Lupus pneumonitis and anti-SSA(Ro) antibodies.

Interstitial pneumonitis has previously been thought to be an uncommon feature in systemic lupus erythematosus (SLE). A review of 63 patients with SLE from 1984 to 1987 at Tulane University revealed a frequency of 25.4% (N = 16) of lupus pneumonitis. Serologic testing for antibodies to SSA(Ro) revealed that 81% (13 of the 16) of the patients with lupus pneumonitis have anti-SSA(Ro) antibodies, compared to a frequency of 38% (24 of the 63) for the entire group with SLE (p less 0.001). The association of lupus pneumonitis and anti-SSA(Ro) antibodies is discussed in light of a speculative immunopathogenic role for the antibody to SSA(Ro) antigen.