Determinação qualitativa e quantitativa de sangue oculto em fezes humanas, através do kit luminol-UFRJ: um teste não invasivo para rastreamento de lesões gastrointestinais

Abstract

The detection of occult blood in stool (FOB) is one of the main non-invasive strategies for screening gastrointestinal diseases, especially those associated with inflammatory, hemorrhagic, or neoplastic processes. This study presents the development and evaluation of an innovative analytical method based on the Luminol Kit produced by the Laboratory for Synthesis and Analysis of Strategic Products (LASAPE/UFRJ), traditionally used in forensic applications due to its ability to emit chemiluminescence in the presence of hemoglobin. The proposal consists of adapting the use of luminol to detect small concentrations of occult blood in fecal samples, exploiting its high sensitivity and potential for rapid and low-cost analysis. The method developed is qualitative and quantitative in nature, incorporating a simple, economically accessible, and easy-to-execute approach, with a view to its use in laboratory and clinical environments. The quantification of hemoglobin concentrations in the samples was performed using computerized densitometry, allowing for the systematic evaluation of essential parameters such as sensitivity, accuracy, and diagnostic capacity. In addition, the performance of the proposed method was qualitatively compared to the immunochromatographic test, currently the most widely used procedure in routine fecal occult blood screening. By enabling the quantification of fecal hemoglobin in patients with different gastrointestinal conditions, this study seeks to demonstrate the potential of the luminol-based method as an alternative tool for early diagnosis and therapeutic monitoring. Thus, the research aims to contribute to the development of innovative, non-invasive, and low-cost strategies capable of offering greater sensitivity, operational simplicity, and applicability in medical practice, especially in relevant diseases such as inflammatory bowel disease and colorectal cancer.