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1.
Helicobacter pylori (H. pylori) is causally associated with peptic ulcer disease and gastric carcinoma. Typically, children get infected during the first decade of life, but diseases associated with H. pylori are seen mainly in adults. Multiple diagnostic methods are available for the detection of H. pylori infection. The aim of this study was to evaluate the correlation and diagnostic accuracy of three invasive methods [rapid urease test (RUT), histology and bacterial culture] and one non-invasive method (IgG serology) for diagnosis of H. pylori infection in a prospective cohort study conducted on 50 symptomatic children between two and eighteen years of age. Endoscopies with gastric biopsies were performed for RUT, culture and histopathological examination, respectively. IgG antibodies were measured in patient sera using a commercially available enzyme-linked immunosorbent assay (ELISA). RUT and positive H. pylori IgG antibodies were concordant in 88% (44/50) of patients. Both tests were negative in 32% (16/50), and both were positive in 56% (28/50). Disagreement occurred in 12% (6/50) of the patients: three of them (6%) had positive RUT and negative H. pylori IgG, and another three (6%) had negative RUT and positive H. pylori IgG. A combination of RUT with non-invasive serology constituted the optimum approach to the diagnosis of H. pylori infection in symptomatic children. The non-invasive serological test (ELISA) could not be used alone as the gold standard because it cannot distinguish between active and recently treated infection; and bacterial culture could not be used alone because of its low sensitivity.  相似文献   

2.
A commercial ELISA for the detection of Helicobacter pylori IgG antibodies was evaluated using serum from 242 patients attending an endoscopy clinic. The efficacy of the ELISA was assessed in relation to the histological detection of H pylori on antral mucosal biopsy specimens. In patients under 61 years of age (n = 138) the ELISA was 97.5% sensitive and 85.5% specific for H pylori infection, with a positive predictive value of 91% and a negative predictive value of 96%. Over the whole group the sensitivity of the ELISA was 93.8% and the specificity 79.3%. The positive predictive value and negative predictive values were, respectively, 90% and 87%. These results suggest that the Bio-Rad GAP IgG H pylori ELISA is suitable for serodiagnosis of H pylori infections for most clinical purposes and thus makes H pylori serology available to routine diagnostic laboratories.  相似文献   

3.
Helicobacter pylori is one of the most common chronic bacterial infection in humans linked to acid peptic diseases, gastric carcinomas and lymphomas. The bacilli produces large amounts of urease and this property has formed the basis of detection of H. pylori by the Christensen's urease test. Where endoscopy is not clinically indicated, serology may be used to establish the diagnosis. This study was undertaken to diagnose H. pylori with the help of Christensen's urease test on endoscopic biopsy specimens & correlated with the detection in Sera, of IgG antibodies against H. pylori, by ELISA technique. The study was conducted on 100 patients suffering from acid peptic disorders out of which 40 (40%) tested positive for H. pylori both by urease and serology. Christensen's urease and ELISA were found to have sensitivities of 85.7% & 90.9% and specificities of 96% and 87.5% respectively. Christensen's urease was taken as a standard method of diagnosis and its correlation with ELISA worked out to (+1) which meant there was a strong positive association between both the tests. Hence either test could be used for primary diagnosis of H. pylori instead of histopathological study and/or culture of H. pylori.  相似文献   

4.
Helicobacter pylori has been known to be associated with gastric adenocarcinoma by case control studies. However, significant portion of patients with gastric carcinoma are negative for H. pylori by serological test. To further detect the presence of H. pylori infection in serum and tissue of patients with gastric adenocarcinoma, paired tissues and serum samples from 32 patients with gastric adenocarcinoma were tested. Antibodies to H. pylori were tested by an enzyme linked immunosorbent assay (ELISA) and a Western blot analysis. H. pylori in tumor and non-tumor parts of gastric tissues were examined by histology and polymerase chain reaction (PCR). For serum antibody, eighteen (56%) of these patients were positive by ELISA while 24 (75%) were positive by Western blot. For tissue H. pylori genome, 14 were positive by histology while 28 (87%) were positive by PCR. Southern blot analysis of both tumor and non-tumor tissues revealed no evidence of integration of H. pylori DNA in the human genomes. These results suggest that H. pylori infection can be detected in most patients with gastric adenocarcinoma, and PCR and Western blot can further identify seronegative patients.  相似文献   

5.
AIMS--To investigate the prevalence of Helicobacter pylori in the saliva of patients infected with this bacterium. METHODS--A novel polymerase chain reaction (PCR) assay was developed to detect H pylori in saliva and gastric biopsy specimens from patients undergoing endoscopy. RESULTS--Our PCR assay amplified a 417 base pair fragment of DNA from all 21 DNAs derived from H pylori clinical isolates but did not amplify DNA from 23 non-H pylori strains. Sixty three frozen gastric biopsy and 56 saliva specimens were tested. H pylori specific DNA was detected by PCR in all 39 culture positive biopsy specimens and was also identified from another seven biopsy specimens which were negative by culture but positive by histology. H pylori specific DNA was identified by PCR in saliva specimens from 30 (75%) of 40 patients with H pylori infection demonstrated by culture or histological examination, or both, and in three patients without H pylori infection in the stomach. CONCLUSION--The results indicate that the oral cavity harbours H pylori and may be the source of infection and transmission.  相似文献   

6.
Benign monoclonal expansion of CD8+ lymphocytes in HIV infection   总被引:7,自引:0,他引:7       下载免费PDF全文
BACKGROUND: A transient expansion of the CD8+ T cell pool normally occurs in the early phase of HIV infection. Persistent expansion of this pool is observed in two related settings: diffuse infiltrative lymphocytosis syndrome (DILS) and HIV associated CD8+ lymphocytosis syndrome. AIM: To investigate a group of HIV infected patients with CD8+ lymphocytosis syndrome with particular emphasis on whether monoclonality was present. METHODS: A group of 18 patients with HIV-1 infection and persistent circulating CD8+ lymphocytosis was compared with 21 HIV positive controls. Serum samples were tested for antinuclear antibodies, antibodies to extractable nuclear antigens, immunoglobulin levels, paraproteins, human T lymphotropic virus type 1 (HTLV-1), Epstein-Barr virus, and cytomegalovirus serology. Lymphocyte phenotyping and HLA-DR typing was performed, and T cell receptor (TCR) gene rearrangement studies used to identify monoclonal populations of T cells. CD4+ and CD8+ subsets of peripheral blood lymphocytes were purified to determine whether CD8+ populations inhibited HIV replication in autologous CD4+ cells. RESULTS: A subgroup of patients with HIV-1 infection was found to have expanded populations of CD8+ T cell large granular lymphocytes persisting for 6 to 30 months. The consensus immunophenotype was CD4- CD8+ DRhigh CD11a+ CD11c+ CD16- CD28+/- CD56- CD57+, consistent with typical T cell large granular lymphocytes expressing cellular activation markers. Despite the finding of monoclonal TCR gene usage in five of 18 patients, there is evidence that the CD8+ expansions are reactive populations capable of mediating non-cytotoxic inhibition of HIV replication. CONCLUSIONS: A subgroup of HIV positive patients has CD8+ lymphocytosis, but despite the frequent occurrence of monoclonal TCR gene usage there is evidence that this represents an immune response to viral infection rather than a malignant disorder.  相似文献   

7.
Occult hepatitis B virus (HBV) is defined by the presence of plasma HBV DNA in individuals with HBV core antibodies (anti‐HBc), but without HBV surface antigen (HBsAg). The prevalence of occult HBV in HIV‐infected patients remains controversial, and the risk factors, clinical significance and effect of highly active antiretroviral therapy (HAART) are unknown. The aim of this study was to determine prevalence, risk factors, and clinical significance of occult HBV in HIV‐infected patients and to evaluate the effect of HAART. Plasma HBV DNA levels were determined in 191 HIV positive, antiretroviral naïve patients, who were anti‐HBc positive and HBsAg negative. Quantitative HBV DNA was determined using a Taqman real‐time nested PCR. Additionally, plasma HIV RNA levels, CD4 cell counts, anti‐HBs‐antibodies, anti‐HCV‐antibodies, ALT, AST, and γGT were determined. Occult HBV (a plasma HBV DNA level >50 copies/ml) was detected in 9/191 (4.7%) of the patients. Among 45 anti‐HBs‐negative patients (isolated anti‐HBc positive), the prevalence was 11.1%. Patients with occult HBV had significantly lower CD4 count compared to anti‐HBc‐positive/HBsAg negative/HBV DNA‐negative patients (105 ± 157 (median ± SD) vs. 323 ± 299 cells/mm3, P = 0.019). When HAART (including lamivudine) was initiated in the patients with occult HBV, HBV DNA was no longer detectable in any of the patients during 3 years of follow‐up. In conclusion, occult HBV was associated with low CD4 counts and may be viewed as opportunistic reactivation of HBV that resolves as a consequence of HAART induced immune reconstitution and/or the effect of lamivudine. J. Med. Virol. 81:441–445, 2009. © 2009 Wiley‐Liss, Inc.  相似文献   

8.
The systemic immune response to Helicobacter pylori was examined in 69 children with recurrent abdominal pain and upper gastrointestinal symptoms. Twenty one (30%) children were histologically positive for H pylori. Eighteen of the 21 positive subjects and two H pylori negative subjects (one with normal mucosa, one with lymphocytic gastritis) were positive for H pylori IgG antibodies by enzyme linked immunosorbent assay (ELISA) (86% sensitivity, 98% specificity). In children with H pylori associated gastritis, there was a significant positive correlation (p less than 0.05) between IgG antibody titres and patient age. Intra-assay comparison of sera from histologically negative adults with those of histologically negative children showed that the cut off for positivity in the ELISA for adults was greater than that for children. Immunoblotting showed IgG positivity in 20 of the 21 patients with H pylori infection (95% sensitivity). Both ELISA and immunoblotting for IgA and IgM H pylori antibodies had poor discriminatory value for determining infection. Serological detection of H pylori IgG antibodies seems to be valuable in the assessment of children presenting with recurrent abdominal pain and other gastrointestinal symptoms, but assays must first be validated in paediatric populations.  相似文献   

9.
Helicobacter pylori infection is common in Jamaica. Describing its epidemiology in a population-based study depends largely on serology, but serologic assays have not been validated in this population. To address this issue, we examined the presence of H. pylori infection in 30 sequential adult patients with gastroduodenal symptoms by three biopsy-based methods (rapid urease test, histology, and culture) as well as by one research and two commercial enzyme-linked immunosorbent assays (ELISAs). A patient was considered H. pylori positive if the organism was detected by at least one biopsy-based method. Eighteen (60%) of the 30 patients were H. pylori positive by these criteria, whereas 21 (70%) were seropositive for H. pylori immunoglobulin G by our research ELISA. The presence of H. pylori infection in patients with gastric cancer and those with chronic gastritis was missed by biopsy-based methods but was detected by serologic assays. This observation indicates that serologic assays may be better suited for the detection of this infection in a population in which H. pylori-associated pathology is prevalent. The performance of our research ELISA in detecting biopsy-based H. pylori-positive cases was excellent, with a sensitivity and specificity of 100% and 75%, respectively. Molecular genotyping of the isolates revealed that the predominant H. pylori genotypes in this cohort of Jamaicans were cagA(+) vacA slb-m1, and iceA2. The validated serologic assay enables us to interpret epidemiologic data from population-based studies in Jamaica by comparison to those from other populations.  相似文献   

10.
Helicobacter pylori is implicated in causation of peptic ulcers and gastric cancer and plays a pivotal role in gastric pathophysiology. In the present study we evaluated the relative efficacy of sonicated and acid-extractable antigens in the serodiagnosis of H. pylori infection in peptic ulcer patients by ELISA. In the present study we evaluated the relative efficacy of sonicated and acid-extractable antigens in the serodiagnosis of H. pylori infection in peptic ulcer patients by ELISA. The two types of antigens mentioned above were prepared from H. pylori subcultures following appropriate procedures. Sera were collected from 13 subjects of whom eight were diagnosed to be suffering from duodenal ulcer (DU) and five from non-ulcer dyspepsia (NUD) and screened for the presence of anti H. pylori antibodies by ELISA. A case was considered seropositive, if the OD value was more than or equivalent to twice the mean OD value of blank. Analysis of our results showed that, with acid extractable antigen at a concentration of 2 mg/mL, 12 cases were seropositive. Contrastingly, with sonicated antigen, at a concentration of 2 mg/mL only eight cases were positive. It is concluded from this study, that the use of relatively purified antigens like acid extractable antigens enhances the sensitivity and specificity of this serodiagnostic test, indicative of its relatively higher efficacy over sonicated lysate containing multiple antigens.  相似文献   

11.
目的 研究HIV感染者/AIDS患者外周血CD4^+ CD25^+ 调节性T细胞(CD4^+ CD25^+ regulatory Tcell,Treg)频率、功能及其临床意义。方法 选择31例HIV感染者/AIDS患者和30例健康对照者,采用流式细胞仪检测各组外周血Treg的表型和频率。采取MACS磁珠分选CD4^+CD25^+T细胞,利用[^3H]胸腺嘧啶掺入法检测CD4^+ CD25^+T细胞在特异性HIV抗原刺激下对CD4^+ CD25-T细胞的增殖影响。结果HIV/AIDS患者组与正常对照组相比较,外周血CD4^+ CD25^+ T细胞频率在统计学上差异无统计学意义。与正常对照组比较,HIV感染者外周血CD4^+ CD25^+ T细胞频率升高,差异有统计学意义(P〈0.01);与正常对照组比较,AIDS患者者外周血CD4^+ CD25^+ T细胞频率降低,差异有统计学意义(P〈0.0001)。HIV RNA病毒载量与患者外周血CD4^+ CD25^+ T细胞数量呈正相关性(P〈0.01)。CD4^+ CD25^+ T细胞具有抑制HIV特异性的CD4^+ CD25^- T细胞的增殖作用。结论HIV感染者/AIDS患者的细胞免疫功能紊乱,CD4^+ CD25^+ T细胞能抑制HIV感染者/AIDS患者的HIV特异性细胞免疫反应,促进HIV病毒复制,与形成持续HIV感染有关。  相似文献   

12.
Aim:  Renal dysfunction may influence the colonization of gastric mucosa by urea-splitting bacteria such as Helicobacter pylori , by increasing urea concentrations in the gastric juice. Our aim was to investigate the prevalence of H. pylori in patients with end-stage renal disease (ESRD), receiving long-term haemodialysis treatment.
Methods:  This study included 40 sera from patients with ESRD (29 male and 11 female) undergoing periodic haemodialysis; mean time of treatment was 42.6 months. Using ELISA technique, we investigated the presence of IgG and IgA antibodies against H. pylori as well as IgG CagA (antibodies specific for CagA(+) strains of H. pylori ). Sera from 40 healthy blood donors were used as a control group.
Results:  H. pylori IgG antibodies were detected in 32 out of 40 (80%) patients in the dialysis group, while 31/40 (77.5%) tested positive for IgA. IgG CagA antibodies were present in 13 out of 40 (32.5%). Prevalence of H. pylori IgG, IgA and CagA IgG antibodies in the control group was 33, 7 and 15%, respectively.
Conclusions:  Although international data suggest that prevalence of H. pylori infection is the same in ESRD patients as in healthy individuals, in our study that seems not to be the case. The higher blood and gastric juice urea levels may be a risk factor (among many others), but more studies are required in order to understand the relation of H. pylori infection in this group of patients.  相似文献   

13.
AIM: To investigate the association between Helicobacter pylori infection and serum pepsinogen (PG) 1 and 2 concentrations in various gastroduodenal diseases. METHODS: Serum PG1 and 2 concentrations and antibodies to H pylori were measured by enzyme linked immunosorbent assay (ELISA); gastric mucosal pH was assessed and urease activity in biopsy tissue was determined. A comparison of the ELISA and urease test results permitted division of the cases into positive, false positive, false negative and negative categories for control, gastritis, and ulcer groups. RESULTS: The gastric mucosal pH and serum PG2 in cases positive for H pylori were significantly increased in ulcer and gastritis cases compared with H pylori negative cases. Similar tendencies were observed for the false positive and false negative categories. CONCLUSIONS: A positive ELISA reaction for antibodies and an increased serum PG2 concentration are reliable indicators of H pylori infection.  相似文献   

14.
BACKGROUND AND INTRODUCTION: It has been suggested that chronic infections may have a role in both the initiation and progression of atherosclerosis. While the majority of available data are focused on coronary artery disease, our aim was to investigate the presence of Chlamydia pneumoniae and Helicobacter pylori in samples from aortoiliac occlusive disease. METHODS: Aorta-iliac atherectomy specimens were collected under sterile conditions from 21 patients (19 male, 2 female) undergoing surgery for aortoiliac occlusive disease. Seventeen macroscopically healthy vessels (12 internal mammary arteries, 3 radial arteries, prepared for coronary artery bypass graft, and 2 traumatic artery specimens, one of which was a superficial femoral artery and the other was a radial artery) were used as control. Blood samples for serological assays were obtained immediately before surgery. The polymerase chain reaction (PCR) was employed to search for H. pylori and C. pneumoniae DNA in atherosclerotic plaques and healthy vessel samples. Group-specific chlamydial lipopolysaccharide (LPS) antigens in atherosclerotic plaques and in healthy vessel samples and serum IgG antibodies to chlamydial LPS were determined by using a commercially available enzyme-linked immunosorbent assay (ELISA). Antibodies to H. pylori were also tested in all cases by means of an in-house ELISA. RESULTS: Chlamydial LPS and DNA were detected in 6 of 21 (28.57%) atherosclerotic lesions using ELISA or PCR, respectively. There was no evidence of H. pylori DNA in any plaque specimens. All cases in which C. pneumoniae DNA was positive were also seropositive for antichlamydial LPS. Neither C. pneumoniae DNA nor antigen nor H. pylori DNA was found in the macroscopically healthy samples. CONCLUSION: Our results suggest that C. pneumoniae but not, as proposed, H. pylori may be involved in the pathogenesis of aortoiliac atherosclerosis.  相似文献   

15.
Twenty-three young adult rhesus monkeys from China were evaluated for the presence of Helicobacter pylori. Gastric body and antral biopsy samples were tested for H. pylori by PCR analysis, culture, rapid urease testing, and histologic evaluation. Serologic testing to detect H. pylori immunoglobulin G (IgG) antibodies was performed by using a commercially available human-based enzyme-linked immunosorbent assay (ELISA) test and an ELISA test which utilized homologous H. pylori antigens and an anti-rhesus IgG conjugate. PCR analysis with H. pylori-specific 26-kDa protein primers detected H. pylori in 21 of the 23 rhesus monkeys (91%). Culture testing identified the organism in 12 of the 23 animals (52%). Rapid urease tests were positive for all animals. H. pylori was diagnosed by histological examination in 11 of 23 monkeys (48%). Of the 21 monkeys positive for H. pylori by PCR, only 3 (14%) had positive results by the commercial ELISA test, yielding a sensitivity of 14%, a specificity of 100%, and an accuracy of 22%. However, 19 of the 21 PCR-positive animals (90%) had positive results by the ELISA test with homologous rhesus H. pylori antigen and anti-monkey conjugate, with predicted index values greater than or equal to 0.7 considered positive and values between 0.5 and 0.7 considered equivocal. This test had a sensitivity of 90%, a specificity of 100%, and an accuracy of 91%. Therefore, the ELISA test with rhesus monkey origin components was more accurate for detecting infected animals than the human-based ELISA.  相似文献   

16.
目的 调查分析某艾滋病治疗示范区人免疫缺陷病毒(HIV)-1感染者中隐匿性乙型肝炎病毒(HBV)感染的情况及其影响因素.方法 采集某艾滋病治疗示范区97例经血感染HIV-1的感染者的血浆,采用酶联免疫吸附试验(ELISA)检测乙型肝炎表面抗原与抗体(HBsAg与抗HBs)、乙型肝炎e抗原与抗体(HBeAg与抗Hbe)、乙型肝炎核心抗体(抗HBc)及丙型肝炎抗体(抗HCV);采用吸附柱法抽提HBV DNA;采用巢式聚合酶链反应(PCR)法检测HBV S区;采用流式细胞仪计数CD4+T淋巴细胞.HBsAg阴性PCR阳性结果 者为合并隐匿性HBV感染者.合并隐匿性HBV感染者为实验组,未合并隐匿性HBV感染者为对照组.结果 97例HIV感染者中HBsAg阴性者92例(94.85%).92例HBsAg阴性者中合并隐匿性HBV感染者27例(29.35%),抗HCV阳性者73例(79.35%).合并隐匿性HBV感染者和未合并HBV感染者CD4+T淋巴细胞数、单独抗HBc阳性率分别为(212.11±133.1)和(318.9±172.2)cells/mm3、62.96%和18.46%,以上两指标两组比较差异均有统计学意义(P<0.01),两组间年龄、性别、是否合并HCV感染及抗HBs阳性率比较差异无统计学意义(P>0.05).结论 经有偿献血途径感染HIV者中存在隐匿性HBV感染;HIV阳性合并隐匿性HBV感染者中易出现单纯抗HBc阳性;CD4+T淋巴细胞数低的HIV感染者更容易合并隐匿性HBV感染.  相似文献   

17.
18.
A 16S ribosomal DNA-based PCR appeared to be a sensitive test for the detection of infection by Helicobacter pylori in 31 patients when compared with culturing and histological and serological techniques. For five patients, PCR was the only test with a positive result. H. pylori DNA was also found in gastrointestinal equipment even after standard intensive combined manual and machine cleaning. We therefore conclude that a reliable validation of PCR for the detection of H. pylori in gastric biopsy specimens is possible only when the cleaning and disinfection method used has been proven to remove all H. pylori DNA from gastrointestinal equipment. An adequate cleaning and disinfection method for the removal of H. pylori DNA from fiberoptic endoscopes is described.  相似文献   

19.
The aim of this study was to evaluate an enzyme-linked immunosorbent assay (ELISA) for the detection of anti-Helicobacter pylori specific IgG antibodies in specimens of oral fluid. Antral biopsy specimens, serum and oral fluid samples were collected from 81 patients attending for upper gastrointestinal endoscopy. The presence or absence of current H. pylori infection was determined by culture, histology and urease detection. Anti-H. Pylori specific IgG was detected in serum by an established in-house ELISA and in oral fluid by an ELISA developed for this study. In all, 34 (42%) of 81 patients were positive for H. pylori by one or more of the 'gold standard' tests (culture, histology and urease detection). The oral fluid ELISA had a sensitivity of 94% and specificity of 85% with regard to current H. pylori infection. The serum ELISA had a sensitivity and specificity of 91%. There was an overall agreement of 88% between serum and oral fluid antibody detection. The detection of anti-H. pylori specific IgG in oral fluid by ELISA is comparable in sensitivity and specificity with serum-based methods. Oral fluid-based ELISA could provide a reliable, non-invasive method for the diagnosis of H. pylori infection, and may be of particular benefit for population surveys.  相似文献   

20.
CD14 is a pattern recognition receptor on the membranes of monocytes and macrophages for several microbial products, of which lipopolysaccharide (LPS) is the best known. A shed form of CD14 is present in serum. As the CD14 gene promoter polymorphism -159C/T and some bacterial infections may affect the sCD14 levels, we compared the impact of both the CD14 promoter polymorphism and Helicobacter pylori infection on serum sCD14 levels in 201 dyspeptic patients (group 1) who had undergone gastroscopy, and 127 staff members (group 2) with no endoscopy. sCD14 was measured from the sera by a commercial enzyme immunoassay (EIA), and CD14 genotyping was carried out with PCR. Helicobacter pylori infection was detected by serology and/or culture or PCR. sCD14 levels were elevated in the subjects carrying the T allele (CT or TT genotype) in both groups when compared with subjects with the CC genotype. Overall, H. pylori-positive subjects tended to have higher sCD14 levels compared with H. pylori-negative subjects. In group 1 consisting of dyspeptic patients, those with gastric ulcer, gastric erosion or duodenal ulcer had significantly elevated levels of sCD14 compared with the patients with normal endoscopic findings or macroscopic gastritis. The recent use of NSAIDs was also associated with enhanced sCD14. Thus, we were able to show several factors, one genetic and the other environmental (H. pylori infection and mucosal lesion), to have an impact on sCD14.  相似文献   

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