[Antibodies to poly (adenosine diphosphate-ribose) in systemic lupus erythematosus and drug induced lupus].

The difference between anti poly (ADP-ribose) antibodies was studied in patients with systemic lupus erythematosus (SLE), progressive systemic sclerosis (PSS) and drug-induced lupus (DIL). Radioimmunoassay showed that high concentrations of anti poly (ADP-ribose) antibodies (10.3-22.2%) were induced by phenobarbital, phenytoin, valproic acid (anti-epileptic agent) and procainamide (anti-arrhythmic agent). Poly (ADP-ribose) antibodies were separated by hydroxylapatite column chromatography. The average chain length of the polymer consisted of 2.4, 10.8 and 28.2 ADP-ribose units. Anti poly (ADP-ribose) antibodies from patients with SLE and PSS reacted with 2.4, 10.8, and 28.2 ADP-ribose units in RIA, but those from patients with DIL reacted only with 28.2 ADP-ribose units in RIA. The binding specificity of anti poly (ADP-ribose) antibodies from pregnant women was found to be very similar to that of the antibodies from case of DIL. The present results clearly demonstrated that anti poly (ADP-ribose) antibodies found in systemic autoimmune diseases bound not only to poly (ADP-ribose) with an average chain length of more than 20 ADP-ribose units, but also to oligo (ADP-ribose) with an average chain length of about 2 ADP-ribose units. Anti poly (ADP-ribose) antibodies found in DIL cases and pregnant women, however, bound only to poly (ADP-ribose) with an average chain length of more than 20 ADP-ribose units.