Inhibitory factors of serum opsonic activity in serum from patients with chronic renal failure.

We investigated the mechanism of impaired serum opsonic activity in patients suffering from chronic renal failure (CRF). Prehemodialysis pooled serum from CRF patients was fractionated using Sephadex G-50 gel chromatography, and the effects of the obtained fractions on serum opsonic activity were examined using luminol-dependent chemiluminescence responses. Number 25-30 fractions in the prehemodialysis serum contained factors that may inhibit serum opsonic activity. The presumed molecular weight of these fractions is between 300 and 2800 daltons. These findings indicate that the inhibitory factors of serum opsonic activity may belong to middle molecules.