HLA-DRB1 gene polymorphism in patients with dilated cardiomyopathy

HLA-DR3 antigen in the resistance to idiopathic dilated cardiomyopathy

Idiopathic dilated cardiomyopathy (IDC) has been hypothesized as a multifactorial disorder initiated by an environment trigger in individuals with predisposing human leukocyte antigen (HLA) alleles. Published data on the association between HLA-DR3 antigen and IDC risk are inconclusive. To derive a more precise estimation of the relationship, a meta-analysis was performed. Studies were identified by searching the PUBMED and Embase database (starting from June 2015). A total of 19 case-control studies including 1378 cases and 10383 controls provided data on the association between HLA-DR3 antigen and genetic susceptibility to IDC. Overall, significantly decreased frequency of HLA-DR3 allele (OR=0.72; 95%CI=0.58-0.90; P=0.004) was found in patients with IDC compared with controls. When stratified by myocardial biopsy or non-biopsy cases, statistically decreased risk was found for IDC in myocardial biopsy cases (OR=0.69; 95%CI=0.57-0.84; P=0.0003). In the subgroup analysis by ethnicity, borderline statistically significantly decreased risk was found among Europeans from 12 case-control studies (OR=0.76; 95%CI=0.58-1.00; P=0.05). In conclusion, our results suggest that individuals with HLA-DR3 antigen may have a protective effect against IDC.

Association of tumor necrosis factor-α gene G-308A polymorphism with dilated cardiomyopathy: a meta-analysis

Published data on the association between tumor necrosis factor-α (TNF-α) G-308A gene polymorphism and dilated cardiomyopathy (DCM) risk are inconclusive. To clarify the association of TNF-α G-308A gene polymorphism and DCM, a meta-analysis of case-control studies was performed. Some databases, such as PubMed and Embase, were searched to indentify related studies. Search terms included dilated cardiomyopathy, tumor necrosis factor-alpha or TNF-α or TNF alpha or tumor necrosis factor alpha, and polymorphism or mutation. Eight case-control studies involving 1487 DCM cases and 1734 normal controls were included in the meta-analysis to assess the purported association between the TNF-α G-308A gene polymorphism and the risk of DCM. A dominant genetic model was used and the comparison of GA/AA genotype versus GG genotype was performed in the present meta-analysis. The odds ratio was 1.42 (95% confidence interval: 1.05, 1.93, P=0.02), manifesting frequency of the TNF-α-308 GA/AA genotype was higher in DCM patients than the control group. TNF-α G-308A nucleotide transition might be associated with the risk of DCM.

Human leukocyte antigen-DQ beta 1 chain (DQB1) gene polymorphisms are associated with dilated cardiomyopathy: a systematic review and meta-analysis

BACKGROUND

Previous studies reported an association between the human leukocyte antigen (HLA)-DQ antigen beta 1 chain (DQB1) alleles and dilated cardiomyopathy (DCM). However, the results of those studies have been inconsistent. To clarify the association between HLA-DQB1 and DCM, we performed a systematic review and meta-analysis of case-control studies.

METHODS

Searches were performed using the PubMed database, the Excerpta Medica Database (EMBASE), the Cochrane Central Register of Controlled Trials database, the Science Citation Index database, the China Biology Medicine disc, the China National Knowledge Information database, the Wanfang database, and the Chinese Scientific and Technological Journal Database (VIP database). The search terms included "dilated cardiomyopathy" and "DQB1." Ten case-controlled studies were included in the systematic review to assess the association between DCM and the HLA-DQB1*0201, *0302, *0504, *0301, and *0602 alleles.

RESULTS

In total, 8 studies were included in the meta-analysis of the HLA-DQB1 *0201 allele. The pooled odds risk (OR) for this allele was .47, with a 95% confidence interval (CI) of .28 to .77 (P < .01). With respect to the HLA-DQB1 *0504 allele, only 3 studies were included in our meta-analysis. The pooled OR was .36 (95% CI, .15 to .84; P < .05). Nine, 8, and 7 studies of the HLA-DQB1 *0301, *0302, and *0602 alleles, respectively, were included in our meta-analysis. No statistically significant difference was evident in the frequency of these 3 alleles between the DCM and normal control groups.

CONCLUSION

The HLA-DQB1 *0201 and *0504 alleles may be protective against DCM.

A meta-analysis of HLA-DR polymorphism and genetic susceptibility to idiopathic dilated cardiomyopathy

Idiopathic dilated cardiomyopathy (IDC) has been hypothesized as a multifactorial disorder initiated by an environment trigger in individuals with predisposing human leukocyte antigen (HLA) alleles. Published data on the association between HLA-DR polymorphism and IDC risk are inconclusive. To derive a more precise estimation of the relationship, a meta-analysis was performed. A total of 19 case-control studies including 1,378 cases and 10,383 controls provided data on the association between HLA-DR polymorphism and genetic susceptibility to IDC. Overall, statistically elevated frequencies of HLA-DR4 (OR 1.58; 95% CI 1.21-2.07; P=0.0009) and HLA-DR5 (OR 1.35; 95% CI 1.05-1.73; P=0.02) alleles were found in patients with IDC compared with controls. Individuals with HLA-DR3 antigen have a protective effect against IDC (OR 0.72; 95% CI 0.58-0.90; P=0.004). In summary, this meta-analysis indicated that certain HLA-DR alleles may be genetic markers for susceptibility and resistance to IDC.

HLA class II polymorphisms in Tunisian patients with dilated cardiomyopathy

Cardiomyopathies (CMs) are primary disorders of cardiac muscle. They are a major cause of morbidity and mortality for all ages and, like acquired forms of cardiovascular disease, often result in heart failure. Molecular genetic studies have made remarkable progress in defining the pathogenesis of CM. The present study was the first report to evaluate the relationship between class II major histocompatibility complex (MHC) genes (HLA-DRB1 and HLA-DQB1) and the genetic susceptibility to primary dilated cardiomyopathy (DCM) in Tunisian patients. The human leukocyte antigen (HLA)-DRB1 and -DQB1 alleles were analyzed in 76 patients with primary DCM and 111 ethnically matched healthy controls using polymerase chain reaction-sequence specific primers technique. An increased frequencies of HLA-DRB1*0401 (OR = 2.67, P < 0.001), HLA-DQB1*0302 (OR = 3.28, P = 0.001) and HLA-DQB1*0401 (OR = 6.26, P = 0.005) alleles were found in the patients with primary DCM compared with healthy controls. Individuals with HLA-DRB1*1301 (OR = 0.24, P < 0.001) and HLA-DQB1*0201 (OR = 0.49, P = 0.002) alleles have a protective effect against primary DCM. Two haplotypes were associated with increased risk of primary DCM: DRB1*0401/DQB1*0302 (OR = 4.53, P = 0.002) and DRB1*0401/DQB1*0401 (OR = 9.42, P = 0.004). In conclusion, our data suggest that the variation in class II HLA alleles could be a genetic factor involved in the susceptibility to primary DCM in the Tunisian population.

Association of HLA class II DRB1, DPA1 and DPB1 polymorphism with genetic susceptibility to idiopathic dilated cardiomyopathy in Chinese Han nationality

Although the aetiology of idiopathic dilated cardiomyopathy (IDC) remains unclear, many immunological abnormalities involving changes in cell-mediated and humoral immunity may be associated with cardiac impairment in IDC. Autoimmune mechanisms are likely to participate in the pathogenesis of at least a subgroup of IDC and components of the major histocompatibility complex may serve as markers for the propensity to develop immune-mediated myocardial damage. Human leukocyte antigen (HLA) class II genes, which are highly polymorphic, play an important role in the activating of immune responses and thus control the predisposition for or protection from IDC. This study explores the possible contribution of HLA-DRB and DP polymorphisms to IDC susceptibility. DNA genotyping for HLA-DRB1, DPA1 and DPB1 was performed using polymerase chain reaction-sequencing based typing (PCR-SBT) method in 198 IDC patients and 136 random selected healthy Han ethnic individuals living in Northern China. IDC patients were, sub-grouped into asymptomatics (subgroup A), with arrhythmia (subgroup B) and with overt congestive heart failure (subgroup C) according to the clinical manifestations and electrocardiogram or echocardiographic characteristics. ADP/ATP autoantibody was detected in IDC group by immunoblot analysis. The results revealed that HLA-DR15, -DPB*0601 frequencies were significantly elevated in IDC group compared with normal control. The DPB1*0601 allele in homozygous form or in combination with allele DPB1*2301 or *3901, was found present more often in IDC patients. The predominance of HLA-DR4 allele was observed in subgroup B after stratification. However, the frequency of DPB1*0101 allele increased in the control than in the IDC group. The frequency of HLA-DPB1*0601 allele was significantly higher in IDC patients with positive autoantibody against ADP/ATP carrier of myocardial mitochondria in contrast to those with negative autoantibody. We conclude that HLA-DR4, -DR15, -DPB1*0601 alleles confers susceptibility to, while DPB1*0101 allele confers protection from IDC among individuals of northern Chinese Han nationality. The glutamate at position 69 in the second exon of DPB1*0601, as a key residue for special conformation of HLA-DP, may confer predisposition to IDC. HLA-DR and -DP alleles polymorphisms may serve as genetic markers for IDC and be involved in the regulation of the immune specific response to auto or exterior anti-myocardium antibodies.