RESUMO
BACKGROUND: The 99mTc-exametazine labelled leukocytes (99mTc-WBC) scintigraphy is an established method for the inflammatory bowel disease (IBD) diagnosis, but the labelled procedure is a large and laborious process. The 111In-labelled human polyclonal immunoglobulin G (111In-IgG) can be an alternative in the non invasive IBD diagnosis. PATIENTS AND METHODS: Thirty-four patients routinely referred for investigation of IBD were studied. The 99mTc-WBC and 111In-IgG were simultaneously injected and images were obtained at 30 min, 3 and 24 h post-injection. The diagnostic was established by histology of endoscopy and/or surgery samples. Images were blindly evaluated by two experienced observers who only knew of the clinical suspicion of IBD. IBD was confirmed in 27 patients (17 with Crohn's disease [CD] and 10 with ulcerative colitis [UC]). RESULTS: Sensitivity, specificity and accuracy were 88.5, 100 and 90.3% respectively for endoscopy, 73.7, 75 and 73.9% for radiology, 59.3, 85.7 and 64.7% for 111In-IgG scan and 96.3, 85.7 and 94.1% for 99mTc-WBC scan. In the diagnosis of CD involvement of small bowel, the 99mTc-WBC scan identified 9/11 patients with confirmed disease, whereas the 111In-IgG scan diagnosed only four of them. In the evaluation of colonic disease, the 99mTc-WBC scan correctly diagnosed 21/22 confirmed patients, being the 111In-IgG scan positive in 13 of them. As far as disease extension concerned, the 99mTc-WBC demonstrated a statistically significance rather number of disease segments than endoscopy, radiology and 111In-IgG scan. CONCLUSIONS: The 99mTc-WBC was an effective method in the diagnosis of suspected IBD patients, both in the evaluation of small bowel disease and colonic disease, with slightly best results for colonic disease, whereas the 111In-IgG scan seems to have no utility neither in diagnosis nor in extension evaluation of IBD.
Assuntos
Endoscopia , Radioisótopos de Índio , Doenças Inflamatórias Intestinais/diagnóstico , Compostos Radiofarmacêuticos , Tecnécio Tc 99m Exametazima , Adolescente , Adulto , Idoso , Colite Ulcerativa/diagnóstico , Colite Ulcerativa/diagnóstico por imagem , Doença de Crohn/diagnóstico , Doença de Crohn/diagnóstico por imagem , Estudos de Avaliação como Assunto , Feminino , Humanos , Imunoglobulina G , Recém-Nascido , Doenças Inflamatórias Intestinais/diagnóstico por imagem , Leucócitos , Masculino , Pessoa de Meia-Idade , Radiografia , Cintilografia , Sensibilidade e EspecificidadeRESUMO
The aim of this study was to investigate the ability of 111In-labelled human polyclonal immunoglobulin G (111In-IgG) to localize bone and joint infections compared with 99Tcm-HMAPO-labelled leukocytes (99Tcm-WBC). Thirty-four patients routinely referred for investigation of bone and joint infections were studied. In all patients, a bone scan using 99Tcm-MDP was initially obtained. Subsequently, 99Tcm-WBC and 111In-IgG were simultaneously injected and images obtained at 30 min, 4 h and 24 h post-injection. Diagnostic accuracy was established by bacteriology of specimens obtained by needle aspiration and/or surgery, other imaging methods and clinical follow-up. The images were read by three experienced observers blinded to any other information; the clinical suspicion of infection and the diagnosis were established when two observers agreed. Infection was confirmed in 11 patients. The 99Tcm-WBC scans gave 8 true-positive, 5 false-positive, 18 true-negative and 3 false-negative results. With 111In-IgG, the figures were 7, 6, 17 and 4, respectively. The sensitivity, specificity and accuracy were 72.7%, 78.2% and 76.4% respectively for the labelled leukocytes and 63.6%, 73.9% and 70.6% respectively for 111In-IgG. There was greater agreement between the observers with 99Tcm-WBC than 111In-IgG. In this study, 111In-IgG was less sensitive and less specific than 99Tcm-WBC scintigraphy for the diagnosis of chronic infections, but these differences were not significant. Both tracers appear to be useful in the diagnosis of bone and joint infections. However, our results were less reliable for the diagnosis of an infected prosthesis.