RESUMEN
The ability of randomly obtained biopsy specimens to identify intestinal metaplasia in the distal esophagus is low. Use of vital staining has been suggested, as stains are taken up by areas histologically identified as specialized intestinal metaplasia (SIM). This study evaluated the role of methylene blue (MB) staining for identification of SIM in GERD patients undergoing a screening endoscopy. Chromoendoscopy of the distal esophagus using 1% MB was performed on 52 GERD patients presenting for their first endoscopy. Biopsies were obtained from areas that were stained darkly, stained lightly, unstained, or macroscopically abnormal. In patients with no MB staining, four-quadrant biopsy of the distal esophagus was performed. Twenty-seven patients (52%) showed staining with MB, while 25 patients did not. Two hundred sixty-six biopsies were obtained. SIM was detected in 11 (21%) subjects (SIM+) but not in the remaining 41 (SIM-). One hundred sixty-five biopsies were unstained (25 SIM+, 140 SIM-) and 101 were stained (12 SIM+, 89 SIM-). The per-biopsy sensitivity and specificity of MB for detection of SIM were 32.4 and 85%, while the per-patient sensitivity and specificity were 63.3 and 51.2%. MB staining for detection of SIM in GERD patients without a macroscopic appearance suggestive of a columnar-lined esophagus is a poor screening tool for SIM.
Asunto(s)
Colorantes , Endoscopía Gastrointestinal/métodos , Reflujo Gastroesofágico/patología , Mucosa Intestinal/patología , Azul de Metileno , Adulto , Femenino , Humanos , Masculino , Metaplasia , Persona de Mediana Edad , Estudios Prospectivos , Sensibilidad y EspecificidadRESUMEN
The U.S. Army administers the hepatitis A virus (HAV) vaccination for prophylaxis against HAV infection. There is little comparative data as to whether prescreening for previous HAV infection before immunization is less costly than universal vaccination. We designed a study to determine the prevalence of previous HAV infection in U.S. Army recruits and then perform a cost analysis. The cost analysis compared selective vaccination versus universal vaccination. Basic demographic information, including age, gender, geographic origin, and ethnicity, were collected after which patients were tested for HAV antibodies. A total of 1,332 individuals was prospectively enrolled with 183 individuals (13.74%) having evidence of previous HAV infection. Minority recruits were found to have a higher prevalence than Caucasian recruits (p = 0.0451. The cost analysis demonstrates that vaccination without prescreening was the least costly of two vaccination strategies for this cohort. To achieve current vaccination goals, all U.S. military recruits should be vaccinated without evaluation for previous HAV immunity.