Possible association between HLA-HRB1 and DQB1 genes frequency and susceptibility or resistance to Helicobacter pylori infection in Kunming Yi ethnic group children / 中华儿科杂志

<p><b>OBJECTIVE</b>To study if there is any association between frequency of HLA-DRB1 and DQB1 genes and susceptibility or resistance to Helicobacter pylori (Hp) infection among children of Yi ethnic group in Kunming for understanding the immunogenetic features of the digestive diseases associated with Hp infection.</p><p><b>METHODS</b>Peripherial blood samples were collected from 156 children of Yi ethnic group in a primary school in Kunming city by cluster sampling and the blood Hp-IgG tests (ELISA) were performed. The samples were divided into two groups (Hp-IgG-positive group and Hp-IgG-negative group) according to the blood Hp-IgG test results. There were 61 children in Hp-IgG-positive group and 95 children in Hp-IgG-negative group. Forty children who were chosen from each group by simple random sampling underwent (13)carbon-urea breath test ((13)C-UBT). Thirty-three children who were Hp-IgG-positive and (13)C-UBT-positive were defined as currently Hp- infected group; 39 children who were Hp-IgG-negative and (13)C-UBT-negative were defined as Hp-non-infected group. DNA specimens were extracted from the lymphocytes of their peripheral blood samples. HLA-DRB1 and DQB1 DNA typing was performed by using polymerase chain reaction with sequence specific primers (PCR-SSP). HLA-DRB1, DQB1 allelic frequency distribution among currently Hp infected and non-infected children was compared.</p><p><b>RESULTS</b>HLA-DRB1 * 12 gene frequency among children in Hp non-infected group was higher than that in the currently Hp-infected group (42.31% vs. 14.52%, P < 0.001, Pc < 0.012); however, HLA-DRB1 * 11 gene frequency in the Hp-non-infected group was lower than that in the currently Hp-infected group (3.85% vs. 12.9%, P < 0.05, Pc > 0.05). HLA-DQB1 * 0301 gene frequency in the Hp non-infected group was higher than that in the currently Hp-infected group (55.13% vs. 32.26%, P < 0.007, Pc < 0.05); however, HLA-DQB1 * 04 gene frequency in the Hp non-infected group was lower than that in currently Hp infected group (2.56% vs. 11.29%, P < 0.05, Pc > 0.05).</p><p><b>CONCLUSIONS</b>HLA-DRB1 * 12 and HLA-DQB1 * 0301 gene may be associated with protection against Hp infection in Kunming Yi ethnic group children. Further studies with larger sample size are needed to clarify if HLA-DRB1 * 11 and HLA-DQB1 * 04 are associated with susceptible gene to Hp infection.</p>

Analysis on molecular characteristic of VP7 and NSP4 / 中华流行病学杂志

<p><b>OBJECTIVE</b>To explore the molecular characteristics and molecular variation of human rotavirus (HRV) strains and to understand the relationship between clinical characteristics and epidemiology of different HRV-VP7 and NSP4.</p><p><b>METHODS</b>Double-strand RNA of rotavirus extracted from stool samples was used as the template for reverse transcription of gene VP7, which was followed by nested PCR for VP7 typing. NSP4 genes from 22 epidemic strains of human rotavirus isolated in Kunming in 2002 and 2003 were amplified with RT-PCR. Then cDNAs were sequenced and compared with 4 human rotavirus NSP4 (Wa, KUN, AU-1, Hochi)) and 3 animal rotavirus NSP4 (EW, OSU, SA11) available in the GenBank while the epidemic strains of human rotavirus isolated in different areas of China were compared, using the Clustal-mp, DNAssist, MEGA2 software. The G serotype of VP7 was analysed by PCR.</p><p><b>RESULTS</b>Serotype G1 was prevalent in 2002 while serotype G3 was the prevalent in Kumming in 2003. The NSP4 genes from 22 epidemic strains of human rotavirus isolated in Kunming in 2002 and 2003 belonged to Wa with highly conservative amino acid. Samples isolated in the same years but not in the same area shared higher homology. Symptoms associated with heavy diarrhea did not seem to be associated with NSP4 molecular variation (P > 0.05).</p><p><b>CONCLUSION</b>Obvious variations of VP7 typing were seen in the same season, as well as in different areas and years. Due to the stable nature of NSP4, it seem to be a better candidate for vaccine production, than VP7.</p>

Immunogenetic analysis of human leukocyte antigen DRB1, DQB1 locus among Han ethnic children with Helicobacter pylori infection in Kunming / 中华流行病学杂志

<p><b>OBJECTIVE</b>To explore the immunogenetic features of human leukocyte antigen DRB1, DQB1 locus and children with Helicobacter pylori (H. pylori) infection in Han ethnic population in Kunming and its association with digestive diseases and H. pylori to better understand the immunogenetic features of the H. pylori infection.</p><p><b>METHODS</b>Polymerase chain reaction-sequence specific primer (PCR-SSP) method was used to study the HLA-DRB1, DQB1 allelic frequency distribution on 35 children with H. pylori infection and 37 healthy controls in Han ethnic population in Kunming.</p><p><b>RESULTS</b>Allelic frequencies of HLA-DRB1 * 0901, DQB1 * 03032 in the H. pylori infection group were lower than those of the healthy control group (7.14% vs. 31.08%, chi(2) = 13.16, Pc < 0.012; 5.71% vs. 25.68%, chi(2) = 10.68, Pc = 0.007) but the rest alleles' frequencies did not show significant differences.</p><p><b>CONCLUSION</b>These result suggested that HLA-DRB1 * 0901, DQB1 * 03032 might protect the H. pylori infection in Han ethnic population in Kunming.</p>