Helicobacter pylori and non-malignant diseases

It is well known that Helicobacter pylori infection is associated with many nonmalignant disorders such as gastritis, peptic ulcer, gastroesophageal reflux disease (GERD), gastric polyp, nonsteroidal anti-inflammatory drug (NSAID)/aspirin-induced gastric injury, and functional dyspepsia. In 2008, interesting articles on the association of H. pylori infection with these disorders were presented, some of which intended to reveal the mechanisms of inter-individual differences in response to H. pylori infection, and have demonstrated that genetic differences in host and bacterial factors as well as environmental factors account for these differences. A decline in the occurrence of peptic ulcer related to H. pylori was confirmed. An inverse relationship between H. pylori infection and GERD was also confirmed but the impact of gastric atrophy on the prevention of GERD remained debatable. For NSAID-induced gastric injury, eradication of H. pylori infection has been recommended. During this year, eradication of H. pylori infection was recommended for patients treated with antiplatelet therapy as well as aspirin and NSAID. It was also reported that for patients with functional dyspepsia, eradication of H. pylori offers a modest but significant benefit.

Presentation and long-term follow-up of refractory celiac disease: comparison of type I with type II

BACKGROUND & AIMS

Refractory celiac disease (RCD) was recently subdivided into 2 subtypes (RCD I and II) based on a normal or abnormal phenotype of intraepithelial lymphocytes (IELs), respectively. It is not clear, however, if these 2 entities differ in their presentation at diagnosis or long-term outcome. We compared the clinical and biological characteristics of RCD I and RCD II at diagnosis, the risk of developing an overt lymphoma, and the predictive factors of survival.

METHODS

Medical files of 14 patients with RCD I and 43 with RCD II were analyzed retrospectively. Predictive factors of overt lymphoma and survival were studied in univariate and multivariate analyses.

RESULTS

At diagnosis, malnutrition, ulcerative jejunitis, and lymphocytic gastritis were more common in patients with RCD II than RCD I (P< .05). Overt lymphomas occurred in 2 patients with RCD I and 16 with RCD II. In the univariate analysis, abnormal IEL phenotype and increased age at diagnosis of RCD were predictive factors for overt lymphoma. Abnormal IEL phenotype (P< .01), clonality (P= .01), and overt lymphoma (P= .001) predicted short survival time. Only abnormal IEL phenotype (P= .03) and overt lymphoma (P= .04) were predictive in the multivariate analysis. The 5-year survival rate was 93% in patients with RCD I and 44% with RCD II.

CONCLUSIONS

RCD II has a much more severe presentation and prognosis than patients with RCD I; <44% of patients with RCD II survive 5 years after diagnosis. Abnormal IEL phenotype is a predictive factor but not a necessary condition for the development of overt lymphoma.

Chlorambucil versus observation after anti-Helicobacter therapy in gastric MALT lymphomas: results of the international randomised LY03 trial

Gastric mucosa-associated lymphoid tissue (MALT) lymphomas are uncommon tumours characterised by a tendency to remain localised for long periods. The aetiological association between MALT lymphomas and Helicobacter pylori is well established. The role of additional chemotherapy after H. pylori eradication in localised MALT lymphomas is unclear. The LY03 trial was designed to establish whether chlorambucil after treatment for H. pylori would help prevent recurrence. Patients were treated with antibiotics for H. pylori infection. Those with successful eradication of H. pylori and no evidence of progression of lymphoma were eligible for randomisation to chlorambucil or observation. Two hundred and thirty-one patients were registered. Ninety-seven percent patients had H. pylori eradicated after antibiotics and 59% achieved macroscopically normal gastric mucosa. One hundred and ten patients were randomised. With a median follow-up of 58 months, six patients were dead and 17 had recurrent/progressive disease. The recurrence/progression rates at 5 years were 11% for chlorambucil, and 21% for observation with a difference of 10%, 95% confidence interval (CI) = −9% to 29%, P = 0·15. No difference was detected in recurrence/progression-free survival [Hazard Ratio (HR) = 0·96, 95% CI = 0·41–2·2, P = 0·91] or overall survival (HR = 1·93, 95% CI = 0·39–9·58, P = 0·42). This is the first randomised trial to show there is no good evidence to support that additional single agent chemotherapy to anti-H. pylori treatment contributes to prevent recurrence in localised gastric MALT lymphomas.

[Helicobacter pylori infection: what to do after first intent treatment failure?]

First intent therapy of H. pylori infection is triple therapy combining PPI, amoxicillin and clarithromycin for 7 to 10 days. Due to the increasing rate of primary resistance to clarithromycin, expected eradication rates are below 70%. Consequently, treatment effect has to be systematically assessed by urea breath test: in case of failure, a second line triple therapy combining PPI, amoxicillin and metronidazole instead of clarithromycin for 14 days should be prescribed. Using this strategy, the global eradication rate after two lines of treatment is 90%. Rescue triple therapies combine PPI and amoxicillin with either levoloxacin or rifabutin for 10 days. Levofloxacin should be used first in order to prevent development of rifabutin resistance among mycobacteria. The increasing rate of quinolone resistance led to the proposal to perform culture with susceptibility testing prior to third line therapy.

Primary hepatic lymphoma of mucosa-associated lymphoid tissue type: a case report with cytogenetic study

Primary hepatic lymphoma of mucosa-associated lymphoid tissue type is extremely rare. Only 38 cases have been reported to date. A case of a 59-year-old man with Helicobacter pylori-resistant gastric ulcers and Buerger disease who was followed up since 1999 is reported. A 2-cm hepatic nodule was incidentally found during partial gastrectomy and corresponded to mucosa-associated lymphoid tissue-type lymphoma without underlying liver disease. Molecular studies showed a clonal immunoglobulin heavy-chain gene rearrangement. Investigations for the mucosa-associated lymphoid tissue lymphoma-associated translocations t(11;18) and t(14;18), as well as the t(3;14)(q27;q32), were negative, whereas trisomy 3 and trisomy 18 were detected.

Inhibition of anti-tuberculosis T-lymphocyte function with tumour necrosis factor antagonists

Reactivation of latent Mycobacterium tuberculosis (Mtb) infection is a major complication of anti-tumour necrosis factor (TNF)-α treatment, but its mechanism is not fully understood. We evaluated the effect of the TNF antagonists infliximab (Ifx), adalimumab (Ada) and etanercept (Eta) on anti-mycobacterial immune responses in two conditions: with ex vivo studies from patients treated with TNF antagonists and with the in vitro addition of TNF antagonists to cells stimulated with mycobacterial antigens. In both cases, we analysed the response of CD4⁺ T lymphocytes to purified protein derivative (PPD) and to culture filtrate protein (CFP)-10, an antigen restricted to Mtb. The tests performed were lymphoproliferation and immediate production of interferon (IFN)-γ. In the 68 patients with inflammatory diseases (rheumatoid arthritis, spondylarthropathy or Crohn's disease), including 31 patients with a previous or latent tuberculosis (TB), 14 weeks of anti-TNF-α treatment had no effect on the proliferation of CD4⁺ T lymphocytes. In contrast, the number of IFN-γ-releasing CD4⁺ T lymphocytes decreased for PPD (p < 0.005) and CFP-10 (p < 0.01) in patients with previous TB and for PPD (p < 0.05) in other patients (all vaccinated with Bacille Calmette-Guérin). Treatments with Ifx and with Eta affected IFN-γ release to a similar extent. In vitro addition of TNF antagonists to CD4⁺ T lymphocytes stimulated with mycobacterial antigens inhibited their proliferation and their expression of membrane-bound TNF (mTNF). These effects occurred late in cultures, suggesting a direct effect of TNF antagonists on activated mTNF⁺ CD4⁺ T lymphocytes, and Ifx and Ada were more efficient than Eta. Therefore, TNF antagonists have a dual action on anti-mycobacterial CD4⁺ T lymphocytes. Administered in vivo, they decrease the frequency of the subpopulation of memory CD4⁺ T lymphocytes rapidly releasing IFN-γ upon challenge with mycobacterial antigens. Added in vitro, they inhibit the activation of CD4⁺ T lymphocytes by mycobacterial antigens. Such a dual effect may explain the increased incidence of TB in patients treated with TNF antagonists as well as possible differences between TNF antagonists for the incidence and the clinical presentation of TB reactivation.

Update on fluoroquinolone resistance in Helicobacter pylori: new mutations leading to resistance and first description of a gyrA polymorphism associated with hypersusceptibility

Helicobacter pylori eradication by standard therapy is decreasing due to clarithromycin and metronidazole resistance. Fluoroquinolones are valuable drugs for alternative therapy, but their activity needs to be updated. We determined minimum inhibitory concentrations (MICs) of the newly marketed fluoroquinolones (levofloxacin, moxifloxacin and gatifloxacin) and assessed the prevalence of resistance in 128 H. pylori strains isolated in 2004-2005. The quinolone resistance-determining region (QRDR) of gyrA was sequenced for all strains. Gatifloxacin MICs (MIC(50) = 0.25 mg/L) were two- to four-fold lower than those of the other fluoroquinolones. The prevalence of resistance (ciprofloxacin MIC > 1 mg/L) was 17.2% (22 strains). All resistant strains harboured one gyrA mutation at codons 86, 87 or 91, including three new mutations (Asp86Asn, Thr87Ile and Asn87Tyr). Ciprofloxacin-susceptible strains were devoid of such gyrA mutations, but harboured a polymorphism at codon 87 that distinguished 18 isolates (17%) with a Thr87 like the reference strain J99 from 88 strains with Asn87 like the reference strain 26695. Strains with Thr87 were four-fold more susceptible to nalidixic acid, pefloxacin, ciprofloxacin and levofloxacin and were equally susceptible to moxifloxacin and gatifloxacin. The high rate of quinolone resistance in H. pylori requires the use/implication of a 'test and treat' strategy that can confidently rely on QRDR gyrA sequencing.

Genetic diversity of the HpyC1I restriction modification system in Helicobacter pylori

Helicobacter pylori is unique because of the unusually high number and diversity of its restriction modification (R-M) systems. HpyC1I R-M was recently characterized and contains an endonuclease which is an isoschizomer of the endonuclease BccI. This R-M is involved in adherence to gastric epithelial cells, a crucial step in bacterial pathogenesis. This observation illustrates the fact that R-M systems have other putative biological functions in addition to protecting the bacterial genome from external DNA. The genomic diversity of HpyC1I R-M was evaluated more precisely on a large collection of H. pylori strains by PCR, susceptibility to BccI digestion and sequencing. The results obtained support the mechanism of gain and loss of this R-M system in the H. pylori genome, and suggest that it is an ancestral system which gradually disappears during H. pylori evolution, following successive steps: (1) inactivation of the endonuclease gene, followed or accompanied by: (2) inactivation of the methyltransferase genes, and then: (3) definitive loss, leaving only short endonuclease remnant sequences.

Frequent and rapid progression of atrophy and intestinal metaplasia in gastric mucosa of patients with MALT lymphoma

OBJECTIVES

Association of gastric mucosa-associated lymphoid tissue (MALT) low-grade lymphoma and adenocarcinoma has repeatedly been reported. The aim of this study was to evaluate the frequency and the spreading of atrophy and intestinal metaplasia in gastric mucosa of patients with gastric MALT lymphoma followed after conservative treatment.

METHODS

Forty-five patients (mean age 45 +/- 2.1 yr) with gastric MALT lymphoma, treated by Helicobacter pylori eradication, chemotherapy with per os single alkylating agents, or both treatments have been followed by gastroscopy with biopsies in antrum and corpus at least once a year. Univariate and multivariate analysis evaluated the association between the appearance of atrophy and intestinal metaplasia in antrum or corpus and different factors related to patients, H. pylori status, lymphoma features, and treatment. In addition, histological aspects of gastric biopsies at the diagnosis period and at the end of follow-up were compared with those of two control groups of age-matched patients with H. pylori gastritis.

RESULTS

At the diagnosis time, only intestinal metaplasia in corpus was more frequent in patients with gastric MALT lymphoma than in patients with nonulcer dyspepsia. Within median follow-up of 54.4 months (range 9-196), the percentage of patients with gastric atrophy and intestinal metaplasia increased significantly and became significantly higher than in age-matched nonulcer dyspepsia patients. Multivariate analysis showed significant association between corpus intestinal metaplasia and corpus atrophy, intestinal metaplasia in antrum, and duration of the follow-up.

CONCLUSIONS

Conservative management of gastric MALT lymphoma including H. pylori eradication is associated with progression of gastric atrophy and intestinal metaplasia with frequent involvement of the corpus which is known to be a precancerous condition. These findings show that long-term endoscopic monitoring should be recommended in such patients.

Efficacy of infliximab in Crohn's disease. Results of a retrospective multicenter study with a 15-month follow-up

OBJECTIVES

To evaluate prescription practices and response to infliximab treatment for Crohn's disease (CD).

PATIENTS AND METHODS

The files of CD patients treated with at least one infusion of infliximab treated in gastroenterology units belonging to university teaching hospitals of the Parisian hospitals group (Assistance Publique-Hôpitaux de Paris (AP-HP) during the year 2000 were analyzed retrospectively.

RESULTS

One hundred and thirty-seven patients (36.0 +/- 12.7 years, 92 females) from 12 centers were studied. Indication for treatment was fistulae or perianal disease in 39% of patients, active Crohn's disease in 45% and mixed conditions in 16%. Mean follow-up was 15.2 +/- 7.2 months. The overall response rate was 85%. No predictive factor of sustained remission could be identified. The mean time to relapse was to 3.9 +/- 3.1 months. Thirty-eight patients were on maintenance therapy at the end of the follow up; 37% exhibiting progressive lost of response to treatment. Immunosuppressive therapy was added to infliximab in 78% of cases but response to infliximab was not modified by addition of immunosuppressive drugs. Adverse events, most frequently minor, were noted in 23% of the patients.

CONCLUSION

This retrospective study confirms the efficacy and safety of infliximab in CD.

Prognostic value of translocation t(11;18) in tumoral response of low-grade gastric lymphoma of mucosa-associated lymphoid tissue type to oral chemotherapy

PURPOSE

To determine the impact of translocation t(11;18) on response to oral alkylating agents in gastric mucosa-associated lymphoid tissue lymphoma (GML).

PATIENTS AND METHODS

Fifty-three patients with a GML were studied. Helicobacter pylori-positive patients (n = 34) received anti-H pylori treatment and H pylori-negative patients (n = 19) or patients who failed to respond to anti-H pylori treatment received oral alkylating agents. t(11;18) was detected by reverse transcription polymerase chain reaction from frozen gastric biopsies.

RESULTS

t(11;18) was detected in 32% of patients. It was more prevalent in H pylori-negative as compared with H pylori-positive patients (12 of 19 v five of 34 patients; P = .0005). Among 31 H pylori-eradicated patients, t(11;18) was detected in three patients, all of whom experienced treatment failure, and it was absent in 28 patients: 21 patients (75%) were in remission and seven patients (25%) experienced treatment failure (P = .03). Among 21 patients who received an alkylating agent, t(11;18) was detected in 12 patients: five patients (42%) were in remission and seven patients (58%) experienced treatment failure. t(11;18) was absent in nine patients: eight patients (89%) were in remission and one patient (11%) experienced treatment failure by the end of treatment. Four patients in remission relapsed during follow-up (median, 7 years): they all had t(11;18). Durable remission was obtained in eight (89%) of the nine patients without t(11;18) versus one of the 12 patients (8%) with t(11;18) (P = .0003).

CONCLUSION

Presence of t(11;18) in GML is predictive of resistance to oral alkylating agents, with less than 10% of durable remission at long-term follow-up.

Metachronous gastric MALT lymphoma and early gastric cancer: is residual lymphoma a risk factor for the development of gastric carcinoma?

BACKGROUND

Helicobacter pylori plays a major role in the pathogenesis of primary gastric MALT lymphoma (GML) and gastric carcinoma. The occurrence of these two diseases metachronously in a same patient is a rare event.

PATIENTS AND METHODS

Gastric biopsies and gastrectomy resection specimens of four patients who developed GML and early gastric cancer (EGC) were analysed by morphology, immunohistochemistry and molecular biology.

RESULTS

Four patients (three males and one female; mean age 48 years) were diagnosed with GML. Helicobacter pylori infection was observed in three cases. Two patients had localized disease (stages IE and IIE, respectively) and were treated with H. pylori eradication therapy followed by an alkylating agent for one patient. Two patients had disseminated disease (stage IV), and were treated with an alkylating agent. Three cases were t(11;18) positive. All patients achieved initially complete lymphoma remission. Long-term endoscopic surveillance detected an EGC at the same location as the lymphoma in all patients at a mean time of 9.5 years (range 2.5-17 years) after lymphoma diagnosis. Gastrectomy specimens showed residual GML in all cases.

CONCLUSION

Prolonged residual GML could constitute an additional risk factor for the development of gastric carcinoma. Long-term endoscopic surveillance is mandatory in patients treated conservatively for gastric MALT lymphoma.

Pancreatic metastases: a multicentric study of 22 patients

AIMS OF THE STUDY

To evaluate the diagnosis, treatment and outcome of patients with pancreatic metastases.

PATIENTS AND METHODS

We retrospectively reviewed the records of patients with pancreatic metastasis managed in the Paris area between 1990 and 2000.

RESULTS

The series analyzed included 22 patients, 10 men and 12 women, mean age 61 years (range: 35-76). The primary tumors were renal-cell carcinoma (N=10), colorectal cancer (N=4), lung cancer (N=4), breast cancer (N=2), cutaneous melanoma (N=1) and ileal carcinoid (N=1). The mean interval between primary treatment and presentation was 73.5 months (range: 2-151). Diagnosis was established because of clinical symptoms (N=15) or during surveillance (N=7). Computed tomography (N=19) and endoscopic ultrasound (EUS) (N=18) mainly showed solitary and hypodense/or hypoechoic masses. Histological diagnosis was obtained before surgery by EUS-guided fine needle aspiration (N=6), ultrasound-guided biopsy (N=3) or duodenoscopy (N=3). Among 10 patients with primary renal-cell carcinoma, 7 were treated by surgery. Median global survival was 33 months. Median survival was 61 months in the event of surgical treatment and 20 months in the other patients (ns). Mean survival depended on the type of primary tumor, 61 months for renal-cell carcinoma and 33 for colorectal cancer (P=0.06).

CONCLUSIONS

Most pancreatic metastases develop from renal-cell carcinoma and can occur several years after nephrectomy. Histological diagnosis is often obtained before surgery. Surgical resection must be discussed as it can allow long-term survival.

Effect of low-dose rabeprazole and omeprazole on gastric acidity: results of a double blind, randomized, placebo-controlled, three-way crossover study in healthy subjects

BACKGROUND

The treatment of acid-related symptoms requires rapid and consistent acid suppression, especially with on-demand regimens.

AIM

To compare the antisecretory activity of low-dose rabeprazole and omeprazole in healthy, Helicobacter pylori-negative subjects.

METHODS

In this randomized, double-blind, placebo-controlled, three-way crossover study, 27 volunteers were given rabeprazole 10 mg, omeprazole 10 mg, or placebo once daily for 7 days with a 10-14-day washout between treatments. Intragastric pH was monitored for 24-h on days 1 and 7 of each treatment.

RESULTS

Median gastric pH was significantly higher with rabeprazole than with omeprazole or placebo: day 1: 2.3, 1.4 and 1.3, respectively (P = 0.0056, rabeprazole vs. omeprazole; P < 0.0001, rabeprazole vs. placebo); day 7: 3.7, 2.2 and 1.3, respectively (P = 0.0016 rabeprazole vs. omeprazole; P < 0.0001, rabeprazole vs. placebo). Time with gastric pH above 4 was significantly higher with rabeprazole than with omeprazole: day 1, 5.8 h vs. 3.7 h, respectively (P < 0.02); day 7, 10.5 h vs. 4.6 h, respectively (P = 0.0008).

CONCLUSIONS

Rabeprazole 10 mg provides more rapid acid inhibition compared with omeprazole 10 mg. After 7 days, the time with pH above 4 is more than doubled with rabeprazole 10 mg vs. omeprazole 10 mg.

Anal carcinoma: incidence and effect of cumulative infections

INTRODUCTION

Human papilloma virus (HPV) causes anal condyloma that is a risk factor for anal carcinoma. The incidence and mechanism of invasive anal carcinoma in patients with anal condyloma are prospectively determined.

PATIENTS AND METHODS

From 1993 to 2002, 228 consecutive patients (164 HIV positive) with anal canal condylomas were included in the study, after curing of their lesions. They were asked to attend follow-up visits at 3- or 6-month intervals. We checked for anal co-infection with syphilis, gonococci, viruses (Epstein-Barr virus, cytomegalovirus, herpes simplex, HPV types), and quantified Langerhans' cells (LC) in anal mucosa at baseline and during follow up. We cured and analysed relapsed condylomas during follow up (3-112 months; median 26). Serum HIV loads and CD4 T-lymphocyte counts were determined at each visit and the densities of LC in consecutive specimens from patients with cancers were compared with that for a matched control group (n = 23).

RESULTS

Analysis of 199 patients showed high-grade dysplasia (HGD) in 13.6% of patients, more in HIV-positive (16%) than in HIV-negative (6%) patients at baseline. During follow up, 3.5% (7/199; six HIV positive) patients developed invasive carcinoma after 13-108 months and 112 (56%) patients relapsed condylomas. HIV and anal co-infection were identified as independent risk factors (P < 0.01) for HGD and cancer: odd ratio (95% confidence interval) of 9.4 (2.4-37.4) and 3.67 (0.95-14.2), respectively. LC densities in anal mucosa were lower in patients with invasive carcinoma than in controls.

CONCLUSION

The risk of invasive carcinoma in HPV-infected patients is increased by HIV and anal co-infection. Decreases in LC numbers in anal mucosa may favour this outcome.

Identification of a genetic marker of Helicobacter pylori strains involved in gastric extranodal marginal zone B cell lymphoma of the MALT-type

BACKGROUND AND AIMS

Gastric extranodal marginal zone B cell lymphoma of the mucosa associated lymphoid tissue (MALT)-type (MZBL) is a rare complication of Helicobacter pylori infection. Currently, no bacterial factor has been associated with the development of this disease. Our aim was to identify genes associated with lymphoma development.

METHODS

We used subtractive hybridisation as a tool for comparative genomics between H pylori strains isolated from a patient with gastric MZBL and from a patient with gastritis only.

RESULTS

When gastric MZBL strains were compared with gastritis strains, two open reading frames (ORFs) were significantly associated with gastric MZBL: JHP950 (74.4% v 48.7%, respectively; p = 0.023) and JHP1462 (25.6% v 2.6%, respectively; p = 0.004). The prevalence of JHP950 was 48.8% (p = 0.024) in duodenal ulcer strains and 39.3% (p = 0.006) in gastric adenocarcinoma strains, which makes this ORF a specific marker for gastric MZBL strains. In contrast, the prevalence of JHP1462 was 16% (p = 0.545) and 35.7% (p = 0.429) in duodenal ulcer and adenocarcinoma strains, respectively. These ORFs were present in reference strain J99 but not in reference strain 26695. JHP950 is located in the plasticity zone whereas the other, JHP1462, is located outside. Both encode for H pylori putative proteins with unknown functions.

CONCLUSION

Despite its low prevalence, the ORF JHP1462 can be considered a candidate marker for H pylori strains involved in severe gastroduodenal diseases. In contrast, the ORF JHP950 has a high prevalence, and is the first candidate marker for strains giving rise to an increased risk of gastric MZBL strains. Further confirmation in other studies is needed.

Fast and accurate quantitative detection of Helicobacter pylori and identification of clarithromycin resistance mutations in H. pylori isolates from gastric biopsy specimens by real-time PCR

Rapid identification of patients infected with clarithromycin-resistant Helicobacter pylori without the need for culture can help to avoid useless prescriptions of clarithromycin. We developed and tested a routine real-time quantitative PCR assay dedicated to that purpose. One hundred ninety-six consecutive gastric biopsy specimens were examined by culture, histology performed by a trained physician, and rapid PCR with the LightCycler apparatus. Infection was defined as (i) positivity of culture, (ii) positivity of histology, or (iii) positivity of PCR if confirmed by positivity of a concomitant indirect test (serology or urea breath test). Susceptibility to clarithromycin was tested by E-test and PCR. The prevalence of infection was 33.7% (66 of 196 samples). The sensitivities of culture, histology, and PCR were 90.9% (60 of 66 samples), 87.9% (58 of 66 samples), and 97.0% (64 of 66 samples), respectively. The specificity of PCR was 94.6% (123 of 130 samples). The linearity of the PCR results was achieved over a 6-log range of input DNA, and we were able to accurately quantify as few as 300 bacteria and to qualitatively detect as few as 30 bacteria per DNA sample. For clarithromycin susceptibility testing, there was 98.2% (55 of 56 samples) concordance between E-test and PCR. Forty-eight strains were clarithromycin susceptible, and 9 strains were clarithromycin resistant. The single discrepancy concerned a culture which was a mixture of mutant and wild type, with a susceptible-to-resistant ratio of 11.5: the resistant population was detected by E-test but not by PCR. Our PCR assay is accurate for fast detection of H. pylori as well as of clarithromycin resistance and is also able to objectively determine bacterial density.

Lymphocytic infiltration and expression of inducible nitric oxide synthase in human duodenal and colonic mucosa is a characteristic feature of ankylosing spondylitis

OBJECTIVE

In patients with ankylosing spondylitis (AS), inflammatory processes have been detected in the ileal and colonic mucosa. The inducible isoform of nitric oxide synthase (iNOS) may be expressed early in the inflammatory process. We investigated iNOS activity and lymphocytic infiltration in the duodenum and colon in patients with AS and ulcerative colitis compared with controls.

METHODS

Gastroscopy with duodenal biopsies and/or colonoscopy with biopsies were conducted in 42 patients with AS treated or not treated with nonsteroidal antiinflammatory drugs (NSAID), in 15 with ulcerative colitis, and in 46 controls. Lymphocytic infiltration in the lamina propria and intraepithelial infiltration were quantified by histological score. iNOS expression was assessed by immunohistochemistry with monoclonal antibodies, and iNOS activity was determined by radiochemical assay.

RESULTS

Endoscopic examination of the gastroduodenal or colonic mucosa did not reveal macroscopic lesions in the AS patients. In the duodenum, mucosal lymphocytic infiltration was found in 83.3% of the AS group compared to 48.6% of controls (p = 0.02), and was independent of the NSAID intake. Intraepithelial lymphocyte infiltration was increased in both duodenum and colon in AS patients compared to controls. iNOS activity in duodenum and colon and expression of iNOS protein in lamina propria inflammatory cells was increased in AS patients compared to controls.

CONCLUSION

Lymphocytic infiltration and iNOS expression and activity were detected in duodenal and colonic mucosa from patients with AS. Such findings may indicate an inflammatory process in the small intestine and colon of patients with AS.