to the severe Stevens-Johnson syndrome (SJS), toxic epidermal necrolysis (TEN), and drug reaction with eosinophilia and systemic symptoms/drug-induced hypersensitivity syndrome (DRESS/DIHS). While studies have identified high-risk human leukocyte antigen (HLA) allotypes, the presence of the HLA allotype at risk is not sufficient to elicit drug hypersensitivity. Recent studies have suggested that insufficient regulation by Tregs may play a role in severe hypersensitivity reactions. Furthermore, immune checkpoint inhibitors, such as anti-CTLA-4 or anti-PD-1, in cancer treatment also induce hypersensitivity reactions including SJS/TEN and DRESS/DIHS. Taken together, mechanisms involving both Tregs as well as coinhibitory and costimulatory receptors may be crucial in the pathogenesis of drug hypersensitivity. In this review, we summarize the currently implicated roles of co-signaling receptors and Tregs in delayed-type drug hypersensitivity in the hope of identifying potential pharmacologic targets.

Clinical Aspects of Stevens-Johnson Syndrome and Toxic Epidermal Necrolysis With Severe Ocular Complications in South Korea

This review describes the current knowledge regarding genetic susceptibilities and treatment strategies for Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN), with ocular complications, in Korea. In a case-control study, the gene frequencies of both HLA-A*0206 (20.0%) and HLA-Cw*0304 (15.0%) increased but the gene frequency of HLA-Cw*0303 (1.3%) decreased with cold medicine (CM)-SJS/TEN with severe ocular complications (SOCs). In a case-series, positive genotyping of HLA-B*5801 was 80.0% in allopurinol-induced SJS/TEN without SOCs. In a genome-wide association study, HLA-A*0206 was substantially related to CM-SJS/TEN with SOCs. Both HLA-A*0206 and prostaglandin-E receptor 3 (PTGER3) single nucleotide polymorphism (SNP) rs1327464 exert a synergistic effect on SOCs in CM-SJS/TEN. In the acute stage, conventional procedures, amniotic membrane transplantation or suture-less amniotic contact lenses are applied. Applications of intravenous Immunoglobulin (IVIG) or mega-dose steroids are attempted in patients with high acute ocular and systemic involvement scores. In the chronic stage, keratolimbal transplantation and penetrating keratoplasty are the standard procedures. Either autologous nasal or oral mucosal grafts, or biomaterial-free cultured oral mucosal epithelial cell sheets are transplanted as alternative therapies. Deep anterior lamellar keratoplasty is attempted. Combined photodynamic therapy with intrastromal bevacizumab injection or intense pulse laser are used to resolve chronic ocular complication. Corneoscleral contact lenses are available for a visual rehabilitation. As a last resort, Seoul-type keratoprosthesis had been transplanted. There are unmet needs to standardize nationwide ocular grading system and to correct tarsal scarring using mucosal grafting. This review provides a perspective on the current practices to treat ocular complications in SJS/TEN.

A Nationwide Study of Severe Cutaneous Adverse Reactions Based on the Multicenter Registry in Korea

BACKGROUND

Because severe cutaneous adverse reactions (SCARs), such as Stevens-Johnson syndrome (SJS), toxic epidermal necrolysis (TEN), and drug reaction with eosinophilia and systemic symptoms (DRESS) rarely occur, clinical data based on large-scale studies are still lacking.

OBJECTIVE

To provide information on culprit drugs and clinical characteristics, including morbidity and mortality of SCARs based on a nationwide registry.

METHODS

SCAR cases that occurred from 2010 to 2015 were recruited to the Korean SCAR registry from 34 tertiary referral hospitals. Demographics, causative drugs, causality, and clinical outcomes were collected by reviewing the medical record.

RESULTS

A total of 745 SCAR cases (384 SJS/TEN cases and 361 DRESS cases) due to 149 drugs were registered. The main causative drugs were allopurinol (14.0%), carbamazepine (9.5%), vancomycin (4.7%), and antituberculous agents (6.3%). A strong preference for SJS/TEN was observed in carbonic anhydrase inhibitors (100%), nonsteroidal anti-inflammatory drugs (84%), and acetaminophen (83%), whereas dapsone (100%), antituberculous agents (81%), and glycopeptide antibacterials (78%) were more likely to cause DRESS. The mortality rate was 6.6% (SJS/TEN 8.9% and DRESS 4.2%). The median time to death was 19 days and 29 days in SJS/TEN and DRESS respectively, and 89.8% of deaths occurred within 60 days after the onset of the skin symptoms.

CONCLUSION

Allopurinol, carbamazepine, vancomycin, and antituberculous agents were the leading causes of SCARs in Korea. Some drugs preferentially caused a specific phenotype. The mortality rate of SCARs was 6.6%, and most of the deaths occurred within 2 months.

Risk factors for cutaneous reactions to allopurinol in Kinh Vietnamese: results from a case-control study

OBJECTIVE

The aim of this study was to investigate risk factors for cutaneous adverse reactions (CARs) in Kinh Vietnamese.

METHODS

All patients were prospectively recruited in Ho Chi Minh City. Presence of the HLA-B*58:01 allele was determined by real-time PCR-sequence-specific amplification by using the PG5801 Detection Kit (Pharmigene, Taipei). Patients with severe (SCARs) and mild (MCARs) CARs and controls were compared for differences in features prospectively collected, and odds ratios (ORs) with 95% confidence intervals (CIs) were estimated.

RESULTS

On comparing 32 patients with SCARs and 395 tolerant controls, we identified eight strong risk factors: increased age (OR 15.1 [95% CI 5.8-40.1], P < 0.0001), female sex (OR 333 [40-43,453], P < 0.0001), allopurinol for asymptomatic hyperuricemia (OR 955 [120-125,847], P < 0.0001), allopurinol starting dose > 150 mg (OR 316 [101-122], P < 0.0001), diuretics intake (OR 304 [35-40,018], P < 0.0001), eGFR < 60 ml/min/1.73 m² (OR 100 [32-353], P < 0.0001), history of allopurinol-induced skin reaction (OR 78 [6-10,808], P = 0.004), and HLA-B*58:01 carriage (OR 147 [45-746], P < 0.0001). HLA-B*58:01 allele frequency in controls was 7.3%. For MCARs (n = 74), risk factors were eGFR < 60 ml/min/1.73 m² (OR 4.9 [1.61-14.6], P = 0.006), history of allopurinol-induced skin reaction (OR 27 [2-3777], P = 0.01), and asymptomatic hyperuricemia (OR 27 [2-3777], P = 0.01).

CONCLUSION

This study confirmed 8 risk factors, including HLA-B*58:01, for SCARs and identified 3 risk factors for MCARs in Kinh Vietnamese. HLA-B*58:01 genotyping could guide the indication for allopurinol in Kinh Vietnamese patients with gout.

The Journal of Allergy and Clinical Immunology: In Practice 2019 Highlights

This article provides highlights of the clinically impactful original studies and reviews published in The Journal of Allergy and Clinical Immunology: In Practice in 2019 on the subjects of anaphylaxis, asthma, dermatitis, drug allergy, food allergy, immunodeficiency, immunotherapy, rhinitis/sinusitis, and urticaria/angioedema/mast cell disorders. Within each topic, practical aspects of diagnosis and management are emphasized. Treatments discussed include lifestyle modifications, allergen avoidance therapy, positive and negative effects of pharmacologic therapy, and various forms of immunologic and desensitization management. We designed this review to help readers consolidate and use this extensive and practical knowledge for the benefit of their patients.