RESUMO
BACKGROUND: The pre-treatment detection of H.p. in the stomach of patients is easily achieved with routine methods. Conversely, with conventional methods, it is difficult to detect the presence of H.p. after treatment. OBJECTIVE: To estimate the actual percentage of successfully treated patients by using a more sensitive and specific technique (PCR) in the same biopsies where standard methods were negative for H.p. MATERIALS AND METHODS: We selected 97 treated patients (31 Gastric Ulcers/66 Duodenal Ulcers, 62 male/35 female, age: 49 +/- 14 years), in whom success of treatment was defined by histological means and CLO Test. In the same gastric biopsies H.p-DNA PCR was performed. Different therapeutic schemes were utilized, but all included Proton Pump Inhibitors + ATB. Eight weeks after the end of the treatment, without medication, the patients were controlled as follows: 5 biopsies per patient, 2 of antrum, 2 of corpus (in different zones) and 1 for CLO Test. H.p. eradication was defined on histological grounds (gastric biopsy histology: 10% formaldehide buffer fixation, paraffin inclusion, Giemsa, HE staining and inmunohistochemistry), CLO Test (Delta West Pty. Ltd. Bentley, Australia) and by the absence of H.p.-DNA by PCR (amplification of a 296 bp of the species-specific antigen of H.p. and visualization of the amplified product in agarose gel with Ethidium Bromide and UV light). RESULTS: [table: see text] CONCLUSIONS: The higher sensitivity of PCR (10(3) fold more than conventional methods) allowed us in this group of patients to detect 13% of false eradication. It would be necessary to follow up this group of patients in order to know whether they develop or not clinical symptoms and/or histological evidence of disease. If such a case PCR could become an important tool for treatment evaluation.