Nobuhiko Sunahara

Selective expression of folate receptor β and its possible role in methotrexate transport in synovial macrophages from patients with rheumatoid arthritis

OBJECTIVE To investigate the expression of folate receptors (FR) and reduced folate carrier (RFC) and determine their relevance to methotrexate (MTX) transport in synovial mononuclear cells (SMC) from patients with rheumatoid arthritis (RA). METHODS Levels of FR and RFC messenger RNA (mRNA) were examined by reverse transcriptase-polymerase chain reaction (RT-PCR) in SMC from RA patients and peripheral blood mononuclear cells from healthy donors. Expression of FR-beta mRNA and protein was determined by Northern blot and Western blot analyses in RA SMC and monocyte/macrophage-lineage cells. FR-beta expression and folic acid binding capacity on the cell surface were examined by flow cytometric analysis and 3H-folic acid binding analysis. Studies of the inhibition of 3H-MTX uptake in the presence of unlabeled folic acid were performed to investigate the uptake of MTX through FR in RA SMC. RESULTS RT-PCR, Northern blot, and Western blot analyses showed that FR-beta mRNA and protein were expressed selectively in activated monocytes and CD14+ RA SMC. These cells exhibited folic acid binding capacity. Furthermore, the FR-beta protein was shown to have folic acid binding capacity. Uptake of 3H-MTX through RA SMC was significantly inhibited in the presence of unlabeled folic acid. CONCLUSION These results demonstrate that FR-beta expression is selectively elevated in RA synovial macrophages and suggest that MTX is transported through FR-beta in RA synovial macrophages. The findings suggest that folate antagonists with higher affinity for FR-beta would be useful in the treatment of RA.

Extracellular high mobility group box chromosomal protein 1 is a coupling factor for hypoxia and inflammation in arthritis

OBJECTIVE Tissue hypoxia is closely associated with arthritis pathogenesis, and extracellular high mobility group box chromosomal protein 1 (HMGB-1) released from injured cells also has a role in arthritis development. This study was thus undertaken to investigate the hypothesis that extracellular HMGB-1 may be a coupling factor between hypoxia and inflammation in arthritis. METHODS Concentrations of tumor necrosis factor alpha, interleukin-6, vascular endothelial growth factor, lactic acid, lactate dehydrogenase, and HMGB-1 were measured in synovial fluid (SF) samples from patients with inflammatory arthropathy (rheumatoid arthritis and pseudogout) and patients with noninflammatory arthropathy (osteoarthritis). The localization of tissue hypoxia and HMGB-1 was also examined in animal models of collagen-induced arthritis (CIA). In cell-based experiments, the effects of hypoxia on HMGB-1 release and its associated cellular events (i.e., protein distribution and cell viability) were studied. RESULTS In SF samples from patients with HMGB-1-associated inflammatory arthropathy (i.e., samples with HMGB-1 levels >2 SD above the mean level in samples from patients with noninflammatory arthropathy), concentrations of HMGB-1 were significantly correlated with those of lactic acid, a marker of tissue hypoxia. In CIA models in which the pathologic phenotype could be attenuated by HMGB-1 neutralization, colocalization of HMGB-1 with tissue hypoxia in arthritis lesions was also observed. In cell-based experiments, hypoxia induced significantly increased levels of extracellular HMGB-1 by the cellular processes of secretion and/or apoptosis-associated release, which was much more prominent than the protein release in necrotic cell injury potentiated by oxidative stress. CONCLUSION These findings indicate that tissue hypoxia and its resultant extracellular HMGB-1 might play an important role in the development of arthritis.

Clinical course of conservatively managed rheumatoid arthritis patients with myelopathy.

Study Design. The clinical course of rheumatoid arthritis patients with myelopathy who do not undergo surgery was studied. Objectives. To establish a more accurate prognosis for rheumatoid arthritis patients who do not undergo surgery. Summary of Background Data. Cervical myelopathy has been reported in two thirds of rheumatoid arthritis patients with atlantoaxial dislocation. Atlantoaxial fusion, or occipitocervical fusion, is widely performed on these patients. However, several researchers reported serious complications from the surgery, including nonunion, worsening myelopathy, and high mortality. The natural course of disease in rheumatoid arthritis patients with myelopathy should be known before definitive treatments can be outlined. Materials and Methods. Twenty‐one rheumatoid arthritis patients with myelopathy resulting from atlantoaxial dislocation were studied. Fourteen of the 21 cases were associated with upward migration of the odontoid process. All of these patients were recommended for surgery, but they refused. Patients were reviewed by direct examination yearly. Radiographic changes and clinical course, including the survival rate, were observed. Results. Atlantodental interval and Redlund‐Johnell measurements deteriorated. The patients showed no neural improvement, and deterioration was found in 16 (76%) cases during follow‐up. All patients became bedridden within 3 years of the onset of myelopathy. Seven of the 21 patients died suddenly for unknown reasons, 3 died of pneumonia, and 1 died of multiple organ failure. The three sudden‐death cases showed progressive upward migration of the odontoid process. The cumulative probability of survival was 0% in the first 7 years after the onset of myelopathy. Conclusions. The clinical results for rheumatoid arthritis patients with myelopathy treated without surgery are extremely poor. Surgical treatment is recommended for rheumatoid arthritis patients with myelopathy.

Prognosis of Patients With Upper Cervical Lesions Caused by Rheumatoid Arthritis : Comparison of Occipitocervical Fusion Between C1 Laminectomy and Nonsurgical Management

Study Design. A matched controlled comparative study of patients with upper cervical lesions caused by rheumatoid arthritis was performed at two different hospitals to evaluate occipitocervical fusion associated with C1 laminectomy and nonsurgical treatment. Objectives. To evaluate the long-term results and advantages of occipitocervical fusion associated with C1 laminectomy, and to compare these results with those of nonsurgical management of patients with myelopathy related to rheumatoid arthritis. Summary of Background Data. Few studies have reported the prognosis of patients with rheumatoid arthritis managed by occipitocervical fusion associated with C1 laminectomy. Methods. In this study, 40 patients with rheumatoid arthritis and myelopathy caused by irreducible atlantoaxial dislocation with or without upward migration of the odontoid process were studied. Of these 40 patients, 19 were treated by occipitocervical fusion using a rectangular rod associated with C1 laminectomy at one hospital, whereas 21 matched patients were treated conservatively at another hospital. The patients were observed by the same protocol to assess the radiologic and clinical results, including functional recovery and survival rate. All the patients were followed until their death. Results. The atlantodental interval was reduced immediately after surgery, and this result had been well maintained at the final follow-up assessment. Redlund-Johnell values did not vary significantly throughout the course of the study. As for neural assessment with the Ranawat classification system, improvement was found in 13 (68%) of the 19 patients who underwent surgery. The survival rate was 84% 5 years after surgery, and 37% in the first 10 years. In the patients who did not undergo surgical treatment, atlantodental interval and Redlund- Johnell values were aggravated. These patients showed no neural improvement, and aggravation was found in 16 (76%) of the 21 cases during the follow-up period. All the patients were bedridden within 3 years after the onset of myelopathy. The survival rate was 0% in the first 8 years. Conclusions. The findings lead to the conclusion that occipitocervical fusion associated with C1 laminectomy for patients with rheumatoid arthritis is useful for decreasing nuchal pain, reducing myelopathy, and improving prognosis.

Functional folate receptor beta-expressing macrophages in osteoarthritis synovium and their M1/M2 expression profiles

Objective: The distribution of folate receptor (FR)-β+ macrophages and their M1/M2 expression profiles were examined in osteoarthritis (OA) synovial tissues, and compared to those in rheumatoid arthritis (RA) synovial tissues and CD163+ macrophages in both OA and RA synovial tissues. Method: The phenotypes and fluorescein isothiocyanate (FITC)–folate uptake of FR-β+ synovial macrophages were analysed by flow cytometry. The distribution of FR-β+ macrophages in OA and RA synovial tissues was examined by immunofluorescent microscopy. Tumour necrosis factor (TNF)-α, inducible nitric oxide synthase (iNOS), interleukin (IL)-10, and transforming growth factor (TGF)-β expression in FR-β+ macrophages was detected by double-immunostaining in both OA and RA synovial tissues. Results: FR-β+ macrophages were predominantly present in the synovial lining layer in OA patients. The proportion of CD163–FR-β+ cells in synovial mononuclear cells (MNCs) was increased in OA compared to RA synovial tissues. FR-βhigh macrophages from OA synovial tissues represented the majority of folic acid-binding cells. Although FR-β+ or CD163+ macrophages in the synovial tissues of OA and RA patients expressed a mixed pattern of M1 and M2 macrophage markers, there were more M2 markers expressing synovial macrophages in OA than in RA patients. Conclusions: The distribution and M1/M2 expression profiles of FR-β+ synovial macrophages were different between OA and RA synovial tissues. Thus, the findings underscore that the M1/M2 paradigm using surface markers FR-β and CD163 is an oversimplification of macrophage subsets. Functional FR-β present on OA synovial macrophages provides a potential tool for the diagnosis and treatment of OA.

3- to 11-Year followup of occipitocervical fusion for rheumatoid arthritis

The relief of myelopathy usually is unsatisfactory by a conventional Gallie type atlantoaxial fusion for patients with rheumatoid arthritis who have irreducible atlantoaxial dislocation. To accomplish a decompressive laminectomy of the atlas in the treatment of myelopathy, the authors have been performing a new surgical procedure since 1985 for occipitocervical fusion using a rectangular rod. The postoperative outcomes for 25 patients with rheumatoid arthritis were evaluated clinically and radiographically with a 3− to 11-year (mean, 6.5 years) followup. A decompressive laminectomy of the atlas accompanied the fusion in 21 of the 25 patients. The incidence of occipital or nuchal pains improved notably in most cases, and myelopathy was relieved in 12 of 18 (67%) cases, showing an improvement of more than one level based on Ranawats criteria. No serious postoperative complications were seen, except for one case of a failed bone union. The cumulative survival in patients with myelopathy was 79.4% in the first 5 years after operation and 27.5% at 10 years. Occipitocervical fusion using a rectangular rod accompanied by a decompressive laminectomy of the atlas can contribute to the relief of a neurologic deficit in an irreducible atlantoaxial dislocation in rheumatoid arthritis.

Biomechanical analysis of buckling alignment of the cervical spine. Predictive value for subaxial subluxation after occipitocervical fusion.

Study Design. A biomechanical analysis of the buckling type of alignment on nonfused cervical segments was carried out in patients with occipitocervical fusion for atlantoaxial dislocation. Objectives. To examine whether biomechanical analysis is useful for preoperative prediction of subaxial subluxation after occipitocervical fusion. Summary of Background Data. Rheumatoid arthritis sometimes causes subaxial subluxation after occipitocervical fusion. At present, there are no widely accepted criteria for determining the appropriate extent of fusion to prevent subluxation. Methods. The subjects were 25 patients with rheumatoid atlantoaxial dislocation and 15 patients with nonrheumatoid atlantoaxial dislocation who underwent occipitocervical fusion. Preoperative and postoperative alignment of the cervical spine were analyzed biomechanically, using a specially developed computer program. Results. Five segments of nonfused cervical spine had subluxation after surgery in the rheumatoid group. For these segments, the preoperative value of buckling averaged 13.5 × 10−4 and exceeded 10 × 10−4 in all cases. For the segments that showed no subluxation after surgery, the preoperative value of buckling averaged 4.5 × 10−4. Subluxation of the nonfused segments did not develop in the nonrheumatoid group. Conclusions. In patients with rheumatoid arthritis, segments that show abnormal buckling before surgery are likely to develop subluxation after occipitocervical fusion. Preoperative values of buckling over 10 × 10−4 constitute a risk factor for subaxial subluxation after occipitocervical fusion.

Preoperative Predictors of Ambulation Ability at Different Time Points after Total Hip Arthroplasty in Patients with Osteoarthritis

The aims of this study were to identify the preoperative factors influencing ambulation ability at different postoperative time points after total hip arthroplasty (THA) and to examine the cutoff values of predictive preoperative factors by receiver operating characteristic (ROC) curves. Forty-eight women with unilateral THA were measured for hip extensor, hip abductor, and knee extensor muscle strength in both legs; hip pain (visual analog scale, VAS); and the Timed Up and Go (TUG) test pre- and postoperatively. Multiple regression analysis indicated that preoperative knee extensor strength (β = −0.379, R 2 = 0.409) at 3 weeks, hip abductor strength (β = −0.572, R 2 = 0.570) at 4 months, and age (β = 0.758, R 2 = 0.561) at 7 months were strongly associated with postoperative ambulation, measured using the TUG test. Optimal preoperative cutoff values for ambulation ability were 0.56 Nm/kg for knee extensor strength, 0.24 Nm/kg for hip abductor strength, and 73 years of age. Our results suggest that preoperative factors predicting ambulation ability vary by postoperative time point. Preoperative knee extensor strength, hip abductor strength, and age were useful predictors of ambulation ability at the early, middle, and late time points, respectively, after THA.

Association between Bone Mineral Density of Femoral Neck and Geriatric Nutritional Risk Index in Rheumatoid Arthritis Patients Treated with Biological Disease-Modifying Anti-Rheumatic Drugs

Treatment of rheumatoid arthritis (RA) with biological disease-modifying anti-rheumatic drugs (bDMARDs) induces rapid remission. However, osteoporosis and its management remains a problem. The Geriatric Nutritional Risk Index (GNRI) evaluates the risk of malnutrition-related complications in elderly patients and has been shown to be a significant predictor of many diseases. We evaluated the correlation between GNRI and RA activity. In addition, risk factors for femoral neck bone loss were evaluated in RA patients treated with bDMARDs. We retrospectively examined the medical records of 146 patients with RA, collecting and recording the patients’ demographic and clinical characteristics. Bone mineral density (BMD) was measured by dual-energy X-ray absorptiometry. Inverse correlations were observed between GNRI and disease duration, disease activity score-28 joint count serum C-reactive protein (CRP), simple disease activity index, modified health assessment questionnaire score and CRP. GNRI showed correlation with femoral neck BMD and femoral neck BMD ≤ 70% of young adult men (YAM). Multiple regression analysis showed that female sex, increased age and lower GNRI were risk factors for lower BMD of the femoral neck. Multivariate binomial logistic regression analysis showed that female sex (odd ratio: 3.67) and lower GNRI (odd ratio: 0.87) were risk factors for BMD ≤ 70% of YAM. Because the GNRI is a simple method, it might be a simple predictor for RA activity and BMD status in RA patients. Complementary nutritional therapies might improve RA activity and osteoporosis in RA patients who have undergone treatment with bDMARDs.

Suppurative Arithritis of Facet Joint of Rheumatoid Arthritis Patient Using Human Monoclonal Antibody Rheumatoid Arthritis

腰痛を主訴として発症したまれなL2/3化膿性椎間関節炎に対し，外科的治療により良好な成績を得たので報告する．（症例）51歳女性．RA罹患歴5年．RA治療として生物学的製剤使用中．平成20年12月4日より左腰殿部痛出現．高熱出現し近医受診．炎症所見認めた為，抗菌薬投与開始．翌1月3日当科紹介入院．左優位の大腿部以下の筋力低下，左大腿内側より足先まで知覚鈍麻認めた．MRIで左L2/3椎間関節付近に造影効果を有するT1低信号，T2高信号の膿腫を認めた．診断確定の為，L2/3椎間関節より穿刺，培養結果でMSSA検出．抗菌薬投与としたが，症状改善認められず．そのため内視鏡下膿腫摘出術実施．術後症状消失，MRIで膿腫の消失が確認．外科的治療により症状改善を得た．