PubMed Health⌕ Search

Biomedical subjects

H Rautelin

Publications and source records attributed to H Rautelin.

At least 37 records · Page 2Linked to original sources

Serologic diagnosis of Helicobacter pylori infection in outpatients aged 45 years or less.

The diagnostic accuracy of serological tests for Helicobacter pylori was studied in 145 consecutive outpatients aged 45 years or less referred for gastroscopy. Helicobacter pylori infection can be detected by serological tests, including rapid whole-blood tests. The low prevalence of the disease in young people may have a negative effect on the positive predictive value of a test. In this study, the presence of Helicobacter pylori was assessed by a biopsy urease test and histological examination, and by several serological tests: a rapid whole-blood test on fingerstick blood, a latex agglutination serum test, a commercial enzyme immunoassay (EIA) test, and an in-house EIA for detection of antibodies of both the IgG and IgA classes. Helicobacter pylori infection was diagnosed with invasive tests in 21 (14.5%) patients. The sensitivity, specificity, and positive and negative predictive values of the EIA-based tests, compared to histological examination, were 100%, 96-97%, 81-84%, and 100%, respectively. The positive predictive value of the latex agglutination test was 78%, whereas it was only 47% for the whole-blood rapid test used. Although the results of the whole-blood rapid test were unsatisfactory, the quantitative EIA-based tests could reliably detect Helicobacter pylori among young patients, in whom the prevalence of the infection is low.

Adult↗

Survival of Helicobacter pylori From complement lysis by binding of GPI-anchored protectin (CD59).

BACKGROUND & AIMS: Although Helicobacter pylori is sensitive to complement lysis in vitro, chronic infection persists for years. We tested whether H. pylori acquires complement resistance by binding glycolipid-tailed inhibitors from the host. METHODS: Gastric biopsy specimens from H. pylori-infected patients (n = 10) and noninfected controls (n = 6) were analyzed for complement deposition and expression of the complement regulators protectin (CD59) and DAF. Protectin binding and complement sensitivity analyses were performed with the NCTC strain 11637 (CagA(+)) and 2 clinical isolates 9:0 (CagA(+)) and 67:20 (CagA(-)). RESULTS: In the noninfected mucosa, protectin was strongly expressed on the membranes of epithelial cells, but in the infected epithelia the expression was granular and more focused to the mucus. H. pylori bacteria in the gastric pits were often positive for protectin but negative for C5b-9. An opposite pattern was seen on the surface mucosa. In vitro analyses using (125)I-CD59 and bacteriolysis assays showed that protectin bound to H. pylori and protected CagA(+) strains against complement killing. In an enzyme-linked immunosorbent assay, the binding of CD59 correlated inversely with the appearance of the C5b-9 neoantigen. CONCLUSIONS: Binding of protectin inhibits membrane attack complex assembly on H. pylori and may thereby contribute to their survival on the gastric mucosa.

Adult↗

Dental caries is common in Finnish children infected with Helicobacter pylori.

Childhood factors such as low socioeconomic status are risk factors for Helicobacter pylori infection and Streptococcus mutans-related dental caries. We examined whether H. pylori infection and dental caries are present today in the same group of children examined previously. We reviewed the public dental health service files of 21 H. pylori-positive children (upper gastrointestinal endoscopy at a median age of 13.5 y) and 27 H. pylori-negative children (endoscopy at a median age of 12.5 y) examined during 1995-98 at the Helsinki University Central Hospital, Finland. All H. pylori-positive children had experienced dental caries in their primary or permanent teeth or in both whereas among H. pylori-negative children the respective proportion was 70% (p < 0.01). At the age of 7 y, 18% (3/17) of the H. pylori-positive children had experienced caries in permanent teeth as compared to 0% among H. pylori-negative children (0/24; p < 0.05). At the age of 12 y, H. pylori-positive children had more decayed, missing or filled permanent teeth than H. pylori-negative children (80% vs. 38%; p < 0.05). Although a causal relationship between H. pylori and dental caries is unlikely, it is possible that H. pylori-infected children have an increased risk of other health problems, such as dental caries, for which proper treatment is needed.

Adolescent↗

Should Helicobacter pylori infection be treated before kidney transplantation?

BACKGROUND: Before the introduction of modern medication for ulcer disease, gastroduodenal complications were often fatal in recipients of kidney transplants. Helicobacter pylori causes gastritis and is an important risk factor for peptic ulcer disease and gastric malignancies. The aim of this study was to evaluate whether H. pylori infection influences the outcomes of kidney transplantation. METHODS: Between 1991 and 1994, serum H. pylori antibodies were determined in samples taken just before transplantation from 500 consecutive recipients of kidney transplants. Clinical data were collected retrospectively by means of questionnaires sent to the patients and from the national kidney transplantation registry. RESULTS: The prevalence of seropositivity of H. pylori was 31% in the 500 renal transplant subjects, and the seropositivity increased with age. There were no differences in patient or graft survival between the seronegative and seropositive patients. During the first 3 months after transplantation, five seronegative and one seropositive patient had gastroduodenal ulcers, with bleeding complications in three of the seronegative ones. After 3 months, there were more ulcers in the seropositive group (6 vs 3%) and more oesophagitis in the seronegative group (9 vs 7%). During the 6-year follow-up, two cases of gastroduodenal malignancies were found in the helicobacter-positive group and none in the seronegative group. CONCLUSIONS: Helicobacter pylori infections did not result in significant postoperative gastric complications. Two of the 155 seropositive patients developed gastroduodenal malignancies.

Adolescent↗

Good adhesion properties of probiotics: a potential risk for bacteremia?

The ability to adhere to human intestinal mucus was tested for lactic acid bacteria of clinical blood culture, human fecal and dairy origin. The blood culture isolates were found to adhere better than the dairy strains. Of the Lactobacillus rhamnosus strains (nine clinical, 10 fecal and three dairy), blood culture isolates adhered better than the fecal strains. Although these results indicate a trend for blood culture isolates to bind to intestinal mucus in higher numbers than strains of dairy and human fecal origin, other factors are also likely to be involved in the etiology of lactobacillemia since some of the clinical Lactobacillus isolates exhibited a relatively low level of adhesion.

Adult↗

Genomic relatedness within five common Finnish Campylobacter jejuni pulsed-field gel electrophoresis genotypes studied by amplified fragment length polymorphism analysis, ribotyping, and serotyping.

Thirty-five Finnish Campylobacter jejuni strains with five SmaI/SacII pulsed-field gel electrophoresis (PFGE) genotypes selected among human and chicken isolates from 1997 and 1998 were used for comparison of their PFGE patterns, amplified fragment length polymorphism (AFLP) patterns, HaeIII ribotypes, and heat-stable (HS) serotypes. The discriminatory power of PFGE, AFLP, and ribotyping with HaeIII were shown to be at the same level for this selected set of strains, and these methods assigned the strains into the same groups. The PFGE and AFLP patterns within a genotype were highly similar, indicating genetic relatedness. The same HS serotypes were distributed among different genotypes, and different serotypes were identified within one genotype. HS serotype 12 was only associated with the combined genotype G1 (PFGE-AFLP-ribotype). These studies using polyphasic genotyping methods suggested that common Finnish C. jejuni genotypes form genetic lineages which colonize both humans and chickens.

Animals↗

Decreasing prevalence of helicobacter antibodies in Finland, with reference to the decreasing incidence of gastric cancer.

Time trends and geographical variation of Helicobacter pylori antibodies in Finland were investigated by enzyme immunoassay in 20- to 34-year-old randomly selected females from six localities during 1969-73 (n = 375), and 15- to 45-year-old females representing nine communities and four geographical areas in 1983 (n = 882) and 1995 (n = 842). In the six communities investigated at three different time points, the overall prevalence declined from 38 to 12%, with an emphasis on the latter 12 years. The regionally varying rate of decrease in helicobacter prevalence changed the pre-existing geographical variation, leaving northern Finland with the highest rate. A 10%-units higher local helicobacter prevalence seemed to predict a 23% (95% CI 3-44%) higher gastric cancer incidence 20 years later. The overall decline in helicobacter seropositivity is consistent with earlier reports from Finland and other developed countries, and supports the cohort theory as an explanation for the age-related increase in H. pylori seroprevalence.

Adolescent↗

cagA, vacA and iceA virulence genes of Helicobacter pylori isolates of children in Finland.

cagA, vacA s and m genotypes and iceA alleles were analyzed from Helicobacter pylori strains isolated from 17 Finnish children and 32 children of non-Finnish origin living in Finland. Twelve children in the latter group were eastern European and 15 were of African origin. Only three children of non-Finnish origin were born in Finland. The vacA sla subtype was more prevalent in the isolates from Finnish children than African children (76% vs. 7%, P<0.001); vacA s1b frequencies were 5% and 67%, respectively (P<0.001). The iceA1 allele was significantly more prevalent in African than Finnish isolates (93% vs. 35%, P< 0.01). Considerable variation was noted in the frequency of vacA s1 subtypes and iceA alleles in children originating from different geographic regions, but the geographic variation of s1 subtypes resembled that described in other reports.

Antigens, Bacterial↗

Cure of Helicobacter pylori infection after failed primary treatment: one-center results from 120 patients.

BACKGROUND: Treatment with a proton pump inhibitor (PPI) and antimicrobials cures Helicobacter pylori infection in about 90% of patients. This is a retrospective overview of our studies aiming to cure the infection in all compliant patients with failed initial therapy. METHODS: We retreated 120 (19% of 644) H. pylori-infected patients whose initial therapy had failed. The retreatments included (i) triple therapy (TT): colloidal bismuth subcitrate, metronidazole, amoxicillin (or tetracycline); (ii) quadruple therapy (QT): TT and a PPI; or (iii) high doses of both a PPI and clarithromycin combined with a further 1-3 individually selected antimicrobials. The eradication results were determined after 6-12 months. RESULTS: The 1st retreatment was successful in 70 of 120 patients. The 2nd retreatment cured 25 of the remaining 42 patients, the 3rd 13 of 17, and the 4th the last 4 patients. The cumulative eradication rate (ITT) was 93% (95% CI: 88.9%-97.9%; 8 patients withdrew after a failed 1st retreatment) and the rate was 100% in the remaining 112 patients who accepted several retreatments. The 1st retreatment with TT cured 23% (95% CI: 12%-34%) of 57 patients and QT 85% (95% CI: 74%-96%) of 41 patients who had initially undergone a failed metronidazole-based treatment. All retreatments were well tolerated. CONCLUSIONS: In this study, high doses of a PPI and clarithromycin combined with 1-3 antimicrobials according to susceptibility data proved to be the best drug combination in the cure of H. pylori infection after failed primary treatment. Giving imidazole- and bismuth-based QT (without clarithromycin) as the first-line treatment of H. pylori infection ensures that the number of failures remains low.

Anti-Bacterial Agents↗

Evaluation of blood tests to predict normal gastric mucosa.

BACKGROUND: To determine the accuracy of blood tests in predicting normal gastric mucosa confirmed by histological examination of gastric biopsy specimens. METHODS: In total, 207 consecutive patients referred for upper endoscopy were included. Two biopsy specimens each from the antrum and corpus were assessed histologically for the presence of Helicobacter pylori, gastritis, and atrophy. Serum samples were studied for H. pylori antibodies by enzyme immunoassay (Pyloriset EIA-G and EIA-A) and by a rapid latex agglutination test (Pyloriset Dry); pepsinogen I was measured by an immunoenzymometric assay (Gastroset PGI), gastrin by radioimmunoassay, and parietal cell antibodies by indirect immunofluorescence. RESULTS: In 101 (49%) of 207 patients, the gastric mucosa on histologic examination was normal. In the 63 patients aged 45 years or less, H. pylori IgG serology was negative in all 47 patients with normal gastric mucosa and none had low serum pepsinogen I levels. Among 144 patients over age 45 years, 72 had negative H. pylori IgG serology. Combining the serum pepsinogen I assay with the results of H. pylori IgG serology, 12 patients with normal serology but low serum pepsinogen I were found. Thus, 60 patients, 52 of whom showed normal gastric histology, had normal IgG serology and serum pepsinogen 1. In the remaining eight patients with normal blood tests, the histologic changes were very mild. CONCLUSIONS: Although negative H. pylori IgG serology alone in younger patients, and in combination with normal serum pepsinogen I levels in older patients, reliably predicted the presence of normal gastric mucosa, gastroscopy is still recommended for patients over 45 years.

Adult↗

Diagnosis of Helicobacter pylori infection in patients with atrophic gastritis: comparison of histology, 13C-urea breath test, and serology.

BACKGROUND: Atrophic gastritis, a risk factor for gastric cancer, is a late consequence of Helicobacter pylori infection in approximately one-third of the infected patients. It has been suggested that gastric cancer would develop less frequently if H. pylori were eradicated. However, the prevalence of H. pylori infection may be underestimated in patients with atrophic gastritis and intestinal metaplasia if only biopsy-based diagnostic methods are used. METHODS: We compared histology, 13C-urea breath test (13C-UBT), and serology in H. pylori diagnostics in 50 male patients with atrophic corpus gastritis. RESULTS: H. pylori was detected in 15 (30%) patients by histology and in 14 (28%) by 13C-UBT, whereas increased serum antibody levels indicating H. pylori infection were found in 41 (82%) patients (P < 0.0001 between serology and both histology and 13C-UBT). H. pylori infection was associated with atrophic corpus gastritis in 84% of the present patients (in one patient with normal antibody titres H. pylori was defined histologically). CONCLUSIONS: H. pylori infection would have been missed in most patients with atrophic gastritis without the analysis of H. pylori antibodies. Therefore, in patients with atrophic gastritis, the use of serology is encouraged in diagnosing H. pylori infection.

Aged↗

Parietal cell antibodies and Helicobacter pylori in children.

BACKGROUND: Gastric autoantibodies are common in Helicobacter pylori-infected adults, and the presence of these antibodies is associated with atrophic gastritis. The role of H. pylori in the autoimmune type of atrophic gastritis is unresolved, and it is not known at what stage the autoantibodies appear in serum during H. pylori infection. Therefore, we screened children with and without H. pylori infection for gastric parietal cell antibodies. METHODS: Seventy-one children with H. pylori infection verified by examination of gastric biopsy specimens (mean age, 9.4 years), 8 children with positive serology but negative histology for H. pylori (mean age, 11.6 years), and 130 children with negative serology for H. pylori (mean age, 7.7 years) were screened for the presence of gastric parietal cell antibodies in serum by indirect immunofluorescence. In addition, 61 children with celiac disease (mean age, 7.1 years) were screened for gastric parietal cell antibodies and H. pylori antibodies. RESULTS: None of the children with H. pylori infection had gastric parietal cell antibodies in serum. Only three positive parietal cell antibody reactions were found: a 14-year-old boy with positive serology for H. pylori but no other signs of infection (titer 5000), a 14-year-old girl with tuberculosis (titer 1250, seronegative for H. pylori) and a 10-year-old girl with insulin-dependent diabetes mellitus (titer 6250, seronegative for H. pylori). CONCLUSIONS: Although gastric autoantibodies are often found in adults with chronic H. pylori gastritis, it seems that H. pylori-infected children are not positive for gastric parietal cell antibodies. It remains to be studied in which H. pylori infections and at what stages gastric autoantibodies appear.

Adolescent↗

A three-year study of Campylobacter jejuni genotypes in humans with domestically acquired infections and in chicken samples from the Helsinki area.

Campylobacter jejuni isolates from stool samples of patients with domestically acquired sporadic infections and from chicken from retail shops were studied during seasonal peaks from June to September over a 3-year period from 1996 to 1998. A large number of pulsed-field gel electrophoresis (PFGE) genotypes (a combined SmaI-SacII pattern) were identified each year. Certain genotypes persisted for the whole study period, and predominant genotypes represented 28 to 52% of the strains during a restricted period of time. The peak level of positive chicken samples was between July and August of each study year, when 10 to 33% of the samples were positive for campylobacter. The same PFGE genotypes found in humans were also detected in the chicken samples. This suggests that common genotypes were circulating in the area.

Animals↗

Atrophic gastritis and Helicobacter pylori infection in outpatients referred for gastroscopy.

BACKGROUND: Atrophic gastritis has been shown to be one of the long term sequelae of Helicobacter pylori infection. AIMS: To determine the prevalence of atrophic gastritis in outpatients, to study the accuracy of serological methods for revealing atrophy, and to define the association of H pylori infection with atrophic gastritis in these patients. PATIENTS/METHODS: A total of 207 consecutive outpatients referred for gastroscopy were included. Biopsy specimens from the antrum and corpus were assessed histologically according to the Sydney system. Serum samples were studied for H pylori IgG and IgA antibodies by enzyme immunoassay, CagA antibodies by immunoblot, pepsinogen I by an immunoenzymometric assay, gastrin by radioimmunoassay, and parietal cell antibodies by indirect immunofluorescence. RESULTS: Histological examination revealed atrophic gastritis in 52 (25%) of 207 patients. H pylori and CagA antibodies were strongly associated with atrophic antral gastritis but poorly associated with atrophic corpus gastritis. Low serum pepsinogen I was the most sensitive and specific indicator of moderate and severe atrophic corpus gastritis. All six patients with moderate atrophic corpus gastritis had H pylori infection but eight of 10 patients with severe atrophic corpus had increased parietal cell antibodies and nine had no signs of H pylori infection. CONCLUSIONS: Atrophic antral gastritis was strongly associated with CagA positive H pylori infection. Severe atrophic corpus gastritis was not determined by H pylori tests but low serum pepsinogen I, high gastrin, and parietal cell antibodies may be valuable in detecting these changes.

Adult↗

Co-expression in Helicobacter pylori of cagA and non-opsonic neutrophil activation enhances the association with peptic ulcer disease.

AIMS: To investigate the association of cagA positivity and non-opsonic neutrophil activation capacity in wild-type Helicobacter pylori strains with peptic ulcer disease or chronic gastritis only. METHODS: Helicobacter pylori were isolated from antral biopsies of 53 consecutive patients with chronic antral gastritis, of whom 24 had peptic ulcer disease endoscopically. The presence of cagA, a marker for the cag pathogenicity island, was determined by polymerase chain reaction with specific oligonucleotide primers, and non-opsonic neutrophil activation capacity by luminol enhanced chemiluminescence. RESULTS: The cagA gene was present in 39 of 53 (73.6%) strains, 20 of which (83.3%) were from the 24 patients with peptic ulcer disease and 19 (65.5%) from the 29 patients with chronic gastritis only. Non-opsonic neutrophil activation was found in 29 (54.7%) strains, 16 of which (66.7%) were from patients with peptic ulcer disease, and 13 (44.8%) from those with chronic gastritis. Non-opsonic neutrophil activation was found more frequently in cagA+ than cagA- strains (59% v 42.9%). Whereas four of the 14 cagA- strains and eight of the 24 non-opsonic neutrophil activation negative strains were from patients with peptic ulcer disease, only two of 24 (8.3%) peptic ulcer disease strains expressed neither cagA nor non-opsonic neutrophil activation. The cagA gene and non-opsonic neutrophil activation capacity were co-expressed in 14 of 24 (58.3%) strains from patients with peptic ulcer disease, and in nine of 29 (31%) strains from individuals with chronic gastritis. CONCLUSIONS: Positivity for cagA and non-opsonic neutrophil activation occur independently in wild-type H pylori strains. However, co-expression of the two markers enhanced the prediction of peptic ulcer disease.

Antigens, Bacterial↗

Campylobacters: the most common bacterial enteropathogens in the Nordic countries.

Campylobacters have been known as important human pathogens since the late 1970s. Campylobacter jejuni and coli are the most common bacterial enteropathogens in the developed countries. During the past years an increasing incidence of campylobacteriosis has been reported in many developed countries. C. jejuni is the most common Campylobacter species while C. coli accounts for about 5-10% of the cases. Although the genome of C. jejuni NCTC 11168 strain was sequenced recently, the exact pathogenetic mechanisms are still not known. Furthermore, there are no reliable animal models available. The epidemiology of this common infection is not well understood; however, eating and handling poultry, contaminated drinking water, and contact with pet animals have been recognized as important risk factors. Most of the cases are sporadic although large water-borne outbreaks have also been reported. Discriminatory typing methods are helpful in tracing the sources and transmission routes. In addition to traditional serotyping, genotyping methods, such as pulsed-field gel electrophoresis, have been developed. As Campylobacter infections probably precede Guillan-Barré syndrome in many cases, a great interest has lately been focused on the possible triggering mechanisms underlying this phenomenon.

Campylobacter Infections↗

Identification of hippurate-negative thermophilic campylobacters.

Twenty-eight thermophilic campylobacter isolates showing negative hippurate hydrolysis were further characterized. Using Campylobacter jejuni and coli specific primers for ceuE gene, five of the isolates with repeatedly negative results in rapid hippurate hydrolysis were positive in C. jejuni-specific polymerase chain reaction (PCR) and 13 isolates were shown to be C. coli. All except one isolate with positive results in C. jejuni PCR were negative in C. coli PCR including those with repeatedly negative hippurate hydrolysis results. One isolate was positive in both PCRs due to a mixed culture. In comparison with PCR, API Campy gave concordant results in only 20 of the 28 isolates tested. Hybridization with PCR probes for ceuE gene of known C. jejuni and coli strains confirmed PCR results in all 27 isolates tested. In contrast to hippurate hydrolysis, PCR seemed to be a more reliable method to identify C. coli.

Bacterial Proteins↗