Antibodies against carbamylated proteins: prevalence and associated disease characteristics in Belgian patients with rheumatoid arthritis or other rheumatic diseases.

Objectives: Anti-carbamylated protein antibodies (anti-CarP) are reported to be associated with increased disease activity and with more severe joint damage in rheumatoid arthritis (RA) patients. The present study investigated the presence of anti-CarP in various rheumatic diseases, and their specific clinical significance in RA, in Belgian rheumatology patients.Method: We tested sera from 254 RA patients, 56 healthy controls, and 153 patients with different rheumatic conditions: juvenile idiopathic arthritis (JIA), axial spondyloarthritis, systemic sclerosis, and Sjögren's syndrome (SS). An in-house enzyme-linked immunosorbent assay was used to detect immunoglobulin G antibodies against carbamylated foetal calf serum.Results: Anti-CarP were detected in 88 RA patients (34.6%), of whom 82% were also positive for anti-citrullinated protein antibodies (ACPAs) and 81% were also rheumatoid factor (RF) positive. Of note, 11 anti-CarP single-positive patients were detected (4.3%). The previously reported association with joint erosions was not detected. However, in ACPA- and RF-negative RA patients, the presence of anti-CarP was associated with higher disease activity and disability. Fifteen per cent of JIA patients and 30% of SS patients also tested positive for anti-CarP and their antibody levels did not differ significantly from those of anti-CarP-positive RA patients. Anti-CarP levels were, however, significantly higher in ACPA- or RF-positive patients.Conclusion: Anti-CarP antibodies were detected in the sera of a cohort of Belgian RA patients. Moreover, they were also detected in primary SS patients and in JIA patients. In the seronegative subset of RA patients, anti-CarP antibodies showed prognostic value.

[Camptocormia: From diagnosis to treatment]. / La camptocormie: Du diagnostic au traitement.

Camptocormia or Bent Spine Syndrome (BSS) is a symptom, often unknown, affecting elderly patients. Camptocormia is a dynamic anteflexion of the trunk occurring during physical exercises or in standing position and reducible in decubitus. It is caused by an impairment of the extensor muscles of the spinal column, either idiopathic or secondary to a muscular or a neurological disease. Its diagnosis is primarily anamnestic and clinical. The use of imaging could highlight a paraver tebral muscular fatty infi l tration with preserved volume in the case of idiopathic disorder and allows exclusion of osteoarticular pathologies. The treatment must be proposed as early as possible, before advanced adipose muscle evolution and significant anteflexion of the trunck. Symptomatic measures apply to primary and secondary forms and include physiotherapy, technical assistances to the walk and equipment by lordosis supporting corsets.

La camptocormie ou Bent Spine Syndrome (BSS) est un symptôme, souvent méconnu, touchant le patient âgé. La camptocormie est une antéflexion dynamique du tronc survenant à l'effort ou en position debout et est réductible en décubitus. Elle est causée par une atteinte des muscles extenseurs du rachis soit d'origine musculaire idiopathique ou secondai re, soit d'origine neurologique. Son diagnostic est essentiellement anamnestique et clinique. Le bilan par imagerie permet d'étudier la musculature paravertébrale et permet d'exclure les pathologies ostéoarticulaires. Le traitement étiologique ou symptomatique doit se faire précocement, avant que l'évolution adipeuse des muscles extenseurs et l'antéflexion soient trop importantes. Dans le traitement de la camptocormie, les mesures symptomatiques s'appl iquant aux formes primaires et secondaires associent de la kinésithérapie, des aides techniques à la marche et l'appareillage par des corsets lordosants.

Oleate Abrogates Palmitate-Induced Lipotoxicity and Proinflammatory Response in Human Bone Marrow-Derived Mesenchymal Stem Cells and Osteoblastic Cells.

Osteoporosis is a metabolic bone disease associated with unequilibrated bone remodeling resulting from decreased bone formation and/or increased bone resorption, leading to progressive bone loss. In osteoporotic patients, low bone mass is associated with an increase of bone marrow fat resulting from accumulation of adipocytes within the bone marrow. Marrow adipocytes are active secretory cells, releasing cytokines, adipokines and free fatty acids (FA) that influence the bone marrow microenvironment and alter the biology of neighboring cells. Therefore, we examined the effect of palmitate (Palm) and oleate (Ole), 2 highly prevalent FA in human organism and diet, on the function and survival of human mesenchymal stem cells (MSC) and MSC-derived osteoblastic cells. The saturated FA Palm exerted a cytotoxic action via initiation of endoplasmic reticulum stress and activation of the nuclear factor κB (NF-κB) and ERK pathways. In addition, Palm induced a proinflammatory response, as determined by the up-regulation of Toll-like receptor 4 expression as well as the increase of IL-6 and IL-8 expression and secretion. Moreover, we showed that MSC-derived osteoblastic cells were more sensitive to lipotoxicity than undifferentiated MSC. The monounsaturated FA Ole fully neutralized Palm-induced lipotoxicity by impairing activation of the pathways triggered by the saturated FA. Moreover, Ole promoted Palm detoxification by fostering its esterification into triglycerides and storage in lipid droplets. Altogether, our data showed that physiological concentrations of Palm and Ole differently modulated cell death and function in bone cells. We therefore propose that FA could influence skeletal health.

Glucose-Dependent Insulinotropic Peptide Prevents Serum Deprivation-Induced Apoptosis in Human Bone Marrow-Derived Mesenchymal Stem Cells and Osteoblastic Cells.

Human bone marrow-derived mesenchymal stem cells (hBMSC) are able to differentiate into cells of connective tissue lineages, including bone and cartilage. They are therefore considered as a promising tool for the treatment of bone degenerative diseases. One of the major issues in regenerative cell therapy is the biosafety of fetal bovine serum used for cell culture. Therefore, the development of a culture medium devoid of serum but preserving hBMSC viability will be of clinical value. The glucose-dependent insulinotropic peptide (GIP) has an anti-apoptotic action in insulin-producing cells. Interestingly, GIP also exerts beneficial effects on bone turnover by acting on osteoblasts and osteoclasts. We therefore evaluated the ability of GIP to prevent cell death in osteoblastic cells cultured in serum-free conditions. In hBMSC and SaOS-2 cells, activation of the GIP receptor increased intracellular cAMP levels. Serum deprivation induced apoptosis in SaOS-2 and hBMSC that was reduced by 30 and 50 %, respectively, in the presence of GIP. The protective effect of GIP involves activation of the adenylate cyclase pathway and inhibition of caspases 3/7 activation. These findings demonstrate that GIP exerts a protective action against apoptosis in hBMSC and suggest a novel approach to preserve viability of hBMSC cultured in the absence of serum.

Increased serum levels of high-mobility group box 1 (HMGB1) in primary Sjögren's syndrome.

OBJECTIVE: To determine serum levels of high-mobility group box 1 (HMGB1) in patients with primary Sjögren's syndrome (pSS) as compared to healthy volunteers and patients with sicca symptoms, and to determine whether serum HMGB1 levels are correlated with disease activity in pSS. METHODS: Serum HMGB1 levels were determined by enzyme-linked immunosorbent assay (ELISA) in 101 patients with pSS, 13 patients with sicca symptoms, and 40 healthy volunteers. Clinical and laboratory variables were also analysed and serum HMGB1 levels were correlated with the Sjögren's Syndrome Disease Activity Index (SSDAI). RESULTS: The serum levels of HMGB1 were significantly increased in pSS patients as compared to patients with sicca symptoms and healthy controls (p = 0.04 and p = 0.01, respectively). In the subgroups of patients with anti-SSA autoantibodies, the serum levels of HMGB1 were significantly higher than those in the subgroup of pSS patients who were anti-SSA negative and in healthy controls and patients with sicca symptoms (p < 0.001, p < 0.001, and p = 0.004, respectively). There was no significant correlation between serum HMGB1 levels (in pSS patients with anti-SSA autoantibodies) and SSDAI score (r = 0.03, p = 0.83). Patients with active disease had higher HMGB1 levels than patients with low disease activity (p = 0.04), but HMGB1 levels did not correlate with the SSDAI. CONCLUSION: Serum HMGB1 levels are increased in pSS patients and more specifically in patients with SSA autoantibodies. There was, however, no correlation of HMGB1 with the SSDAI.

[Multifocal diabetic myonecrosis]. / Infarctus musculaire multifocal diabétique.

Diabetic muscle infarction is a rare and often unrecognized complication of diabetes. It typically occurs in patients with poorly controlled and multi-complicated diabetes. Typical clinical presentation is an indurate muscle pain, mainly localized in the lower limb with an acute onset. In most cases, diabetes myonecrosis is focal and sometimes can be recurrent. Diagnosis is clinical but can used magnetic resonance imaging (MRI). Muscle biopsy is sometimes necessary in cases of doubt or to confirm the imaging diagnosis. Elevation of muscle enzymes (CPK) is present in half of cases. Management is conservative and the clinical and imaging evolution is usually favourable. We report the case of a patient presenting a subacute hyperalgesic lomboradiculopathy.

[Treatment of bone diseases with cell therapy]. / Le traitement des maladies osseuses par thérapie cellulaire.

Osteonecrosis of the femoral head is a rare disease that affects young patients and is characterized by the occurrence of a necrotic lesion in the femoral head, loss of mechanical resistance of dead bone and collapse of the femoral head. Patients complain of hip pain and loss of function that could lead to total hip replacement. So far, osteonecrosis was considered as a vascular disease due to vascular section or compression leading to bone necrosis. We studied the physiopathology of the osteonecrosis considering it as a bone disease. We demonstrated as well as other teams that the number of mesenchymal stem cells, precursors of bone cells and osteoblastic cells, were reduced in patients with osteonecrosis. We initiated a controlled double blind trial to study the efficacy of stem cells implantation--obtained from concentrated bone marrow--in the osteonecrosis zone. This study showed that bone marrow implantation could delay disease progression to the fractural stage and improve hip pain and joint symptoms. We then tried to improve this treatment by developing a bone cell therapy product formed of osteoblastic cells. A novel cell therapy product formed ofosteoblastic cells, PREOB was developed. PREOB was tested in a randomized, controlled phase II trial in osteonecrosis of the femoral head and showed its superiority compared to concentrated bone marrow. Today, this cellular therapy product is developed by Bone Therapeutics, a spin-offcompany of the "Université libre de Bruxelles". Other bone diseases are characterized by reduced activities of stem cells that are unable to meet the need of bone remodelling due to a non-union fracture, for example. Clinical studies also showed that concentrated bone marrow could be implanted into the non-union. However, its efficacy was dependent on the number of implanted stem cells. The cellular therapy product is currently tested in a phase I trial with promising preliminary results. Cellular therapy for bone diseases is a novel therapeutic approach that evolves from stem cells to the use of the differentiated cells of interest.

Osteonecrosis in inflammatory bowel diseases: a review of the literature.

INTRODUCTION: Osteonecrosis (ON) of the femoral head can lead to femoral head collapse, necessitating total hip replacement. Reports of patients suffering from both ON and Inflammatory Bowel Diseases (IBD) have prompted us to evaluate the relationship between ON and IBD, especially Crohn's disease and ulcerative colitis. METHODS: A review of the data from three new cases, along with data from all the published cases of patients presenting ON and IBD found through a systematic search of the Pub Med database. RESULTS: We encountered some diagnostic problems: The ON diagnosis could not be confirmed in some patients who did not meet the ON diagnostic criteria. Reviewed data was too weak to assess the exact incidence of ON in IBD. Corticosteroid therapy, especially in high dose regimens, is likely the most important etiological factor. No evidence supporting other physiopathological hypothesis, such as total parenteral nutrition, osteoporosis, or coagulation disorders, was found. Finally, the multifocal form of ON appears particularly common in IBD, with some patients presenting multiple lesions of the hip, shoulder, knee and talus. CONCLUSIONS: ON in IBD, which is frequently multifocal, appears to be a complication of corticosteroid therapy, especially when high doses are used. We recommend regular ON checkups for corticosteroid-treated IBD patients.

Evidence-based guidelines for the use of biochemical markers of bone turnover in the selection and monitoring of bisphosphonate treatment in osteoporosis: a consensus document of the Belgian Bone Club.

OBJECTIVES: To review the clinical value of bone turnover markers (BTM), to initiate and/or monitor anti-resorptive treatment for osteoporosis compared with bone mineral density (BMD) and to evaluate suitable BTM and changes in BTM levels for significance of treatment efficiency. METHODOLOGY: Consensus meeting generating guidelines for clinical practice after review and discussion of the randomised controlled trials or meta-analyses on the management of osteoporosis in postmenopausal women. RESULTS: Although the correlation between BMD and BTM is statistically significant, BTM cannot be used as predictive markers of BMD in an individual patient. Both are independent predictors of fracture risk, but BTM can only be used as an additional risk factor in the decision to treat. Current data do not support the use of BTM to select the optimal treatment. However, they can be used to monitor treatment efficiency before BMD changes can be evaluated. Early changes in BTM can be used to measure the clinical efficacy of an anti-resorptive treatment and to reinforce patient compliance. DISCUSSION: Determining a threshold of BTM reflecting an optimal long-term effect is not obvious. The objective should be the return to the premenopausal range and/or a decrease at least equal to the least significant change (30%). Preanalytical and analytical variability of BTM is an important limitation to their use. Serum C-terminal cross-linked telopeptide of type I collagen (CTX), procollagen 1 N terminal extension peptide and bone specific alkaline phosphatase (BSALP) appear to be the most suitable. CONCLUSION: Consensus regarding the use of BTM resulted in guidelines for clinical practice. BMD determines the indication to treat osteoporosis. BTM reflect treatment efficiency and can be used to motivate patients to persist with their medication.

[The rheumatology and physical medicine department]. / Le Service de Rhumatologie et de Médecine Physique.

Actually, 18 rheumatologists and specialists in physical therapy are collaborating in the Department, allowing to develop possibilities for the diagnosis and therapeutic challenge of patients suffering from disorders of the locomotor system. Accordingly, the knowledge, the know-how, the experience plus the willingness to make a good job are used for helping the patient, for contributing to medical progress and also for the education of future medical doctors. Our department has significantly contributed to a better understanding and therapeutic approach of rheumatoid arthritis, Sjogren's syndrome, aseptic necrosis, osteoporosis, osteoarthritis, and inflammation; it has been among the first in the world to offer new therapeutic modalities, otherwise not accessible and, to help a series of hopeless patients. In addition, a new sector for a performing rehabilitation has been recently developed. Accordingly, during these mast twenty years, a performing department with a motivated team has been developed offering a maximum of medical services for the community and ready for the challenges of tomorrow.

Analgesic effect of intravenous pamidronate on chronic back pain due to osteoporotic vertebral fractures.

Pamidronate, a bisphosphonate analogue has been evaluated in a retrospective study for its analgesic effect on chronic back pain due to vertebral fractures in 26 patients suffering from senile osteoporosis or glucocorticoid-induced osteoporosis. Sixty milligrams of pamidronate was administered intravenously every 3 months for one year. After three months of treatment, the pain score fell from 3.2 +/- 0.1 to 1.2 +/- 0.2 in both groups. In conclusion, intravenous pamidronate seems to be a valuable treatment for chronic back pain due to osteoporotic vertebral fractures.

Bone morphogenetic proteins induce the expression of noggin, which limits their activity in cultured rat osteoblasts.

Bone morphogenetic proteins (BMPs) induce the differentiation of cells of the osteoblastic lineage and enhance the function of the osteoblast. Growth factors are regulated by binding proteins, but there is no information about binding proteins for BMPs in skeletal cells. Noggin specifically binds BMPs, but its expression by cells of the osteoblastic lineage has not been reported. We tested for the expression of noggin and its induction by BMP-2 in cultures of osteoblast-enriched cells from 22-d-old fetal rat calvariae (Ob cells). BMP-2 caused a time- and dose-dependent increase in noggin mRNA and polypeptide levels, as determined by Northern and Western blot analyses. The effects of BMP-2 on noggin transcripts were dependent on protein, but independent of DNA synthesis. BMP-2 increased the rates of noggin transcription as determined by nuclear run-on assays. BMP-4, BMP-6, and TGF-beta1 increased noggin mRNA in Ob cells, but basic fibroblast growth factor, platelet- derived growth factor BB, and IGF-I did not. Noggin decreased the stimulatory effects of BMPs on DNA and collagen synthesis and alkaline phosphatase activity in Ob cells. In conclusion, BMPs induce noggin transcription in Ob cells, a probable mechanism to limit BMP action in osteoblasts.

Insulin-like growth factor II promoter expression in cultured rodent osteoblasts and adult rat bone.

Insulin-like growth factor (IGF)-II stimulates bone formation by increasing the replication of cells of the osteoblastic lineage and by enhancing the differentiated function of the osteoblast. Although IGF-II is synthesized by skeletal cells, little is known about the mechanisms involved and its regulation by growth factors. IGF-II expression is tissue specific and is developmentally regulated. In the present study, we examined the expression of IGF-II in fetal rat, newborn mouse and MC3T3-E1 osteoblastic (Ob) cells, and in adult rat calvariae. We also determined mechanisms involved in the regulation of IGF-II by platelet-derived growth factor (PDGF) BB, fibroblast growth factor-2 (FGF-2), and transforming growth factor (TGF) beta1. Northern analysis revealed IGF-II transcripts of 3.6 and 1.2 kb in osteoblastic cells and adult rat calvariae. Ribonuclease (RNase) protection assay using probes specific to the three known IGF-II promoters, P1, P2, and P3, demonstrated messenger RNA (mRNA) expression driven by P3 in osteoblasts and adult rat calvariae, but no expression of P1 or P2 transcripts. PDGF BB, FGF-2, and TGF beta1 inhibited the expression of IGF-II P3 mRNA by 50%. PDGF BB, FGF-2, and TGF beta1 also decreased the rates of IGF-II transcription in rat Ob cells as determined by nuclear run-on assays and did not modify the decay of IGF-II in transcriptionally arrested rat Ob cells. In conclusion, the synthesis of IGF-II in osteoblastic cells and in adult rat calvariae is driven by IGF-II P3 and is regulated by skeletal growth factors acting at the transcriptional level using the IGF-II P3.

Interleukin-6 with its soluble receptor enhances the expression of insulin-like growth factor-I in osteoblasts.

Interleukin (IL)-6, a cytokine produced by skeletal cells and known to increase bone resorption, has mitogenic effects for bone cells, possibly by regulating the synthesis of other local factors. We tested the effects of IL-6 and its soluble receptor (IL-6sR) on the expression of insulin-like growth factor (IGF)-I and IGF-II in cultured osteoblast-enriched cells from fetal rat calvariae (Ob cells). IL-6 did not modify IGF-I messenger RNA (mRNA) levels, but when tested in the presence of IL-6sR, IL-6 at 1 to 100 ng/ml increased IGF-I transcripts by up to 3.2-fold after 24 h. IL-6sR caused a small increase in IGF-I mRNA levels when tested alone. IL-6 and IL-6sR increased immunoreactive IGF-I levels by 2.4-fold after 24 h and 6.4-fold after 48 h. Cycloheximide prevented, and indomethacin markedly decreased, the effect of IL-6 and IL-6sR on IGF-I mRNA levels, but hydroxyurea did not. IL-6 and IL-6sR did not alter the decay of IGF-I mRNA in transcriptionally arrested Ob cells, and the half-life of the predominant 6.5-kb IGF-I transcript was about 11 h in control and treated cells. In addition, IL-6 and IL-6sR increased the levels of IGF-I heterogeneous nuclear RNA. IL-11 also increased IGF-I mRNA levels, whereas oncostatin M and leukemia-inhibitory factor did not. In contrast to their effects on IGF-I, IL-6 and IL-6sR caused only a modest increase in IGF-II mRNA and polypeptide levels. In conclusion, IL-6, in the presence of IL-6sR, increases IGF-I synthesis in Ob cells; this effect may lead to a secondary increase in bone formation.

Calretinin is transiently expressed in tendon fibroblasts of the paravertebral region of the chick embryo.

Although calretinin is an intracellular calcium acceptor protein essentially located in neurons, we have previously shown that calretinin was also expressed in the mesenchymal cells forming the intervertebral disc. Here, we describe, using immunohistochemistry, the transient expression of calretinin in fibroblasts responsible for the tendon formation in the paravertebral region. We have looked at chick embryos from embryonic day 4 to day 18. At embryonic day 6, calretinin immunoreactivity was detected in chick embryo cells located laterally to the spinal cord between two groups of developing muscular cells. At embryonic day 8, calretinin immunoreactivity intensity was the highest in cells showing a fibroblast morphology. After embryonic day 8, when fibroblast proliferation decreased and differentiation increased, calretinin immunoreactivity progressively disappeared. Interestingly, calretinin could not be detected in fibroblasts of the anterior and posterior limbs at any investigated age. Because calretinin expression appeared selectively and transiently in the fibroblasts of the paravertebral region, we may conclude that the phenotype of those fibroblasts is different from the limbs fibroblasts.

Cerebellar spongiform degeneration induced by acute lithium intoxication in the rat.

Cerebellar syndrome has been described after acute lithium intoxication in human. Neuropathological studies have demonstrated neuronal loss and spongiosis in the cerebellum. We describe an animal model of acute lithium-induced cerebellar degeneration. Five hours following administration of lithium chloride (250 mg/kg, i.p.), the cerebellar white matter of seven rats out 14 exhibited extensive spongiform changes. Microdialysis study in the rat cerebellar cortex demonstrated basal concentrations of dopamine (DA), hydroxy-3-methoxyphenylacetic acid (HVA) and 5-hydroxy-3-indolacetic acid (5-HIAA). These metabolites were unaffected by acute lithium intoxication suggesting that the cerebellar toxicity is not due to a modification of dopaminergic or serotoninergic neurotransmission.