Estudo da permeabilidade intestinal em pacientes HIV-positivos: determinação e aplicação de um novo parâmetro farmacológico

Abstract

Studies on changes in intestinal permeability using molecular sugar probes have been developed recently. Because of their special characteristícs, mannitol and lactulose are the most important molecules for determining noninvasive intestinal lesions in various diseases: both are hydrophilic, lipophobic and both have very low affinity to the glicidic carrier system of intestinal cells and neither suffers metabolic modifications. As lactulose is absorved between cell junctions and mannitol through the epithelial cells, mucosal lesion results in increased absorption of lactulose, as the changes in the mucosal absorption area compromises mannitol permeation. High performance liquid-chromatography with pulsed amperometric detection (HPLC-PAD) is an alternative to overcome all the major problems of complicated and very slow readings of probe sugars with the enzymathic and chromatographic methods available today. Due to high incidence of intestinal disturbances in patients with AIDS we decided to study possible alterations of intestinal permeability in positive-HIV patients by employing this technique. The research was done prospectively at Hospital São José in Fortaleza (state of Ceará, Brazil) between May and June 1994. We have followed forty patients with acquired human immunodeficiency syndrome divided in two groups: A- Control with 20 HIV-positíve patients without diarrhea; B- Cases including 20 HIV-positive patients presenting a chronic or persistent diarrhea. Patients emptied their urinary bladder in the morning, after overnight fast, then took 20 ml of fresh water solution containing 4 g of lactulose and 1 g of mannitol. After five hours of urinary collection, 20 ml were withdrawn from each sample and kept at -20° C until lactulose and mannitol were quantified by HPLC-PAD, at the Laboratory of University of Virginia.