Bone marrow analysis of immune cells and apoptosis in patients with systemic lupus erythematosus.
OBJECTIVE
To examine the immune cell profile in the bone marrow of systemic lupus erythematosus (SLE) patients and to assess its clinical relevance.


METHODS
Sixteen bone marrow samples from 14 SLE patients were compared with seven healthy control samples. The numbers of immune cells and apoptotic cells in the bone marrow were examined by immunohistochemistry. The association between immune cell subsets and clinical features was investigated.


RESULTS
CD4+ T cells, macrophages and plasma cells were more common in the bone marrow of SLE patients than in healthy controls (p=0.001, p=0.004 and p<0.001, respectively). Greater numbers of CD4+ T cells and macrophages were associated with high-grade bone marrow damage. The percentage of apoptotic cells in bone marrow of SLE patients was significantly higher than that in controls (p<0.001) and was positively correlated with the number of plasmacytoid dendritic cells (p=0.013). Increased number of plasma cells along with high interleukin-6 expression was correlated with anti-double stranded DNA antibody levels and the SLE disease activity index (p=0.031 and 0.013, respectively).


CONCLUSIONS
Bone marrow from SLE patients showed a distinct immune cell profile and increased apoptosis. This, coupled with a correlation with disease activity, suggests that the bone marrow may play a critical role in the pathogenesis of SLE.
Division of Rheumatology, Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Korea.
J W
JW
Park
Department of Laboratory Medicine, Seoul National University College of Medicine, Seoul, Korea.
S Y
SY
Moon
Division of Rheumatology, Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Korea.
J H
JH
Lee
Division of Rheumatology, Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Korea.
J K
JK
Park
Department of Laboratory Medicine, Seoul National University College of Medicine, Seoul, Korea.
D S
DS
Lee
Department of Pathology, Seoul National University College of Medicine, Seoul, Korea.
K C
KC
Jung
Division of Rheumatology, Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Korea.
Y W
YW
Song
Division of Rheumatology, Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Korea leb7616@snu.ac.kr.
E B
EB
Lee
D000293:Adolescent; D000328:Adult; D000974:Antibodies, Antinuclear / Q000097:blood; D017209:Apoptosis; D015415:Biomarkers / Q000032:analysis / Q000097:blood; D001854:Bone Marrow Cells / Q000276:immunology* / Q000473:pathology*; D001856:Bone Marrow Examination; D016022:Case-Control Studies; D004247:DNA / Q000276:immunology; D003713:Dendritic Cells / Q000276:immunology / Q000473:pathology; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D015850:Interleukin-6 / Q000032:analysis; D008180:Lupus Erythematosus, Systemic / Q000097:blood / Q000276:immunology* / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D010950:Plasma Cells / Q000276:immunology / Q000473:pathology; D011237:Predictive Value of Tests; D012720:Severity of Illness Index; D055815:Young Adult
D000974:Antibodies, Antinuclear; D015415:Biomarkers; C508600:IL6 protein, human; D015850:Interleukin-6; D004247:DNA
Systemic lupus erythematosus; apoptosis; bone marrow