Abstracts

A currently favored hypothesis in the pharmacoresistant epileptic patienst, is the overexpression of multidrug transporters, specially P-glycoprotein (Pgp-170), this is normally expressed in biliary canalicular surfaces of hepatocytes and it is responsible for the excretion of cationic metabolites from the liver. The MIBI is a substrate for Pgp-170. The aim of the present study was to determine the MIBI liver clearence characteristcs in refractory epileptic patients We included 12 epileptic patients( EP) and 7 normal control (NC). The mean age was EP: 34,25 y ( 22-50) and NC :48 (44-51), 12 females. After the intravenous administration of 15 mCi of MIBI, we adquired 60/1 minute images, over the abdomen. We generated activity/times curves over the liver in order to calculated the excretion mean time(T1/2)( time to reach the 50% of maximun liver uptake). The patients and controls fasten 3 hours prior to the study. The kinetic study was analysed blinded to the clinic characteristics or pharmacological response. The NC T1/2 was 7789.7s(sd:3739). The EP T1/2 was 3200s(sd 2637.7),in four patients of this group the kinetics was identical to the NC. All of them have good pharmacological response( RP). The other eight EP, have an accelerate T1/2 (p:0.001)and the entire group corresponding to the pharmacoresistant epileptic patients (NRP). Our results, suggest that in patients with pharmacoresistant epilepsy (RE), the drug excretion mechanism could be overexpressed and actived, resulting in an accelerated drugs liver clearence. As visualized in real time by this MIBI kinetic study. We don[apos]t know if this accelerated kinetic results are secondary to the develop of refractory phenotype, or they are present as an early feature of this patients.
We conclude that the liver clearence of MIBI could be a kinetic useful and non invasive tool for better characterization of patient with pharmacoresistant epilepsy[table1][table2] (Supported by Instituto de Investigaciones Neurologicas [quot]Dr. Raul Carrea[quot]. Fundacion Lucha Enfermedades Neurologicas de la Infancia-FLENI
Buenos Aires, Argentina)