Macroamylasemia induced by hydroxyethyl starch--confirmation by gel filtration analysis of serum and urine.

The concentration of alpha-amylase in blood rose significantly (Student's t-test) in seven normovolemic healthy subjects after they were given 30 g/m2 body surface area of hydroxyethyl starch 350/0.60 (HES 350/0.60, a new volemic colloid). Concomitant with elevated activity in blood, amylase clearance (Cam) was markedly reduced, even though clearance of creatinine (Ccr) was within normal limits. Similar findings were observed for one male subject given 500 ml (30 g) of HES 450/0.70. Sephadex G-100 gel elution profiles of serum recovered from one male subject after the infusion of HES 350/0.60 revealed the presence of a macroamylase complex eluted with the void volume. Small macroamylase complexes were also detected in urine voided from the same subject. By 24 to 48 hours postinjection, the high activity of alpha-amylase in blood was returning to basal levels, and this was observed to parallel the reduction of macroamylase complexes both serum and urine. The macroamylasemia induced by HES 350/0.60 represents the nonpathologic formation of large colloid-enzyme complexes not easily filtered at the renal glomerulus, and should be differentiated clinically from disease- or drug-induced hyperamylasemia.