Association of reactive oxygen and nitrogen intermediate and complement levels with apoptosis of peripheral blood mononuclear cells in lupus patients.
OBJECTIVE
Both increased production of reactive oxygen and nitrogen intermediates (RONI) and reduced levels of complement may play a role in the increased apoptosis and reduced clearance of apoptotic cells in systemic lupus erythematosus (SLE). The objective of this study was to evaluate both processes in a parallel, prospective, longitudinal manner.


METHODS
Sixty-seven SLE patients were evaluated during multiple visits, and 31 healthy control subjects were evaluated once or twice. Clinical and laboratory features of SLE disease activity were determined, and blood was collected for measurement of serum nitrate plus nitrite (NOx) levels and for isolation of peripheral blood mononuclear cells (PBMCs). PBMCs were cultured with a nitric oxide (NO) donor and SLE or control plasma, with or without heat inactivation, cobra venom factor (CVF), or lipopolysaccharide plus interferon-gamma treatment. Cells were analyzed for apoptotic index (AI), cellular subsets, and RONI production.


RESULTS
The PBMC AI was associated with SLE and was inversely associated with complement levels over time. Changes in the AI with addition of a NO donor was longitudinally associated with serum NOx levels, and stimulation of SLE PBMCs led to parallel increases in RONI production and apoptosis. Addition of SLE plasma resulted in a greater PBMC AI, an effect that was increased with heat inactivation and was corrected with CVF treatment.


CONCLUSIONS
These data suggest that the greater AI observed in SLE PBMCs relates to increased PBMC RONI production and reduced complement levels. The longitudinal nature of these parallel associations within individuals suggests that these processes are dynamic and additive.
Oates
James C
JC
Medical University of South Carolina, Department of Medicine, Division of Rheumatology, Charleston, SC 29425, USA. oatesjc@musc.edu
Farrelly
Libby W
LW
Hofbauer
Ann F
AF
Wang
Wei
W
Gilkeson
Gary S
GS
D000328:Adult; D000998:Antiviral Agents / Q000494:pharmacology; D017209:Apoptosis / Q000187:drug effects / Q000276:immunology*; D002478:Cells, Cultured; D051056:Complement Inactivating Agents / Q000494:pharmacology; D003165:Complement System Proteins / Q000378:metabolism*; D004546:Elapid Venoms / Q000494:pharmacology; D005260:Female; D006801:Humans; D007371:Interferon-gamma / Q000494:pharmacology; D007963:Leukocytes, Mononuclear / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D008070:Lipopolysaccharides / Q000494:pharmacology; D008137:Longitudinal Studies; D008180:Lupus Erythematosus, Systemic / Q000276:immunology / Q000378:metabolism*; D008297:Male; D020030:Nitric Oxide Donors / Q000494:pharmacology; D026361:Reactive Nitrogen Species / Q000378:metabolism*; D017382:Reactive Oxygen Species / Q000378:metabolism*
D000998:Antiviral Agents; D051056:Complement Inactivating Agents; D004546:Elapid Venoms; D008070:Lipopolysaccharides; D020030:Nitric Oxide Donors; D026361:Reactive Nitrogen Species; D017382:Reactive Oxygen Species; C016310:cobra venom factor; D007371:Interferon-gamma; D003165:Complement System Proteins