Overlapping Stevens-Johnson Syndrome and DRESS Syndrome Caused by Phenobarbital: A Vietnamese Case Report.

Drug Reaction with Eosinophilia and Systemic Symptoms (DRESS) Syndrome and Stevens-Johnson Syndrome (SJS) are severe cutaneous adverse reactions to drugs. Those reactions which are rare in children can be especially severe and challenging to diagnose and manage. Herein we present a 59-month-old male who presented with a rash, fever, and multiple organ dysfunction initiation of Phenobarbital for epilepsy. Diagnosis of ovelaping SJS and DRESS syndrome had been made based on clinical manifestations accompanied with skin biopsy according to RegisSCAR diagnostic criteria. A therapy with intravenous immune globulin (IVIG), corticosteroids and supportive care was given successfully for the patient. This case underscored the significance of promptly and effectively recognizing and managing these intricate reactions.

Genetic susceptibilities and prediction modeling of carbamazepine and allopurinol-induced severe cutaneous adverse reactions in Vietnamese.

Aims: To determine genetic susceptibility markers for carbamazepine (CBZ) and allopurinol-induced severe cutaneous adverse reactions (SCARs) in Vietnamese. Methods: A case-control study was performed involving 122 patients with CBZ or allopurinol-induced SCARs and 120 drug tolerant controls. Results:HLA-B*58:01 was strongly associated with allopurinol-induced SCARs and strongly correlated with SNP rs9263726. HLA-B*15:02 was associated with CBZ-induced Stevens-Johnson syndrome/toxic epidermal necrolysis but not with drug-induced hypersensitivity syndrome/drug rash with eosinophilia and systemic symptoms. No association was found between HLA-A*31:01 and CBZ-induced SCARs. HLA-B*58:01 and rs3909184 allele A with renal insufficiency were shown to increase the risk of allopurinol-induced SCARs. Conclusion:HLA-B*58:01 and HLA-B*15:02 confer susceptibility to allopurinol-induced SCARs and CBZ-induced SJS/TEN in Vietnamese. SNP rs9263726 can be used as a surrogate marker in identifying HLA-B*58:01.

Gene expression profiling in allopurinol-induced severe cutaneous adverse reactions in Vietnamese.

Aim: To examine gene expression in different clinical phenotypes of allopurinol-induced severe cutaneous adverse reactions (SCARs). Materials & methods: Gene expression profiling was performed using microarray on 11 RNA samples (four controls, three hypersensitivity syndrome/drug rash with eosinophilia and systemic symptoms, four Stevens-Johnson syndrome/toxic epidermal necrolysis) followed by quantitative real-time PCR in a total of 11 SCARs patients and 11 controls. Results: The biological pathways which were significantly enriched in differentially expressed genes in Stevens-Johnson syndrome/toxic epidermal necrolysis compared with hypersensitivity syndrome/drug rash with eosinophilia and systemic symptoms patients included; cell surface interactions at the vascular wall, immunoregulatory interactions at the immunological synapse and MyD88 signaling pathways. Overexpression of miR146a occurred in allopurinol-tolerant HLA-B*58:01 carriers. Conclusion: Biological pathways are identified which appear to be implicated in determining clinical phenotypes in allopurinol-induced SCARs. Overexpression of miR146a is potentially important for allopurinol tolerance in HLA-B*58:01 carriers.

Successful management of severe diabetic ketoacidosis in a patient with type 2 diabetes with insulin allergy: a case report.

BACKGROUND: Diabetic ketoacidosis (DKA) is an acute, major, life-threatening complication of diabetes that requires immediate treatment. Allergic reaction to insulin is rare, especially when using recombinant human insulin. The clinical presentation of insulin allergy can range from minor local symptoms to a severe generalized allergic reaction such as anaphylaxis. A limited number of cases have been reported on the treatment of severe DKA in patients with type 2 diabetes with insulin allergy. Here, we describe a patient with type 2 diabetes with insulin allergy in which severe DKA resolved after the initiation of continuous intravenous (IV) recombinant human insulin infusion. CASE PRESENTATION: A 58-year-old man with type 2 diabetes initiated subcutaneous insulin administration (SIA) after failure of oral antidiabetic treatment. Symptoms of an allergic reaction developed, including pruritic wheals appearing within 10 min of injection and lasting over 24 h. Both skin prick and intradermal tests were positive with different types of insulin. Two days before admission, he stopped SIA because of allergic symptoms and then experienced weakness and upper abdominal pain. On admission, he was in severe metabolic acidosis with a pH of 6.984 and bicarbonate of 2.5 mmol/litre. The blood glucose level was 20.79 mmol/litre, BUN 4.01 mmol/litre, creatinine 128 µmol/litre, and urinary ketone 11.44 mmol/litre. Over 24 h, metabolic acidosis was refractory to IV fluids, bicarbonate and potassium replacement, as well as haemodialysis. Ultimately, he received continuous IV recombinant human insulin infusion at a rate of 0.1 units/kg/hour, in combination with haemodiafiltration, and no further allergic reactions were observed. On day 5, ketonaemia and metabolic acidosis completely resolved. He had transitioned from IV insulin infusion to SIA on day 14. He was discharged on day 21 with SIA treatment. Three months later, he had good glycaemic control but still had allergic symptoms at the insulin injection sites. CONCLUSIONS: In this patient, SIA caused an allergic reaction, in contrast to continuous IV insulin infusion for which allergic symptoms did not appear. Continuous IV recombinant human insulin infusion in combination with haemodiafiltration could be an option for the treatment of severe DKA in patients with diabetes with insulin allergy.

Human leukocyte antigen-associated severe cutaneous adverse drug reactions: from bedside to bench and beyond.

Despite their being uncommon, severe cutaneous adverse drug reactions (SCARs) result in a very great burden of disease. These reactions not only carry with them a high mortality (10%-50%) and high morbidity (60%) with severe ocular complications, alopecia, oral and dental complications and development of autoimmune diseases, but also create a substantial economic burden for patients' families and society. SCARs are, therefore, an important medical problem needing a solution in many countries, especially in Asia. The clinical spectrum of SCARs comprises Stevens-Johnson syndrome, toxic epidermal necrolysis, DRESS (drug rash with eosinophilia and systemic symptoms) (also known as drug hypersensitivity syndrome or drug-induced hypersensitivity syndrome) and acute generalised exanthematous pustulosis. Recent crucial advances in determining genetic susceptibility and understanding how T cells recognise certain medications or their metabolites via the major histocompatibility complex and the effects of cofactors, have led to the implementation of cost-effective screening programs enabling prevention in a number of countries, and to further understanding of the patho-mechanisms involved in SCARs and their significance. In this review, we document comprehensively the journey of SCARs from bedside to bench and outline future perspectives in SCARs research.

Developing pharmacogenetic screening methods for an emergent country: Vietnam.

BACKGROUND: The finding of strong associations between certain human leukocyte antigen (HLA) genotypes and the development of severe cutaneous adverse drug reactions (SCARs), [for example, HLA-B*57:01 and abacavir (ABC), HLA-B*15:02 and carbamazepine (CBZ) and HLA-B*58:01 and allopurinol], has led to HLA screening being used to prevent SCARs. Screening has been shown to be of great benefit in a number of studies. Clinical translation from bench to bedside, however, depends upon the development of simple, rapid and cost-effective assays to detect these risk alleles. In highly populated developing countries such as Vietnam, where there is a high prevalence of HLA-B*15:02 and HLA-B*58:01 correlating with a high incidence of CBZ- and allopurinol-induced SCARs, the crucial factor in the implementation of comprehensive screening programs to detect these major risk HLA alleles is the availability of suitable assays. BODY: We have summarized the role and economic benefits of HLA screening, reviewed published HLA screening methods used currently in pharmacogenetic screening and examined the advantages and disadvantages of assays developed specifically for use in screening for risk alleles in the prevention of HLA-associated SCARs in Vietnam. CONCLUSION: The optimal approach we propose may serve as a template for the development of screening programs in other emergent countries.

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.

Validation of a novel real-time PCR assay for detection of HLA-B*15:02 allele for prevention of carbamazepine - Induced Stevens-Johnson syndrome/Toxic Epidermal Necrolysis in individuals of Asian ancestry.

OBJECTIVES: Screening for the HLA-B*15:02 allele has been recommended to prevent carbamazepine (CBZ) - induced Stevens-Johnson syndrome (SJS) and Toxic Epidermal Necrolysis (TEN) in individuals with Asian ancestry. We aimed, therefore, to develop and validate a robust and inexpensive method for detection of the HLA-B*15:02 allele. METHODS: Real-time PCR using TaqMan® probes followed by SYBR® Green was used to detect the HLA-B*15:02 allele prior to treatment with CBZ therapy. RESULTS: A total of 121 samples were tested. The assay has a sensitivity of 100% (95% CI: 76.84-100.0%), a specificity of 100% (95% CI: 96.61-100%), a positive predictive value of 100% (95% CI: 76.84-100%) and a negative predictive value of 100.0% (95% CI: 96.61-100.0%), respectively. There was 100% agreement between our results and genotyping using Luminex SSO/SBT/SSP. The lowest limit of detection of the TaqMan® probe is 0.05ng/µl and the SYBR® Green is 0.5ng/µl of DNA. The unit cost of using the TaqMan® probe followed by SYBR® Green is only $4.7 USD. CONCLUSION: We developed a novel assay for the detection of the HLA-B*15:02 allele, which is robust, inexpensive and suitable for screening individuals of Asian ancestry in the prevention of CBZ-induced SJS/TEN.

HLA-B*1502 and carbamazepine-induced severe cutaneous adverse drug reactions in Vietnamese.

BACKGROUND: In Vietnam, we observed a high incidence of carbamazepine (CBZ)-induced severe cutaneous adverse drug reactions (SCARs)-Stevens-Johnson syndrome (SJS)/toxic epidermal necrolysis (TEN), and drug-induced hypersensitivity rash with eosinophilia and systemic symptoms (DRESS). In other Asian countries, HLA-B(*)1502 is an established risk factor for SCARs. OBJECTIVE: The aim of our study was to determine the frequency of HLA-B(*)1502 in SCARs patients at a large University Medical Center in Hanoi, Vietnam. METHODS: Thirty-eight cases of SCARs caused by CBZ and 25 patients with epilepsy tolerating CBZ were enrolled in a case-controlled study. Clinical manifestations and laboratory findings were recorded for each subject. Genomic DNA was isolated using the QIAamp DNA purification system. The combination of polymerase chain reaction and sequence specific oligonucleotide probes with the Luminex 100×MAP flow cytometry dual laser system was then used to quantitate fluorescently labelled oligonucleotides attached to colour-coded microbeads. RESULTS: Cases comprised 20 SJS (52.6%), 7 TEN (18.4%), 8 overlap syndrome (21.1%), and 3 DRESS patients (7.9%). A strong association between HLA B(*)1502 and bullous skin reactions such as SJS/TEN and overlap was confirmed with an odds ratio (OR) of 33.78 (95% confidence interval [CI], 7.55-151.03), p < 0.0001, Sensitivity 91.4%, Specificity 76.0%, positive predictive value 84.2%, and negative predictive value 86.4%. We did not, however, observe any correlation between the presence of this allele and CBZ-induced nonbullous skin reactions (DRESS) (OR, 6.33; 95% CI, 0.48-82.74; p = 0.1592). CONCLUSION: Our results indicate the presence of HLA-B(*)1502 in Vietnamese is a pharmacogenetic risk factor for developing CBZ-induced SJS/TEN.