Altered poly(ADP-ribose) metabolism in family members of patients with systemic lupus erythematosus.

OBJECTIVE

To determine whether the previously detected decrease in poly(ADP-ribose) synthesis in systemic lupus erythematosus (SLE) is familial.

METHODS

Poly(ADP-ribose) metabolism was studied in the peripheral blood lymphocytes of members of 3 families with lupus and in healthy controls.

RESULTS

Synthesis, as determined by the incorporation of 3H NAD into acid precipitable counts was 30% of normal in the patients with SLE (p < 0.001) and 70% of normal in the unaffected family members (p < 0.05). Family members also had increased prevalence of antinuclear antibodies but the presence of these antibodies did not correlate with abnormalities in poly(ADP-ribose) metabolism.

CONCLUSION

The healthy biologic relatives of patients with SLE have a decrease in poly(ADP-ribose) synthesis similar to, but less marked than, their affected relatives. Poly(ADP-ribose) polymerase activity appears to be an inherited trait and abnormalities in it may be one of the susceptibility factors for SLE. If this is the case, then further investigation of this gene and its regulation is warranted.