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 (O-2(-)) production by neutrophils, mediated by Fc gamma R and Fc gamma R/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). O-2(-) production was evaluated by a lucigenin-dependent chemiluminescent assay in neutrophils stimulated with ICIgG opsonized or not with complement. No difference in O-2(-) 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 O-2(-) production mediated by the IgG receptor ( Fc gamma R) with the cooperation of complement receptors ( Fc gamma R/ CR) than observed in the SLE-II, SLE-III, and healthy groups; ( 2) neutrophils from the SLE-II group showed a decreased O-2(-) production mediated by Fc gamma R/ CR compared to the SLE-III group, ( 3) SLE-III neutrophils produced more O-2(-) than neutrophils from the SLE-II and control groups, and ( 4) CR showed inefficiency in mediating the O-2(-) production by neutrophils from the SLE-I group. Comparative experiments on the kinetics of chemiluminescence ( CL; T-max and CLmax) disclosed differences only for the SLE- I group. Taken together, these results suggest that differences in oxidative metabolism of neutrophils mediated by Fc gamma R/ CR may reflect an acquired characteristic of disease associated with distinct clinical manifestations.