AIM: To investigate the associations of hepatitis B virus (HBV) genotype with HBeAg and anti-HBe status, alanine aminotransferase (ALT) levels and HBV-DNA detection in different groups of HBV-infected patients in sout...AIM: To investigate the associations of hepatitis B virus (HBV) genotype with HBeAg and anti-HBe status, alanine aminotransferase (ALT) levels and HBV-DNA detection in different groups of HBV-infected patients in southwest Iran. METHODS: A total of 89 HBsAg-positive serum samples were collected from the same number of patients. All sera were then investigated to determine HBV DNA and serological markers. For all the polymerase chain reaction (PCR)-positive samples, biochemical, histopathological assays and genotyping were also performed. RESULTS: Genotype D was the only type of HBV foundin different clinical forms of acute and chronic infections. There was a high prevalence of HBeAg-negative HBV- infected patients with chronic hepatitis (52.7%). Out of 55 patients with chronic hepatitis, seven (12.7%) were diagnosed with cirrhosis. A significant association between the presence of anti-HBe antibody and an increase in ALT level, among either HBeAg-negative (P = 0.01) or HBeAg-positive (P = 0.026) patients, was demonstrated. No significant differences were observed between the clinical outcomes of HBeAg-positive and -negative individuals (P = 0.24). CONCLUSION: Genotype D has been recognized as the only type of HBV found in different clinical forms of HBV infections, including cirrhosis, among the residents of southwest Iran. Anti-HBe possibly plays a role in disease progression in some patients with chronic hepatitis, at least for a period of disease.展开更多
AIM： To investigate the clinical significance and presence of mutations in the surface （S） and overlapping polymerase gene of hepatitis B patients with coexisting HBsAg and anti-HBs. METHODS： Twenty-three patients...AIM： To investigate the clinical significance and presence of mutations in the surface （S） and overlapping polymerase gene of hepatitis B patients with coexisting HBsAg and anti-HBs. METHODS： Twenty-three patients with chronic hepatitis B were studied. Of the 23 patients, i i were both positive for hepatitis B virus （HBV） surface antigen （HBsAg） and antibody to HBV surface antigen （anti-HBs）, 12 were negative for anti-HBs while positive for HBsAg. DNA was extracted from 200 μL serum of the patients. Nucleotide of the surface and overlapping polymerase gene from HBV-infected patients was amplified by PCR, and the PCR products were sequenced. RESULTS： Forty-one mutations were found within the surface gene protein of HBV in 15 patients （10 with coexisting HBsAg and anti-HBs）. Six （14.6%） out of 41 mutations were located at ＂α＂ determinant region in 5 patients （4 positive for HBsAg and anti-HBs）. Eleven mutations （26.8%） occurred in the downstream or upstream of ＂α＂ determinant region. Lamivudine （LMV）- selected mutations were found in three patients who developed anti-HBs, which occurred in amino acid positions （196, 198, 199） of the surface protein and in YMDD motif （M204I/V） of the polymerase protein simultaneously. Presence of these mutations did not relate to changes in ALT and HBV DNA levels.CONCLUSION： Besides mutations in the ＂α＂ determinant region, mutations at downstream or upstream of the ＂α＂ determinant region may contribute to the development of anti-HBs. These mutations do not block the replicating competency of HBV in the presence of high titer of anti-HBs.展开更多
AIM: To look for a rapid low-cost technique for the detection of HBV variants.METHODS: Two patients who underwent orthotopic liver transplantation (OLT) for HBV infection were treated with lamivudine (100 mg daily) an...AIM: To look for a rapid low-cost technique for the detection of HBV variants.METHODS: Two patients who underwent orthotopic liver transplantation (OLT) for HBV infection were treated with lamivudine (100 mg daily) and HBV infection recurred in the grafted livers. The patients were monitored intensively for liver enzymes, hepatitis B surface antigen (HBsAg) and HBV DNA in serum. Liver biopsy was performed regularly. HBV DNA in a conserved polymerase domain (the YMDD locus) was amplified from serum of each patient by PCR and sequenced. HBV genotypes were analyzed by restriction fragment length polymorphism (RFLP) of the PCR products generated from a fragment of the polymerase gene.RESULTS: YMDD wild-type HBV was detected in one patient by PCR-RFLP and DNA sequencing 19 mo after OLT, and YIDD mutant-type HBV in the other patient, 16 mo after OLT.CONCLUSION: PCR-RFLP assay is an accurate and simple method for genotyping lamivudine-resistant HBV variants.展开更多
AIM:To improve competitively differentiated polymerase chain reaction (CD-PCR) in detection of HBV basal core promoter mutation. METHODS: Recombinant plasmid of double point mutation A1762T/G1764A in basal core promot...AIM:To improve competitively differentiated polymerase chain reaction (CD-PCR) in detection of HBV basal core promoter mutation. METHODS: Recombinant plasmid of double point mutation A1762T/G1764A in basal core promoter of HBV constructed by site-directed mutagenesis was used as mutant control. To reveal the deficiency mechanism of CD-PCR, relationship between the circle number of PCR and the increased speed of products of each competitive primer was comparatively studied. Diversified amount of dNTPs and mutual primer of the competitive primers were tried to optimize CD-PCR. Optimized CD-PCR was evaluated by detecting A1762T/G1764A mutation in recombinant plasmids and clinical sera from patients with HBV infection. RESULTS: The deficiency mechanism of CD-PCR was that the products of mismatched competitive primer grew fast when the amplification of matched primer entered into plateau stage, which led to decrease in or disappearance of the difference in the amount of their products. This phenomenon could be eliminated by reducing dNTPs to 10μmol/L and mutual primer to about 100μmol/L Optimized CD-PCR could detect both mutant and wild strain independent of the amount of templates and the number of PCR cycles. Its detection limit was 103 copies/mL, about 50 copies/reaction. About 10% of mutant DNAs among wild type DNAs could be detected. A1762T/G1764A mutant was detected in 41.8% (51/122) of patients with HBV infection, but not detected in controls with negative HBsAg. CONCLUSION: Optimized CD-PCR can detect mutation independent of the amount of initial templates and the number of PCR cycles.展开更多
Objective: In order to elucidate the molecular mechanisms that might be responsible for hepatocarcinogenesis, we examined microsatellite instability (MSI), mismatch repair gene hMLH1 mutation and methylation in hepato...Objective: In order to elucidate the molecular mechanisms that might be responsible for hepatocarcinogenesis, we examined microsatellite instability (MSI), mismatch repair gene hMLH1 mutation and methylation in hepatocellular carcinoma. Methods: Fifty-two cases of surgically resected sporadic hepatocellular carcinoma (HCC) were studied. hMLH1 mutation was examined by two-dimensional electrophoresis and DNA sequencing; hMLH1 methylation was determined by methylation-specific PCR(MSP); and MSI at BAT26 was analyzed by PCR-based methods. Results: MSI at BAT26 was found in 3 of 52 cases (5.8%) of the tumors analyzed. No hMLH1 mutation or hypermethylation was found in these 52 cancerous tissues. No correlation existed between MSI and clinico-pathological characteristics of the patients. Conclusion: Our results suggest that MSI at BAT26 is rarely associated with carcinogenesis of chinese HCC. The genesis of sporadic HCC may occur in an alternative pathway that is probably different from MSI pathway.展开更多
AIM:To evaluate the possible relationship between the Ku80 gene polymorphism and the risk of gastric cancer in China.METHODS:In this hospital-based case-control study of gastric cancer in Jiangsu Province,China,we inv...AIM:To evaluate the possible relationship between the Ku80 gene polymorphism and the risk of gastric cancer in China.METHODS:In this hospital-based case-control study of gastric cancer in Jiangsu Province,China,we investigated the association of the Ku80 G-1401T (rs828907) polymorphism with gastric cancer risk.A total of 241 patients with gastric cancer and 273 age-and sexmatched control subjects were genotyped and analyzed by polymerase chain reaction-restriction fragment length polymorphism.RESULTS:The frequencies of genotypes GG,GT and TT were 65.6%,22.8% and 11.6% in gastric cancer cases,respectively,and 75.8%,17.6% and 6.6% in controls,respectively.There were significant differences between gastric cancer and control groups in the distribution of their genotypes (P=0.03) and allelic frequencies (P=0.002) in the Ku80 promoter G-1401T polymorphism.CONCLUSION:The T allele of Ku80 G-1401T may be associated with the development of gastric cancer.展开更多
Objective： To investigate the association of XRCC4 polymorphic variants at G-1394T （rs6869366） with colorectal cancer susceptibility. Methods： In this hospital-based case-control study, the association of XRCC4 po...Objective： To investigate the association of XRCC4 polymorphic variants at G-1394T （rs6869366） with colorectal cancer susceptibility. Methods： In this hospital-based case-control study, the association of XRCC4 polymorphism with colorectal cancer risk in Chinese population was investigated. In total, 171 patients with colorectal cancer and 171 healthy individuals matched for age and gender were selected. The genomic DNAs of the patients and controls were extracted from peripheral blood and the 300 bp target DNA was amplified with Polymerase Chain Reaction. The products were then digested with restriction endonuclease HinclI, followed by agarose electrophoresis to identify the genotype. Results： We found a significant difference in the frequency of the XRCC4 G-1394T genotype between the colorectal cancer and control groups in female （1/127 vs 8/122, P〈0.05）. Those with G/T at XRCC4 G-1394T showed a decreased risk of colorectal cancer susceptibility compared with those with T/T （OR 0.113, 95%CI 0.014-0.932）. However, in overall population or in male, there was no significant difference of the distribution between the colorectal cancer and control groups. Conclusion： Our findings with decreased risk of colorectal cancer susceptibility suggested that the G allele of XRCC4 G-1394T were associated in female.展开更多
Objective This study aims to investigate the etiological relationship among hepatitis B virus （HBV）, hepatitis C virus （HCV）, and alcohol as risk factors in a cohort of hepatocellular carcinoma （HCC） patients fr...Objective This study aims to investigate the etiological relationship among hepatitis B virus （HBV）, hepatitis C virus （HCV）, and alcohol as risk factors in a cohort of hepatocellular carcinoma （HCC） patients from India. The clinical and biochemical profiles and tumor characteristics in the HCC cases were also evaluated. Methods A total of 357 consecutive cases of HCC fulfilling the diagnostic criteria from the Barcelona-2000 EASL conference were included in the study. The blood samples were evaluated for serological evidence of HBV and HCV infection, viral load, and genotypes using serological tests, reverse transcription-polymerase chain reaction, and restriction fragment length polymorphism. Results The male/female ratio for the HCC cases was 5.87：1. Majority of the HCC patients （33.9%） were 50 to 59 years of age, with a mean age of 4±13.23 years. More than half the cases （60.8%） had underlying cirrhosis at presentation. Among the HCC patients, 68.9% were HBV related, 21.3% were HCV related, 18.8%, were alcoholic, and 18.2% were of cryptogenic origin. The presence of any marker positive for HBV increased the risk for developing HCC by almost 27 times [OR： 27.33; （12.87-60.0）]. An increased risk of 10.6 times was observed for HCC development for cases positive for ally HCV marker [OR： 10.55; （3.13-42.73）]. Heavy alcohol consumption along with HCV RNA positivity in cirrhotic patients was found to be a risk for developing HCC by 3 folds ]OR： 3.17; （0.37-70.71）]. Conclusions Patients of chronic HBV infection followed by chronic HCV infection were at higher risk of developing HCC in India. Chronic alcohol consumption was found to be a risk factor in cirrhotic cases only when it was associated with HCV RNA positivity. Most of the patients had a large tumor size （〉5 cm） with multiple liver nodules, indicating an advanced stage of the disease thus making curative therapies difficult.展开更多
Objective To study the relationship of the large multifunctional proteasome 7 (LMP7) gene polymorphism with susceptibility to type 1 diabetes mellitus (DM-1) and the DR3 gene in south Chinese Han population.Methods LM...Objective To study the relationship of the large multifunctional proteasome 7 (LMP7) gene polymorphism with susceptibility to type 1 diabetes mellitus (DM-1) and the DR3 gene in south Chinese Han population.Methods LMP7 genotypes and the DR3 gene were identified in 71 DM-1 patients and 86 healthy persons (as controls) by polymerase chain reaction-restriction fragment length polymorphism. DM-1 patients and controls were divided into DR3-positive and DR3-negative subjects. The frequencies of LMP7 genotypes and alleles were compared between DM-1 patients and controls respectively in the random subjects and in the DR3-matched subjects. Furthermore, DM-1 patients were divided into 3 groups according to the age of diabetic onset: group A≤14 years, group B 15-30 years, group C≥31 years.Results In the random subjects, the frequency of LMP7-B/B was lower (39% vs 58%, P<0.05) and that of LMP7-B/A was higher (54% vs 31%, P<0.01) in DM-1 patients than that in controls. In DR3-positive subjects, the frequencies of LMP7 genotypes and alleles showed no differences between DM-1 patients and controls. In DR3-negative subjects, the frequency of LMP7-B/B was decreased (40% vs 61%) and that of LMP7-B/A was increased (55% vs 28%, P<0.01) in DM-1 patients. The frequencies of LMP7 genotypes and alleles showed no significant differences among different ages of diabetic onset.Conclusions LMP7-B/B may be the protective genotype, and LMP7-B/A may be the susceptible genotype of DM-1, and this may not be affected by the DR3 gene. Persons with LMP7-B/B may have a decreased risk, and those with LMP7-B/A have an increased risk suffering from DM-1. The LMP7 gene may not be associated with the age of diabetic onset.展开更多
文摘AIM: To investigate the associations of hepatitis B virus (HBV) genotype with HBeAg and anti-HBe status, alanine aminotransferase (ALT) levels and HBV-DNA detection in different groups of HBV-infected patients in southwest Iran. METHODS: A total of 89 HBsAg-positive serum samples were collected from the same number of patients. All sera were then investigated to determine HBV DNA and serological markers. For all the polymerase chain reaction (PCR)-positive samples, biochemical, histopathological assays and genotyping were also performed. RESULTS: Genotype D was the only type of HBV foundin different clinical forms of acute and chronic infections. There was a high prevalence of HBeAg-negative HBV- infected patients with chronic hepatitis (52.7%). Out of 55 patients with chronic hepatitis, seven (12.7%) were diagnosed with cirrhosis. A significant association between the presence of anti-HBe antibody and an increase in ALT level, among either HBeAg-negative (P = 0.01) or HBeAg-positive (P = 0.026) patients, was demonstrated. No significant differences were observed between the clinical outcomes of HBeAg-positive and -negative individuals (P = 0.24). CONCLUSION: Genotype D has been recognized as the only type of HBV found in different clinical forms of HBV infections, including cirrhosis, among the residents of southwest Iran. Anti-HBe possibly plays a role in disease progression in some patients with chronic hepatitis, at least for a period of disease.
基金Supported by the National Natural Science Foundation of China,No.30271182
文摘AIM： To investigate the clinical significance and presence of mutations in the surface （S） and overlapping polymerase gene of hepatitis B patients with coexisting HBsAg and anti-HBs. METHODS： Twenty-three patients with chronic hepatitis B were studied. Of the 23 patients, i i were both positive for hepatitis B virus （HBV） surface antigen （HBsAg） and antibody to HBV surface antigen （anti-HBs）, 12 were negative for anti-HBs while positive for HBsAg. DNA was extracted from 200 μL serum of the patients. Nucleotide of the surface and overlapping polymerase gene from HBV-infected patients was amplified by PCR, and the PCR products were sequenced. RESULTS： Forty-one mutations were found within the surface gene protein of HBV in 15 patients （10 with coexisting HBsAg and anti-HBs）. Six （14.6%） out of 41 mutations were located at ＂α＂ determinant region in 5 patients （4 positive for HBsAg and anti-HBs）. Eleven mutations （26.8%） occurred in the downstream or upstream of ＂α＂ determinant region. Lamivudine （LMV）- selected mutations were found in three patients who developed anti-HBs, which occurred in amino acid positions （196, 198, 199） of the surface protein and in YMDD motif （M204I/V） of the polymerase protein simultaneously. Presence of these mutations did not relate to changes in ALT and HBV DNA levels.CONCLUSION： Besides mutations in the ＂α＂ determinant region, mutations at downstream or upstream of the ＂α＂ determinant region may contribute to the development of anti-HBs. These mutations do not block the replicating competency of HBV in the presence of high titer of anti-HBs.
基金Supported by the National Natural Science Foundation of China, No. 30170363 the Major Science and Technology Program of Ministry of Education, No. 01003 the Major State Basic Research Development Program of China, No. 2002CB513100 the National Key Technology Research and Development Program of China during the 10~(th) Five-Year Plan Period, No. 2001BA703B05
文摘AIM: To look for a rapid low-cost technique for the detection of HBV variants.METHODS: Two patients who underwent orthotopic liver transplantation (OLT) for HBV infection were treated with lamivudine (100 mg daily) and HBV infection recurred in the grafted livers. The patients were monitored intensively for liver enzymes, hepatitis B surface antigen (HBsAg) and HBV DNA in serum. Liver biopsy was performed regularly. HBV DNA in a conserved polymerase domain (the YMDD locus) was amplified from serum of each patient by PCR and sequenced. HBV genotypes were analyzed by restriction fragment length polymorphism (RFLP) of the PCR products generated from a fragment of the polymerase gene.RESULTS: YMDD wild-type HBV was detected in one patient by PCR-RFLP and DNA sequencing 19 mo after OLT, and YIDD mutant-type HBV in the other patient, 16 mo after OLT.CONCLUSION: PCR-RFLP assay is an accurate and simple method for genotyping lamivudine-resistant HBV variants.
基金Supported by the Science Foundation of Guangdong Province,No.99M04801G
文摘AIM:To improve competitively differentiated polymerase chain reaction (CD-PCR) in detection of HBV basal core promoter mutation. METHODS: Recombinant plasmid of double point mutation A1762T/G1764A in basal core promoter of HBV constructed by site-directed mutagenesis was used as mutant control. To reveal the deficiency mechanism of CD-PCR, relationship between the circle number of PCR and the increased speed of products of each competitive primer was comparatively studied. Diversified amount of dNTPs and mutual primer of the competitive primers were tried to optimize CD-PCR. Optimized CD-PCR was evaluated by detecting A1762T/G1764A mutation in recombinant plasmids and clinical sera from patients with HBV infection. RESULTS: The deficiency mechanism of CD-PCR was that the products of mismatched competitive primer grew fast when the amplification of matched primer entered into plateau stage, which led to decrease in or disappearance of the difference in the amount of their products. This phenomenon could be eliminated by reducing dNTPs to 10μmol/L and mutual primer to about 100μmol/L Optimized CD-PCR could detect both mutant and wild strain independent of the amount of templates and the number of PCR cycles. Its detection limit was 103 copies/mL, about 50 copies/reaction. About 10% of mutant DNAs among wild type DNAs could be detected. A1762T/G1764A mutant was detected in 41.8% (51/122) of patients with HBV infection, but not detected in controls with negative HBsAg. CONCLUSION: Optimized CD-PCR can detect mutation independent of the amount of initial templates and the number of PCR cycles.
文摘Objective: In order to elucidate the molecular mechanisms that might be responsible for hepatocarcinogenesis, we examined microsatellite instability (MSI), mismatch repair gene hMLH1 mutation and methylation in hepatocellular carcinoma. Methods: Fifty-two cases of surgically resected sporadic hepatocellular carcinoma (HCC) were studied. hMLH1 mutation was examined by two-dimensional electrophoresis and DNA sequencing; hMLH1 methylation was determined by methylation-specific PCR(MSP); and MSI at BAT26 was analyzed by PCR-based methods. Results: MSI at BAT26 was found in 3 of 52 cases (5.8%) of the tumors analyzed. No hMLH1 mutation or hypermethylation was found in these 52 cancerous tissues. No correlation existed between MSI and clinico-pathological characteristics of the patients. Conclusion: Our results suggest that MSI at BAT26 is rarely associated with carcinogenesis of chinese HCC. The genesis of sporadic HCC may occur in an alternative pathway that is probably different from MSI pathway.
基金Supported by Grants from the National Natural Science Foundation of China,No. 30672486the Natural Science Foundation of Jiangsu Province,No. BK2006525"333 Project" and "Qinglan Project" Funds for the Young Academic Leader of Jiangsu Province to Wang B
文摘AIM:To evaluate the possible relationship between the Ku80 gene polymorphism and the risk of gastric cancer in China.METHODS:In this hospital-based case-control study of gastric cancer in Jiangsu Province,China,we investigated the association of the Ku80 G-1401T (rs828907) polymorphism with gastric cancer risk.A total of 241 patients with gastric cancer and 273 age-and sexmatched control subjects were genotyped and analyzed by polymerase chain reaction-restriction fragment length polymorphism.RESULTS:The frequencies of genotypes GG,GT and TT were 65.6%,22.8% and 11.6% in gastric cancer cases,respectively,and 75.8%,17.6% and 6.6% in controls,respectively.There were significant differences between gastric cancer and control groups in the distribution of their genotypes (P=0.03) and allelic frequencies (P=0.002) in the Ku80 promoter G-1401T polymorphism.CONCLUSION:The T allele of Ku80 G-1401T may be associated with the development of gastric cancer.
文摘Objective： To investigate the association of XRCC4 polymorphic variants at G-1394T （rs6869366） with colorectal cancer susceptibility. Methods： In this hospital-based case-control study, the association of XRCC4 polymorphism with colorectal cancer risk in Chinese population was investigated. In total, 171 patients with colorectal cancer and 171 healthy individuals matched for age and gender were selected. The genomic DNAs of the patients and controls were extracted from peripheral blood and the 300 bp target DNA was amplified with Polymerase Chain Reaction. The products were then digested with restriction endonuclease HinclI, followed by agarose electrophoresis to identify the genotype. Results： We found a significant difference in the frequency of the XRCC4 G-1394T genotype between the colorectal cancer and control groups in female （1/127 vs 8/122, P〈0.05）. Those with G/T at XRCC4 G-1394T showed a decreased risk of colorectal cancer susceptibility compared with those with T/T （OR 0.113, 95%CI 0.014-0.932）. However, in overall population or in male, there was no significant difference of the distribution between the colorectal cancer and control groups. Conclusion： Our findings with decreased risk of colorectal cancer susceptibility suggested that the G allele of XRCC4 G-1394T were associated in female.
文摘Objective This study aims to investigate the etiological relationship among hepatitis B virus （HBV）, hepatitis C virus （HCV）, and alcohol as risk factors in a cohort of hepatocellular carcinoma （HCC） patients from India. The clinical and biochemical profiles and tumor characteristics in the HCC cases were also evaluated. Methods A total of 357 consecutive cases of HCC fulfilling the diagnostic criteria from the Barcelona-2000 EASL conference were included in the study. The blood samples were evaluated for serological evidence of HBV and HCV infection, viral load, and genotypes using serological tests, reverse transcription-polymerase chain reaction, and restriction fragment length polymorphism. Results The male/female ratio for the HCC cases was 5.87：1. Majority of the HCC patients （33.9%） were 50 to 59 years of age, with a mean age of 4±13.23 years. More than half the cases （60.8%） had underlying cirrhosis at presentation. Among the HCC patients, 68.9% were HBV related, 21.3% were HCV related, 18.8%, were alcoholic, and 18.2% were of cryptogenic origin. The presence of any marker positive for HBV increased the risk for developing HCC by almost 27 times [OR： 27.33; （12.87-60.0）]. An increased risk of 10.6 times was observed for HCC development for cases positive for ally HCV marker [OR： 10.55; （3.13-42.73）]. Heavy alcohol consumption along with HCV RNA positivity in cirrhotic patients was found to be a risk for developing HCC by 3 folds ]OR： 3.17; （0.37-70.71）]. Conclusions Patients of chronic HBV infection followed by chronic HCV infection were at higher risk of developing HCC in India. Chronic alcohol consumption was found to be a risk factor in cirrhotic cases only when it was associated with HCV RNA positivity. Most of the patients had a large tumor size （〉5 cm） with multiple liver nodules, indicating an advanced stage of the disease thus making curative therapies difficult.
文摘Objective To study the relationship of the large multifunctional proteasome 7 (LMP7) gene polymorphism with susceptibility to type 1 diabetes mellitus (DM-1) and the DR3 gene in south Chinese Han population.Methods LMP7 genotypes and the DR3 gene were identified in 71 DM-1 patients and 86 healthy persons (as controls) by polymerase chain reaction-restriction fragment length polymorphism. DM-1 patients and controls were divided into DR3-positive and DR3-negative subjects. The frequencies of LMP7 genotypes and alleles were compared between DM-1 patients and controls respectively in the random subjects and in the DR3-matched subjects. Furthermore, DM-1 patients were divided into 3 groups according to the age of diabetic onset: group A≤14 years, group B 15-30 years, group C≥31 years.Results In the random subjects, the frequency of LMP7-B/B was lower (39% vs 58%, P<0.05) and that of LMP7-B/A was higher (54% vs 31%, P<0.01) in DM-1 patients than that in controls. In DR3-positive subjects, the frequencies of LMP7 genotypes and alleles showed no differences between DM-1 patients and controls. In DR3-negative subjects, the frequency of LMP7-B/B was decreased (40% vs 61%) and that of LMP7-B/A was increased (55% vs 28%, P<0.01) in DM-1 patients. The frequencies of LMP7 genotypes and alleles showed no significant differences among different ages of diabetic onset.Conclusions LMP7-B/B may be the protective genotype, and LMP7-B/A may be the susceptible genotype of DM-1, and this may not be affected by the DR3 gene. Persons with LMP7-B/B may have a decreased risk, and those with LMP7-B/A have an increased risk suffering from DM-1. The LMP7 gene may not be associated with the age of diabetic onset.
