OBJECTIVE: We aimed to investigate the genetic predisposition of co-trimoxazole-induced SCAR.
METHODS: We conducted a multicountry case-control association study that included 151 patients with of co-trimoxazole-induced SCAR and 4631 population controls from Taiwan, Thailand, and Malaysia, as well as 138 tolerant controls from Taiwan. Whole-genome sequencing was performed for the patients and population controls from Taiwan; it further validated the results from Thailand and Malaysia.
RESULTS: The whole-genome sequencing study (43 case patients vs 507 controls) discovered that the single-nucleotide polymorphism rs41554616, which is located between the HLA-B and MICA loci, had the strongest association with co-trimoxazole-induced SCAR (P = 8.2 × 10-9; odds ratio [OR] = 7.7). There were weak associations of variants in co-trimoxazole-related metabolizing enzymes (CYP2D6, GSTP1, GCLC, N-acetyltransferase [NAT2], and CYP2C8). A replication study using HLA genotyping revealed that HLA-B∗13:01 was strongly associated with co-trimoxazole-induced SCAR (the combined sample comprised 91 case patients vs 2545 controls [P = 7.2 × 10-21; OR = 8.7]). A strong HLA association was also observed in the case patients from Thailand (P = 3.2 × 10-5; OR = 3.6) and Malaysia (P = .002; OR = 12.8), respectively. A meta-analysis and phenotype stratification study further indicated a strong association between HLA-B∗13:01 and co-trimoxazole-induced drug reaction with eosinophilia and systemic symptoms (P = 4.2 × 10-23; OR = 40.1).
CONCLUSION: This study identified HLA-B∗13:01 as an important genetic factor associated with co-trimoxazole-induced SCAR in Asians.
METHODS: This qualitative study used in-depth interviews and focus group discussions to obtain information from patients with gout under follow-up in primary care and doctors who cared for them. Patients and doctors shared their gout management experiences and views on implementing HLA-B*58:01 screening in primary care. Data were coded and analysed using thematic analysis.
RESULTS: 18 patients and 18 doctors from three different healthcare settings (university hospital, public health clinics, private general practitioner clinics) participated. The acceptability to HLA-B*58:01 screening was good among the doctors and patients. We discovered inadequate disclosure of severe side effects of allopurinol by doctors due to concerns about medication refusal by patients, which could potentially be improved by introducing HLA-B*58:01 testing. Barriers to implementation included out-of-pocket costs for patients, the cost-effectiveness of this implementation, lack of established alternative treatment pathway besides allopurinol, counselling burden and concern about genetic data security. Our participants preferred targeted screening for high-risk populations instead of universal screening.
CONCLUSION: Implementing HLA-B*58:01 testing in primary care is potentially feasible if a cost-effective, targeted screening policy on high-risk groups can be developed. A clear treatment pathway for patients who test positive should be made available.
METHODS: We performed a case-control association study by genotyping the HLA-B alleles of 55 patients with AIS [11 toxic epidermal necrolysis (TEN), 21 Steven Johnson syndrome (SJS) 22 drug reaction wit eosinophilia and systemic symptoms (DRESS) and one acute generalized exanthematous pustulosis (AGEP)] and 42 allopurinol-tolerant controls (ATC).
RESULTS: HLA-B*58:01 was positive in 89.1 and 14.3% of the AIS and ATC study groups [odds ratio (OR) = 49.0, 95% confidence interval (CI) = 14.6-164.4, P < 0.0001)], respectively. Our data showed that 93.8% of the AIS-SJS/TEN patients and 86.4% of the AIS-DRESS patients were HLA-B*58:01 positive (AIS-SJS/TEN, OR = 90, 95% CI = 16.9-470.1, P < 0.0001 and AIS-DRESS OR = 38, 95% CI = 8.5-169.2, P < 0.0001). Stratification by ethnicity and clinical phenotypes revealed a significant increased risk between HLA-B*58:01 and Chinese-AIS patients (OR = 137.5, 95% CI = 11.3-1680.2, P < 0.0001), in particular Chinese patients with AIS-SJS/TEN phenotype (100% HLA-B*58:01 positive). HLA-B*58:01 was positive in 90.9% Chinese AIS-DRESS (P < 0.0001). Highly significant associations of HLA-B*58:01 were observed in Malay AIS-SJS/TEN (OR = 78, 95% CI = 9.8-619.9, P < 0.0001) and Malay AIS-DRESS (OR = 54, 95% CI = 6.6-442.9, P < 0.0001). Although the number of Indian-AIS patients was relatively small (n = 2), both were HLA-B*58:01 positive.
CONCLUSION: Our data suggest strong associations between HLA-B*58:01 and AIS in Malaysian population with Chinese and Malays ethnicity. The strong association was also observed in three different clinical phenotypes of AIS, mainly the AIS-SJS/TEN.
METHODS: DNA was extracted from eighty-six patients. The patients were genotyped by AS-PCR. Computational modeling of the HLA-B*15:02 followed by docking studies were performed to screen 26 AEDs that may induce ADR among HLA-B*15:02 carriers.
RESULTS: Odd ratio for CBZ induced SJS/TEN and HLA-B*15:02 was 609.0 (95% CI: 23-15873; p=0.0002). Molecular modeling studies showed that acetazolamide, ethosuxiamide, lamotrigine, oxcarbazepine, phenobarbital, phenytoin, primidone and sodium-valproate may induce ADR in HLA-B*15:02 carriers alike CBZ. Conclusion. We confirmed HLA-B*15:02 as a predictor of SJS/TEN and recommend pre-screening. Computational prediction of DIHR is useful in personalized medicine.