Serum oxidative stress influences neurological recovery after surgery to treat acutely worsening symptoms of compression myelopathy: a cross-sectional human study.

BACKGROUND: Recent reports indicate that oxidative stress induced by reactive oxygen species is associated with the pathobiology of neurodegenerative disorders that involve neuronal cell apoptosis. Here we conducted a cross-sectional study to evaluate serum levels of oxidative stress in cervical compression myelopathy. METHODS: Thirty-six serum samples were collected preoperatively from patients treated for acutely worsening compression myelopathy (AM) and chronic compression myelopathy (CM). Serum levels of oxidative stress markers were evaluated by measuring derivatives of reactive oxygen metabolites (ROM), which reflect concentrations of hydroperoxides. ROM in healthy individuals range from 250 to 300 (U. CARR), whereas ROM >340-400 and > 400 define moderate and severe levels of oxidative stress, respectively. Difference of ROM by the cause of disorders whether cervical spondylotic myelopathy (CSM) or cervical ossification of longitudinal ligament (OPLL), correlations between ROM and patient age, body mass index (BMI), history of smoking, existence of diabetes were examined. Neurological evaluations according to Japanese Orthopaedic Association (JOA) scores were performed and correlated with ROM. RESULTS: ROM increased to 349.5 ± 54.8, representing a moderate oxidative stress, in CM samples. ROM increased to 409.2 ± 77.9 in AM samples, reflecting severe oxidative stress which were significantly higher than for CM samples (p < 0.05). There was no significant difference by the cause of disorders (CSM or OPLL). ROM were significantly increased in AM serum samples from female patients versus AM male and CM patients (p < 0.05). There were no correlations between ROM and age, BMI, history of smoking, and existence of diabetes. A negative correlation between ROM and recovery rate of JOA score (R2 = 0.454, p = 0.047) was observed in the AM group. CONCLUSIONS: Although moderate oxidative stress was present in patients with CM, levels of oxidative stress increased in severity in patients with AM. These results suggest that postsurgical neurological recovery is influenced by severe oxidative stress in AM.

A new single nucleotide polymorphism affects the predisposition to thoracic ossification of the posterior longitudinal ligament.

BACKGROUND: Thoracic ossification of the posterior longitudinal ligament (T-OPLL) is one of the common factors that cause thoracic spinal stenosis, which results in intractable myelopathy and radiculopathy. Our previous study first reported rs201153092A site mutation in the collagen 6A1 (COL6A1) gene as a potentially pathogenic locus for T-OPLL. We aimed to determine whether the rs201153092A site mutation causes abnormal expression of the COL6A1 in Han Chinese patients with T-OPLL and whether this locus is also associated with cervical-OPLL. METHODS: Peripheral blood was collected from a total of 60 patients with T-OPLL disease (30 patients carrying the rs201153092A site mutation in COL6A1 and 30 wild-type patients) and 400 northern Chinese individuals (200 cervical-OPLL patients and 200 control subjects) using the Sequenom system. The expression of COL6A1 was analyzed by enzyme-linked immunosorbent assay, reverse transcription-quantitative polymerase chain reaction, and Western blotting. RESULTS: rs201153092A mutation resulted in markedly increased COL6A1 gene expression levels in peripheral blood samples. The allele frequency and genotype frequency results showed that this locus is no difference between cervical-OPLL patients and controls. CONCLUSIONS: The rs201153092A site mutation of COL6A1 can significantly increase the expression of COL6A1. The COL6A1 gene rs201153092A site polymorphism is a potential pathogenic mutation in T-OPLL disease, which may be only associated with the occurrence of T-OPLL.

IL17RC affects the predisposition to thoracic ossification of the posterior longitudinal ligament.

BACKGROUND: Thoracic ossification of the posterior longitudinal ligament (T-OPLL) can cause thoracic spinal stenosis, which results in intractable myelopathy and radiculopathy. The etiology of T-OPLL is unknown and the condition is difficult to treat surgically. Whole-genome sequencing identified a genetic variant at rs199772854 of the interleukin 17 receptor C (IL17RC) gene as a potentially pathogenic locus associated with T-OPLL. We aimed to determine whether the rs199772854A site mutation causes abnormal expression of the IL17RC in Han Chinese patients with T-OPLL and predict the possible pathogenic mechanisms of T-OPLL. Analyses were performed to determine whether IL17RC is involved in the pathogenicity of T-OPLL. METHODS: Peripheral blood and OPLL tissue were collected from a total of 72 patients with T-OPLL disease (36 patients carrying the rs199772854A site mutation in IL17RC and 36 wild-type patients). The expression of IL17RC was analyzed by enzyme-linked immunosorbent assay, reverse transcription-quantitative polymerase chain reaction, immunohistochemistry, and Western blotting. RESULTS: rs199772854A mutation resulted in markedly increased IL17RC gene expression levels in peripheral blood samples and the OPLL tissue obtained following clinical surgery (P < 0.05). CONCLUSIONS: The results suggest that the rs199772854A site mutation of IL17RC can significantly increase the expression of IL17RC. The IL17RC gene rs199772854A site polymorphism is a potential pathogenic mutation in T-OPLL disease, which may be associated with the occurrence of T-OPLL.

MicroRNA-10a, -210, and -563 as circulating biomarkers for ossification of the posterior longitudinal ligament.

BACKGROUND CONTEXT: The presence of ossification of posterior longitudinal ligament (OPLL) can lead to symptomatic spinal cord compression and myelopathy. The surgical approach in patients with myelopathy is influenced by the presence of OPLL. Diagnose of OPLL currently requires computed tomography which incurs a large dose of radiation. Circulating disease-specific microRNAs (miRNAs) may serve as promising diagnostic markers with no radiation and easy accessibility for OPLL patients. PURPOSE: The purpose of this study is to evaluate the accuracy and significance of OPLL-specific microRNAs in discriminating OPLL from normal and intervertebral disc degenerated (IDD) patients by detecting the microRNAs' plasma level. STUDY DESIGN/PATIENT SAMPLES: The level of microRNAs in OPLL patients' plasma or serum were detected and compared to that of normal and IDD patients to evaluate the accuracy and significance of diagnosing OPLL. METHODS: Taking advantage of the high through-put microRNA sequencing data, we selectively tested the ten most differentially regulated microRNAs in patients with: (1) radiologically diagnosed OPLL (n = 68), (2) radiologically diagnosed disc herniated patients with no evidence of OPLL (n = 45), (3) non-OPLL and nonmyelopathy patients (n = 53).The feasibility of the biomarkers in identifying OPLL was assessed through analysis of sensitivity, specificity, accuracy, negative predictive value, positive predictive value, and area under the curve (AUC) values. RESULTS: Of the ten miRNAs validated, miR-10a-3p, miR-10a-5p, miR-563, miR-210-3p, and miR-218-3p showed significance between OPLL and non-OPLL blood samples. While miR-10a-5p, miR-563, and miR-210-3p showed high accuracy and significance in identifying OPLL from other groups individually, and an index that combines these miRNAs achieved the highest accuracy and AUC among these individual miRNAs. CONCLUSIONS: Analysis of miR-10a-5p, miR-563, and miR-210-3p may be of important value in diagnosing OPLL. These markers maybe useful in a clinical setting in the early detection of OPLL patients by blood testing.

Metabolite profiling of plasma in patients with ossification of the posterior longitudinal ligament.

BACKGROUND: Metabolomics is one of the "omics" technologies, and is a comprehensive analysis of small molecule metabolites which include amino acid, nucleotides, carbohydrates and fatty acid. The purpose of the present study was to compare the differences of metabolite profiling between patients with ossification of the posterior longitudinal ligament (OPLL) and control subjects. METHODS: We analyzed plasma metabolites in patients with cervical OPLL (n = 10) and in control subjects (n = 10). Ionic metabolites were analyzed using capillary electrophoresis time-of-flight mass spectrometry (CE-TOFMS) and lipophilic metabolites were analyzed using liquid chromatograph time-of-flight mass spectrometry (LC-TOFMS). RESULTS: A total of 259 metabolites (144 metabolites in CE-TOFMS and 115 metabolites in LC-TOFMS) were detected. Among the 259 metabolites, six metabolites, namely acylcarnitine (AC) (14:0), palmitoylcarnitine, AC (18:2), fatty acid (FA) (24:2), thyroxine, thiaproline were significantly larger in OPLL group, even in analyzes excluding patients with diabetes mellitus and hyperlipidemia. CONCLUSIONS: We examined the metabolite profiling in patients with OPLL for the first time and detected six metabolites showing suggestive association with disease. These results of the present study could lead to new insights into clarifying the molecular pathomechanisms of OPLL.

Roles and mechanisms of leptin in osteogenic stimulation in cervical ossification of the posterior longitudinal ligament.

BACKGROUND: Hyperleptinemia is a common feature of obese people, and leptin, an adipocyte-derived cytokine, is believed to be an important factor in the pathogenesis of cervical ossification of the posterior longitudinal ligament(C-OPLL). So this research was to identify the relation between the serum leptin and bone metabolic markers and how the leptin induced osteogenic effect in C-OPLL. METHODS: Sixty-four samples were selected to determine the concentration of leptin, insulin, and alkaline phosphatase. And the association of leptin with these factors was also examined. We also evaluate the effect of leptin on the development of C-OPLL and further explored the possible underlying mechanism in vitro. RESULTS: We found that serum leptin concentrations were higher in females than in males. Serum leptin and ALP concentrations were increased significantly in C-OPLL females compared to non-OPLL females. In OPLL subjects, the serum leptin concentration corrected for body mass index correlated negatively with the ALP concentrations. In C-OPLL cells, leptin treatment led to a significant increase in mRNA expressions of ALP and OCN and formation of mineralized nodule. Our experiments reported here that osteogenic effect of leptin in C-OPLL cells could be mediated via ERK1/2, p38 MAPK, and/or JNK signaling pathways. CONCLUSIONS: From this research, we got that leptin treatment led to a significant increase in mRNA expressions of ALP and OCN and formation of mineralized nodule. And the osteogenic effect of leptin in C-OPLL cells could be mediated via ERK1/2, p38 MAPK, and/or JNK signaling pathways.

Multiplex analysis of serum hormone and cytokine in patients with cervical cOPLL: towards understanding the potential pathogenic mechanisms.

Cervical ossification of the posterior longitudinal ligament (cOPLL) is one of the major causes of myelopathy. However, the mechanism underlying remains elusive. In the present study, using MILLIPLEX magnetic bead panel, we investigated four serum hormones and six serum cytokines in cOPLL patients and healthy subjects. The results showed that tumor necrosis factore-α (TNF-α) were significantly increased, and DDK-1 was significantly decreased in the serum from male and female cOPLL patients compared with those from healthy controls, respectively. Osteopontin (OPN) and fibroblast growth factor-23 (FGF-23) were significantly increased in male cOPLL patients compared with that in healthy male controls. Further analysis showed that FGF-23 and OPN significantly increased, dickkopf-1 (DKK-1) decreased in the extensive cOPLL group. In addition, a significant positive correlation between the OPN and FGF-23 was observed in male cOPLL patients. The results are useful for understanding the mechanism underlying cOPLL.

Serum biomarkers in patients with ossification of the posterior longitudinal ligament (OPLL): Inflammation in OPLL.

BACKGROUD: Ossification of the posterior longitudinal ligament (OPLL) is characterized by replacement of ligamentous tissue by ectopic new bone formation. OPLL causes narrowing of the spinal canal, resulting in neurological impairment. However, the pathogenesis of OPLL has not been fully elucidated. We investigated whether inflammation occurs in OPLL or not using high-sensitivity CRP (hs-CRP) in a case-control study. METHODS AND FINDINGS: This study included 103 patients with OPLL in the patient group and 95 age- and sex-matched volunteers with degenerative spinal disease in the control group. Of the 103 OPLL patients, 88 patients who were available for more than 2 years follow-up were checked for OPLL progression. A blood sample was obtained and Hs-CRP, and other routine data, including total protein (TP), albumin (ALB), lactate dehydrogenase (LDH), alkaline phosphatase (ALP), glucose (Glu), calcium (Ca), inorganic phosphate (Pi), white blood cell count (WBC), hemoglobin (Hb) and platelet (PLT), were analyzed. The data were compared between the patients with OPLL and the controls. The severity of the ossified lesions in the whole spine were evaluated by the ossification index (OS index) in patients with OPLL. The data were also compared between the patients with OPLL progression (the progression group) and the patients without OPLL progression (the non-progression group). In the results, the mean hs-CRP in the OPLL group was higher than that in the controls. The Pi in the OPLL group was lower than that in the control group. A negative correlation was found between the Pi and the OS index. The mean hs-CRP in the progression group was higher than that in the non-progression group. There was a positive correlation between the average length of the OPLL progression per year and the hs-CRP. CONCLUSIONS: The results may suggest the occurrence of local inflammation in OPLL and the inflammation might cause OPLL progression. These facts are important for understanding the pathology of OPLL.

Correlation of blood bone turnover biomarkers and Wnt signaling antagonists with AS, DISH, OPLL, and OYL.

BACKGROUND: Wnt signaling plays an important role in development and maintenance of many organs and tissues. The most-studied secreted Wnt inhibitors are sclerostin (SOST), Dickkopf-related protein 1 (DKK-1), and secreted frizzled related protein 1 (SFRP-1) which play important roles in bone turnover. The present study investigated the relationship between serum Wnt inhibitors and diseases with excessive ossification structures, such as ossification of posterior longitudinal ligament (OPLL), ankylosing spondylitis (AS), diffuse idiopathic skeletal hyperostosis (DISH), and ossification of yellow ligament (OYL). METHODS: Twenty-five patients with AS, DISH, OPLL, or OYL were recruited in this study. Fasting peripheral blood samples were collected from all patients and nine controls. Various biomarkers of bone turnover including osteocalcin (OSC), osteoprotegerin (OPG), SFRP-1, DKK-1, and SOST were investigated. RESULTS: Our data showed that serum levels of OSC were higher, but Dkk-1 levels were lower in AS, DISH, OPLL, and OYL patients than those in the controls. Serum levels of SFRP-1 were significantly higher in DISH patients than those in the controls. Serum levels of SOST were significantly higher in DISH and OPLL patients than both levels in the controls. Serum levels of OPG were lower in AS patients than those in the controls. Serum levels of OSC were higher in the OPLL patients than those in the AS patients. Serum levels of DKK-1, SFRP-1, SOST, and OPG were not significantly different between the different disease groups. CONCLUSIONS: In this exploratory study, both OSC and DKK-1 levels are correlated with the clinical conditions associated with excessive ossification, indicating that blood OSC and DKK-1 levels may serve as diagnostic biomarkers for AS, DISH, OPLL, and OYL. These findings may also help discover potential drug therapies for management of these diseases in the future.

Circulating sclerostin and dickkopf-1 levels in ossification of the posterior longitudinal ligament of the spine.

Sclerostin and dickkopf-1(DKK1) are Wnt/ß-catenin signal antagonists that play an important role in bone formation. Ossification of the posterior longitudinal ligament (OPLL) of the spine is characterized by pathological ectopic ossification of the posterior longitudinal ligament and ankylosing spinal hyperostosis. The aims of this study were to evaluate serum sclerostin and DKK1 levels in persons with OPLL and to identify its relationship with bone metabolism and bone mass in persons with OPLL. This was a case-control study, and 78 patients with OPLL were compared with 39 age- and sex-matched volunteers without OPLL. We analyzed the relationship with calciotropic hormones, bone turnover markers, OPLL localization, number of ossified vertebrae, and bone mineral density of total hip (TH-BMD). Serum sclerostin levels in men with OPLL were significantly higher than in men in the control group (control group: mean = 45.3 pmol/L; OPLL group: mean = 75.7 pmol/L; P = 0.002). Age and sclerostin levels were positively correlated in men with OPLL (r = 0.43; P = 0.002). Serum sclerostin levels in men with OPLL had a positive correlation with TH-BMD Z-score (r = 0.511; P = 0.011, n = 30). There was a strong negative correlation between serum sclerostin levels and serum DKK1 levels in men with OPLL (r = -0.506; P < 0.001). Bone and mineral metabolism in OPLL differs between men and women. In men with OPLL, systemic secretion of sclerostin increases with advancing age and with higher bone mass. These two Wnt/ß-catenin signal antagonists have the opposite effect in persons with OPLL, and higher serum sclerostin levels are counterbalanced by underproduction of DKK1.

Prevalence and progression of radiographic ossification of the posterior longitudinal ligament and associated factors in the Japanese population: a 3-year follow-up of the ROAD study.

SUMMARY: The prevalence of radiographic cervical ossification of the posterior longitudinal ligament (OPLL) in 1,562 Japanese from a population-based cohort was 1.9 %. The presence of OPLL showed a significant association with the femoral neck bone mineral density (BMD), presence of diffuse idiopathic skeletal hyperostosis (DISH) and plasma pentosidine levels. Only one new case of radiographic OPLL was detected, but OPLL progressed in all affected subjects. INTRODUCTION: The purpose of this study was to clarify the prevalence and progression of radiographic OPLL and the associated factors, using the population-based cohort Research on Osteoarthritis/osteoporosis Against Disability (ROAD). METHODS: In the ROAD study, 1,690 participants underwent X-ray examination of the entire spine and both knees. Radiographic OPLL, lumbar spondylosis, knee osteoarthritis and DISH were diagnosed by a single, well-experienced orthopaedic surgeon. An interviewer-administered questionnaire and tests for anthropometric measurements were administered, and the BMDs of the lumbar spine and proximal femur were determined. A new OPLL case was considered if heterotopic ossification in the posterior longitudinal ligament was absent at baseline but present during follow-up. Progression was defined as an increase in the maximum length or width of the ossification at follow-up over that at baseline. RESULTS: Radiographic OPLL was detected in 30 (17 men, 13 women) of 1,562 individuals who underwent X-ray examination of the cervical spine (prevalence = 1.9 %). Its prevalence was significantly higher in men than in women (p = 0.007), but no association with age was observed. In a logistic regression analysis, OPLL showed a significant association with the femoral neck BMD, presence of DISH and plasma pentosidine levels. Only one new case of radiographic OPLL was detected, but OPLL progressed in all affected subjects. CONCLUSION: This population-based study clarified the prevalence of radiographic OPLL in the Japanese population as well as its progression. OPLL showed significant association with plasma pentosidine levels, BMD and DISH.

A case of psoriasis vulgaris with diffuse idiopathic skeletal hyperostosis involved with ossifications of posterior and anterior longitudinal ligament.

Diffuse idiopathic skeletal hyperostosis (DISH) is difficult to distinguish from various forms of inflammatory arthritis, including psoriatic arthritis (PsA), rheumatoid arthritis, and ankylosing spondylitis. A 67-year-old Japanese male had been treated for psoriasis vulgaris for 13 years. Numbness of his right arm and lower limbs and spinal stiffening had developed 7 years prior to his initial evaluation at our facility. He noticed pain mainly while exercising. There were symmetrical marginal syndesmophytes in the spine, from the thoracic vertebrae to the upper lumbar vertebrae, on radiological examinations. We therefore suspected DISH. Furthermore, ossifications of the posterior and anterior longitudinal ligaments were noted in the cervical spine. Laboratory examinations revealed a normal peripheral white blood cell count, serum C-reactive protein, and erythrocyte sedimentation rate, and he was negative for rheumatoid factor. We detected human leukocyte antigen B39 but not B27. All distal interphalangeal joints were swollen but without pain. X-ray imaging showed narrowing of the joint space, and the consolidation of the joint was recognized, but there was no new juxta-articular bone formation. Based on clinical and radiological findings, we concluded that he had DISH and not PsA. DISH was indicated by marked radiological features of the axial skeleton, particularly the thoracic spine, but may also have involved the peripheral joints. DISH is one of the entheseal disorders, and 10% of Japanese middle-aged and elderly men have DISH. Therefore, the differentiation of DISH from PsA is necessary in psoriasis patients with spinal involvement.

Association between interleukin 15 receptor, alpha (IL15RA) polymorphism and Korean patients with ossification of the posterior longitudinal ligament.

OBJECTIVES: Recently, a number of evidences have been reported concerning the genetic factor involved in the development of ossification of the posterior longitudinal ligament (OPLL). The purpose of this study was to investigate single nucleotide polymorphisms (SNPs) of the interleukin 15 receptor, alpha (IL15RA) gene as a risk factor in Korean patients with OPLL. DESIGN: To investigate the genetic association, two coding SNPs (rs2296139, Thr73Thr; rs2228059, Asn182Thr) in IL15RA were genotyped in 166 OPLL patients and 230 control subjects. SNPStats, SNPAnalyzer, and Helixtree programs were used for association analysis. RESULTS: In the present study, we found the association between a missense SNP (rs2228059) and the risk of OPLL in codominant (p = 0.0028, OR = 1.58, 95% CI = 1.17-2.14), dominant (p = 0.0071, OR = 1.82, 95% CI = 1.17-2.82), and recessive models (p = 0.036, OR = 1.79, 95% CI = 1.04-3.09). The frequency of rs2228059 allele was significantly associated with the susceptibility of OPLL (p = 0.0043, OR = 1.52, 95% CI = 1.14-2.02). After Bonferroni correction, the missense SNP (rs2228059, Asn182Thr) still had significant correlations (p = 0.0056 in codominant model; p = 0.0142 in dominant model; p = 0.0086 in allele analysis). Haplotype variation in IL15RA was associated with OPLL (global haplotype test, p = 0.025). CONCLUSIONS: These results suggest that IL15RA polymorphism may be associated with the susceptibility of OPLL in Korean population.

Association between serum leptin and bone metabolic markers, and the development of heterotopic ossification of the spinal ligament in female patients with ossification of the posterior longitudinal ligament.

Obesity is a risk factor for ossification of the posterior longitudinal ligament (OPLL) of the spine, which is characterized by heterotopic bone formation in the posterior longitudinal spinal ligament. Hyperleptinemia is a common feature of obese people and leptin is believed to be an important factor in the pathogenesis of OPLL. However, the association between leptin and bone metabolism and the development of OPLL is not understood fully. The objective of the present study was to determine the association between serum leptin concentration and bone metabolic markers and the extent of heterotopic ossification of the spinal ligament in patients with OPLL. The serum concentrations of leptin, insulin, fructosamine, bone-specific alkaline phosphatase, and carboxyterminal propeptide of type I procollagen, urine deoxypyridinoline levels, and the number of vertebrae with OPLL involvement were measured in 125 (68 males and 57 females) patients with OPLL. The correlation between leptin and these other factors was then examined. Serum leptin and insulin concentrations were increased significantly in OPLL females compared to non-OPLL female controls. In the females with OPLL, serum leptin concentrations corrected for body mass index correlated positively with the number of vertebrae with OPLL involvement. In females, serum leptin levels were significantly higher in patients in whom OPLL extended to the thoracic and/or lumbar spine than in patients in whom OPLL was limited to the cervical spine. Our results suggest that hyperleptinemia, in combination with hyperinsulinemia, may contribute to the development of heterotopic ossification of the spinal ligament in female patients with OPLL.

Comparative analysis of serum proteomes to discover biomarkers for ossification of the posterior longitudinal ligament.

STUDY DESIGN: Serum proteomes from normal subjects and the patients with ossification of the posterior longitudinal ligament (OPLL) were analyzed by using proteomics. OBJECTIVES: To identify novel serologic biomarkers for diagnosing OPLL. SUMMARY OF BACKGROUND DATA: OPLL can compress the spinal cord, and special planning is required for surgeries that are done from the front of the cervical spine. However, the definitive serologic biomarkers for OPLL are still unclear. METHODS: The 2-dimensional electrophoresis patterns of sera from OPLL patients and normal subjects were compared. The differentially expressed spots were identified by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry and electrospray ionization quadruple time-of-flight mass spectrometry. RESULTS: Nine spots that were differentially expressed in the sera of OPLL patients were found and were identified. PRO2675, human serum albumin in a complex with myristic acid and tri-iodobenzoic acid, an unknown protein, chain B of the crystal structure of deoxy-human hemoglobin beta6, pro-apolipoprotein, ALB protein, retinol binding protein and chain A of human serum albumin mutant R218h complexed with thyroxine (3,3',5,5', tetraiodo-L-thyronine), were up-regulated in the sera of OPLL patients, whereas alpha1-microglobulin/bikunin precursor was down-regulated. CONCLUSIONS: These proteins could be used as diagnostic biomarkers of OPLL.

High serum levels of menatetrenone in male patients with ossification of the posterior longitudinal ligament.

STUDY DESIGN: This work was performed to investigate the role of vitamin K (VK) in the pathogenesis of ossification of posterior longitudinal ligament (OPLL), by analyzing the biochemical markers of the blood samples of OPLL patients and responses of ligament cells derived from OPLL lesion to VK2. OBJECTIVES: The pathogenesis of OPLL, classified as a form of diffuse idiopathic skeletal hyperostosis, is still unclear. In this study, we investigated the role of menaquinone (VK2) in patients with OPLL (OPLL patients) and the effects of VK2 on ligament cells isolated from OPLL lesion. METHODS: Serum levels of intact osteocalcin, glu-osteocalcin, MK-4, -7 (VK2 variants) and other minerals in spot blood samples were measured in 24 OPLL patients and in 24 age-matched control patients (non-OPLL patients). The cultured cells isolated from an OPLL patient were treated with MK-4. Alkaline phosphatase (Al-p) activity and osteocalcin release were measured after 2 weeks of culture. RESULTS: In the clinical study, the serum MK-4 in male OPLL patients was significantly higher than that in male non-OPLL patients. However, among female patients, the difference was not significant. Although the serum osteocalcin in females was significantly higher than that in males, there was no significant difference between the OPLL and non-OPLL groups. In in vitro study, MK-4 did not increase Al-p activity in the ligament cells isolated from nonossified region of OPLL patient. Osteoblastic activity of the cultured cells was not stimulated by MK-4. CONCLUSION: From these results and previous reports, we propose the possibility of the impediment in VK2 metabolism in OPLL patients. The results also implicate the gender tendency in OPLL, because the difference of serum level of MK-4 in OPLL patients was significant only in male.

Significance of bone formation markers in patients with ossification of the posterior longitudinal ligament of the spine.

STUDY DESIGN: Serum concentrations of bone formation markers were correlated with the type, location, and progression of ossification of the posterior longitudinal ligament. OBJECTIVE: To determine the relation between bone formation markers and ossification of the posterior longitudinal ligament. SUMMARY OF BACKGROUND DATA: Few reports have correlated bone formation markers with ossification of the posterior longitudinal ligament. METHODS: In this study, 43 patients with cervical ossification of the posterior longitudinal ligament and myelopathy underwent laminoplasty. The patients were observed for more than 10 years, after which plain radiographs and tomograms of the cervical region were taken. The radiographs were selectively performed to address thoracic and lumbar ossification of the posterior longitudinal ligament. Serum concentrations of bone formation markers (intact osteocalcin, osteocalcin, carboxyterminal propeptide of human type 1 procollagen, and bone-specific alkaline phosphatase) were measured and correlated with these radiographic studies. RESULTS: A positive correlation was observed between intact osteocalcin, osteocalcin, and carboxyterminal propeptide of human type 1 procollagen in patients with combinations of cervical, thoracic, or lumbar ossification of the posterior longitudinal ligament. CONCLUSIONS: Serum concentrations of intact osteocalcin, osteocalcin, and carboxyterminal propeptide of human type 1 procollagen may reflect the activity of general ectopic bone formation in patients with ossification of the posterior longitudinal ligament.

Response of peripheral lymphocytes from patients with ossification of posterior longitudinal ligament.

The in vitro response of peripheral blood mononuclear cells or enriched CD4+ T cells from patients with ossification of the posterior longitudinal ligament to anti-CD3 monoclonal antibody has been studied. The response in both was significantly lower in patients with the continuous-type ossification than in patients with the segmental-type ossification and in healthy volunteers, and was inversely correlated with the number of vertebral bodies with ossified ligament. In patients with the segmental-type ossification, the response of peripheral blood mononuclear cells was significantly lower than that in healthy volunteers, but that of the enriched T cells was not. B cell proliferation in response to fixed Staphylococcus aureus cells was significantly lower in patients with the continuous-type ossification than in healthy volunteers but was not correlated with the number of vertebral bodies with ossified ligament. The B cell response in patients with the segmental-type ossification was not lower than that in healthy volunteers. Serum concentrations of transforming growth factor-beta1 and basic fibroblast growth factor also were higher in patients with the continuous-type ossification than in patients with the segmental-type ossification and in healthy volunteers. The findings raise the possibility that continuous-type ossification of posterior longitudinal ligament might develop differently from segmental-type ossification.

The efficacy of biochemical markers in patients with ossification of posterior longitudinal ligament of the spine.

STUDY DESIGN: Serum levels of carboxyterminal propeptide of type I collagen (PICP), osteocalcin (OC), carboxyterminal telopeptide of type I collagen (ICTP) and urinary levels of pyridinoline (Pyr) and deoxypyridinoline (Dpyr) were measured in patients with ossification of posterior longitudinal ligament of the spine (OPLL) and age-matched control subjects. OBJECTIVES: To evaluate the efficacy of these biochemical markers of the patients with OPLL. SETTING: Department of Orthopedic Surgery, Hamamatsu University School of Medicine, Hamamatsu, Japan. METHODS: Spot urine and blood samples were obtained from 20 healthy males aged 45 - 78 (mean+/-SD; 63. 0+/-11.5) and 22 male patients with OPLL aged 46 - 77 (mean+/-SD; 59. 9+/-8.8), and serum levels of PICP, OC, ICTP and urinary levels of Pyr and Dpyr were measured. RESULTS: There were no significant difference in age, serum PICP, OC, ICTP, urinary Pyr and Dpyr levels between OPLL and control group. CONCLUSION: Neither bone formation nor bone resorption was accelerated in the patients with OPLL.

Genetic analysis of ossification of the posterior longitudinal ligament.

STUDY DESIGN: The human leukocyte antigen (HLA) haplotypes in families of patients with known ossification of the posterior longitudinal ligament (OPLL) were reviewed. OBJECTIVE: To clarify how genetic factors relate to the development of OPLL. SUMMARY OF BACKGROUND DATA: The association between genetic factors and the development of OPLL is still unknown. MATERIALS AND METHODS: The association between HLA haplotypes and OPLL was studied in families of 24 patients with OPLL. RESULTS: The prevalence of OPLL was higher in the siblings showing a higher share of identical HLA haplotypes: 10 (53%) of 19 with concurrence of two strands, and 5 (24%) of 21 with concurrence of one strand. Of 21 subjects who had no HLA haplotype identical with that in OPLL patients, only one showed evidence of OPLL. CONCLUSION: Genetic factors predispose toward the development of OPLL.