Increased superoxide production by polymorphonuclear leukocytes in systemic lupus erythematosus.

Normal and lupus PMN show an enhancement in superoxide production in vitro when stimulated with lupus serum. When N-formyl-methionyl-leucyl-phenylalanine (FMLP) was used, lupus PMN showed an O2- production of 2.1 nmol/min/10(7) cells, which is 5.2 times the response of normal PMN stimulated by FMLP. Our results show the existence of serum factors in SLE patients that can stimulate O2- production by PMN. Lupus neutrophils showed an increased response to membrane stimuli such as FMLP, capable of triggering the cell respiratory burst. Lupus neutrophils appeared more responsive to membrane stimuli. The serum and cellular factors seemed to indicate an increase rate of superoxide production by PMN in lupus patients, which could be relevant factors in the development of vasculitis and tissue damage.

[Neutrophil-dependent inflammatory reactions in systemic lupus erythematosus]. / Reacciones inflamatorias neutrofilo-dependientes en Lupus Eritematoso Sistémico.

We studied the possible role of polymorphonuclear neutrophil (PMN) aggregation in Systemic Lupus Erythematosus (SLE) by the capacity of sera from 32 lupus patients to induce in vitro normal PMN aggregation. Neutrophil aggregating activity (NAA) in this group was significantly greater than that found in 8 inactive SLE patients and in 8 controls. In patients with SLE, there was a positive correlation between disease severity and the quantitative measure of NAA. High levels of NAA were particularly characteristic of central nervous system SLE. These data suggest that the formation of intravascular leukoaggregates may contribute to morbidity in SLE. Normal PMN increase their spontaneous superoxide anion production (0.21 nmol/min 10(7) PMN) when stimulated with sera from SLE patients. Lupus PMN also show an enhancement of 100% in superoxide production in vitro when stimulated with lupus sera. When N formyl methionine leucyl phenylalanine (FMLP) was used, lupus PMN showed an O2-production of 2.1 nmol/min 10(7) which is 5-fold the response of normal PMN stimulated by FMLP. Our results show the existence of seric factors in SLE patients that can stimulate O2-production by PMN. Lupus neutrophils show an increased response to membrane stimuli such as FMLP, capable of triggering the respiratory burst. Lupus neutrophils appear more responsive membrane stimuli such as FMLP, capable of triggering the respiratory burst. Lupus neutrophils appear more responsive to membrane stimuli. The seric and the cellular factors seem to indicate an increased rate of superoxide production by PMN in SLE patients, which can be relevant to vasculitis and tissue damage.

[Catastrophic antiphospholipid syndrome. Communication of 2 forms of presentation]. / Síndrome antifosfolipídico catastrófico. Comunicación de dos formas de presentación.

Antiphospholipid syndrome is characterized by recurrent fetal loss, arterial and venous thromboses, thrombocytopenia and circulating antiphospholipid antibodies. Few patients have a rapidly progressive, fatal outcome. We report two young patients with systemic lupus erythematosus and antiphospholipid antibodies who died after a short course of disease. Although clinical and laboratory findings differed in both patients--small vessel thromboses and microangiopathic hemolytic anemia mimicking thrombotic thrombocytopenic purpura predominated in one of the patients while small and medium size vessel thromboses without hemolysis were present in the other case--autopsy revealed widespread visceral thromboses in both of them, features consistent with a diagnosis of catastrophic antiphospholipid syndrome. This syndrome has not been reported to occur in association with Pneumocistis carinii pneumonia as we describe in one of our patients.