142 PLGF Expression By Tumor Stromal Cells Is Induced Via Tumor Cell-Tumor Stromal Crosstalk and Substantially Contributes to Tumor Growth

Abstract

BACKGROUND: Antimicrobial resistant strains of Helicobacter pylori (H. pylori) have been increasing in the United States and Europe, which may account for constant decreasing eradication rates reported in the literature (most recent trials reported eradication rate as low as 57-73% for 7-day triple therapy and 67-79% for 10 day triple therapy (Gastroenterology 2007;113:985-1001). The common methods to test chemosusceptibility are agar dilution, disk diffusion and the E-Test, that consist of performing the test on culture agar-based media with different types of supplements. All these methods require from 7-14 days obtaining results. Recently a 20 hours Elisa chemosusceptibility rapid test for H. pylori has been patented by Alma Mater Studio rum, University of Bologna (PCT/IT2007/000270) not based on DNA amplification, that reduce the time required from the 7-14 days to 20-24 hours. AIM: To assess the accuracy of the new “20 hours Elisa chemosusceptibility rapid test for H. pylori” compared to a gold standard (agar dilution method). METHODS: One hundred-five out of 115 H. pylori positive biopsies were tested for chemosusceptibility to Clarithromycin (≥ 1 micro/ml) Metronidazole (≥ 8 micro/ml) by the gold standard and by the new 20 hours Elisa chemosusceptibility rapid test for H. pylori (PCT/IT2007/000270). RESULTS: According to chemosusceptibility to clarithromycin, 75 sensitive cultures and 30 resistant cultures have been identified with the gold standard. Taking the new method into consideration, all 75 have been sensitive (sensitivity of the method 100%), while 28 out of 30 have been identified as resistant, and two have been falsely sensitive (method specificity 93.3%). According to chemosusceptibility to metronidazole, 68 sensitive cultures and 37 resistant cultures have been identified with gold standard. Taking the new method into consideration, 63 have been sensitive and 5 falsely resistant (method sensitivity 92.6%), while 32 out of 37 have been identified as resistant, and 5 have been falsely sensitive (method specificity 86.5%). CONSLUSION: A new simple rapid test for susceptibility of antibiotics against H pylori has been validated which is simple to perform, reduce the incubation time from 14 days to 20 hours and does not need molecular biology techniques.