Serum prealbumin and retinol-binding protein in the prealbumin-related senile and familial forms of systemic amyloidosis.

In a series of 13 elderly patients with proven prealbumin-related senile systemic amyloidosis (SSA), depressed serum prealbumin values (110.7 +/- 14.1 micrograms/ml) were found as compared to an age-matched control group (175.1 +/- 20.3 micrograms/ml). As expected, there was a significant correlation between serum prealbumin and serum retinol-binding proteins in both groups of patients. Patients with reactive amyloid protein AA amyloidosis had slightly depressed serum prealbumin concentrations, whereas patients with prealbumin-related familial amyloidosis of Swedish type had prealbumin values within normal limits. Since the serum levels of the acute phase reactants, haptoglobin and amyloid-related serum protein AA, were higher in the group of patients with reactive amyloidosis than in patients with SSA, the depression of the prealbumin levels in SSA is not a result of inflammation. Since SSA is known to contain prealbumin, it is possible that a disturbed prealbumin metabolism in old age results in low prealbumin serum values and deposition of amyloid.