PTH analoga: vergelijkbaar of verschillend?

Momenteel bestaan er 2 verschillende PTH-analoga: PTH 1-34 (teriparatide) en PTH 1-84. Teriparatide is in Nederland vanaf februari 2005 verkrijgbaar; inmiddels is sinds januari 2007 ook PTH 1-84 beschikbaar. Teriparatide is geregistreerd voor de behandeling van vastgestelde osteoporose bij postmenopauzale vrouwen en bij mannen met een verhoogd risico op botbreuken, PTH 1-84 voor de behandeling van postmenopauzale vrouwen met een verhoogd fractuurrisico. Teriparatide bestaat uit de eerste 34 aminozuren van het humane parathormoon, op recombinante wijze geproduceerd, het actieve gedeelte van dit hormoon. De resterende 50 aminozuren staan te boek als het “inactieve” gedeelte van het parathormoon. PTH 1-84 daarentegen bestaat uit 84 aminozuren, het “volledige” parathormoon; ook dit wordt recombinant gesynthetiseerd. In dit artikel zal worden ingegaan op de overeenkomsten en de eventuele verschillen in effectiviteit en veiligheid van teriparatide en PTH 1-84. Wat betreft de effectiviteit is voor beide middelen een overtuigende reductie van wervelfracturen aangetoond; alleen voor teriparatide is reductie van niet-wervelfracturen aangetoond. Een andere belangrijke overeenkomst is dat beide middelen sterk anabool werkzaam zijn, het werkingsmechanisme is essentieel verschillend van bisfosfonaten en van strontiumranelaat. Beide middelen zijn daarmee voor oudere patiënten met ernstige osteoporose een welkome aanvulling van het therapeutisch arsenaal. Dit betreft vooral patiënten die ondanks behandeling met bisfosfonaten of raloxifen of strontiumranelaat na twee wervelinzakkingen opnieuw één of meerdere fracturen krijgen (“inadequate response”), dan wel bovengenoemde drie middelen niet verdragen. Het is hierbij van belang dat beide middelen voorgeschreven dienen te worden door de behandelend medisch specialist, bijvoorbeeld de klinisch geriater. Vanwege de hoge kosten van deze medicamenten, worden deze middelen alleen vergoed bij patiënten die aan bovenstaande criteria voldoen

SCOPE: a scorecard for osteoporosis in Europe

Summary The scorecard summarises key indicators of the burden of osteoporosis and its management in each of the member states of the European Union. The resulting scorecard elements were then assembled on a single sheet to provide a unique overview of osteoporosis in Europe. Introduction The scorecard for osteoporosis in Europe (SCOPE) is an independent project that seeks to raise awareness of osteoporosis care in Europe. The aim of this project was to develop a scorecard and background documents to draw attention to gaps and inequalities in the provision of primary and secondary prevention of fractures due to osteoporosis. Methods The SCOPE panel reviewed the information available on osteoporosis and the resulting fractures for each of the 27 countries of the European Union (EU27). The information researched covered four domains: background information (e.g. the burden of osteoporosis and fractures), policy framework, service provision and service uptake e.g. the proportion of men and women at high risk that do not receive treatment (the treatment gap). Results There was a marked difference in fracture risk among the EU27. Of concern was the marked heterogeneity in the policy framework, service provision and service uptake for osteoporotic fracture that bore little relation to the fracture burden. For example, despite the wide availability of treatments to prevent fractures, in the majority of the EU27, only a minority of patients at high risk receive treatment for osteoporosis even after their first fracture. The elements of each domain in each country were scored and coded using a traffic light system (red, orange, green) and used to synthesise a scorecard. The resulting scorecard elements were then assembled on a single sheet to provide a unique overview of osteoporosis in Europe. Conclusions The scorecard will enable healthcare professionals and policy makers to assess their country’s general approach to the disease and provide indicators to inform future provision of healthcare

Proprioception mediates the association between systemic inflammation and muscle weakness in patients with knee osteoarthritis: Results from the Amsterdam Osteoarthritis cohort

Objectives: To determine whether systemic inflammation is associated with poor proprioception; to confirm that systemic inflammation is associated with muscle weakness; and to determine whether poor proprioception mediates the association between systemic inflammation and muscle weakness in knee osteoarthritis. Design: Cross-sectional study. Subjects: A total of 689 participants with knee osteoarthritis from the Amsterdam Osteoarthritis (AMS-OA) cohort. Methods: Systemic inflammation was assessed by erythrocyte sedimentation rate, knee proprioception by determining the joint motion detection threshold, and muscle strength with an isokinetic dynamometer. Linear regression models were used to estimate direct associations between systemic inflammation, proprioception and muscle strength, and the indirect association (mediation) between systemic inflammation and muscle strength via proprioception adjusted for potential confounders. Results: Higher erythrocyte sedimentation rates were associated with poor proprioception (p = 0.022). Poor proprioception (p < 0.001) and higher erythrocyte sedimentation rates (p < 0.001) were associated with muscle weakness. Poor proprioception mediated the association between systemic inflammation and muscle weakness (p = 0.035). Conclusion: Results suggest that systemic inflammation is associated with poor proprioception in knee osteoarthritis. Poor proprioception may be a pathway through which systemic inflammation is associated with muscle weakness in patients with knee osteoarthritis

The clinical response to infliximab in rheumatoid arthritis is in part dependent on pretreatment tumour necrosis factor α expression in the synovium

Objective: To determine whether the heterogeneous clinical response to tumour necrosis factor (TNF)alpha blocking therapy in rheumatoid arthritis (RA) can be predicted by TNF alpha expression in the synovium before initiation of treatment. Methods: Prior to initiation of infliximab treatment, arthroscopic synovial tissue biopsies were obtained from 143 patients with active RA. At week 16, clinical response was evaluated using the 28-joint Disease Activity Score (DAS28). Immunohistochemistry was used to analyse the cell infiltrate as well as the expression of various cytokines, adhesion molecules and growth factors. Stained sections were evaluated by digital image analysis. Student t tests were used to compare responders (decrease in DAS28 >= 1.2) with non-responders (decrease in DAS28 <1.2) and multivariable regression was used to identify the independent predictors of clinical response. Results: Synovial tissue analysis confirmed our hypothesis that the baseline level of TNF alpha expression is a significant predictor of response to TNF alpha blocking therapy. TNF alpha expression in the intimal lining layer and synovial sublining were significantly higher in responders than in non-responders (p = 0.047 and p = 0.008, respectively). The numbers of macrophages, macrophage subsets and T cells (all able to produce TNF alpha) were also significantly higher in responders than in non-responders. The expression of interleukin (IL)1 beta, IL6, IL18, IL10, E-selectin, intercellular adhesion molecule (ICAM)-1, vascular cell adhesion molecule (VCAM)-1, vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF) was not associated with response to anti-TNF alpha treatment. Conclusion: The effects of TNF alpha blockade are in part dependent on synovial TNF alpha expression and infiltration by TNF alpha producing inflammatory cells. Clinical response cannot be predicted completely, indicating involvement of other as yet unknown mechanism

Acquired resistance of human T cells to sulfasalazine: stability of the resistant phenotype and sensitivity to non-related DMARDs.

2.5 weeks) resumption of SSZ resistance and ABCG2 expression as in the original CEM/SSZ cells. CEM/SSZ cells displayed diminished sensitivity to the DMARDs leflunomide (5.1-fold) and methotrexate (1.8-fold), were moderately more sensitive (1.6-2.0 fold) to cyclosporin A and chloroquine, and markedly more sensitive (13-fold) to the glucocorticoid dexamethasone as compared with parental CEM cells. CONCLUSION: The drug efflux pump ABCG2 has a major role in conferring resistance to SSZ. The collateral sensitivity of SSZ resistant cells for some other (non-related) DMARDs may provide a further rationale for sequential mono- or combination therapies with distinct DMARDs upon decreased efficacy of SSZ

Reproducibility of bone mineral density measurement in daily practice.

BACKGROUND: Bone mineral density (BMD) measurements are frequently performed repeatedly for each patient. Subsequent BMD measurements allow reproducibility to be assessed. OBJECTIVE: To examine the reproducibility of BMD by dual energy x ray absorptiometry (DXA) and to investigate the practical value of different measures of reproducibility in a group of postmenopausal women. METHODS: Ninety five women, mean age 59.9 years, underwent two subsequent BMD measurements of spine and hip. Reproducibility was expressed as smallest detectable difference (SDD), coefficient of variation (CV), and intraclass correlation coefficient (ICC). Sources of variation were investigated by multilevel analysis. RESULTS: The median interval between measurements was 0 days (range 0-45). The mean difference (SD) between the measurements (g/cm(2)) was -0.001 (0.02) and -0.0004 (0.02) at L1-4 and the total hip, respectively. At L1-4 and the total hip, SDD (g/cm(2)) was +/-0.05 and +/-0.04 and CV (%) was 1.92 and 1.59, respectively. The ICC at spine and hip was 0.99. CONCLUSIONS: Reproducibility in the postmenopausal women studied was good. In a repeated DXA scan a BMD change exceeding 2 radical 2CV (%), the least significant change (LSC), or the SDD should be regarded as significant. Use of the SDD is preferable to use of the CV and LSC (%) because of its independence from BMD and its expression in absolute units. Expressed as SDD, a BMD change of at least +/-0.05 g/cm(2) at L1-4 and +/-0.04 g/cm(2) at the total hip should be considered significant

A 57-year-old man who developed arthritis during R-CHOP chemotherapy for non-Hodgkin lymphoma

Rituximab is a chimeric human-mouse anti-CD20 monoclonal antibody, which is used in the treatment of both B-cell lymphomas and rheumatic diseases. We describe a case of a previously healthy 57-year-old man developing arthritis while being treated with rituximab-CHOP chemotherapy (R-CHOP) for a non-Hodgkin lymphoma. The remittant arthritis developed at successively shorter time-intervals after R-CHOP administration and only improved after rituximab was removed from the chemotherapy schedule, suggesting a rituximab-related phenomenon, as extensive diagnostic testing ruled out any other diagnosis