Photoeradication of Helicobacter pylori using 5-aminolevulinic acid: preliminary human studies.
OBJECTIVE
Helicobacter pylori (HP) is an endemic pathogenic bacterium causing gastritis and gastroduodenal ulceration in humans and is linked to the development of gastric malignancies. These first human in vivo studies investigated the photoeradication of HP using laser and white light.


METHODS
In 13 HP-positive volunteers, a zone of gastric antrum was irradiated with laser (410 nm, 50 J/cm(2)) or endoscopic white light (10 J/cm(2)) 45 minutes after oral 5-aminolevulinic acid (5-ALA) 20 mg/kg. HP-eradication was assessed by biopsy urease test and HP-culture from irradiated and control zones 5 minutes, 4 and 48 hours post-irradiation.


RESULTS
A maximum eradication effect was achieved at 4 hours post-irradiation when 85% of biopsies in the monochromatic and 66% in the white light exposed zones, and 58 and 33% in the respective control zones were HP-negative.


CONCLUSIONS
HP numbers were greatly reduced following exposure to 5-ALA and either laser or white light in vivo. Photoeradication appears feasible, but further light dosimetry and the development of convenient application methods is required.
Wilder-Smith
Clive H
CH
Gastrointestinal Group Practice and Nociception Research Group, Bubenbergplatz 11, CH-3011 Berne, Switzerland. cws@ggp.ch
Wilder-Smith
Petra
P
Grosjean
Pierre
P
van den Bergh
Hubert
H
Woodtli
Alain
A
Monnier
Philippe
P
Dorta
Gian
G
Meister
Friedrich
F
Wagnières
Georges
G
D000328:Adult; D000622:Aminolevulinic Acid / Q000494:pharmacology* / Q000627:therapeutic use; D001706:Biopsy; D005260:Female; D005756:Gastritis / Q000150:complications / Q000188:drug therapy / Q000382:microbiology / Q000532:radiotherapy; D005773:Gastroscopy; D016481:Helicobacter Infections / Q000150:complications / Q000188:drug therapy* / Q000382:microbiology / Q000532:radiotherapy*; D016480:Helicobacter pylori / Q000187:drug effects* / Q000528:radiation effects*; D006801:Humans; D008027:Light; D028022:Low-Level Light Therapy / Q000379:methods*; D008297:Male; D008875:Middle Aged; D010437:Peptic Ulcer / Q000150:complications / Q000188:drug therapy / Q000382:microbiology / Q000532:radiotherapy; D017319:Photosensitizing Agents / Q000494:pharmacology* / Q000627:therapeutic use; D010789:Phototherapy / Q000379:methods*; D013270:Stomach / Q000187:drug effects / Q000382:microbiology; D013997:Time Factors
D017319:Photosensitizing Agents; D000622:Aminolevulinic Acid