C1Q complexes with beta-2-microglobulin and amyloid P-component in sera of patients with dialysis-associated amyloidosis.

We studied complexes composed of Clq and β2-microglobulin (Clq·β2M) or serum amyloid P-component (Clq- SAP) in the sera of 38 patients receiving hemodialysis (HD) and 20 healthy control subjects using an enzyme-linked immunoassay. We also compared complex levels in HD patients with and without symptoms of HD-associated amyloidosis (HA). Serum Clq β2M levels were significantly higher in HD patients without HA than in healthy control subjects and significantly higher in HD patients with HA than in HD patients without HA. Serum Clq · SAP levels were significantly lower in patients with HA than in those without HA. These results suggest that Clq β2M may contribute to HA.