The authors investigated the association between Helicobacter pylori infection (Hp-I) and Alzheimer disease (AD) by using histology for diagnosis of Hp-I. Fifty patients with AD and 30 iron deficiency anemic control participants without AD were included. The histologic prevalence of Hp-I was 88% in patients with AD and 46.7% in controls (p < 0.001).

Infectious agents have been proposed as potential causes of Alzheimer's disease (AD). Recently, we documented a high prevalence of Helicobacter pylori (Hp) infection in patients with AD. We aim to access the effect of Hp eradication on the AD cognitive (MMSE: Mini Mental State Examination and CAMCOG: Cambridge Cognitive Examination for the Elderly) and functional (FRSSD: Functional Rating Scale for Symptoms of Dementia) status parameters. In the first part of the study, a total of 50 consecutive patients with AD and 30 age-matched anaemic controls underwent an upper gastrointestinal endoscopy, and gastric mucosal biopsies were obtained to detect the presence of Hp infection by histologic analysis and rapid urease test. Serum anti-Hp-specific IgG level was analysed by enzyme-linked immunosorbent assay. In the second part, Hp-positive AD patients received a triple eradication regimen (omeprazole, clarithromycin and amoxicillin), and all patients were followed up for 2 years, while under the same treatment with cholinesterase inhibitors. Hp was detected in 88% of AD patients and in 46.7% of controls (P < 0.001). Hp eradication was successful in 84.8% of treated patients. At the 2-year clinical endpoint, cognitive and functional status parameters improved in the subgroup of patients where Hp eradication was successful (P < 0.001 and P = 0.049 for MMSE and CAMCOG, respectively; P < 0.001 for FRSSD), but not in the other patients. Hp eradication may positively influence AD manifestations, suggesting a possible common link between Hp and AD.

Hp eradication regimen in AD patients is associated with a higher 5-year survival rate.

The association of Helicobacter pylori infection and Alzheimer's disease (AD) has recently been addressed, but no relative data exist regarding mild cognitive impairment (MCI), a prodromal phase of AD. The aim of this prospective study was to evaluate H. pylori infection, by histology in a Greek MCI cohort. Sixty-three consecutive patients with amnestic MCI and 35 normal controls underwent upper gastrointestinal endoscopy, histologic and serological examinations. The prevalence of H. pylori infection was 88.9% (56/63) in MCI patients and 48.6% (17/35) in anaemic controls, as confirmed by biopsy (P < 0.001, odds ratio: 8.47, 95% CI: 3.03-23.67). Mean serum anti-H. pylori IgG concentration and plasma total homocysteine (Hcy) titre were higher in MCI patients than controls (74.86 +/- 57.22 vs. 17.37 +/- 9.30 U/ml; and 16.03 +/- 4.28 vs. 13.5 +/- 1.20 micromol/l; P < 0.001 and P = 0.015, respectively). When compared with the anaemic participants, MCI patients exhibited more often multifocal (body and antral) gastritis (92.1% vs. 68.6%; P = 0.03); in H. pylori positive MCI patients cognitive state correlated with serum anti-H. pylori IgG concentration. In conclusion, H. pylori prevalence was significantly higher in MCI patients than controls. This infection might contribute, at least in part, to the pathophysiology of MCI, possibly through induction of chronic atrophic gastritis and elevated Hcy consequences.

The aim of this study was to investigate a possible association between Helicobacter pylori infection and acute inflammatory demyelinating polyradiculoneuropathy (AIDP). Of 17 consecutive patients with Guillain-Barre syndrome (GBS), 13 patients (six females; mean age 50 +/- 24 years) with AIDP were investigated. Clinical status was evaluated according to Hughes' score, and electrophysiological tests were performed within 2 weeks from disease onset. Helicobacter pylori infection was detected histologically and serum H. pylori-specific IgG antibodies were analysed by ELISA. Twenty asymptomatic patients (12 females; mean age 63 +/- 8 years), undergoing upper gastrointestinal endoscopy for investigation of mild iron deficiency anaemia, served as controls. Helicobacter pylori was found in 12 of 13 AIDP patients (92%), and in 10 of 20 controls (50%), (P = 0.02). Electrophysiological studies showed demyelination in all AIDP patients. High levels of anti-H. pylori IgG antibodies correlated with advanced clinical status. Five of seven AIDP patients with high levels of anti-H. pylori IgG antibodies had delayed F-wave latencies, indicating affection of proximal segments of peripheral nerves. Helicobacter pylori infection seems to be more frequent in AIDP patients. Anti-H. pylori titre might reflect advanced clinical status. Anti-H. pylori IgG antibodies are also associated with involvement of the proximal parts of peripheral nerves in AIDP.