Mechanical prophylaxis is a heparin-independent risk for anti-platelet factor 4/heparin antibody formation after orthopedic surgery.

Platelet-activating antibodies, which recognize platelet factor 4 (PF4)/heparin complexes, induce spontaneous heparin-induced thrombocytopenia (HIT) syndrome or fondaparinux-associated HIT without exposure to unfractionated heparin (UFH) or low-molecular-weight heparin (LMWH). This condition mostly occurs after major orthopedic surgery, implying that surgery itself could trigger this immune response, although the mechanism is unclear. To investigate how surgery may do so, we performed a multicenter, prospective study of 2069 patients who underwent total knee arthroplasty (TKA) or hip arthroplasty. Approximately half of the patients received postoperative thromboprophylaxis with UFH, LMWH, or fondaparinux. The other half received only mechanical thromboprophylaxis, including dynamic (intermittent plantar or pneumatic compression device), static (graduated compression stockings [GCSs]), or both. We measured anti-PF4/heparin immunoglobulins G, A, and M before and 10 days after surgery using an immunoassay. Multivariate analysis revealed that dynamic mechanical thromboprophylaxis (DMT) was an independent risk factor for seroconversion (odds ratio [OR], 2.01; 95% confidence interval [CI], 1.34-3.02; P = .001), which was confirmed with propensity-score matching (OR, 1.99; 95% CI, 1.17-3.37; P = .018). For TKA, the seroconversion rates in patients treated with DMT but no anticoagulation and in patients treated with UFH or LMWH without DMT were similar, but significantly higher than in patients treated with only GCSs. The proportion of patients with ≥1.4 optical density units appeared to be higher among those treated with any anticoagulant plus DMT than among those not treated with DMT. Our study suggests that DMT increases risk of an anti-PF4/heparin immune response, even without heparin exposure. This trial was registered to www.umin.ac.jp/ctr as #UMIN000001366.

Successful treatment of a fracture of a huge Achilles tendon ossification with autologous hamstring tendon graft and gastrocnemius fascia flap: a case report.

BACKGROUND: Fracture of an ossified Achilles tendon is a rare entity, and no standard treatment has been established. This is the first report to describe the use of a hamstring tendon graft and gastrocnemius fascia flap for Achilles tendon reconstruction. CASE PRESENTATION: We present the case of a 50-year-old woman with fracture of an ossified Achilles tendon. She presented to our clinic with acute right hindfoot pain, which started suddenly while going up the stairs. Plain radiography and magnetic resonance imaging revealed a massive ossification on the right Achilles tendon extending over 14 cm in length; the ossification was fractured at 5 cm proximal to the calcaneus insertion. Surgical treatment included removal of the ossified tendon and reconstruction with an autologous hamstring tendon graft and gastrocnemius fascia flap. One year after surgery, she was able to walk with little pain or discomfort and to stand on her right tiptoe. CONCLUSION: Our novel surgical procedure may be useful in the treatment of fractured ossified Achilles tendons and large Achilles tendon defects.

Vertebral fractures affect functional status in postmenopausal rheumatoid arthritis patients.

Functional disability is a major concern in patients with rheumatoid arthritis (RA). This retrospective study investigated the risk factors for vertebral fractures (VFs) in postmenopausal RA patients and determined the impact of VFs on functional status. Data from a cohort of 200 postmenopausal RA patients in a single hospital registry were analyzed. Demographic and clinical data, imaging data from spine radiographs, and bone mineral density (BMD) data were collected from the patients at baseline and at the final visit (a mean of 2.9 years after the first visit). Risk factors for incident VFs and their impact on the modified health assessment questionnaire (mHAQ) were analyzed. Twenty-eight patients (14%) developed new VFs (NVFs). Logistic regression analysis adjusted for age, BMI, and disease duration revealed that daily dose of prednisolone, femoral neck BMD, use of active vitamin D3, and use of a bisphosphonate at baseline were factors associated with NVF, with odds ratios (95% confidence interval) of 1.27 (1.05-1.54), 0.94 (0.91-0.97), 0.34 (0.13-0.89), and 0.31 (0.12-0.82), respectively. Patients with NVF exhibited worse mHAQ scores and a greater increase in mHAQ scores from baseline compared with those without NVF. In conclusion, incident VFs were associated with reduced functional status in postmenopausal patients with RA. It is important to prevent VFs to maintain the functional status of RA patients.

Endogenous prostaglandin E2 inhibits aberrant overgrowth of rheumatoid synovial tissue and the development of osteoclast activity through EP4 receptor.

OBJECTIVE: We recently developed an ex vivo cellular model of pannus, the aberrant overgrowth of human synovial tissue. This study was undertaken to use that model to investigate the role of prostaglandin E2 (PGE2) and its receptor subtypes in the development of pannus growth and osteoclast activity in rheumatoid arthritis (RA). METHODS: Inflammatory cells that infiltrated pannus from patients with RA were collected without enzyme digestion and designated synovial tissue-derived inflammatory cells. Their single-cell suspensions were cultured in medium alone to observe an aberrant overgrowth of inflammatory tissue in vitro. Levels of cytokines produced in culture supernatants were measured using enzyme-linked immunosorbent assay kits. Osteoclast activity was assessed by the development of resorption pits in calcium phosphate-coated slides. RESULTS: Primary culture of the synovial tissue-derived inflammatory cells resulted in spontaneous reconstruction of inflammatory tissue in vitro within 4 weeks, during which tumor necrosis factor α, PGE2, macrophage colony-stimulating factor, and matrix metalloproteinase 9 were produced in the supernatant. This aberrant overgrowth was inhibited by antirheumatic drugs including methotrexate and infliximab. On calcium phosphate-coated slides, synovial tissue-derived inflammatory cells showed numerous resorption pits. In the presence of inhibitors of endogenous prostanoid production such as indomethacin and NS398, exogenous PGE1 and EP4-specific agonists significantly inhibited all these activities of synovial tissue-derived inflammatory cells in a dose-dependent manner. Addition of indomethacin, NS398, or EP4-specific antagonist resulted in the enhancement of these cells' activities. EP2-specific agonist had a partial effect, while EP1- and EP3-specific agonists had no significant effects. CONCLUSION: These results suggest that endogenous PGE2 produced in rheumatoid synovium negatively regulates aberrant synovial overgrowth and the development of osteoclast activity via EP4.

Risk of postoperative complications in rheumatoid arthritis relevant to treatment with biologic agents: a report from the Committee on Arthritis of the Japanese Orthopaedic Association.

PURPOSE: Since biologic agents were introduced to treat rheumatoid arthritis (RA) in 2003, the number of orthopedic surgical procedures under treatment with biologic agents has been increasing in Japan. However, whether biologic agents cause an increase in the prevalence of postoperative complications is as yet unknown. The Committee on Arthritis of the Japanese Orthopedic Association investigated the prevalence of postoperative complications in patients with RA in teaching hospitals in Japan. METHODS: Between January 2004 and November 2008, surveillance forms about medications and surgical procedures in patients with RA were sent to 2,019 teaching hospitals. Data were analyzed by the Rheumatoid Arthritis Committee. RESULTS: Biologic agents were administered to RA patients in 632 of 1,245 hospitals (50.8%); 430 of the 1,245 hospitals (34.5%) used surgical intervention under treatment with biologic agents. The number of surgical procedures under treatment with biologic agents was 3,468, and the prevalence of infection was 1.3% (46 cases). The prevalence of infection was 1.0% (567 procedures) in 56,339 procedures under treatment with nonbiologic disease-modifying anti-rheumatic drugs. There were no significant differences between biological and nonbiological treatment groups with respect to the prevalence of infection. In the joint arthroplasty group, the number of procedures under biological and nonbiological treatment was 1,626 and 29,903, and the prevalence of infection was 2.1% (34 procedures) and 1.0% (298 procedures), respectively. There was a significant difference between groups. The odds ratio was 2.12 (95% confidence interval 1.48-3.03, P < 0.0001). CONCLUSION: The chance of having biological treatment with joint arthroplasty was more than twofold greater in patients with surgical-site infections compared with those treated with nonbiologic agents. Caution is required for surgical procedure, perioperative course, and obtaining consent for joint arthroplasty for patients with RA undergoing surgery under biological agents.

Neutrophil CD64 expression as a diagnostic marker for local infection and crystal-induced arthritis.

The usefulness of neutrophil CD64 expression was examined in diagnosing local infection, including soft tissue, bone, and joint infections. Among 99 patients suspected of local infection, 31 were confirmed and 68 patients were not. The CD64 level of patients with local infection was significantly higher than in those without infection [4,193 ± 1,132 vs. 1,017 ± 59 molecules/cell (mean ± standard deviation); p < 0.001]. The area under the curve of CD64 calculated by receiver operating characteristic curve analysis was larger than that of C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), or white blood cell (WBC) count. In addition, CD64 levels of patients with crystal-induced arthritis remained within cutoff value (2,000 molecules/cell). These data suggest that measuring CD64 expression can be a useful diagnostic marker for local musculoskeletal infection and crystal-induced arthritis.

Prevalence of joint replacement surgery in rheumatoid arthritis patients: cross-sectional analysis in a large observational cohort in Japan.

The purpose of this study was to describe the prevalence of total joint arthroplasty (TJA) in Japanese rheumatoid arthritis (RA) patients undergoing conventional drug treatment in a large observational cohort in Japan. A total of 5,177 RA patients were studied for the prevalence of TJA, who were enrolled in the NinJa database during the fiscal year of 2006. The cases of 2,695 RA patients with more than ten years of disease duration were extracted and subjected to further analysis. The prevalence of TJA increased in accordance with the disease duration, and the prevalence was markedly increased after ten years. Among the 2,695 patients with more than ten years of disease duration, 1,431 TJAs were performed in 645 (24.6%) patients. The patients with TJA had higher disease activity than those without TJA. In this cross-sectional study, TJAs were performed in approximately a quarter of the Japanese RA patients with more than ten years of disease duration. The result showed that patients with higher disease activity required TJA.

Zonal gene expression of chondrocytes in osteoarthritic cartilage.

OBJECTIVE: To determine the chondrocyte metabolism in respective zones of osteoarthritic (OA) cartilage. METHODS: OA cartilage was obtained from macroscopically intact areas of 4 knee joints with end-stage OA. The cartilage was divided into 3 zones, and gene expression profiles were determined in the respective zones by a custom-designed microarray that focused on chondrocyte-related genes. For the genes whose expression was significantly different among the zones, the expression was compared between OA and control cartilage in the respective zones by an analysis using laser capture microdissection and real-time polymerase chain reaction (PCR). For some genes, the correlation of expression was investigated in specific cartilage zones. RESULTS: A total of 198 genes (approximately 40% of those investigated) were found to be expressed at significantly different levels among the zones. Expression of 26 of those genes was evaluated by laser capture microdissection and real-time PCR, which confirmed the validity of microarray analysis. The expression of cartilage matrix genes was mostly enhanced in OA cartilage, at similar levels across the zones but at different magnitudes among the genes. The expression of bone-related genes was induced either in the superficial zone or in the deep zone, and positive correlations were found among their expression in the respective zones. The expression of 5 proteinase genes was most enhanced in the superficial zone, where their expression was correlated, suggesting the presence of a common regulatory mechanism(s) for their expression. CONCLUSION: In OA cartilage, the metabolic activity of chondrocytes differed considerably among zones. Characteristic changes were observed in the superficial and deep zones.

Proinflammatory role of amphiregulin, an epidermal growth factor family member whose expression is augmented in rheumatoid arthritis patients.

BACKGROUND: The epidermal growth factor (EGF) and EGF receptor (EGFR) families play important roles in the hyperplastic growth of several tissues as well as tumor growth. Since synovial hyperplasia in rheumatoid arthritis (RA) resembles a tumor, involvement of the EGF/EGFR families in RA pathology has been implied. Although several reports have suggested that ErbB2 is the most important member of the EGFR family for the synovitis in RA, it remains unclear which members of the EGF family are involved. To clarify the EGF-like growth factors involved in the pathology of RA, we investigated the expression levels of seven major EGF-like growth factors in RA patients compared with those in osteoarthritis (OA) patients and healthy control subjects. METHODS: The expression levels of seven EGF-like growth factors and four EGFR-like receptors were measured in mononuclear cells isolated from bone marrow and venous blood, as well as in synovial tissues, using quantitative RT-PCR. Further evidence of gene expression was obtained by ELISAs. The proinflammatory roles were assessed by the growth-promoting and cytokine-inducing effects of the corresponding recombinant proteins on cultured fibroblast-like synoviocytes (FLS). RESULTS: Among the seven EGF-like ligands examined, only amphiregulin (AREG) was expressed at higher levels in all three RA tissues tested compared with the levels in OA tissues. The AREG protein concentration in RA synovial fluid was also higher than that in OA synovial fluid. Furthermore, recombinant human AREG stimulated FLS to proliferate and produce several proinflammatory cytokines, including angiogenic cytokines such as interleukin-8 and vascular endothelial growth factor (VEGF), in a dose-dependent manner. The VEGF mRNA levels in RA synovia and VEGF protein concentrations in RA synovial fluid were significantly higher than those in the corresponding OA samples and highly correlated with the levels of AREG. CONCLUSION: The present findings suggest that AREG functions to stimulate synovial cells and that elevated levels of AREG may be involved in the pathogenesis of RA.

LIGHT induces cell proliferation and inflammatory responses of rheumatoid arthritis synovial fibroblasts via lymphotoxin beta receptor.

OBJECTIVE: To investigate the effects of LIGHT (lymphotoxin-like, exhibits inducible expression and competes with herpes simplex virus glycoprotein D for herpes virus entry mediator, a receptor expressed by T lymphocytes) on the proliferation and gene expression of fibroblast-like synoviocytes (FLS) from patients with rheumatoid arthritis (RA). METHODS: We measured LIGHT levels in RA synovial fluids (SF) by ELISA, and compared them with those in osteoarthritis (OA) SF. Levels of LIGHT and its receptors in RA-FLS and synovium were assessed using real-time quantitative polymerase chain reaction (PCR). RA-FLS proliferation was examined by a bromodeoxyuridine assay. Expression of intercellular adhesion molecule-1 (ICAM-1) and several chemokines, such as interleukin 8 (IL-8), monocyte chemoattractant protein-1 (MCP-1), and macrophage inflammatory protein-1alpha (MIP-1alpha), was examined by real-time quantitative PCR, ELISA, and flow cytometry. The effects of LIGHT on nuclear factor-kappaB (NF-kappaB) activation were investigated using immunofluorescence and Western blotting. RESULTS: LIGHT was upregulated in both SF and synovium of RA patients compared with OA patients. Herpes virus entry mediator (HVEM) and lymphotoxin beta receptor (LTbetaR), but not LIGHT, were detected in RA-FLS. LIGHT significantly promoted RA-FLS proliferation and induced expression of MCP-1, IL-8, MIP-1alpha, and ICAM-1 by RA-FLS. As well, LTbetaR small interfering RNA (siRNA), but not HVEM siRNA, inhibited these effects of LIGHT. LIGHT induced IkappaBa degradation and NF-kappaB translocation, and a NF-kappaB inhibitor suppressed the effects of LIGHT on RA-FLS. CONCLUSION: Our findings suggest that LIGHT signaling via LTbetaR plays an important role in the pathogenesis of RA by affecting key processes such as the proliferation and activation of RA-FLS. Regulation of LIGHT-LTbetaR signaling may represent a new therapeutic target for RA treatment.

Regional differences in chondrocyte metabolism in osteoarthritis: a detailed analysis by laser capture microdissection.

OBJECTIVE: To determine the change in metabolic activity of chondrocytes in osteoarthritic (OA) cartilage, considering regional difference and degree of cartilage degeneration. METHODS: OA cartilage was obtained from knee joints with end-stage OA, at both macroscopically intact areas and areas with various degrees of cartilage degeneration. Control cartilage was obtained from age-matched donors. Using laser capture microdissection, cartilage samples were separated into superficial, middle, and deep zones, and gene expression was compared quantitatively in the respective zones between OA and control cartilage. RESULTS: In OA cartilage, gene expression changed markedly with the site. The expression of cartilage matrix genes was highly enhanced in macroscopically intact areas, but the enhancement was less obvious in the degenerated areas, especially in the upper regions. In contrast, in those regions, the expression of type III collagen and fibronectin was most enhanced, suggesting that chondrocytes underwent a phenotypic change there. Within OA cartilage, the expression of cartilage matrix genes was significantly correlated with SOX9 expression, but not with SOX5 or SOX6 expression. In OA cartilage, the strongest correlation was observed between the expression of type III collagen and fibronectin, suggesting the presence of a certain link(s) between their expression. CONCLUSION: The results of this study revealed a comprehensive view of the metabolic change of the chondrocytes in OA cartilage. The change of gene expression profile was most obvious in the upper region of the degenerated cartilage. The altered gene expression at that region may be responsible for the loss of cartilage matrix associated with OA.

Development of an ex vivo cellular model of rheumatoid arthritis: critical role of CD14-positive monocyte/macrophages in the development of pannus tissue.

OBJECTIVE: To establish an ex vivo cellular model of pannus, the aberrant overgrowth of human synovial tissue (ST). METHODS: Inflammatory cells that infiltrated pannus tissue from patients with rheumatoid arthritis (RA) were collected without enzyme digestion, and designated as ST-derived inflammatory cells. Single-cell suspensions of ST-derived inflammatory cells were cultured in medium alone. Levels of cytokines produced in culture supernatants were measured using enzyme-linked immunosorbent assay kits. ST-derived inflammatory cells were transferred into the joints of immunodeficient mice to explore whether these cells could develop pannus. CD14 and CD2 cells were depleted by negative selection. RESULTS: Culture of ST-derived inflammatory cells from 92 of 111 patients with RA resulted in spontaneous reconstruction of inflammatory tissue in vitro within 4 weeks. Ex vivo tissue contained fibroblasts, macrophages, T cells, and tartrate-resistant acid phosphatase-positive multinucleated cells. On calcium phosphate-coated slides, ST-derived inflammatory cell cultures showed numerous resorption pits. ST-derived inflammatory cell cultures continuously produced matrix metalloproteinase 9 and proinflammatory cytokines associated with osteoclastogenesis, such as tumor necrosis factor alpha, interleukin-8, and macrophage colony-stimulating factor. More importantly, transferring ST-derived inflammatory cells into the joints of immunodeficient mice resulted in the development of pannus tissue and erosive joint lesions. Both in vitro development and in vivo development of pannus tissue by ST-derived inflammatory cells were inhibited by depleting CD14-positive, but not CD2-positive, cells from ST-derived inflammatory cells. CONCLUSION: These findings suggest that overgrowth of inflammatory cells from human rheumatoid synovium simulates the development of pannus. This may prove informative in the screening of potential antirheumatic drugs.

Production of interleukin-6 and interleukin-8 by nurse-like cells from rheumatoid arthritis patients after stimulation with monocytes.

It has been reported that nurse-like cells (NLCs) play a critical role in the pathogenesis of rheumatoid arthritis (RA). The interaction between NLCs established from RA patients (RA-NLCs), and freshly isolated blood monocytes was analyzed to further elucidate the pathogenesis of RA. RA-NLC lines were established from the synovium of RA patients. The RA-NLCs were cultured with monocytes freshly isolated from peripheral blood of healthy donors, and induction of interleukin (IL)-6 and IL-8 as well as the mRNA expression of these cytokines was examined. The levels of IL-6 were over 400 times higher in the supernatant from coculture of RA-NLCs and monocytes than in those from cultures of RA-NLCs alone. Anti-tumor necrosis factor (TNF)-alpha monoclonal antibody inhibited the induction of both cytokine in a dose-dependent fashion, although there was no detectable level of TNF-alpha in the supernatant from coculture. In addition, coculture of RA-NLCs and monocytes without direct cell contact did not induce cytokine production. To determine IL-6 producing cells, RA-NLCs and monocytes were separated into each fraction after coculture for 24 h. Cocultured RA-NLCs contained approximately 80 times higher IL-6 mRNA than the RA-NLCs cultured alone. The levels of IL-8 were also much higher (about 900 times) in the supernatant from coculture than in those from cultures of RA-NLCs alone. Cocultured RA-NLCs expressed IL-8 mRNA about 620 times higher than those cultured alone. These results indicate that NLCs produce high levels of IL-6 and IL-8 after cell-cell interaction with monocytes/macrophages via membrane-bound TNF-alpha, and that activation of NLCs by monocytes/macrophages may be involved in the pathogenesis of RA through maintenance of synovial inflammation.