Analysis of protein absorbed by LDL column (Liposorber) with special reference to complement component factor D.

Background: A dextran sulfate column (Liposorber) has been developed and proven effective in LDL apheresis for removing LDL from patients with hyperlipemia. Chronic renal failure (CRF) patients with arteriosclerosis obliterans (ASO) treated with Liposorber have been shown good results.

Methods: We analyzed proteins absorbed by Liposorber in CRF patients with ASO by means of 2-dimensional electrophoresis and found some noteworthy protein spots. One of these proteins was purified by Sephacryl S-100 column and DEAE Sepharose fast flow column chromatography.

Results: The purified protein was finally identified as complement factor D by Western blotting. The average of recovery amount from three experiments was 6.5 mg. The total recovered amount of factor D was calculated to be about 21.7% out of the estimated amount of factor D in the plasma of CRF patients with ASO receiving LDL apheresis using Liposorber.

Conclusions: These results indicate that Liposorber absorbs factor D remarkably well.