Laboratory handling of Helicobacter pylori critically influences the results of in-vitro metronidazole resistance determination.

In-vitro metronidazole resistance rates of Helicobacter pylori determined by Etest are high, and the predictive value of metronidazole resistance is low. It was hypothesised that altered laboratory methods could reduce the overestimation of resistance and improve the predictive value of the Etest. Pre-treatment isolates (n = 150) of H. pylori from 150 patients were investigated by Etest with incubation for 72 h. Treatment with metronidazole, tetracycline and bismuth for 10 days failed to eradicate H. pylori in 23 patients. After isolate storage for 3 years, resistance determination results by agar dilution and Etest, with incubation for 72 and 31 h, were compared. The rate of metronidazole resistance was reduced significantly during storage, and instability of resistance was associated significantly with treatment outcome. Isolates that retained in-vitro resistance had significantly (p 0.008) higher treatment failure rates (n = 13; 42%) than isolates that lost resistance (n = 3; 9%). The reproducibility achieved by dual testing with agar dilution and Etest was 41% and 70% for +/- 1 and +/- 2 log2 dilutions, respectively, after incubation for 72 h, and 85% and 92%, respectively, after incubation for 31 h. Thus, the predictive value was improved from 25% to 50% by the altered laboratory conditions (p 0.04). MIC values of 2-8 mg/L signified an intermediate risk of treatment failure.

[Argon plasma coagulation--a new method in therapeutic endoscopy]. / Koagulasjon med argonplasma--en ny metode i terapeutisk endoskopi.

BACKGROUND: By argon plasma coagulation (APC), a current is applied to tissues as ionised gas. Special probes have recently been developed for applying the gas through flexible endoscopes. In the field of therapeutic endoscopy, this method is promising for several diseases in the gastrointestinal tract. MATERIAL AND METHODS: At Ostfold Hospital in Fredrikstad, Norway, 122 treatments in 80 patients were performed during the years 1997-99. RESULTS: The new method was useful for endoscopic treatment of haemorrhages, tumour debulking and tumour ingrowth and overgrowth in oesophageal stents. Abdominal pain was related to insufflation of air and gas. Complications related to the method were not observed. INTERPRETATION: Our experience with this new method was very positive. The method was effective, had a very low complication rate, and the equipment was easy to use. The application of APC in premalignant conditions is discussed.

[Assessment of the need of 24-hour availability of endoscopy]. / Evaluering av behovet for døgnkontinuerlig endoskopitilbud.

BACKGROUND: Endoscopy is the cornerstone of the diagnosis and treatment of acute conditions in the upper part of the gastrointestinal tract. The need for 24-hour availability of gastroscopy for these conditions has not previously been assessed. MATERIAL AND METHODS: We assessed the need for emergency gastroscopy in cases of acute upper gastrointestinal bleeding and obstruction by foreign bodies. The assessment was made by a gastroenterologist before gastroscopy was performed, and was based on the available clinical data for the period lasting from admission to hospital to the time of examination. RESULTS: A total of 162 patients were referred and examined. About half of them arrived at the hospital outside working hours. Of these, 47% were assessed as being in need of emergency gastroscopy. We therefore found that emergency gastroscopy outside working hours was needed twice a month per 100,000 people. INTERPRETATION: Round-the-clock endoscopy should be available at acute-care hospitals in the same way as other emergency help.

Highly effective second-line anti-Helicobacter pylori therapy in patients with previously failed metronidazole-based therapy.

BACKGROUND: In this study we compared the cure rates of two clarithromycin-based regimens in patients in whom anti-Helicobacter pylori therapy had previously failed. METHODS: Thirty-three patients were randomized to receive either regimen OAC (20 mg omeprazole, 750 mg amoxicillin, and 250 mg clarithromycin) or BTC (240 mg bismuth subcitrate, 750 mg oxytetracycline, and 250 mg clarithromycin), all twice daily for 10 days. A further 28 patients were all treated with OAC. Previously failed therapy included combinations of bismuth (B), omeprazole (O), tetracycline (T), metronidazole (M), amoxicillin (A), or clarithromycin (C) in BTM (n = 48), OAM (n = 13), OA (n = 7), OCM (n = 2), or BCM (n = 1). H. pylori infection was confirmed by culture of biopsy specimens, and antimicrobial susceptibility testing was performed with the E test. RESULTS: H. pylori infection was cured in all patients (n = 18) with OAC and in 8 patients (53%) with BTC (P = 0.001) in the randomized group and in 27 patients (96%) receiving OAC in the open-label group. CONCLUSIONS: Ten-day OAC is highly effective and superior to BTC in patients in whom metronidazole-based treatment has previously failed.

Accuracy of IgG serology and other tests in confirming Helicobacter pylori eradication.

BACKGROUND: In this study we assessed the accuracy of IgG serology and other tests in confirming Helicobacter pylori eradication. METHODS: The outcome of anti-H. pylori therapy was established by at least two of the following tests: rapid urease test (RUT), culture, 14C urea breath test (non-capsule or capsule UBT), and IgG serology (Orion Diagnostica Pyloriset New EIA-G). RESULTS: Successful H. pylori eradication was confirmed in 698 of 794 patients (88%). The percentage decrease in IgG antibody titre was related to the patients' pre-treatment IgG titre and time interval after treatment. A decrease in IgG titres of 40% or more confirmed H. pylori eradication with 100% specificity, whereas the sensitivity was 82%, 90%, 98%, and 98% 3, 4, 5, and 6 months after therapy, respectively. The 40% cut-off confirmed eradication 3 to 6 months after therapy in 328 of 339 patients (97%) with pre-treatment IgG titres of >700, in 36 of 45 patients (80%) with pre-treatment titres of 300-700, and in 5 of 12 patients (42%) with pretreatment titres of <300. The sensitivity and specificity of the other tests 2 months after treatment were as follows: RUT, 84% and 100%; culture, 88% and 100%; non-capsule UBT, 100% and 89%; and capsule UBT, 100% and 97%. CONCLUSION: A decrease in IgG antibody titre of 40% or more 3 to 6 months after therapy and the capsule 14C UBT at the 2-month follow-up were both highly accurate in confirming H. pylori eradication.

[Treatment of Helicobacter pylori infection]. / Behandling av Helicobacter pylori.

The article presents information gained from a survey among Norwegian hospitals in March 1997 concerning their treatment of infections with Helicobacter pylori. Altogether 52 hospitals answered the questionnaire. A combination of proton pump inhibitors, metronidazole and clarithromycin was used by 59% as first choice and urea quick test (94%) and urea breath test (42%) as the primary diagnostic procedures, whereas serology was in little use (17%). Besides ordinary ulcer disease, indications for treatment were: ulcer induced by non-steroid anti-inflammatory drugs (79%), gastrooesophageal reflux (37%), non-ulcer dyspepsia (14%) and cancer prophylaxis (14%). The gastro group at the Department of Pharmacotherapeutics at the University of Oslo invited specialists from all health regions to discuss indications for treatment of H pylori, the diagnosis and the role of general practitioners. The extensive use of clarithromycin might be doubtful due to development of resistance. Indications for treatment of H pylori other than ulcer disease and mucosa associated lymphoid tissue lymphoma are still uncertain. Uncritical use of serological tests in primary care should be discouraged. At present there is no uniform strategy for the diagnosis and treatment of H pylori infection, and a coordinated strategy between general practitioners and specialists is needed.

Accuracy of seven different tests for the diagnosis of Helicobacter pylori infection and the impact of H2-receptor antagonists on test results.

BACKGROUND: In this study we compared the accuracy of seven diagnostic tests in diagnosing Helicobacter pylori infection. METHODS: Over 1 year 351 consecutive dyspeptic patients were tested for H. pylori infection by means of antral biopsy specimens for the rapid urease test (RUT), culture, microscopy (acridine stain), and the laboratory urease test (LUT) and, in addition, with 14C urea breath test (UBT), IgG serology, and IgA serology (Orion Diagnostica Pyloriset New EIA-G and New EIA-A). The criterion for H. pylori infection was a minimum of three positive tests. Before being tested, 38% of the patients had used an H2-receptor antagonist (H2RA). RESULTS: Two-hundred and twenty-four patients (64%) were H. pylori-positive. The sensitivity and specificity of the tests were as follows (percentages): RUT, 85, 99; culture, 93, 100; microscopy, 81, 98; LUT, 80, 100; UBT, 95, 95; IgG serology, 99, 91; and IgA serology, 88, 91. The accuracy of the RUT and LUT was reduced in patients receiving H2RA therapy (P=0.04 and 0.01, respectively). CONCLUSIONS: Culture, UBT, and IgG serology were all superior to the other four tests in diagnosing H. pylori infection. Invasive urease-based tests were less accurate in patients receiving H2RAs.

Highly effective twice-daily triple therapies for Helicobacter pylori infection and peptic ulcer disease: does in vitro metronidazole resistance have any clinical relevance?

OBJECTIVES: To compare cure rates of Helicobacter pylori (H. pylori) infection, ulcer healing, and side effects of three simplified regimens of triple therapy in patients with peptic ulcer disease. METHODS: Two hundred thirty-one patients were prospectively randomized to receive either regimen OAM (omeprazole 20 mg b.i.d., amoxicillin 750 mg b.i.d., and metronidazole 400 g b.i.d.), OCM (omeprazole 20 mg b.i.d., clarithromycin 250 mg b.i.d., and metronidazole 400 mg b.i.d.), or BCM (bismuth subcitrate 240 mg b.i.d., clarithromycin 250 mg b.i.d., and metronidazole 400 mg b.i.d.), all for 10 days. Side effects were reported immediately afterward in a self-administered questionnaire. Upper endoscopy was carried out before treatment and 2 months after treatment. Three antral and three corpus biopsy specimens were analyzed microbiologically and with rapid urease test to determine the presence of H. pylori. Altogether 143 patients (62%) had an active ulcer at start of treatment. Metronidazole resistant (M-R) H. pylori strains were found in 30% of patients, while none had clarithromycin resistant (C-R) strains. RESULTS: According to intention-to-treat analysis, H. pylori cure rates were 91, 95, and 95% with OAM, OCM, and BCM, respectively (p = 0.63). In patients with metronidazole-sensitive (M-S) strains versus M-R strains, the cure rates were 96 versus 77% with OAM (p = 0.025), 94 versus 94% with OCM, and 94 versus 96% with BCM. Ulcer healing rates were 95, 94, and 92%, respectively (p = 0.91). There were no significant differences in side effects between the regimens, and only five patients (2%) had to stop the treatment prematurely. CONCLUSIONS: All treatment regimens were highly effective for cure of H. pylori infection and for ulcer healing. Metronidazole resistance reduced the efficacy of OAM, but was of no importance for the efficacy of OCM or BCM. Side effects were of minor importance.

Simplified 10-day bismuth triple therapy for cure of Helicobacter pylori infection: experience from clinical practice in a population with a high frequency of metronidazole resistance.

OBJECTIVE: To evaluate the cure rate of Helicobacter pylori infection, including the impact of in vitro metronidazole resistance (M-R), and the side effects of a simplified 10-day bismuth triple therapy in routine clinical practice. METHODS: From September 1995 to March 1996, 248 consecutive H. pylori-positive patients received 10 days of bismuth subnitrate 150 mg, oxytetracycline 500 mg, and metronidazole 400 mg, all t.id. Before treatment, upper endoscopy, including biopsy specimens for microbiological analysis and IgG serology were performed. M-R was found in 45% of females and 36% of males. At least 2 months after treatment, H. pylori status was assessed by the 14C urea breath test (n = 131), endoscopy (n = 37), urea breath test and endoscopy (n = 63), or solely by IgG serology (n = 7). Ten patients withdrew. IgG serology was performed again after 1 yr. RESULTS: H. pylori infection was cured in 205 patients: 86% by all-patients-treated analysis and 83% by intention-to-treat analysis. When patients were classified according to pretreatment metronidazole susceptibility, cure of infection was achieved in 76% of females harboring M-R strains versus 96% of those with sensitive strains (p = 0.002) and in 81% versus 88% (p = 0.34) of males with M-R versus sensitive strains, respectively. Twelve patients (5 %) had to stop treatment prematurely because of severe side effects, but eight of them were treated successfully. One case of H. pylori infection (0.6 %) was detected at 1-yr follow-up. CONCLUSIONS: Ten-day bismuth triple therapy t.i.d. was effective in curing H. pylori infection in the context of routine clinical practice. The efficacy was reduced in females harboring M-R strains.

A comparison between omeprazole-based triple therapy and bismuth-based triple therapy for the treatment of Helicobacter pylori infection: a prospective randomized 1-yr follow-up study.

OBJECTIVES: To compare the efficacy and side effects of standard bismuth triple therapy with those of omeprazole-based triple therapy in patients with Helicobacter pylori infection and duodenal ulcer disease. METHODS: One hundred patients were prospectively recruited and randomized to receive either bismuth subnitrate 75 mg q.i.d., oxytetracycline 500 mg q.i.d., and metronidazole 400 mg b.i.d. (regimen BTM), or omeprazole 20 mg b.i.d., amoxicillin 750 mg b.i.d., and metronidazole 400 mg b.i.d. (regimen OAM), both for 14 days. Upper endoscopy (with antral biopsy specimens for microbiology and antral and corpus biopsy specimens for histology) was performed before treatment, after 2 months, and again 1 yr after treatment. Serum samples for serology (IgG) were taken. Patients with in vitro metronidazole-resistant (M-R) H. pylori strains were excluded. In a nonrandomized study, 41 patients with M-R strains were given either BTM or OAM. RESULTS: According to intention-to-treat analysis, H. pylori cure rates were 91% and 96% with BTM and OAM, respectively (p = 0.45). In the BTM group, the mean total side effect score was higher (p < 0.001), and more severe side effects were reported (32% vs. 4%, p < 0.001). In the nonrandomized group of patients with M-R strains, H. pylori cure rates were 88% and 67% with BTM and OAM, respectively. All of the successfully treated patients were still H. pylori-negative after 1 yr. CONCLUSIONS: Both treatment regimens were highly effective in curing H. pylori infection in patients with metronidazole-sensitive strains. Omeprazole-based triple therapy was tolerated better than standard bismuth-based triple therapy.