Concentrations of transferrin and carbohydrate-deficient transferrin in postmortem human brain from alcoholics

Transferrin (T f) and its carbohydrate-deficient isoform (CDT) were measured by radioimmunoassay in phosphate-buffered saline extracts of two informative areas of cerebral cortex tissue obtained at autopsy from alcoholics without other associated disease (n = 4); alcoholics with cirrhosis of the liver (n = 4) and agematched controls (n = 4). Total T f was also measured in two informative cortical areas from five dementia cases. All cases were male. Total immunoreactive T f was assayed directly in the extract, CDT immunoreactivity in the concentrated eluate after the sialylated form was removed by passing through DEAE-Sephacel at pH 5.65. Brain CDT averaged 10% of total T f overall. Although replicate extractions of individual samples gave consistent assays for both substances, there was wide variation both between different cortical areas from a given case and between cases within groups. There were no significant differences between total T f levels in uncomplicated alcoholics, dementia cases and controls, but cirrhotic alcoholics gave significantly higher values. The CDT: T f ratio was not increased in the brains of either group of alcoholics compared to controls. Whereas the serum CDT: T f ratio is an excellent marker of recent alcohol consumption, brain T f and CDT concentrations do not mark alcoholism nor dementia, and their biological variability diminishes their usefulness as disease indices. However, brain T f may be a marker of cirrhosis-induced changes.