Detection of myeloid precursors (granulocyte/macrophage colony forming units) in the bone marrow adjacent to rheumatoid arthritis joints.
Various cytokines were recently found to be involved in the pathogenesis of rheumatoid arthritis (RA) and particularly, cytokines with hematopoietic activity have been detected in synovial tissues. We counted the number of myeloid precursors in terms of granulocyte/macrophage colony forming units (CFU-GM) and the number of stromal cell progenitors in terms of fibroblast colony forming units (CFU-F) in the tibial bone marrow adjacent to the joints affected by RA (n = 21), osteoarthritis (OA) (n = 10), and trauma (n = 2) using the colony formation unit assay. We also quantitated the amounts of interleukin 1 beta (IL-1 beta), IL-6, and granulocyte/macrophage colony stimulating factor (GM-CSF) in the culture supernatant of synovial tissue explants of these patients by enzyme linked immunosorbent assay (ELISA). The mean number (+/- SEM) of CFU-GM in patients with RA (7.4 +/- 4.9) was greater than that in patients with OA (0.5 +/- 0.2), while CFU-GM was not detected in trauma patients. The number of CFU-GM in the tibial bone marrow of patients with RA correlated well with the amount of IL-1 beta (r = 0.64, p < 0.01), but not with GM-CSF or with IL-6 from synovial tissues. These findings suggest that active bone marrow is present adjacent to the affected joints in patients with RA and that hematopoietic activity is influenced by IL-1 beta produced in nearby synovial tissues.
Kotake
S
S
Institute of Rheumatology, Tokyo Women's Medical College, Japan.
Higaki
M
M
Sato
K
K
Himeno
S
S
Morita
H
H
Kim
K J
KJ
Nara
N
N
Miyasaka
N
N
Nishioka
K
K
Kashiwazaki
S
S
D000368:Aged; D001172:Arthritis, Rheumatoid / Q000473:pathology*; D001853:Bone Marrow / Q000473:pathology*; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D016178:Granulocyte-Macrophage Colony-Stimulating Factor / Q000032:analysis; D006098:Granulocytes / Q000473:pathology; D006412:Hematopoietic Stem Cells / Q000473:pathology*; D006801:Humans; D007375:Interleukin-1 / Q000032:analysis; D015850:Interleukin-6 / Q000032:analysis; D007596:Joints / Q000473:pathology*; D008264:Macrophages / Q000473:pathology; D008297:Male; D008875:Middle Aged; D010003:Osteoarthritis / Q000473:pathology; D013583:Synovial Membrane / Q000737:chemistry / Q000473:pathology; D013977:Tibia; D014947:Wounds and Injuries / Q000473:pathology
D007375:Interleukin-1; D015850:Interleukin-6; D016178:Granulocyte-Macrophage Colony-Stimulating Factor