幽门螺杆菌感染与胃癌的相关性研究

目的：为了研究幽门螺杆菌（Hp）感染与胃癌及肠化类型的关系。方法：对胃癌高发区1333例普查人群的胃活检组织和30例胃癌手术标本病理切片做Warthin－starry染色，对慢性萎缩胃炎伴肠化生、慢性浅表胃炎伴肠化生、癌旁肠化生用粘液组化方法染色分型。结果：Hp感染与十二指肠球部溃疡高度相关，与胃溃疡、慢性浅表活动性胃炎、早期胃癌显著相关，与单纯萎缩性胃炎、萎缩胃炎伴肠化生、胃增生性息肉亦相关（P均＜0．05）；进展期胃癌的Hp感染率与慢性非活动性胃炎相比较，差异无显著性（P＞0．05）；各型胃癌中以腺癌Hp检出率高（75．4％），与粘液细胞癌Hp检出率（30％）相比较，差异有非常显著性（P＜0．01）。各型肠化生之间的Hp检出率比较，差异无显著性（P均＞0．05）。结论：Hp感染与胃癌有相关性。     

抗SSA和SSB抗体与HLA-Ⅱ基因的相关性分析

目的：探讨云南汉族系统性红斑狼疮（SLE）患者抗SSA和SSB抗体与HLA－DRB1、DQA1、DQB1等位基因及单体型的相关性。方法：采用多聚酶链反应－序列特异性引物（PCR－SSP）技术对63例云南汉族SLE患者和54名同民族健康对照进行DRB1、DQA1、DQB1基因分型。结果：云南汉族SLE患者中DR15（P＜0．01）、DR16（P＜0．05）、DQA1＊0102（P＜0．05）、DQA1＊0103（P＜0．01）、DQB1＊0601（P＜0．05）等位基因频率明显增高；抗SSA和SSB抗性阳性的SLE病人中DQA1＊0103频率均显著增高（P＝0．042，P＝0．006）；抗SSB抗体阳性的SLE患者中的DQA1＊0501 频率均显著增高（P＝0．009）。结论：云南汉族SLE 抗SSA和SSB抗体的产生与DQA1＊0103等位基因相关；抗SSB抗体的产生还与DQA1＊0501相关。     

白细胞介素-1基因多态性与类风湿关节炎病情活动及骨代谢的相关性

目的 探讨IL－1α和β基因多态性与类风湿关节炎（RA）疾病活动性和骨代谢的相关以及IL－1基因多态性与RA优势基因（motif gene）之间的相关关系。方法 检测了65例RA 患者和60例非风湿病患者的IL－1等位基因分布。IL－1基因多态性分析采用PCR－RFLP方法,HLA－DR分型采用PCR－SSOP方法。Fisher's检验及方差分析被用于基因频率和携带率及临床统计。结果 IL－1α的频率和携带率在RA病人和对照组之间差异无显著性。在女性RA病人IL－1β纯合子等位基因2的出现频率更高,在男性RA病人中等位基因1的频率较高而等位基因2的携带率较低。IL－1β等位基因2携带率与C反应蛋白（CRP）、红细胞沉降率（ESR）、关节痛和骨质密度（BMD）呈相关,与尿脱氧吡啶／肌酐比值（Udpd/Crea）水平及维生素D3水平呈负相关。IL－1α等位基因1与CRP呈负相关,与类风湿因子（RF）和关节肿胀呈正相关。IL－1α等位基因2的出现伴随较高的ESR、健康质量评估积分（HAQ）,维生素D3水平和较低的RF滴度、肿胀关和（SJC）和BMD。HLA－DRB1 RA优势等位基因和IL－1β等位基因2的同时出现对RA 的一些临床参数并没有影响。结论 RA与IL－1基因多态性显著相关,特别是IL－1β等位基因2与病 情活动及骨密度增高直接。HLA－DRB1RA优势等位基因和IL－1β等位基因2的同时出现并不预示RA病情更严重。     

上海地区Ⅰ型自身免疫性肝炎与HLA-DRB1等位基因的相关性研究

目的 分析HLA－DRB1等位基因与上海地区I型自身免疫性肝炎（AIH）的相关性，探讨AIH的遗传易感背景。方法 采用序列特异性多聚酶链反应（PCR－SSP），对32例I型AIH患者和48例健康对照者进行HLA－DRB1等位基因及有关基因亚型的分析。结果 HLA－DR4基因频率在I型AIH患者中较健康对照组显著增高[46.9%与20.8%；相对危险度（RR）＝3．35，χ^2=5.99,P=0.014]。其他等位基因在两组间差异无显著性。进一步对HLA－DR4等位基因亚型的分析表明，I型AIH患者组DRB1^*0405的基因频率较健康对照组有增加趋势（21．9％与6．3％，χ^2=4.23,P=0.04，但Pc=0.08)。HLA－DRβ分子的第3等位基因高变区第71位精氨酸残基的频率在I型AHI患者中显著增高（46.9%与18.8%,χ^2=7.14,P=0.008)。结论 上海地区I型AIH的发病与HLA－DR4以及HLA－DRB1第3高变区DR7位精氨酸残基相关。     

乙型肝炎病毒感染者人类白细胞抗原的检测

目的：探讨宿主人类白细胞抗原（HLA）Ⅱ类分子与HBV感染相关性。方法：利用PCR技术检测30例慢性乙型肝炎患者和56例HBV感染自动恢复者的HLA Ⅱ类分子及其等位基因。结果：与慢性乙型肝炎患者相比，HLA Ⅱ类分子DR12在恢复者中的分布频率显著增高（10％比38％，rr,0.19;P矫正＜0．025）；HLA－DR12的等位基因DRB1＊1201的分布频率也显著增高（3％比32％；rr,0.07;P矫正＜0．005）。而R9（43％比18％；rr,3.52;P矫正＜0．025）和DQ9（43％比20％；rr,3.13;P矫正＜0．05）在慢性乙型肝炎患者中的分布频率显著高于恢复者。结论：HLA－DR12和DRB1＊1201可能对机体免受HBV长期感染有保护性意义。而HLA－DR9或DQ9可能使宿主易发生HBV持续感染。     

新疆巴州地区幽门螺杆菌感染与胃癌的关系

目的探讨Hp感染与胃癌的关系，为预防胃癌提供理论依据．方法收集1992－01／1997－079534例内镜病理证实为胃癌的167例为病例组，由性别、族别相同，年龄，检查日期相近的胃炎患者为对照组，进行回顾性分析．结果男133例，女34例，老年（≥50岁）141例，青年26例，汉、维、蒙、哈族分别为101例、52例、12例、2例．Hp感染胃癌总检出率1．75％，胃窦、胃体、胃贲门、胃角各占36．5％，35．9％，19．16％，8．3％，其腺癌比例为96．4％，非责门部腺癌Hp感染64．6％，明显高于对照组41．8％，二者P＜0．05，胃癌男性79．6％，女性20．3％，男：女=3．9：1，老年占84．4％，Hp阳性率56．7％，青年占15．6％，Hp阳性率76．9％，二者P＜0．01，胃癌中汉、维、蒙、哈族各占60．4％，31．1％，7．18％，0．59％，Hp检出率74．04％，37．03％，9．25％，0．92％，各组间差异显著P＜0．01．结论胃非贲门腺癌发生与Hp感染有关．男性聚餐多，汉、维族群聚，经口传播机会多．青年组Hp感染高于老年组，胃癌病例Hp感染显著高于对照组，表明Hp感染可能与胃癌发病有关，可能是胃癌发生的始动因素之一．普查及有效根治…感染可作为一种胃癌预防措施应予重视．     

HLA—DRB1、DQB1基因多态性与流行性出血热的相关性

目的从基因水平探讨HLA—DRB1、DQB1等位基因多态性与流行性出血热的相关性,以阐述其免疫遗传学特征。方法应用序列特异性引物聚合酶链反应技术检测流行性出血热患者和正常对照组各50例的HLA—DRB1、DQB1等位基因。结果流行性出血热患者与正常对照组比较,HLA—DRB1＊16等位基因分布频率明显增高（Pc=0．0106）,两组间其余HLA-DRB1、-DQB1等位基因分布频率差异无统计学意义（Pc〉0．05）。结论HLA-DRB1＊16等位基因与流行性出血热呈正相关,可能为流行性出血热易感基因之一。     

GD药物引起粒细胞减少与等位基因的关系

采用多聚酶链式反应-序列特异引物（per—ssp）方法检测65例GD病人抗甲状腺药物引起粒细胞减少（1）组，65例GD病人并发粒细胞减少（2）组，65例非GD病人粒细胞减少（3）组，65例正常参照人群（4）组的HLA—DRB1＊08032 DRB1＊1501的等位基因频率。结果1：（1）组HLA—DRB1＊08032 DRB1＊1501的基因频率高于（2）组（P〈0．05）。2：（1）组HLA—DRB1＊08032 DRB1＊1501的基因频率明显高于（3）组（4）组，（P〈0．01）。3：（2）组HLA—DRB1＊08032 DRB1＊1501的基因频率高于（4）组（P〈0．05）。结论：GD病人应用抗甲状腺药物引起粒细胞减少与HLA—DRB1＊08032 DRB1＊1501等位基因频率增加有关。     

Runx3、Sp1、Bcl-2在胃腺癌中的表达及对预后的影响

目的探讨Runx3、Sp1、Bcl-2在胃腺癌中的表达,为评估患者预后提供实验依据。方法采用免疫组织化学SP法检测Runx3、Sp1、Bcl-2蛋白在63例胃腺癌、19例低级别上皮内瘤变及10例正常胃黏膜组织中的表达。结果胃腺癌组织中Runx3表达降低,Sp1和Bcl-2蛋白表达增高。Runx3低表达与肿瘤细胞的分化程度、浸润深度及淋巴结转移有关（P〈0.05）;Sp1高表达与肿瘤细胞浸润深度、淋巴结转移及临床分期有关（P〈0.05）;Bcl-2高表达与肿瘤细胞分化程度有关（P〈0.05）。胃腺癌组织中Runx3与Bcl-2阳性表达呈负相关（P〈0.01）;Sp1与Bcl-2阳性表达呈正相关（P〈0.01）;Runx3与Sp1的表达无明显相关性。Runx3及Sp1阳性表达率与患者总生存率关系密切。结论 Runx3蛋白低表达及Sp1蛋白高表达与胃腺癌的发生、发展及预后密切相关。     

幽门螺杆菌感染与胃癌的关系

目的研究幽门螺杆菌（Hp）与胃癌发生的关系。方法病例组62例均为胃腺癌，正常胃粘膜组34例．每个研究对象均在胃窦部取三块活检组织，胃癌患者在癌灶周围再取三块活检组织．然后进行快速尿素酶试验和细菌培养．结果Hp阳性以细菌培养为标准，两项试验均阳性为Hp阳性．结果病变组Hp阳性数38例，对照组为4例，两组比较OR＝11．9，95％CI＝4．2～33．7，X2＝21．89，P＜0．01，两组间有显著性差异，提示Hp感染与胃癌的危险性相关．进一步研究Hp与胃癌的类型及部位的关系发现，Hp在肠型腺癌和弥漫型腺癌的检出率分别为78％（32／41），29％（6／21），OR分别为26．7，3，95％CI分别为8．8～81．7，＜1，P分别为P＜0．01，P＞0．1．提示Hp感染与肠型胃癌有关．Hp在胃窦和幽门部胃癌检出率为83％（24／29），与正常组比较OR＝36，95％CI＝12．6～102．6，P＜0．01；在胃体和胃底部胃癌检出率为79％，OR＝27．5，95％CI＝6．6～114，P＜0．01；在贲门部胃癌检出率为16％，OR＝1．4，95％CI＜1，P＞0．5，提示Hp感染与非贲门部胃腺癌密切相关，与贲门部胃癌无关。结论Hp感染与胃癌的发生有相关性，与非贲门部胃癌密切相关，与肠型胃癌有关，与弥漫型胃癌无关．     

Contribution of major histocompatibility complex genes to susceptibility and resistance in Helicobacter pylori related diseases.

BACKGROUND/AIM: Although there have been numerous reports concerning the virulence factors of isolates for investigating the pathogenesis of Helicobacter pylori infection, few studies have been carried out regarding the association of HLA class II genes of the host with H. pylori related diseases. Two published studies have only analysed the HLA DQ locus alone. The aim of this study was thus to determine the association of HLA class II genes (DR, DQ and DP) with H. pylori related diseases using the DNA typing method. METHODS: Fifty-eight patients with H. pylori positive gastric ulcers, 44 patients with H. pylori positive duodenal ulcers, 45 patients with H. pylori positive gastritis and 34 healthy subjects without H. pylori infection were typed for HLA class II genes by means of DNA typing with the polymerase chain reaction-sequence specific oligonucleotide probes method. RESULTS: A negative association with DRB1*1501, DQA1*01021 and DQB1*0602 alleles was noted in all three of the patient groups studied. Compared with the healthy controls, a positive association with DPA1*0201 (P= 0.032) and DPB1*0901 (P=0.005) in gastric ulcers, a positive association with DRB1*0405 (P=0.022) and DQB1*0401 (P=0.044) in duodenal ulcers, and a positive association with DPB1*0901 (P=0.016) in gastritis were observed. A haplotype analysis showed that the association of alleles with H. pylori related disease was with the haplotype rather than with either of the alleles individually. After correction for multiple comparisons, all the significant associations obtained between H. pylori related diseases and HLA class II genes disappeared. CONCLUSIONS: The interplay between host immunogenetic factors, bacterial virulence factors and environmental conditions may thus play a more important role in the outcome of H. pylori infection than immunogenetic factors alone.     

Association of the HLA-DRB1 gene locus with gastric adenocarcinoma in Japan

BACKGROUND AND AIM: Helicobacter pylori infection is associated with gastric adenocarcinoma, however, the odds ratio is relatively low. The aim of the present study was to investigate host genetic factors that increase the risk of gastric adenocarcinoma among H. pylori-infected individuals. METHODS: A total of 70 patients with early gastric adenocarcinoma and 121 unrelated healthy controls were examined for H. pylori infection and HLA-DRB1 genotyping. The frequencies of HLA-DRB1 alleles were compared among groups. RESULTS: The allele frequency of DRB1*04051 was significantly higher in patients with gastric adenocarcinoma (17.9%) than in controls (7.9%) (P(correct) = 0.045). The odds ratio of gastric adenocarcinoma associated with the presence of the HLA-DRB1*04051 allele compared with its absence was 2.55 (95% confidence limits, 1.35-4.83). This genetic risk was not associated with H. pylori infection. There was no significant difference in the HLA-DRB1 allele frequency between H. pylori-positive and H. pylori-negative controls. The frequency of genotypes that possessed the DRB1*04051 allele in gastric adenocarcinoma patients (34.3%) was significantly higher than that in H. pylori-negative controls (11.9%) (p = 0.0089) and H. pylori-positive controls (15.2%) (p = 0.0066). CONCLUSION: These findings suggest that immunogenetic factors for susceptibility to gastric adenocarcinoma are present in the host, the HLA-DRB1*04051 allele is a host genetic risk factor for gastric adenocarcinoma, and that this genetic risk is independent of H. pylori infection.     

In the European population HLA-class II genes are not associated with Helicobacter pylori infection.

OBJECTIVE : Genetic variability influences susceptibility to several diseases and depends on the specific ethnic background of individuals. HLA-class II genes have repeatedly been investigated as candidate genes for predisposition to Helicobacter pylori infection. Certain HLA-DQA1 alleles have been reported to be associated with gastric and duodenal ulcer disease in infected patients in the Japanese population. But conflicting results were reported on European and Japanese populations. METHODS : HLA-DRB1 typing of 382 German individuals with well-defined H. pylori status and different clinical course of the disease was performed by polymerase chain reaction and allele-specific oligonucleotide hybridization. RESULTS : No association with the infection status itself was observed in the German cohort. Similar results have been found in other European populations. In contrast, re-analysis of published data in a Japanese cohort revealed a highly significant association of DRB1*1501 with uninfected controls (P = 0.00035). In the German population, the carrier frequency of DRB1*15 was higher in H. pylori-positive individuals with gastric or duodenal ulcer but without statistical significance (gastric ulcer: odds ratio, 2.13; chi2 = 3.77; P = 0.05; Bonferroni correction, Pc = not significant; and duodenal ulcer: odds ratio, 2.15; chi2 = 3.4; P = 0.06; Pc = not significant). In infected individuals, autoantibodies to gastric mucosa were investigated, but no statistical significant difference in carrier frequencies of HLA-DRB1 alleles was evident. CONCLUSION : The DRB1*1501-DQA1*01021-DQB1*0602 haplotype seems to provide protection from H. pylori infection in the Japanese population, whereas genetic variability in HLA-class II genes has only a minor impact on H. pylori infection and its clinical course in the European population.     

HLA-DRB1、-DQB1基因多态性与食管鳞癌遗传关联性

目的　从基因水平探讨食管鳞癌HLA DRB1 , DQB1等位基因的遗传易感性 ,以阐述其免疫遗传学特征。方法　运用序列特异性引物聚合酶链反应技术 ,检测无亲缘关系湖北汉族健康人 1 36例、食管鳞癌患者 42例的HLA DRB1 , DQB1等位基因。结果　湖北汉族人食管鳞癌患者与正常人比较 ,HLA DRB1 0 90 1等位基因分布频率显著增高 (0 .2 50 0比 0 .1 397,P =0 .0 2 8,OR =2 .0 53 ,病因分数 =0 .1 2 82 ) ,HLA DQB1 0 30 1基因分布频率显著增高 (0 .2 976比 0 .1 875 ,P =0 .0 4 6 ,OR =1 .835 ,病因分数 =0 .1 35 4)。两者间其余HLA DRB1、 DQB1等位基因分布频率差异均无显著性。结论　HLA DRB1 0 90 1及 DQB1 0 30 1等位基因均与食管鳞癌正关联 ,为其易感基因。该两等位基因测序结果与其基因库第 2外显子序列吻合。     

Influence of shared epitope–negative HLA–DRB1 alleles on genetic susceptibility to rheumatoid arthritis

Objective

Most patients with rheumatoid arthritis (RA) express the shared epitope (SE). It is not known whether SE‐negative HLA–DRB1 alleles influence the development of RA. This study examined the influence of SE‐negative HLA–DR alleles (DRB1*X) on the development of RA in 3 different French populations.

Methods

HLA–DRB1 alleles were defined by polymerase chain reaction with sequence‐specific oligonucleotide hybridization or sequence‐specific primers. SE‐negative alleles were classified according to the electric charge of their P4 pocket. HLA–DRB1 alleles *0103, *0402, *07, *08, *11 (except *1107), *12, and *13 have a neutral or negative P4 charge and are called DRB1*XP4n. HLA–DRB1*03, *0403, *0406, *0407, *0901, *1107, *14, *15, and *16 have a positive P4 charge and are called DRB1*XP4p.

Results

Among the SE‐negative subjects, DRB1 genotypes with 1 or 2 DRB1*XP4n alleles were significantly overrepresented in the control subjects compared with the RA patients, whereas DRB1*XP4p/XP4p genotypes were equally represented in the patients and controls. In single‐dose SE–positive subjects, SE/XP4n genotypes were equally represented in the patients and controls. However, SE/XP4p genotypes were significantly overrepresented in the RA patients.

Conclusion

The DRB1*X allele polymorphism influences susceptibility to RA. Alleles that have a neutral or negative electric charge in their P4 pocket (DRB1*XP4n), such as DRB1*0103, *0402, *07, *08, *11 (except *1107), *12, and *13, protect against RA. Alleles that have a positive electric charge in their P4 pocket (DRB1*XP4p), such as DRB1*03, *0403, *0406, *0407, *0901, *1107, *14, *15, and *16, have no influence on the predisposition to RA.

     

Association of human leukocyte antigen class II genes with autoantibody profiles, but not with disease susceptibility in Japanese patients with systemic sclerosis.

OBJECT: To examine the role of human leukocyte antigen (HLA) class II genes in the development of systemic sclerosis (SSc) as well as in the clinical and serologic expression of SSc in patients. METHODS: HLA-DRB1, DRB3, DRB4, DQB1, and DPB1 alleles were determined by genotyping; and serum antinuclear antibodies were identified using indirect immunofluorescence, double immunodiffusion and immunoprecipitation. PATIENTS: One hundred and five Japanese patients with SSc and 104 race-matched healthy controls. RESULTS: Frequencies of DRB1 and DQB1 alleles were not different between SSc patients and healthy controls, while DPB1*0901 was marginally increased in SSc patients. In contrast, SSc-related autoantibodies were closely associated with the clinical features. HLA class II genes were detected as follows: anti-DNA topoisomerase I antibody with diffuse cutaneous involvement, pulmonary fibrosis, and DRB1*1502-DQB1*0601-DPB1*0901; anti-U1RNP antibody with overlapping features of lupus and/or myositis and DRB1*0401/*0802-DQB1*0302; and anticentromere antibody with limited cutaneous involvement and DRB1*0101-DQB1*0501-DPB1*0402. In the analysis of the association of HLA class II and the clinical features in SSc patients significant differences were obtained only for the increased frequencies of arthritis and rheumatoid factor in patients with DRB1*0405 compared to those without. CONCLUSION: HLA class II genes strongly influence the production of SSc-related autoantibodies rather than the development of SSc. In addition, SSc is a composite disease of distinctive subsets defined by serum autoantibodies, which have specific clinical and HLA class II associations.     

Promoter methylation of E-cadherin gene in gastric mucosa associated with Helicobacter pylori infection and in gastric cancer

BACKGROUND:E-cadherin is an adhesion molecule involved in tumour invasion/metastasis. Silencing of E-cadherin by promoter CpG methylation has been shown in both familial and sporadic gastric cancers. Helicobacter pylori is a class I carcinogen in gastric cancer. AIMS: This study was undertaken to investigate the association between methylation of E-cadherin and H pylori in gastric mucosa from dyspeptic patients, and in intestinal metaplasia and primary and metastatic adenocarcinoma from surgical specimens of patients with gastric cancer. METHODS: E-cadherin methylation was studied using methylation specific polymerase chain reaction in microdissected tissue from biopsies or surgical resection specimens. E-cadherin expression was studied by immunohistochemistry. RESULTS: E-cadherin methylation was present in 31% (11/35) of gastric mucosae from dyspeptic patients, and was associated with H pylori infection (p=0.002), but was independent of the age of the patient or presence or absence of gastritis. E-cadherin methylation was present in 0% (0/8) of normal mucosa, 57% (12/21) of intestinal metaplasias, and 58% (15/26) of primary and 65% (21/32) of metastatic cancers. E-cadherin methylation status was concordant in 92% (11/12) of intestinal metaplasias and primary cancers, and in 85% (17/20) of primary and metastatic cancers from the same resected specimen. E-cadherin methylation in gastric cancer was associated with depth of tumour invasion (p=0.02) and regional nodal metastasis (p=0.05). CONCLUSION:E-cadherin methylation is an early event in gastric carcinogenesis, and is initiated by H pylori infection.     

Relationship between Helicobacter pylori CagA status and colorectal cancer

OBJECTIVES: Infection with Helicobacter pylori, particularly with strains positive for CagA protein, increases the risk of gastric adenocarcinoma. Few studies have explored the possible association between H. pylori infection and colorectal cancer. This study evaluated whether the seroprevalence of CagA in H. pylori-infected patients affected risk for colorectal cancer independently of H. pylori status. METHODS: In this study, we tested serum IgG antibodies against H. pylori (ELISA) and CagA protein (Western blot assay) in 67 patients with colorectal adenocarcinoma, 36 with gastric adenocarcinoma, 47 with other malignancies (cancer controls), and 45 hospitalized for transesophageal echocardiography (TEE controls). Colonic cancer and gastric cancer patients with H. pylori infection were compared to each control group and to the pooled controls using simple and adjusted analyses. RESULTS: H. pylori infection was noted in 50 colon cancer patients, 31 gastric cancer patients, 31 cancer controls, and 32 TEE controls. In all, 41 (82%), 29 (94%), 11 (35%), and 13 (41%), respectively, of these H. pylori-positive sera expressed CagA reactivity (p < 0.001 for all pairwise comparisons between cases and controls). In the adjusted analysis, infection with H. pylori CagA+ compared to H. pylori CagA- was associated with increased risk for colorectal adenocarcinoma (odds ratio = 10.6; 95% CI = 2.7-41.3; p = 0.001) and gastric adenocarcinoma (odds ratio = 88.1; 95% CI = 6.3-1229.2; p = 0.001). CONCLUSIONS: Among patients infected with H. pylori, CagA+ seropositivity is associated with increased risk for both gastric and colonic cancer. This finding should stimulate additional research into the role of cagA+ H. pylori infection in the development of colorectal cancer.     

Expression of cell-cycle related proteins in Helicobacter pylori gastritis and association with gastric carcinoma

Helicobacter pylori (H. pylori) infection is associated with changes in epithelial turnover, through their significance of these in gastric carcinogenesis is still controversial. The purpose of this study was to determine the influence of H. pylori infection on cell proliferation and the relation with the cell-cycle regulators, and finally to provide insights into the mechanism by which H. pylori may lead to gastric carcinogenesis. We investigated Ki-67, p53, p21(Waf1/Cip1), cyclin D1 expression in 55 patients with H. pylori gastritis, and compared the results with patients those of non-H. pylori gastritis patients (n=21), gastric adenocarcinoma patients (n=8) and samples with normal gastric mucosa (n=12). Gastric biopsies were histologically evaluated for inflammatory reaction, intestinal metaplasia and atrophy according to the Sydney system. Overexpression of Ki-67, p53, p21(Waf1/Cip1) and cyclin D1 was found in H. pylori gastritis patients (32.7%, 10.9%, 20.0% and 7.3%, respectively), whereas only scattered expression in cells in the neck region of the crypts, but no overexpression was found in gastric antral epithelial cells in biopsy specimens from patients with non-H. pylori gastritis and noninflammed mucosa. A significant relationship was found between the grade of H. pylori colonization and Ki-67, p53, p21(Waf1/Cip1) and cyclin D1 expression. Expression was significantly higher in patients with intestinal metaplasia with atrophy, whereas no overexpression was found in patients without intestinal metaplasia with atrophy (p=0.05). H. pylori infection is associated with increased cell proliferation, increased epithelial DNA damage, and atrophy, which might contribute to the development of gastric cancer. Even if the exact mechanism has not been elucidated yet, our results suggest that H. pylori infection acts as a cofactor in gastric carcinogenesis.     

Preservation of gastric acid secretion may be important for the development of gastroesophageal junction adenocarcinoma in Japanese people, irrespective of the H. pylori infection status

BACKGROUND: We have previously reported that Helicobacter pylori infection prevents reflux esophagitis (RE) and Barrett's esophagus (BE) by decreasing gastric acid secretion. Gastroesophageal (GE) junction adenocarcinoma, including Barrett's adenocarcinoma, has been thought to be a complication of gastroesophageal reflux disease (GERD). However, the relationship between H. pylori infection, gastric acid secretion, and GE junction adenocarcinoma has not yet been investigated in Japan. The aim of this study was to evaluate this relationship in the Japanese population. METHODS: A total of 168 Japanese patients (RE alone: 80, short-segment BE (SSBE): 16, long-segment BE (LSBE): 20, GE junction adenocarcinoma: 12, distal early gastric cancer (EGC): 40; male/female = 106/62; mean age 61.5 yr) and 80 Japanese control subjects who had no localized lesions in the upper gastrointestinal tract (male/female = 43/37, mean age 58.1 yr) were enrolled for this study. The prevalence of H. pylori infection was determined by biopsy, the rapid urease test, and measurement of the serum H. pylori IgG antibody. Gastric acid secretion was assessed by the endoscopic gastrin test (EGT). RE was diagnosed according to the Los Angeles classification. RESULTS: The prevalence of H. pylori infection in the patients with RE alone (30%) was significantly lower than that in control subjects (71.2%). There was also a tendency for the prevalence of H. pylori infection to be lower in patients with BE (SSBE, 18.7%; LSBE, 0%) when compared to that in patients with RE alone. On the other hand, while the prevalence of H. pylori infection in patients with GE junction adenocarcinoma (58.3%) was significantly lower than that in patients with EGC (87.5%), it tended to be higher than that in patients with RE alone or BE. The mean EGT value in patients with RE alone (3.74 mEq/10 min) was significantly higher than that in control subjects (1.83). The mean EGT value in patients with BE (SSBE, 4.74; LSBE, 4.76) tended to be even higher than that in patients with RE alone. The mean EGT value in patients with GE junction adenocarcinoma (3.94) was significantly higher than that in control subjects and patients with EGC (0.67), but it was comparable to that independent of the H. pylori infection status in patients with RE alone or BE. CONCLUSION: Preservation of gastric acid secretion may be important for the development of GE junction adenocarcinoma in Japanese people, irrespective of the H. pylori infection status.