Relation between HLA-DQA1 genes and genetic susceptibility to duodenal ulcer in Wuhan Hans

Advance in genetic factors influencing hepatitis B virus infection

Hepatitis B virus (HBV) infection is a major global health problem. A complex combination of environment and virus, especially host genetic factors, play a critical role in determining both susceptibility to HBV persistence and different clinical outcomes after HBV infection. In this review, we summarized the main relevant genes such as human leukocyte antigen (HLA), tumor necrosis factor (TNF), interleukins (ILs), interferons (IFNs), etc. However, in order to identify all the relevant polymorphisms that affect the outcome of HBV infection, alternative strategies such as genome-wide association studies with large sample sizes are required to define the majority of the related genes.

Association between HLA classⅡgenes and severity of chronic hepatitis B

AIM: To investigate the association between the polymorphism of HLA -DRB1, -DQA1 and -DQB1 alleles and severity of chronic hepatitis B.

METHODS: HLA-DRB1, -DQA1 and -DQB1 alleles in 54 patients with chronic hepatitis B and 32 patients with chronic severe hepatitis B were analyzed by using polymerase chain reaction/sequence specific primer (PCR/SSP) technique.

RESULTS: The frequency of HLA-DRB1*1 001 allele in the chronic severe hepatitis B group was markedly higher than that in the chronic hepatitis B group (14.1% vs 1.9%, x² = 19.2997, Pc = 0.0281, RR = 9.78). No significant different allele frequencies of HLA-DQA1 and HLA-DQB1 alleles were observed between the chronic severe hepatitis B group and the chronic hepatitis B group.

CONCLUSION: HLA-DRB1*1 001 is closely associated with the severity of chronic hepatitis B, and may be a valuble marker of evaluating the prognosis of patients with chronic hepatitis B.

Association between HLA class II gene and susceptibility or resistance to chronic hepatitis B

AIM: To investigate the association between the polymorphism of HLA-DRB1, -DQA1 and -DQB1 alleles and viral hepatitis B.

METHODS: HLA-DRB1, -DQA1 and -DQB1 alleles in 54 patients with chronic hepatitis B, 30 patients with acute hepatitis B and 106 normal control subjects were analyzed by using the polymerase chain reaction/sequence specific primer (PCR/SSP) technique.

RESULTS: The allele frequency of HLA-DRB1*0301 in the chronic hepatitis B group was markedly higher than that in the normal control group (17.31% vs 5.67%), there was a significant correlation between them (χ² = 12.3068, Pc = 0.0074, RR = 4.15). The allele frequency of HLA-DQA1*0501 in the chronic hepatitis B group was significantly higher than that in the normal control group (25.96% vs 13.68%), there was a significant correlation between them (χ² = 9.2002, Pc = 0.0157, RR = 2.87). The allele frequency of HLA-DQB1*0301 in the chronic hepatitis B group was notably higher than that in the normal control group (35.58% vs 18.87%), there was a significant correlation between them (χ² = 15.5938, Pc = 0.0075, RR = 4.07). The allele frequency of HLA-DRB1*1101/1104 in the chronic hepatitis B group was obviously lower than that in the normal control group (0.96% vs 13.33%), there was a significant correlation between them (χ² = 11.9206, Pc = 0.0145, RR = 18.55). The allele frequency of HLA-DQA1*0301 in the chronic hepatitis B group was remarkably lower than that in the normal control group (14.42% vs 30%), there was a significant correlation between them (χ² = 8.7396, Pc = 0.0167, RR = 0.35).

CONCLUSION: HLA-DRB1*0301, HLA-DQA1*0501 and HLA-DQB1*0301 are closely related with susceptibility to chronic hepatitis B, and HLA-DRB1*1101/1104 and HLA-DQA1*0301 are closely related with resistance to chronic hepatitis B. These findings suggest that host HLA class II gene is an important factor determining the outcome of HBV infection.

Relationship between genotype and phenotype of flagellin C in Salmonella

AIM: To discover the relationship between the genotype and antigen serotype of flagellin C among Salmonella strains.

METHODS: Fragment of Salmonella flagellin C in plasmid pLS408 was cloned, sequenced and compared with the corresponding sequence in other strains. Salmonella strains including two typhi strains, one paratyphoid strain, one enteritidis and one typhimurium strain were isolated from outpatients. Genome DNA was purified respectively from these clinical isolates, then the corresponding flagellin C fragment was amplified by polymerase chain reaction, and the amplification products were analyzed by agarose gel electrophoresis.

RESULTS: The cloned fragment includes 582 nucleotides encoding the variable region and partial conservative region of Salmonella flagellin C in plasmid pLS408. With comparison to the corresponding sequences reported previously, there is only a little difference from other strains with the same flagellar serotype in both nucleotide and amino acid level. Specific PCR products were amplified in Salmonella strains with flagellar serotype H-1-d including S. muenchen, typhi and typhimurium, but not in S. paratyphoid C or S. enteritidis strains.

CONCLUSION: In this experiment, the specificity of nucleotide sequence could be found in flagellin C central variable regions as it exists in flagellar serotypes in Salmonella. It may be helpful to developing a rapid, sensitive, accurate and PCR-based method to detect Salmonella strains with serotype H-1-d.