DNA methylation of ITGB2 contributes to allopurinol hypersensitivity.

BACKGROUNDS: HLA-B*58:01 allele was strongly associated with allopurinol induced severe cutaneous adverse drug reaction (SCAR). However, HLA-B genotype is not sufficient to predict the occurrence of allopurinol-induced SCAR. OBJECTIVE: To discover DNA methylation markers for allopurinol-induced SCAR which may improve the prediction accuracy of genetic testing. STUDY DESIGN: The study was designed as a retrospective case-control clinical study in multicenter hospitals across Taiwan, Mainland China, Malaysia and Canada. 125 cases of allopurinol-induced SCAR patients and 139 cases of allopurinol tolerant controls were enrolled in this study during 2005 to 2021. RESULTS: The results of genome-wide DNA methylation assay of 62 patients revealed that ITGB2 showed strong discriminative ability of allopurinol-induced SCAR in both HLA-B*58:01 positive and negative patients with AUC value of 0.9364 (95% CI 0.8682-1.000). In validation study, significant hypermethylation of ITGB2 were further validated in allopurinol-induced SCAR patients compared to tolerant controls, especially in those without HLA-B*58:01(AUC value of 0.8814 (95% CI 0.7121-1.000)). Additionally, the methylation levels of 2 sites on ITGB2 were associated with SCAR phenotypes. Combination of HLA-B*58:01 genotyping and ITGB2 methylation status could improve the prediction accuracy of allopurinol-induced SCAR with the AUC value up to 0.9387 (95% CI 0.9089-0.9684), while the AUC value of HLA-B*58:01 genotyping alone was 0.8557 (95% CI 0.8030-0.9083). CONCLUSIONS: Our study uncovers differentially methylated genes between allopurinol-induced SCAR patients and tolerant controls with positive or negative HLA-B*58:01 allele and provides the novel epigenetic marker that improves the prediction accuracy of genetic testing for prevention of allopurinol-induced SCAR.

Extensive cutaneous iatrogenic Kaposi's sarcoma after bullous pemphigoid treatment with oral methylprednisolone: a rare Chinese case report.

Bullous pemphigoid (BP) is an autoimmune disease that requires immunosuppressive therapy. Systemic corticosteroids are considered the standard treatment for moderate-to-severe BP. Kaposi's sarcoma (KS) is a rare multifocal endothelial tumour that affects the skin, mucosa and viscera. As an angioproliferative disease of obscure aetiopathogenesis and histogenesis, KS is associated with human herpesvirus 8 (HHV-8). This current case report describes a rare occurrence of extensive cutaneous KS in a 60-year-old Chinese male patient after oral methylprednisolone treatment for BP with an emphasis on its pathological characterization. A total of more than 40 nodules were found on his trunk and lower limbs covering more than 20% of his body surface area. Immunohistochemical staining of biopsy samples from the lesion showed the patient was positive for HHV-8, CD31, CD34, XIIIa, ERG and Ki-67. The Epstein-Barr virus test showed the patient tested negative for immunoglobulin (Ig)A and IgM, but was positive for IgG. Immunosuppression associated with the treatment for BP may activate a latent HHV-8 infection and induce the development of KS.

HLA-A*02:07 Allele Associates with Clarithromycin-Induced Cutaneous Adverse Drug Reactions in Chinese Patients.

Genetic risk factors could cause cutaneous adverse drug reactions (cADRs) in patients after treatment with clarithromycin. This study explored the association of HLA class I genes with clarithromycin-cADRs in Han Chinese patients. A total of 12 clarithromycin-cADR patients and 34 clarithromycin-tolerant controls were recruited for the high-resolution genotyping of HLA class I genes (HLA-A, HLA-B and HLA-C). The population controls consisted of 283 Han Chinese retrieved from the MHC database for validated comparison. A molecular docking analysis of HLA-A*02:07 protein and clarithromycin was conducted using glide module with Schrödinger Suite. Among all tested HLA alleles, the carrier frequencies of HLA-A*02:07 (58% versus 5.9%, OR = 22.40, 95% CI = 3.58-139.98, p = 8.20 × 10E-5, pc = 1.1 × 10E-3) and HLA-B*46:01 (50% versus 5.9%, OR = 16.00, 95% CI = 2.59-98.99, p = 0.002, pc = 0.03) were significantly higher in clarithromycin-cADRs than in clarithromycin-tolerant controls. However, when compared to population controls, only HLA-A*02:07, and not HLA-B*46:01, reached statistical significance (58% versus 15.5%, OR = 7.61, 95% CI = 2.31-25.04, p = 1.2 × 10E-4, pc = 1.7 × 10E-3). Furthermore, molecular docking data revealed that clarithromycin could bind to and interact with HLA-A*02:07 in two possible binding situations. These data suggest that HLA-A*02:07 might be a genetic risk factor for developing clarithromycin-cADRs in Han Chinese and serve as a useful biomarker for personalized medicine to prevent clarithromycin-cADRs.

A correlation study on the effects of DNMT1 on methylation levels in CD4(+) T cells of SLE patients.

OBJECTIVE: To study the effect of DNMT1 on CD4(+) T cells in the peripheral blood of systemic lupus erythematosus (SLE) patients. METHODS: To investigate the differential expression of DNMT1 in CD4(+) T cells of SLE patients and healthy individuals, a DNMT1 lentiviral plasmid (pLenti6.3/V5-DNMT1) and a control plasmid (pLenti6.3/V5-GW/LacZ) were constructed and transfected into CD4(+) T cells from the peripheral blood of SLE patients. The transcriptional and translational expression of DNMT1, global genomic DNA methylation, and the production of IgG antibody in the CD4(+) T cells in the peripheral blood of SLE patients were assessed using qPCR analysis, western blotting, flow cytometry, and ELISA, respectively. RESULTS: The expression level of DNMT1 in SLE patients was significantly lower than that in normal humans. The expression of DNMT1 was found to be positively correlated with the methylation level of genomic DNA and negatively correlated with the IgG titration level. DNA sequencing results confirmed that the DNMT1 lentiviral plasmid was successfully constructed. After the CD4(+) T cells from the peripheral blood of SLE patients were transfected with the pLenti6.3/V5-DNMT1 plasmid, the transcription level of the DNMT1 gene was upregulated and abundance of DNMT1 protein significantly increased. Global genomic DNA methylation was enhanced, while the production of IgG antibody was reduced. CONCLUSION: DNMT1 can inhibit the autoimmune response in SLE patients by reversing the abnormally low DNA methylation level in the CD4(+) T cells.

Toxic epidermal necrolysis: performance of SCORTEN and the score-based comparison of the efficacy of corticosteroid therapy and intravenous immunoglobulin combined therapy in China.

Toxic epidermal necrolysis (TEN) represents the most severe drug-related skin condition that is potentially life-threatening with no well-established treatments. The application of corticosteroid therapy is controversial, whereas recently intravenous immunoglobulin (IVIG) therapy is emerging as a promising new method. A severity-of-illness score for TEN (SCORTEN) has gained acceptance in some western countries. In this study, our objectives were to assess the applicability of SCORTEN in Chinese patients with TEN and to evaluate the efficacy of the combination therapy of IVIG and corticosteroid in these patients. We performed a retrospective review of data from 61 patients with TEN treated at our intensive care unit from 2000 to 2010 to assess the performance of SCORTEN. In particular, 55 patients between 2002 and 2010 were grouped as a series to compare the therapeutic effects of corticosteroid therapy and IVIG combined therapy contemporaneously. During this period, 16 patients were administered with corticosteroid therapy and 39 were treated with the combination therapy. An initial dose of 1.5 mg/kg/day of methylprednisolone was given to all TEN patients. The combination therapy was combined with a total dose of 2 g/kg IVIG within 5 days. Areas under receiver operating characteristic curves and Hosmer-Lemeshow statistic were analyzed to illustrate the performance of SCORTEN. The comparison of the efficacy of the two therapies was conducted on the basis of clinical outcomes, standardized mortality ratio (SMR), and survival analysis. The overall actual mortality of patients between 2000 and 2010 was 16% (10/61), statistically insignificantly lower than predicted (24%, SMR = 67.98). Excellent discriminatory power (the areas under the receiver operating characteristic curves: 88.9, 88.2, 90.6%) and good calibration (P = .637, .833, .530) were found in all the groups. In patients admitted between 2002 and 2010, IVIG combined therapy showed a trend toward reducing the mortality rate (13%, SMR = 52.35), whereas corticosteroid monotherapy suggested no such difference (31%, SMR = 123.92). Besides, the cumulative survival rates of the combination therapy were higher at almost all the levels of SCORTEN (P = .002), especially at the score of 5 (P = 3.10 × 10⁻7). Compared with corticosteroid alone, the combination therapy arrested progression earlier (P = .013), although it did not significantly lead to a tapering of corticosteroid or a reduction of the time of hospitalization. We concluded that SCORTEN was generally applicable to Chinese patients with TEN. The comparison of the effect indicated that the combination therapy might achieve a better therapeutic effect than the administration of corticosteroid alone, especially in severe TEN patients.

HLA-B*58:01 allele is associated with augmented risk for both mild and severe cutaneous adverse reactions induced by allopurinol in Han Chinese.

AIM: Allopurinol is widely used as an effective urate-lowering drug and is one of the most frequent causes of cutaneous adverse drug reactions (cADRs). Recently, a strong association of HLA-B*58:01 with allopurinol-induced severe cADRs was identified. This study investigated the predisposition to different types of allopurinol-cADRs conferred by HLA-B*5801 in a Han population from mainland China. PATIENTS & METHODS: HLA-B genotyping was performed on 38 Chinese patients with different types of allopurinol-cADRs from 2008 to 2011. RESULTS: All the allopurinol-cADR patients carried HLA-B*58:01, in contrast with only 11.11% (7/63) in the allopurinol-tolerant patients (odds ratio [OR] = 580.07; p < 0.0001) and 13.99% (80/572) in a Han Chinese population from the human MHC database (dbMHC; OR: 471.09; p < 0.0001) carried the genotype. Each type of allopurinol cADRs revealed a statistically significant association with HLA-B*58:01. In particular, the risk of allopurinol-induced maculopapular eruption was significantly higher in patients with HLA-B*58:01 (OR: 339.00; p < 0.0001). CONCLUSION: The strong association of both the mild and severe types of allopurinol cADRs with the HLA-B*58:01 allele were observed. The results indicated that the prospective use of a genetic test of HLA-B*58:01 might reduce the prevalence of allopurinol-induced cADRs. Original submitted 7 March 2012; Revision submitted 21 May 2012.