Masato Sonobe

Embryonic Stem Cells form Articular Cartilage, Not Teratomas, in Osteochondral Defects of Rat Joints

Embryonic stem (ES) cells are considered to be a potential tool for repairing articular cartilage defects, but so far it has been impossible to cause these cells to differentiate into chondrocytes exclusively, either in vivo or in vitro. To explore a potential new cell source of cell transplantation for articular cartilage defects, we transplanted ES cells into articular cartilage defects in immunosuppressed rats. ES cells (AB2.2 or CCE cells) were transplanted into articular cartilage defects in the patellar groove of immunosuppressed rats treated with cyclosporine. The cells were histologically observed until 8 weeks after transplantation. To determine whether the repair tissue in the defect in the AB2.2-transplanted group was derived from the transplanted cells, the neomycin-resistant gene, which had been transfected into AB2.2 cells but does not exist in rat cells, was used for detection. The cells produced cartilage, resulting in repair of the defects from 4 weeks until 8 weeks after the transplantation without forming any teratomas. The neomycin-resistant gene was detected in every sample, demonstrating that the repair tissue in the AB2.2-transplanted group was derived from the transplanted AB2.2 cells. The environment of osteochondral defects is chondrogenic for ES cells. ES cells may thus be a potential tool for repairing articular cartilage defects.

Identification of clinical parameters associated with serum oxidative stress in patients with rheumatoid arthritis

Abstract Objectives. Reactive oxygen species (ROS) are considered to be involved in the pathobiology of rheumatoid arthritis (RA); however, their association with disease activity has not been elucidated. In this study, we measured reactive oxygen metabolites (ROM) in patients with RA using a new Free Radical Analytical System and determined clinical parameters associated with ROM. Methods. One hundred and fifty-two patients with RA and 80 patients with diabetes mellitus (DM) were included in this observational study. To measure ROM, the d-ROM test was performed on blood samples drawn from all subjects. The correlation between ROM and biomarkers, disease activity, doses of methotrexate (MTX), and prednisolone (PSL) were investigated. Results. There were significant, positive correlations between ROM and CRP, matrix metalloproteinase 3 (MMP3), Disease Activity Score 28–erythrocyte sedimentation rate (DAS28-ESR), Clinical Disease Activity Index (CDAI), and the Simplified Disease Activity Index (SDAI). Multiple regression analysis revealed that CRP and DAS28-ESR were correlated with ROM. Conclusions. The serum level of ROM was associated with CRP and DAS28-ESR, suggesting that ROM, in conjunction with CRP and MMP3, may be able to be used as a new biological disease marker to evaluate the disease activity of RA.

Radiographic progression of large joint damage in patients with rheumatoid arthritis treated with biological disease-modifying anti-rheumatic drugs

Abstract Objectives: Radiographic progression of damage to the small joints in patients with rheumatoid arthritis (RA) is well known; however, it has not been studied fully in the large joints. In this study, we looked at the prevalence of radiographic progression of large joint damage in patients with RA treated with biological disease-modifying anti-rheumatic drugs (bDMARDs). Methods: A total of 273 large joints in the upper and lower extremities of 67 patients with RA treated with bDMARDs were investigated. Radiographs for tender and/or swollen large joints were taken at least twice during the study period (mean 18.6 months), and the progression of damage was evaluated. Results: Progressive damage was found in 20.9% of patients and 6.2% of joints. A multivariate analysis revealed that the Larsen grade (LG) alone was a risk factor for progressive damage. The LG cutoff value was determined to be 2.5 (sensitivity: 0.529, specificity: 0.805). Conclusions: The only factor to predict progressive damage was the LG of the joints with symptoms, and the damage must be stopped within LG II. Regular radiographic examinations for large joints should be performed in addition to routine examinations for small joints, such as the hand and foot.

Delayed Neurologic Deficit due to Foraminal Stenosis following Osteoporotic Late Collapse of a Lumbar Spine Vertebral Body

We report an 85-year-old woman with an L3 vertebral body fracture who presented with back pain, bilateral leg pain, and weakness after four months of conservative treatment. Because of unstable pseudoarthrosis, the L3 vertebral body collapsed in the standing position and the L3 nerve root was compressed. The indicated surgery decompressed the L3-L4 foramen and fused the unstable segment. The back pain and neurologic symptoms improved significantly following surgery. We propose that delayed neurologic deficit following an osteoporotic fracture of the lumbar body may be caused not only by retropulsion of vertebral body fragments with significant canal compromise, but also by foraminal stenosis with the late collapse of the vertebral fracture. This new pathomechanism for delayed neurologic deficit has not been previously described. If a collapse takes place in the caudal part of the vertebral body below the base of the pedicle, spine surgeons should be aware of the possibility of foraminal stenosis.

Phosphorylated neurofilament subunit NF-H becomes elevated in the cerebrospinal fluid of patients with acutely worsening symptoms of compression myelopathy

It is known that the severity of compression myelopathy sometimes worsens rapidly and results in poor functional recovery because of limited axonal regeneration. Levels of phosphorylated neurofilament subunit NF-H (pNF-H), which indicate axonal degeneration, are elevated in other neurological disorders. To our knowledge, there has been no examination of pNF-H levels in compression myelopathy. Therefore, we conducted a pilot cross-sectional study to evaluate pNF-H levels in the cerebrospinal fluid (CSF) of patients with worsening symptoms of cervical compression myelopathy. From January 2011 to March 2013, 51 samples of CSF were collected from patients at the time of myelography before spinal surgery. The indications for surgery were acutely worsening compression myelopathy (AM) in eight, chronic compression myelopathy (CM) in six, and lumbar canal stenosis (LCS) in 37 patients. The pNF-H levels were measured using a standard enzyme-linked immunosorbent assay. The mean ± standard deviation pNF-H value was 2127.1 ± 556.8 pg/ml in AM patients, 175.8 ± 67.38 pg/ml in CM patients and 518.7 ± 665.7 pg/ml in LCS patients. A significant increase in pNF-H levels was detected in the CSF of patients with AM compared with those with either CM or LCS. The clinical outcome of surgical treatment for patients with cervical myelopathy was satisfactory in both AM and CM patients. Despite the limitations of small sample size and lack of healthy CSF control data due to ethical considerations, our results suggest that pNF-H in CSF can act as a biomarker that reflects the severity of AM.

Intra-Articular Giant Heterotopic Ossification following Total Knee Arthroplasty for Charcot Arthropathy

Although the Charcot arthropathy may be associated with serious complications, total knee arthroplasty (TKA) is the preferred choice of treatment by patients. This case report presents an 80-year-old man with intra-articular giant heterotopic ossification following loosening of femoral and tibial implants and femoral condylar fracture. He had undergone TKA because of Charcot neuropathy seven years ago and had been doing well since. Immediately after a left knee sprain, he became unable to walk. Because he had developed a skin ulcer on his left calf where methicillin-resistant Staphylococcus aureus was detected, we postponed revision surgery until the ulcer was completely healed. While waiting, intra-articular bony fragments grew larger and formed giant heterotopic ossified masses. Eventually, the patient underwent revision surgery, and two major ossified masses were carefully and successfully extirpated. It should be noted that intra-articular heterotopic giant ossification is a significant complication after TKA for neuropathic arthropathy.

Health assessment questionnaire-disability index (HAQ-DI) score at the start of biological disease-modifying antirheumatic drug (bDMARD) therapy is associated with radiographic progression of large joint damage in patients with rheumatoid arthritis

Abstract Objectives: Radiographic progression of damage (RPD) to large joints in patients with rheumatoid arthritis (RA) has not been fully studied. We previously demonstrated that Larsen grade of the large joints was associated with RPD of large joints in patients treated with biological disease-modifying anti-rheumatic drugs (bDMARDs); however, no factors associated with background characteristics of patients were identified. Methods: A total of 400 large joints in the upper and lower extremities, including the shoulder, elbow, knee, and ankle, of 88 patients with RA treated with bDMARDs for 1–3 years were investigated. Radiographs of tender and/or swollen large joints were acquired at least twice during the study period (mean, 16.4 months), and the RPD was evaluated. Results: A multivariate analysis revealed that health assessment questionnaire-disability index (HAQ-DI) score at the start of bDMARD treatment was associated with RPD. The cutoff value that discriminated progression from non-progression, determined by a receiver operating characteristic (ROC) curve, was 1.4375 (sensitivity: 0.778, specificity: 0.894). Conclusions: HAQ-DI score at the start of bDMARD treatment was associated with RPD to large joints during a therapeutic period of 1–3 years. Progressive damage is expected to increase when functional disability exceeds an HAQ-DI score of 1.5.

Relative expression and correlation of tumor necrosis factor-α, interferon-γ, and interleukin-17 in the rheumatoid synovium

Although tumor necrosis factor-α (TNF-α), interferon-γ (IFN-γ), and interleukin-17 (IL-17) play important roles in RA, their relative expression and possible correlation in synovial tissues are not well understood. In this study, mRNA expression levels of IFN-γ, IL-17, and TNF-α were investigated in individual patients with RA and the correlations between pairs of these three pro-inflammatory cytokines were analyzed. Synovial tissues were obtained during arthroplasties from 24 joints of 24 RA patients. After harvesting synovial tissues, total RNA was isolated then quantitative real-time polymerase chain reaction (qRT-PCR) for IFN-γ, IL-17, and TNF-α was performed. Correlation of expression levels between them was also analyzed. Expression levels of TNF-α, IFN-γ, and IL-17 in patients receiving TNF inhibitors (TNFi) and those treated with conventional synthetic disease-modifying antirheumatic drugs (csDMARDs) alone were also compared between groups. Based on relative expression levels of the three pro-inflammatory cytokines, patients were classified into three major types; an IFN-γ plus TNF-α-dominant type, an IL-17-dominant type, and the other type. TNF-α expression levels were correlated with IFN-γ. In addition, there was a negative correlation between TNF-α and IL-17, and IFN-γ and IL-17. Median relative expression levels of TNF-α have no significant difference between the TNFi and the csDMARDs groups. In the rheumatoid synovial tissues, expression levels of TNF-α were modulated in parallel with IFN-γ, and TNF-α and IL-17, or IFN-γ and IL-17 did not co-express at high levels. This characteristic expression pattern of the three pro-inflammatory cytokines may be clinically useful information in the current cytokine-targeted treatment with biological DMARDs for RA.

Predictive factors for radiographic progression of large joint damage in patients with rheumatoid arthritis treated with biological disease-modifying antirheumatic drugs (bDMARDs): results of 3 to 4 years of follow-up

Abstract Objectives: Little information is available regarding long-term follow-up of radiographic progression of damage (RPD) to large joints during treatment of rheumatoid arthritis (RA) with biological disease-modifying antirheumatic drugs (bDMARDs). We evaluated 3- to 4-year follow-up results and the associations between RPD and patient background and Larsen grade (LG) of joints. Methods: Seventy-one RA patients receiving bDMARDs for 3 to 4 years or who achieved bDMARD-free status were included. The mean age and disease duration at the start of bDMARDs were 62.4 years and 10.8 years, respectively. A total of 314 joints, including shoulders, elbows, hips, knees, and ankles, were evaluated to determine whether RPD was present by comparing radiographs before and after treatment. Results: RPD was observed in 24 patients (33.8%) and 34 joints (10.8%). Joints with an LG of III or higher had significantly higher rates of RPD than those with LGs I and II. Multivariate logistic regression analysis revealed that stage and health assessment questionnaire (HAQ) score at 18-months were independent risk factors for RPD (cut-off value: 2.5, odds ratio: 7.222 for stage; cut-off value: 0.9375, odds ratio: 6.278 for HAQ at 18-months). Conclusion: Stage, HAQ at 18-months, and LG at the start of bDMARDs were predictive of RPD after 3 to 4 years. bDMARDs should be started before both stage and LG exceed III and the therapeutic strategy should be determined so that HAQ does not exceed 1.0 during treatment.

Axonal damage is remarkable in patients with acutely worsening symptoms of compression myelopathy: biomarkers in cerebrospinal fluid samples

PurposeTo determine levels of biomarkers reflecting damage to axon, myelin, astrocytes, and neuron in cerebrospinal fluid (CSF) of patients with cervical compression myelopathy.MethodsWe collected 69 CSF samples from patients before spinal surgery for acutely worsening compression myelopathy (AM, 20), chronic compression myelopathy (CM, 20), and lumbar canal stenosis (LCS 29; control). We measured levels of phosphorylated neurofilament subunit H (pNF-H), tau (reflecting axonal damage), myelin basic protein (MBP) (reflecting demyelination), S100b (reflecting astrocyte damage), and neuron-specific enolase (NSE) (reflecting neuronal damage). Change of neurological function by surgery was determined using a Japanese Orthopaedic Association (JOA) score for cervical myelopathy.ResultsSignificantly higher levels of pNF-H were detected in AM compared with those in either CM or LCS (P < 0.01). Significantly higher levels of tau were detected in AM compared with those in CM (P < 0.05). Levels of MBP were undetectable in almost all the patients. Levels of S100b were equivalent in the three groups. Levels of NSE in AM and CM were significantly lower than those in LCS (P < 0.01). The recovery rate of JOA score was significantly greater for patients with AM than CM. We found a positive correlation between pNF-H and recovery of JOA score (r = 0.381, P = 0.018).ConclusionThe present results suggest that axonal damage is remarkable compared with demyelination, astrocytic, and neuronal damage in AM. Better clinical outcome in AM with high CSF levels of pNF-H indicates that axonal compensatory plasticity in spinal cord is preserved, and pNF-H can be predictive of good surgical outcome for AM.Graphical abstractThese slides can be retrieved under Electronic Supplementary Material.