Stabilizing effect of total ankle arthroplasty by distal translation and lateralization of talus in varus ankle deformity.

BACKGROUND: In end-stage arthritis indicated for total ankle arthroplasty (TAA), full-thickness cartilage damage, subchondral bone defect/shaving, and fluttering of the talar dome occur, shortening the distance between the tibial and talar insertions of ligaments and leading to laxity of ligaments surrounding the ankle joint. Under such conditions, medial ligaments (including the deltoid ligament) would not be expected to function properly. To stabilize the ankle joint during the stance phase, medial ligament function under tension is important. This study therefore examined whether TAA contributes to lengthening of the medial tibio-talar joint as evaluated radiographically, as a preferable method for achieving tensile effects on medial ligaments. MATERIALS AND METHODS: Twenty-four feet with end-stage varus deformity of the ankle joint that underwent TAA were retrospectively investigated, excluding cases with any malleolar osteotomy or fracture. Distance between proximal and distal insertions of medial ligaments, lateralization of the talus, and talar tilt angle under valgus/varus stress condition were evaluated pre- and postoperatively. RESULTS: Distance between proximal and distal insertions of medial ligaments was significantly elongated after TAA. At the same time, the talus showed significant lateralization. Furthermore, talar tilt under valgus/varus stress conditions was also significantly reduced after TAA. CONCLUSION: TAA affects distal translation and lateralization of the talus in cases of varus ankle deformity. These effects might contribute to re-providing tensile force on lax medial ligaments, improving ligament function.

Limited VH gene usage in B-cell clones established with nurse-like cells from patients with rheumatoid arthritis.

OBJECTIVES: Nurse-like stromal cells (NLC) in synovia and bone marrow of patients with rheumatoid arthritis (RA) can support pseudoemperipolesis, protect from apoptosis and enhance immunoglobulin production of peripheral blood B cells isolated from healthy individuals, suggesting the profound contribution of hyperactivation of B cells in RA. In the course of establishing RA-NLC from RA patients, we observed the growth of B cells in the presence of RA-NLC. METHODS: We cloned B cells from the synovium or bone marrow of RA patients using the limiting dilution technique. For established clones, nucleotide sequences of immunoglobulin and surface antigens were investigated. To investigate the dependence of these clones on NLC, differences in the proliferation and the amount of immunoglobulin produced in the presence or absence of NLC were compared. Immunocytochemical staining of various cells was performed using the antibody these clones produced. RESULTS: Nine B-cell clones established from RA patients showed RA-NLC-dependent growth. These B-cell clones expressed CD19, CD20, CD38, CD39 and CD40, suggesting that the cloned cells were mature and activated. All clones secreted immunoglobulins in culture media, which were specific for intracellular components of various cell lines, including RA-NLC. Interestingly, we found limited usage of immunoglobulin heavy-chain variable regions (VH) among B-cell clones from RA patients. These repertoires were reported to be detected preferentially in fetal livers. CONCLUSION: The present study provides a novel insight into the involvement of RA-NLC in the immunopathogenesis of RA via an autoreactive B cell development and/or activation mechanism.

Comparison of the activities of multinucleated bone-resorbing giant cells derived from CD14-positive cells in the synovial fluids of rheumatoid arthritis and osteoarthritis patients.

OBJECTIVE: To investigate the morphology and function of multinucleated bone-resorbing giant cells derived from CD14-positive cells in the synovial fluids (SF) of patients with rheumatoid arthritis (RA) or osteoarthritis (OA). METHODS: CD14-positive cells were obtained by magnetic-activated cell sorting of primary cultures of mononuclear cells from the SF. Multinucleated bone-resorbing giant cells were induced from the CD14-positive cells in the presence or absence of cytokines. We examined various characteristics, including osteoclast markers, fusion index and bone-resorption activities of the multinucleated giant cells. RESULTS: Multinucleated giant cells were induced from the CD14-positive cells in the SF of the RA and OA patients by the addition of interleukin (IL)-3, IL-5 and IL-7, or granulocyte-macrophage colony-stimulating factor (GM-CSF), respectively. These multinucleated giant cells were positive for tartrate-resistant acid phosphatase (TRAP), carbonic anhydrase II, actin, vitronectin receptor and the calcitonin receptor. However, the average values for the number of nuclei, fusion index and bone-resorption functions of the SF cells from the RA patients were significantly higher than those derived from the OA patients. CONCLUSION: These results suggest that the induction and activities of multinucleated bone-resorbing giant cells may play a pivotal role in bone destruction, and that these processes may be enhanced significantly in RA patients.

Early closure of growth plate causes poor growth of long bones in collagen-induced arthritis rats.

Abnormalities of the epiphyseal growth plate that occur in collagen-induced arthritis (CIA) were studied. CIA was induced in 6-week-old Lewis rats by immunization with type II collagen. Radiographic examination revealed the early closure of the epiphyseal growth plate with growth retardation of the femur and tibia. Histological evaluation confirmed the early closure of the epiphyseal growth plate accompanied by decreased intensity of safranin-O staining indicating decreased amounts of proteoglycans in the extracellular matrix (ECM) of the cartilage. Immunohistochemical methods showed that the number of chondrocytes expressing matrix metalloproteinase (MMP)-3 and/or vascular endothelial growth factor (VEGF) increased in the growth plates of CIA rats. This study confirmed that disturbances of long bone growth with early closure of the epiphyseal growth plates occur in CIA. There appeared to be overexpression of MMP-3, which may be involved with proteoglycan degradation. Additionally, VEGF, which is associated with cartilage ossification and angiogenesis, might also play a role in this event. Further clarification of the mechanism of the growth disturbance in CIA may yield clinical benefits, especially in prevention of the premature closure of growth plate that is seen in juvenile rheumatoid arthritis and other diseases.

Expression of proteinases and inflammatory cytokines in subchondral bone regions in the destructive joint of rheumatoid arthritis.

OBJECTIVE: We previously described abnormalities in the bone marrow of patients with rheumatoid arthritis (RA), but were able to shed little light on the pathogenic roles of inflammatory cytokines and proteinases in joint destruction in the subchondral region in RA. This is the first report to describe the co-localization of cytokines and proteinases in this area. METHODS: Decalcified paraffin-embedded sections from 10 patients with RA and five patients with osteoarthritis (OA) were examined for the immunolocalization of cathepsins B, K and L and the localization of messenger RNAs for interleukin 1beta (IL-1beta), tumour necrosis factor alpha (TNF-alpha) and matrix metalloproteinase 9 (MMP-9). The cells were double-stained with anti-CD68 or anti-prolyl 4-hydroxylase (PH) antibody. RESULTS: An immunohistochemical study confirmed the expression of cathepsins B and L by CD68-positive mononuclear cells at the sites of significant cartilage and bone erosion from the subchondral region in all RA specimens. Osteoclast-like cells showed intense staining for cathepsin K and MMP-9. Osteoblast-like cells strongly expressed MMP-9. Analysis of serial sections revealed that expression of the IL-1beta and TNF-alpha genes occurred near that of the cathepsins and MMP-9 in the subchondral region. CONCLUSION: We conclude that inflammatory cytokines and tissue-damaging proteinases play important roles in joint destruction in the subchondral region in RA.

[Bone marrow plays an important role in joint destruction in patients with rheumatoid arthritis].

In iliac bone marrow the absolute number of mononuclear cells (MNCs) was increased in RA patients compared with the non-RA controls. In CD8 positive cell and myeloid cell fractions, significant differences were recognized between RA patients and non-RA controls. The presence of abnormal myeloid lineage cells in epiphyseal bone marrow adjacent to joints affected with severe RA was shown. Stroma cell lines from RA bone marrow with nursing activity were established and shown to play a pivotal role in the pathogenesis in RA bone marrow. Histologic study also shows that subchondral region expressing tissue-damaging proteinases plays an important role in joint destruction in RA.

Transcription factor decoy for NFkappaB inhibits cytokine and adhesion molecule expressions in synovial cells derived from rheumatoid arthritis.

OBJECTIVE: Numerous cytokines are expressed in lesions of synovial hyperplasia of patients with rheumatoid arthritis (RA), and their pathophysiological contributions have been the subject of speculation. These genes are regulated by the transcription factor NFkappaB which in turn is activated by tumour necrosis factor-alpha (TNF-alpha) and cytokines. In this study we examined the inhibition of the production of pro-inflammatory cytokines, adhesion molecule and matrix metalloproteinase (MMP) from synovial tissue of patients with RA by the introduction of synthetic double-stranded DNA with high affinity for the NFkappaB binding site. METHOD: NFkappaB decoy oligonucleotides (ODN) were introduced with the aid of the haemagglutinating virus of Japan (HVJ)-liposome method into synovial tissue or synovial cells derived from patients with RA. The levels of interleukin-1beta (IL-1beta), IL-6, TNF-alpha, intercellular adhesion molecule-1 (ICAM-1) and MMP-1 were determined by means of enzyme-linked immunosorbent assay (ELISA) and Northern blotting analysis. A cell counting kit was used to study the effect of NFkappaB decoy ODN on synovial cell proliferation. RESULTS: The production of these mediators was significantly inhibited by the introduction of NFkappaB decoy ODN compared with the effect of scrambled decoy ODN. Transfection of NFkappaB decoy ODN resulted in a significant inhibition of synovial cell proliferation as compared with that of scrambled decoy ODN. CONCLUSION: The results demonstrated in this study suggest the potential usefulness of NFkappaB decoy ODN for gene therapy of inflammatory synovitis of RA.