Substances such as bilirubin that bind tightly to plasma proteins cannot readily be removed from blood. The use of affinity chromatography is described as a new approach to the removal of protein bound metabolites and toxins from blood. Agarose beads were coupled via cyanogen bromide to human serum albumin so as to contain 30 to 50 mg of albumin/g wet wt. Such beads, when exposed to plasma from a patient with congenital nonhemolytic jaundice labeled with [ 14C] bilirubin, bound more than 150 μg bilirubin/g of beads. The binding was saturable, concentration dependent, relatively independent of flow rate, and reversible by elution with plasma, albumin, or 50% (vol/vol) ethanol. The beads could be repeatedly reused without loss of efficiency after ethanol elution and long storage in the cold. Salicylate, cortisol, and taurocholate, which bind weakly to albumin, were retarded by the beads but eluted with neutral buffer. Thyroxine, taurolithocholate, chenodeoxycholate, and digitoxin bound tightly but were eluted with 50% ethanol. Digoxin did not bind at all. When whole blood was passed over agarose albumin beads, bilirubin was removed, calcium and magnesium fell slightly, but red cells, white cells, platelets, clotting factors, and a variety of electrolytes and proteins were substantially unchanged. Agarose albumin beads may be useful for removing protein bound substances from the blood of patients with liver failure, intoxication with protein bound drugs, or specific metabolic deficits. Furthermore, it may be possible to make useful adsorbents by attaching other proteins to agarose or other polymer beads.
|Original language||English (US)|
|Number of pages||8|
|Journal||Journal of Clinical Investigation|
|State||Published - 1974|
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