Research on Susceptible Genes and Immunological Pathogenesis of Cutaneous Adverse Drug Reactions in Chinese Hans

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.

Association between the HLA-B*1502 gene and mild maculopapular exanthema induced by antiepileptic drugs in Northwest China

BACKGROUND

The relationship between the HLA-B*1502 gene and maculopapular exanthema (MPE) induced by antiepileptic drugs (AEDs) has not yet been elucidated. In this study, we investigated the association between AED-induced MPE (AED-MPE) and the HLA-B*1502 gene in patients in Northwest China.

METHODS

We enrolled 165 subjects including nine patients with AED-MPE and 156 AED-tolerant patients as controls. HLA-B*1502 gene polymorphism was detected using digital fluorescence molecular hybridization (DFMH). The results of HLA genotyping were expressed as positive or negative for the HLA-B*1502 allele. An analysis of AED-MPE risk factors was performed using binary logistic regression, and differences in genotype frequencies between groups were assessed with the continuity correction chi-square test.

RESULTS

We found that the HLA-B*1502 gene was a risk factor for AED-MPE (P = 0.028). The incidence of MPE induced by the two types of AEDs was different, and the incidence of aromatic AEDs use was higher that of non-aromatic AEDs use (P = 0.025). The comparison of the gene frequencies of the HLA-B*1502 allele between the two groups taking aromatic AEDs was also statistically significant (P = 0.045). However, there were no significant differences in terms of age, gender, ethnicity, or region in patients with MPE induced by AEDs. In addition, no association between the HLA-B1502 allele and CBZ- or OXC-induced MPE was found.

CONCLUSIONS

In northwestern China, the HLA-B*1502 allele was associated with aromatic AED-MPE. Since MPE can develop into Stevens-Johnson syndrome (SJS) or toxic epidermal necrolysis (TEN), the HLA-B*1502 gene should be evaluated before administering AEDs.

HLA-B*58:01 screening to prevent allopurinol-induced severe cutaneous adverse reactions in Chinese patients with chronic kidney disease

Human leukocyte antigen (HLA)-B*58:01 allele is a significant risk factor for allopurinol-induced severe cutaneous adverse reactions (SCARs) which is potentially fatal. In some studies, chronic kidney disease (CKD) was also implicated to compound the risk of SCARs. We aim to investigate if pre-treatment HLA-B*58:01 screening can prevent allopurinol-induced SCARs in Chinese patients with CKD and its cost-effectiveness. We prospectively recruited Chinese CKD patients who required allopurinol during 2011-2015 and performed pre-treatment HLA testing (HLA screening group). Patients tested positive for HLA-B*58:01 were refrained from allopurinol while those tested negative were prescribed allopurinol. The incidence of SCARs in the HLA screening group was compared with the historical control in previous 5 years and the cost-effectiveness of HLA testing was analyzed. In the historical control (2006-2010), 3605 patients on allopurinol were screened, 22 out of 1027 (2.14%) CKD Chinese patients newly started on allopurinol developed SCARs, including 6 SJS/TEN. In the HLA screening group, 28 out of 192 patients (14.6%) tested HLA-B*58:01 positive were advised to avoid allopurinol; 156 out of 164 HLA-B*58:01-negative patients received allopurinol and none developed SCARs. The incidence rate of SCARs was significantly lower in the HLA screening group compared with controls (0% vs 2.14% respectively, p = 0.037*). The targeted HLA screening approach was associated with lower healthcare costs compared with no HLA screening (US$ 92,430 vs US$ 281,226). Pre-treatment HLA-B*58:01 screening is cost-effective to target on patients with CKD in Chinese to prevent allopurinol-induced SCARs.

Trends in the characteristics of vitrectomy in Eastern China

BACKGROUND

Several new instruments and techniques for pars plana vitrectomy (PPV) have been widely used in recent years, but information about the related characteristics of PPV in China is limited. To investigate the trends in the characteristics of PPV in Eastern China, an 8-year retrospective study was conducted.

PATIENTS AND METHODS

We collected data from patients who underwent PPV at the Eye, Ear, Nose and Throat Hospital of Fudan University, Shanghai, China, in November 2007, November 2011, and November 2015. Cases of trauma-related retinopathy were excluded. Data on the patient demographics, surgical procedures, and the prophylactic use of IOP-lowering medications were collected and analyzed.

RESULTS

In 2015, most PPVs were conducted with a 23-gauge system, whereas all PPVs in 2007 and 2011 were conducted with a 20-gauge system. The proportions of macular disease in the population in 2007, 2011, and 2015 were 9.1%, 10.7%, and 21.5%, respectively (P<0.001). The proportion of PPV that was combined with lens extraction and intraocular lens (IOL) implantation increased significantly from 12.81% in 2007 to 25.95% by 2015 (P<0.001). The proportions of patients treated with IOP-lowering drugs in 2007, 2011, and 2015 were 27.40%, 38.20%, and 12.60%, respectively (P<0.001). In 2007, systemic carbonic anhydrase inhibitors (CAI-Ss) and beta blockers (BBs) were the two main types of prophylactic IOP-lowering drugs administered, but their use had decreased in 2015 (P<0.001). The preventive use of adrenergic agonists (AAs), topical carbonic anhydrase inhibitors (CAI-Ts), and prostaglandin analogs (PGAs) became increasingly frequent from 2007 to 2015 (P<0.05).

CONCLUSION

The 23-gauge system, rather than the 20-gauge system, had become the mainstream PPV instrument by 2015. The proportion of macular disease patients requiring PPV in China clearly increased, and the rate of prophylactic IOP-lowering drug use decreased by 2015.

Association between HLA-B*5901 and methazolamide-induced Stevens-Johnson syndrome/toxic epidermal necrolysis: a systematic review and meta-analysis

Methazolamide-induced Stevens-Johnson syndrome and toxic epidermal necrolysis (SJS/TEN) are life-threatening adverse drug reactions. Based on previous studies, HLA genotypes may play an important role in methazolamide-induced SJS/TEN. Therefore, to identify the associations between HLA genotypes and methazolamide-induced cutaneous adverse drug reactions (cADRs) (i.e., SJS/TEN and hypersensitivity syndrome), a systematic review and meta-analysis were performed. Two studies (one study in Korean and another in Han Chinese) met the inclusion criteria. The studies included 13 patients with methazolamide-induced SJS/TEN, 30 methazolamide-tolerant, and 768 population controls. Associations between HLA-B*5901, HLA-B*5901-Cw*0102 haplotype, and methazolamide-induced SJS/TEN were identified in methazolamide-tolerant and population controls. Overall ORs were 305.0 (95% CI = 11.3-8, 259.4) in methazolamide-tolerant and 715.3 (95% CI = 83.1-6,158.5) in population control. In addition, statistically significant associations between the HLA-Cw*0102 and methazolamide-induced SJS/TEN were found in methazolamide-tolerant (OR = 12.1; 95% CI = 1.3-111.7) and population control (OR = 17.5; 95% CI = 3.2-96.6). Since HLA-B*5901 and HLA-B*5901-Cw*0102 haplotype are associated with methazolamide-induced SJS/TEN, genetic screening prior to methazolamide therapy in Asian populations is warranted.

Association between the HLA-B alleles and carbamazepine-induced SJS/TEN: A meta-analysis

PURPOSE

From our current understanding, the association between the human leukocyte antigen (HLA), HLA-B*1502, and carbamazepine(CBZ)-induced Stevens-Jonson syndrome and toxic epidermal necrolysis (SJS/TEN) in the Asian population is quite clear. However the relationship between other HLA-B alleles and CBZ-induced severe cutaneous adverse drug reactions (SCADRs) remains unclear. We aimed to identify other non-HLA-B*1502 alleles in patients with CBZ-induced SCADRs through a meta-analysis.

MATERIALS AND METHODS

A thorough literature search was performed using Embase, PubMed, Web of Knowledge and Cochrane databases. A meta-analysis was performed from their inceptions to May 31, 2016. Studies investigating the association of HLA-B alleles and CBZ-induced SJS/TEN were retrieved. Two reviewers independently extracted the data. Overall odds ratios (ORs) with corresponding 95% confidence intervals (CIs) were calculated using the RevMan 5.3 software.

RESULTS

A total of 11 studies met the inclusion criteria, totaling 343 CBZ-induced SJS/TEN cases, 838 CBZ tolerant controls, and 978 population controls. We observed HLA-B*1511 as a risk marker, and HLA-B*4001 and HLA-B*4601 as protective markers for the development of SJS/TEN in patients taking CBZ. SJS/TEN cases were found to be significantly associated with HLA-B*1511 in both the tolerant group (OR=17.43;95%CI=3.12-97.41;P=0.001) and the population-control group (OR=11.11; 95%CI=2.62-47.09; P=0.001). The sensitivity analysis found that HLA-B*5801 was a protective marker in the Southeast Asian population (OR=0.23; 95%CI=0.09-0.58; P=0.002).

CONCLUSION

Our study demonstrated that in the Asian population, HLA-B*4001, HLA-B*4601, HLA-B*5801 were strong protective factors in the development of CBZ-induced SJS/TEN whereas HLA-B*1511 was a risk factor. While more studies may be needed in order to confirm these findings, consideration should be taken into testing Asian patients for at-risk alleles prior to CBZ therapy initiation.

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.

Approach to the Patient with a Suspected Cutaneous Adverse Drug Reaction

CADRs are common and generally have a mild, self-resolving course with minimal associated morbidity and mortality. However, subsets of CARDs are more severe, require intervention, and have significant risk of associated morbidity and mortality. For this reason, it is crucial that the clinician recognize signs and symptoms worrisome for a more severe CARD so that appropriate triage, work-up, and treatment are initiated. In all CADRs the most important first step is identification and withdrawal of the culprit medications.