Superoxide anion production by neutrophils is associated with prevalent clinical manifestations in systemic lupus erythematosus

To determine the relation between neutrophil function and the clinical characteristics of systemic lupus erythematosus (SLE), the superoxide anion () production by neutrophils, mediated by FcγR and FcγR/CR cooperation, was studied in 64 SLE patients classified according to their prevalent clinical manifestations. Three clinically distinct patterns were designated: (1) manifestations associated with the occurrence of cytotoxic antibodies (SLE-I group); (2) manifestations associated with circulating immune complexes (IC; SLE-II group), and (3) manifestations associated with IC and cytotoxic antibodies (SLE-III group). production was evaluated by a lucigenin-dependent chemiluminescent assay in neutrophils stimulated with IC-IgG opsonized or not with complement. No difference in production was observed when neutrophil responses from healthy controls were compared to the unclassified patients. However, when the SLE patient groups were considered, the following differences were observed: (1) SLE-I neutrophils showed lower production mediated by the IgG receptor (FcγR) with the cooperation of complement receptors (FcγR/CR) than observed in the SLE-II, SLE-III, and healthy groups; (2) neutrophils from the SLE-II group showed a decreased production mediated by FcγR/CR compared to the SLE-III group, (3) SLE-III neutrophils produced more than neutrophils from the SLE-II and control groups, and (4) CR showed inefficiency in mediating the production by neutrophils from the SLE-I group. Comparative experiments on the kinetics of chemiluminescence (CL; T _max and CL_max) disclosed differences only for the SLE-I group. Taken together, these results suggest that differences in oxidative metabolism of neutrophils mediated by FcγR/CR may reflect an acquired characteristic of disease associated with distinct clinical manifestations.