Increased rate of apoptosis and decreased expression of bcl-2 protein in peripheral blood lymphocytes from patients with active systemic lupus erythematosus.
Defective regulation of apoptosis may play a role in the development of autoimmune diseases, and the proto-oncogene bcl-2 is known to inhibit cells from undergoing apoptosis. We studied the rate of apoptosis with the expression of bcl-2 in peripheral blood lymphocytes of patients with systemic lupus erythematosus (SLE). A lower proportion of lymphocytes were bcl-2+ in SLE patients with active disease (median 84.9%) than in patients with inactive disease or normal (medians 95.3% and 97.1% respectively, p < 0.05). The rate of apoptosis of freshly isolated PBL was significantly higher in SLE patients than in normal (medians 1.2% vs 0.5%, p < 0.05). After 48-hour culture the apoptotic rate was further increased in SLE patients, particularly those with active disease (SLE overall 34.2%, active 62% inactive 27.5%, normal 11.25%). These findings support the theory that in SLE patients increased apoptosis may provide a source of extracellular nuclear antigens which stimulate the autoimmune response and form immune complexes with autoantibodies.
Chan
E Y
EY
Department of Pathology, University of Hong Kong, Queen Mary Hospital, Hong Kong.
Ko
S C
SC
Lau
C S
CS
D017209:Apoptosis; D005260:Female; D006801:Humans; D008180:Lupus Erythematosus, Systemic / Q000097:blood / Q000473:pathology*; D008214:Lymphocytes / Q000378:metabolism / Q000473:pathology*; D008297:Male; D000090063:Proto-Oncogene Mas; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000096:biosynthesis*
C000715470:MAS1 protein, human; D000090063:Proto-Oncogene Mas; D019253:Proto-Oncogene Proteins c-bcl-2