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.

What is the role of serology in assessing Helicobacter pylori eradication?

AIM: To assess the decline in Helicobacter pylori antibodies after eradication of infection. METHODS: The H. pylori status was determined at entry (D0) by culture and histology performed on antral biopsies and after eradication treatment at day 42 (day 42) and after 6 months (M6) by the 13C-urea breath test. The EIA kits used to determine the anti-H. pylori antibody titre were HM-CAP (immunoglobulin-G) and PP-CAP (immunoglobulin-A) kits (Enteric Products, Inc.) and Pyloriset EIA-G (Orion Diagnostica). RESULTS: Ninety-three patients were included. For 82 patients who were successfully treated, no kit was sufficiently accurate at D42 to show eradication. The antibody titre decreased for HM-CAP, PP-CAP and Pyloriset EIA-G by a mean of 35.6%, 41.2% and 64.7% between D0 and M6, respectively. According to the cut-off values defined by the manufacturers, 8.5% (PP-CAP, Pyloriset EIA-G) and 9.7% (HM-CAP) of the patients became H. pylori negative at M6. Using a 25% decrease in antibody titre between D0 and M6 as a threshold for H. pylori eradication, specificity was 100% for HM-CAP, 89.9% for Pyloriset EIA-G and 100% for PP-CAP, whereas the sensitivity was 76.8%, 98.8% and 72%, respectively. CONCLUSION: An antibody titre decrease of 25% at M6 was found to be accurate in confirming H. pylori eradication.

Evaluation of the performance of the Helico Blot 2.1 as a tool to investigate the virulence properties of Helicobacter pylori.

Knowledge of the cagA status of Helicobacter pylori infection could be relevant for the treatment and prevention of possible complications of infection. This goal can be achieved using serology since CagA is highly immunogenic. The aim of this study was to correlate the presence of the cagA gene detected by polymerase chain reaction (PCR) with the presence of serum antibodies against the CagA protein using a recently available commercial immunoblotting assay, the Helico Blot 2.1 kit. Considering the results obtained by PCR, Helico Blot 2.1 presented sensitivity, specificity, and positive and negative predictive values for CagA status of 97.4%, 87.7%, 80.9% and 98.5%, respectively.

Diagnosis of Helicobacter pylori infection: noninvasive methods compared to invasive methods and evaluation of two new tests.

OBJECTIVES: Current guidelines recommending Helicobacter pylori eradication treatment without performing endoscopy in certain patients highlight the importance of noninvasive tests. Our aim was to determine the accuracy of two new tests: the antigen stool test and Helicoblot 2.1 (an immunoblot used on serum) as well as the 13C urea breath test and ELISA serology in comparison to invasive tests for the pretreatment diagnosis of H. pylori infection. METHODS: Helicobacter pylori infection was diagnosed prospectively in 104 untreated patients using eight different tests. Invasive tests included culture, urease test (CLOtest), histology, and PCR; noninvasive tests included the 13C urea breath test, IgG serology (Pyloriset EIA-G), immunoblot (Helicoblot 2.1), and antigen stool detection (Premier Platinum HpSA). A predefined gold standard based on biopsy tests was used to define H. pylori status, as well as an empirical approach. RESULTS: There was no statistically significant difference between the different tests. The sensitivity of the noninvasive tests ranged between 88.9% and 95.6% (stool test: 88.9%, 95% CI: 82.7-95.1, and Helicoblot 2.1: 95.6%, 95% CI: 91.5-99.6) and the specificity ranged between 92.6 and 98.1% (stool test: 94.4%, 95% CI: 84.6-98.8, and Helicoblot 2.1: 92.6%, 95% CI: 91.5-96.2) when a predefined gold standard was used. CONCLUSIONS: Most tests had sensitivities, specificities, and predictive values >90%. The noninvasive tests are accurate for the diagnosis of H. pylori infection. Helicoblot 2.1 performed as well as the best ELISA kit. The HpSA is a promising direct noninvasive test that can be applied easily to evaluate H. pylori status.

Complete nucleotide sequence of the genome of a severe cherry isolate of apple chlorotic leaf spot trichovirus (ACLSV).

The genome of the Balaton 1 severe cherry isolate of apple chlorotic leaf spot trichovirus (ACLSV-Bal1) has been cloned and sequenced. The genomic RNA is 7549 nucleotide long, excluding the poly A tail. The genomic organization, with three overlapping open reading frames (ORF), is similar to that of the other sequenced ACLSV isolates. Sequence comparisons indicate a high variability between ACLSV isolates, with overall nucleotide sequence homology levels between 76 and 82%. The coat protein, encoded internally inside a larger ORF, is the most conserved protein (identity levels between 87 and 93%) while the central ORF, encoding the putative movement protein, is the most divergent (77 to 85% identity).

Clinical and CNS effects of oral and I.V. Thyrotropin-releasing hormone in depressed patients.

Both oral and intravenous TRH produce systematic alterations in brain function of depressive patients as determined by scalp-recorded computerized cerebral biopotentials (computer EEG). The computer EEG (CEEG) profiles of both formulations are not only very similar to each other, but also resemble the CEEG profiles of psychostimulant compounds (Bio-availability). As in CEEG findings, TSH plasma levels also indicate that oral TRH is indeed an active compound. Although some "antidepressive" effects were observed after both formulations, they were not present in every patient, and it was not always the case after repetitive TRH administration, nor were the effects on depressed mood too impressive. On the other hand, in almost all patients certain behavioral effects of TRH were seen which related to "life instincts" and "life performance". The increase of interest, desire and drive for work, food and sex was one of the most striking findings, particularly after intravenous TRH. This may be responsible for the "antidepressive" effects of TRH in patients in whom depression may be the result of an inhibition of "instinctive" functions.