Unique motif shared by HLA-B*59:01 and HLA-B*55:02 is associated with methazolamide-induced Stevens-Johnson syndrome and toxic epidermal necrolysis in Han Chinese

BACKGROUND

Methazolamide (MTZ) has been occasionally linked to the lethal Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN), which are associated with HLA-B*59:01. However, some MTZ-induced SJS/TEN (MTZ-SJS/TEN) cases are negative for HLA-B*59:01, implying that other genetic factors besides HLA-B*59:01 are contributing to MTZ-SJS/TEN.

OBJECTIVES

To comprehensively identify HLA and non-HLA genetic susceptibility to MTZ-SJS/TEN in Han Chinese.

METHODS

Eighteen patients with MTZ-SJS/TEN, 806 subjects of the population control and 74 MTZ-tolerant individuals were enrolled in this study. Both exome-wide and HLA-based association studies were conducted. Molecular docking analysis was employed to simulate the interactions between MTZ and risk HLA proteins.

RESULTS

We found a strong signal in the major histocompatibility complex region on chromosome 6 with 22 SNPs reaching exome-wide significance. Compared with MTZ-tolerant controls, a significant association of HLA-B*59:01 with MTZ-SJS/TEN was validated (odds ratio [OR] = 146.00, 95% confidence interval [CI]: 16.12-1321.98; P = 6.19 × 10^-10 ). Moreover, 66.7% of MTZ-SJS/TEN patients negative for HLA-B*59:01 were carriers of HLA-B*55:02, while 2.7% of the tolerant individuals were observed with HLA-B*55:02 (OR = 71.00, 95% CI: 7.84-643.10; P = 1.43 × 10^-4 ). Within HLA-B protein, the E45-L116 motif could completely explain the association of HLA-B*59:01 and HLA-B*55:02 with MTZ-SJS/TEN (OR = 119.33, 95% CI: 29.19-1227.96; P = 4.36 × 10^-13 ). Molecular docking analysis indicated that MTZ binds more stably to the pocket of HLA-B*59:01 and HLA-B*55:02 than to that of non-risk alleles of HLA-B*40:01 and HLA-C*01:02.

CONCLUSIONS

This study confirmed the association of HLA-B*59:01 with MTZ-SJS/TEN and identified HLA-B*55:02 as a novel risk allele in Han Chinese with the largest sample size to date. Notably, the rs41562914(A)-rs12697944(A) haplotype, encoding E45-L116, is capable of serving as a powerful genetic predictor for MTZ-SJS/TEN with a sensitivity of 89% and specificity of 96%.

A case report of toxic epidermal necrolysis (TEN) in a patient with COVID-19 treated with hydroxychloroquine: are these two partners in crime?

BACKGROUND

Stevens-Johnson Syndrome/Toxic Epidermal Necrolysis (SJS/TEN) is the most Serious Cutaneous Adverse Reaction (SCAR) often with a fatal outcome. Coronavirus Disease (COVID-19) is caused by Severe Acute Respiratory Syndrome-Coronavirus-2 (SARS-COV2) and is an emergent pandemic for which no cure exist at the moment. Several drugs have been tried often with scant clinical evidence and safety.

CASE PRESENTATION

Here we report the case of 78-years-old woman with cardiometabolic syndrome and COVID-19. A multidrug regimen including others hydroxychloroquine, antibiotics, dexamethasone and paracetamol, low-molecular-weight-heparin and potassium canrenoate was started. After almost 3 weeks, the patient started to display a violaceous rash initially involving the flexural folds atypical targetoid lesions and showing a very fast extension, blister formation and skin detachments of approximately 70% of the total body surface area and mucous membranes involvement consistent with toxic epidermal necrolysis (TEN). The ALDEN algorithm was calculated inserting all drugs given to the patient in the 28 days preceding the onset of the skin manifestations. The highest score retrieved was for hydroxychloroquine. Other less suspicious drugs were piperacillin/tazobactam, ceftriaxone and levofloxacin.

CONCLUSIONS

To our knowledge, this is the first case of TEN in a patient suffering from COVID-19 probably associated with hydroxychloroquine. Given the activation of the immune system syndrome induced by the virus and the widespread off-label use of this drug, we suggest a careful monitoring of skin and mucous membranes in all COVID-19 positive patients treated with hydroxychloroquine in order to early detect early signs of toxicities.

Association of cutaneous adverse drug reactions due to antiepileptic drugs with HLA alleles in a North Indian population

PURPOSE

Aromatic antiepileptic drugs (AEDs) are frequently implicated in cutaneous adverse drug reactions (cADRs), a few of which are associated with certain human leukocyte antigen (HLA) alleles in some populations. We aimed to find HLA-associations with AED-related cADRs among North Indians.

METHODS

North Indian subjects with cADR due to an AED, and those who were AED-tolerant were recruited as cases and controls, respectively. Genotyping for HLA-A, B and DRB1 were performed. Statistical analysis to compare carrier-rates and allele-frequencies between cases and controls (and healthy population, where necessary), was done for HLA-alleles occurring more than twice in either group.

RESULTS

120 cases {11 - Lamotrigine (LTG), 14 -Valproic acid (VPA), 8 -Levetiracetam (LEV), 35 -Carbamazepine (CBZ) and 52 - Phenytoin (PHT)}, and 250 controls were recruited. Presence of HLA-A*31:01 and HLA-B*51:01 were found to increase the risk of Maculopapular exanthema (MPE) due to CBZ and PHT (OR = 6.38; 95% CI: 1.46-27.75; OR = 4.60; 95% CI: 1.54-13.72, respectively). Among the severe cADRs, HLA-B*57:01(OR = 11.00 95% CI: 1.41-85.81) and HLA-DRB1*07:01 (OR = 7.25; 95% CI: 1.09-48.18) were noted to be significantly associated with CBZ-induced Stevens Johnson Syndrome (SJS)/Toxic Epidermal Necrolysis (TEN); HLA-B *51:01 was associated with drug reaction eosinophilia and systemic symptoms (DRESS) caused by PHT (OR = 6.90; 95% CI: 1.38-34.29).

CONCLUSIONS

We found significant associations of some HLA alleles with specific cADRs to CBZ and PHT in North Indians, which may need to be tested before AED-initiation; only screening for HLA-B*15:02 may not help in this population.

Epidermal exfoliation of over 95% after a burn in an 18-month-old boy: Case report and review of the literature

This report concerns an 18-month-old boy who presented with a 6% total body surface area scald. The subject of this report is unique in that he developed the largest exfoliation described in literature. After 3 days an epidermal exfoliation with the appearance of a deliberately inflicted scald developed. As the exfoliation progressed to over 95% total body surface area the suspicion of child abuse or neglect could be abandoned. The diagnosis Staphylococcal scalded skin syndrome was set, due to the finding of Staphylococcus aureus on swabs, the lack of mucosal engagement, and the patient's age. The boy's skin healed within 3 weeks. The few reports published are all case reports and most frequently described visually infected burns with smaller epidermal exfoliations, and clinically based exfoliation diagnosis. S. aureus often cause burn wound infections that can lead to complications caused by cross-infection. It is important for burn surgeons and intensive care specialists to be aware of the increased possibility of Staphylococcal scalded skin syndrome occurring in patients who have a reduced barrier to infection such as burn patients and also, that the diagnosis can be difficult to make.