Further studies on serum lipoproteins in connective tissue diseases

Men with ankylosing spondylitis (AS) and females with systemic lupus erythematosus (SLE) were found to have low total serum lipid concentrations similar to results previously obtained in patients with rheumatoid arthritis (RA). In AS men total serum TG was about 50% of control values and in AS men and SLE women total serum cholesterol was 78% of control values but close to corresponding RA concentrations. This was explained mainly by low LDL concentrations. There was a marked difference between RA patients and AS and SLE patients in that the two latter groups had normal HDL cholesterol concentrations whereas in RA patients the HDL cholesterol concentration was only 70% of control values. Thus in spite of similar and low total serum lipid concentrations, differences in lipoprotein composition were found in the three different rheumatic diseases, underlining the importance of lipoprotein analyses in the study of dyslipoproteinaemia.