Abnormal expression of apoptosis-related antigens, Fas and bcl-2, on circulating T-lymphocyte subsets in primary Sjögren's syndrome.
OBJECTIVE
To clarify the pathological role of the apoptosis-related molecules expressed on peripheral blood (PB) lymphocyte subsets in primary Sjögren's syndrome (SS).


METHODS
The levels of apoptosis-regulating proteins, Fas and bcl-2, were determined in the PB lymphocyte subsets from 21 patients with SS and 14 healthy controls by 2-color flow cytometry.


RESULTS
In the PB from SS patients, lymphocytopenia, especially CD4+ cell-lymphocytopenia, was prominent. As observed in previous studies, the percentages of CD4+ CD45RA+ cells were lower in the SS patients than in the controls, while activated (DR+) cells were increased in CD4+ cells from the patients. Fas+ cells were also increased in the patients' CD4+ cells and CD8+ cells, but not in their B cells or natural killer cells. Furthermore, we observed several positive correlations among the percentages of activated cells (DR+ cells or CD45RA-cells) and Fas+ cells recognized in the CD4+ and/or CD8+ cells from the patients. On the other hand, intra-cellular bcl-2 proteins measured as mean fluorescence intensity were significantly diminished in the CD4+ cells, CD8+ cells, CD19+ cells, CD45RO+ cells and Fas+ cells from 14 SS patients compared with 12 healthy controls. In addition, the numbers and/or percentages of CD4+ cells and Fas+ cells positively correlated with their expression of bcl-2 in SS patients.


CONCLUSIONS
The abnormal balance between Fas and bcl-2 expression detected in the PB lymphocyte subsets from SS patients relates, at least partially, to the lymphocytopenia observed in the patients.
Ichikawa
Y
Y
Department of Internal Medicine, Tokai University School of Medicine, Kanagawa, Japan.
Arimori
K
K
Yoshida
M
M
Horiki
T
T
Hoshina
Y
Y
Morita
K
K
Uchiyama
M
M
Shimizu
H
H
Moriuchi
J
J
Takaya
M
M
D000328:Adult; D000368:Aged; D000945:Antigens, Differentiation, T-Lymphocyte / Q000097:blood; D017209:Apoptosis / Q000502:physiology*; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D018655:Lymphocyte Count; D008297:Male; D008875:Middle Aged; D011518:Proto-Oncogene Proteins / Q000097:blood*; D019253:Proto-Oncogene Proteins c-bcl-2; D012859:Sjogren's Syndrome / Q000276:immunology* / Q000473:pathology; D016176:T-Lymphocyte Subsets / Q000276:immunology*; D019014:fas Receptor / Q000097:blood*
D000945:Antigens, Differentiation, T-Lymphocyte; D011518:Proto-Oncogene Proteins; D019253:Proto-Oncogene Proteins c-bcl-2; D019014:fas Receptor