EFICACIA DIAGNÓSTICA PARA HELICOBACTER PYLORI COMPARANDO PRUEBA DE UREASA CONTRA BIOPSIA HISTOPATOLÓGICA

Abstract

Introduction: Infection by Helicobacter pylori has been associated with the development of peptic ulcers witch have high chance of progression to adenocarcinoma or lymphoma MALT type. That is why it´s identification has been considered of vital importance, in order to providing the patient from a right to prompt treatment diagnosis. The various diagnostic methods for diagnostic methods for helicobacter pylori,not all are available to all health service. The identification of this organism for it´s particular characteristics has served to develop various diagnostic methods such as urease test , which is a quick and easy method and we can get results before the patient leaves the room of endoscopy. Aim: Compare test of urease with a concentration 50% bromothymol blue compared against biopsy histopathologic and measure the reaction time of the same. Material and methods : A comparative, cross, study was conducted in the Cabinet of endoscopy of the Central Military Hospital (Mexico) with volunteers referrals for realization of endoscopy with diagnostic dyspepsia, Gastroesophageal or suspicion of ulcerative gastropatia. They estimate a sample size of 34 patients for each group with the power sample size version 23.1.2 program. We Weight in the Multidisciplinary Laboratory of the Graduate Military School of Health items and prepare a solution of urea with Phenol Red, and a second solution of urea to the 50% phenol red and bromothymol blue. The solutions prepared were subjected to sterilization process with ultraviolet light in the clinical laboratory of the Hospital. Endoscopy with biopsy of antrum takes took and took 2 biopsies for pathology and 2 for the two reactive of urea, and take the time shift of both solutions Results: Were selected 85 patients than doorposts requirements for study in the period from 1 August to 28 October 2011, excluding 6 cases, subtracting 79 patients, ages 14-79 years. The 68.36% were female and the 31.64% of male, finding a higher incidence of cases between 30 and 59 years. We found 46 patients with evidence of positive urease which correlated with the report's positive histopatology biopsy for helicobacter were obtained. 27 patients test negative urease and biopsy negative histopatology, 2 cases with negative biopsies and proof of positive urease, and 4 cases with test, urease positive and negative biopsy report. Performed a table of 2 x 2, with a 95% confidence interval and obtained thereby a sensitivity of the test of the 95.8%, specificity of 87.1%, with a VPP of 92.0%, the 93.1 VPN %, a PFP of 12.9% and/d ratio of false negatives of 4.2%, exactly from 92.4 % , odds ratio of 155.25, index of 0.8 Yourden, probability of 7.43 coefficient and a probability pre-test of 60.8%. In addition a rate of concordance of the reaction times of 0.020, which is a total variability of 2% for the two concentrations was obtained. Eventually both urease testing responses to two concentrations, a coefficient of variation of 0.999 Pearson, which indicates that there is no difference between the two reagents is obtained Not found any difference between the concentration response to 100% and 50%, whereas our 50% solution is as effective as the urease test. During the endoscopy procedure don’t existed any complication. CONCLUSIONS: Urease test 50% is as effective as the urease test is 100% and correlates according to its sensitivity and specificity with the biopsy histopatologycal. Likewise the reports can be made at any level of health care. Compared with histopathologyc biopsy found the sensitivity and specificity are high and similar to the comparative literature. The capture of biopsy by endoscopy continues been sure