Helicobacter pylori: Past, Present, and Future J . J . MISIEWICZ Dept. of Gastroenterology and Nutrition, Central Middlesex Hospital. London, U . K . Misiewicz JJ. Helicobacter pylori: past. present, and future. Scand J Gastroenterol 1992;27 Suppl 194:25-29.

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Helicohacter pylori has now been recognized as one of the most common chronic human infections. It has been accepted as an important aetiologic agent in non-immune chronic gastritis and plays a key role in the aetiology of duodenal ulcer. It may also be involved in the pathogenesis of gastric cancer. Key words: Duodenal ulcer; gastric cancer; gastric ulcer; gastritis; Helicobacrer pylori

J. J . Misiewicz, M . D . , Joint Director, Depr. of Gasrroenrerology and Nurririon, Central Middlesex Hospital, Acron Lane, London NWlO 7NS. UK

Helicobacter pylori-like organisms have been sporadically reported in the past, but only with the relatively recent ability to culture the organism has their importance in some diseases of the proximal gut disease been fully appreciated and their morphology and metabolic properties characterized (1-3). The information explosion of scientific data describing various aspects of H . pylori testifies to its importance in the aetiology , epidemiology and treatment of various gastric and duodenal disorders. H . pylori is probably one of the most widespread chronic human infections and has been found in every country in which it has been looked for (4-7). In the West the prevalence of infection is higher in the older age groups; this has been interpreted as evidence of poorer environmental conditions obtaining earlier in this century. Humans are the only host so far recognized that harbours the organism. Although H . pylori provokes humoral and local cellular immune responses, it appears that once acquired, the infection is very rarely, if ever, cleared spontaneously, and it is always accompanied by gastritis of varying severity. The diagnosis of colonization of the gastric antral epithelium by H . pylori is within the reach of every department of gastroenterology. Several techniques are applicable. The organism can be shown on histopathologic preparations of endoscopic antral biopsy specimens. The Giemsa stain is usually sufficient to show the presence of H . pylori, and it is rarely necessary to use the more expensive and difficult Warthin-Starry technique (8). Since H . pylori possesses abundant urease activity (9-1 l ) , this characteristic of the bacterium has been exploited for various urease-based reactions, performed on biopsy specimens, giving a result within minutes of obtaining the specimen (12). Culturing H . pylori from biopsy samples requires special bacteriologic techniques, which are becoming increasingly available; culture is needed to determine the sensitivity of the bacterium to

antimicrobial agents, especially to metronidazole. The criteria for obtaining diagnostic biopsy specimens have been suggested by an International Working Party (8). Humoral immune response to H . pylori forms the basis of, usually enzyme-linked immunosorbent assay (EL1SA)based (13), serologic techniques for diagnosis. The serologic tests are becoming increasingly refined and possess very satisfactory specificities and sensitivities (14). Serologic tests measure the immunologic memory of colonization of the host by H . pylori, but the titres decrease after eradication of active infection and have been advocated for monitoring the results of antimicrobial treatment (15). However, the titres take time to decline after eradication, and there is some overlap between the eradicated and non-eradicated groups in some studies. The main use of immunologic techniques at present would seem to be for epidemiologic and screening studies. For example, screening out H . pylorinegative younger (aged

Helicobacter pylori: past, present, and future.

Helicobacter pylori has now been recognized as one of the most common chronic human infections. It has been accepted as an important aetiologic agent ...
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