Clinical significance of myeloperoxydase and proteinase 2 antibodies in patients with systemic lupus erythematosus

: Content of antibodies to neutrophil cytoplasma--myeloperoxidase (MPO)--and proteinase-3 (PR-3) was measured in the sera of 65 patients with SLE and 20 donors. Antibodies to MPO (a-MPO) and proteinase-3 (a-PR-3) significantly outnumbered those of the control. The number of a-MPO appeared elevated in 13, lowered in 7, moderate in 6 cases and directly correlated with anemia, pulmonary lesions, a-PR-3 level, inversely correlated with cerebrovasculitis and polyneuritis. The number of a-PR-3 was elevated in 14 cases (10 low titers and 4 moderate titers). High levels of both a-PR-3 and a-MPO were recorded in 8 sera. The content of a-PR-3 correlated directly with age of SLE onset but inversely with leukocyte count. Neither course of the disease nor inflammation activity were related to level of neutrophil antibodies. Factor analysis has identified groups of elements influencing the value of a-MPO and a-PR-3.