RESUMO
Background: Multifocal chronic gastritis, associated to intestinal metaplasia, is considered a preneoplastic lesion, closely associated to intestinal type gastric cancer. Aim: To study the frequency of microsatellite instability (MSI) and loss of heterozygosity (LOH) in areas of chronic gastritis and intestinal metaplasia in gastric biopsies of patients without cancer. Material and methods: Gastric biopsy samples from 34 patients without cancer (22 with multifocal atrophic gastritis and 12 with diffuse antral gastritis), were studied. Glands from areas of chonic gastritis and intestinal metaplasia and lymphocytes, were collected using laser microdissection of paraffin embedded samples. The analysis of 15 mono and dinucleotide microsatellites was used to assess LOH and MSI. Results: LOH and MSI were found in some of the markers in 55% (12/22) and 59% (13/22) of cases with intestinal metaplasia, respectively. Only one of 12 areas with diffuse atrophic gastritis had MSI and a different area had LOH (p <0.05 or less, when compared with areas of multifocal atrophic gastritis). Three areas of normal epithelium in patients with multifocal atrophic gastritis, also had alterations. Most of these alterations were concordant with adjacent areas with intestinal metaplasia. Conclusions: LOH and MSI was found in areas of intestinal metaplasia in more than half of the studied cases and in few areas of atrophic gastritis without intestinal metaplasia. These findings suggest that genotypic alterations may precede phenotypic modifications and that intestinal metaplasia is a preneoplastic lesion (Rev Méd Chile 2003; 131: 1365-74).
Assuntos
Humanos , Gastrite/genética , Intestinos/patologia , Perda de Heterozigosidade , Repetições de Microssatélites/fisiologia , Doença Crônica , Mucosa Gástrica/patologia , Gastrite Atrófica/complicações , Gastrite Atrófica/genética , Gastrite/complicações , Metaplasia/complicações , Metaplasia/genética , Metaplasia/patologia , Lesões Pré-Cancerosas/genética , Lesões Pré-Cancerosas/patologia , Neoplasias Gástricas/genética , Neoplasias Gástricas/patologiaRESUMO
Se presentan 60 pacientes con síntomas consistentes con reflujo gastroesofágico (RGE) y gastritis crónica. Los síntomas más importantes encontrados fueron: pirosis 98.3 por ciento, regurgitación 93.8 por ciento, faringitis a repetición 83.3 por ciento, laringitis frecuente 80 por ciento, disfagia 80 por ciento, disfonía 78.3 por ciento, dolor epigástrico 98.3 por ciento, dispepsia 90 por ciento. todos los pacientes (100 por ciento) presentaron una gastritis crónica antral con 51.6 por ciento de tipo crónica superficial y 48.4 por ciento crónica atrófica. solamente seis pacientes (9.6 por ciento) tenían algún tipo de metaplasia. De los pacientes con gastritis crónica antral, 18 (30 por ciento) tenían Helicobacter pylori en las biopsias de antro. Veintidós pacientes (36.6 por ciento) presentaron una esofagitis péptica demostrada histológicamente pero ninguno mostró Helicobacter. Se discute la estrecha relación encontrada entre reflujo gastroesofágico y gastritis antral y su posible fisiopatología, así como la falta de correlacción entre el reflujo y la presencia delHelicobacter en el esófago.