Altered anion handling by choroid plexus in renal insufficiency

Abnormal localization of 99mTc pertechnetate was detected in the choroid plexus of patients with renal insufficiency despite the administration of potassium perchlorate. This was found in 8 of 21 studies on patients on conservative medical treatment, in 35 of 41 studies in patients on hemodialysis, in 12 of 22 studies in renal transplant recipients, and in 1 of 5 with acute renal insufficiency, but not in any of 33 persons free of renal disease. Abnormal retention of pertechnetate was also observed in the salivary glands of 21 renal patients. The increased localization of 99mTc pertechnetate could not be related to high blood levels of radioactivity, altered protein binding, increased erythrocyte labeling or to impaired gastrointestinal absorption of potassium perchlorate. It is proposed that this finding represents a manifestation of choroid plexus dysfunction resulting in altered handling of anions by this organ. A possible relation to neurological disease in chronic renal insufficiency is suggested.