Reactions between polyribonucleotides and low density lipoproteins in sera of patients with progressive systemic sclerosis.

A high percentage (58%) of sera from patients with progressive systemic sclerosis reacted with synthetic polyribonucleotides to give precipitin lines. This was demonstrated by counterimmunoelectrophoresis. The synthetic polyribonucleotides included polyuridylic acid (poly U), polyadenylic acid (poly A), and co-polymers of poly A-poly U. The reactive factor in serum was not immunoglobulin but was associated with low density lipoprotein.