Increase in bone mineral density of patients with rheumatoid arthritis treated with anti-TNF-alpha antibody: a prospective open-label pilot study

OBJECTIVE

To determine the changes in bone mineral density (BMD) in patients with rheumatoid arthritis (RA; without osteoporosis) treated with infliximab.

METHODS

Twenty-six patients (19 women, seven men) aged 54.2 yr (range 27-75), with persistently active RA despite a high dose of non-steroidal anti-inflammatory drugs and/or treatment with methotrexate or leflunomide, were studied. Mean duration of disease was 9.8 yr. Patients receiving or having received bisphosphonates or hormone replacement therapy were excluded. The patients were treated with 3.5 mg/kg infliximab at weeks 0, 2, 6 and then every 6-8 weeks. Lumbar and femoral BMD was measured by dual-energy X-ray absorptiometry at baseline and 12 months later. Serum osteocalcin and serum crosslaps were measured at baseline (week 0) and after 12 months. Twelve patients were taking calcium (1 g/day) and vitamin D (800 IU/day). Twenty patients were receiving methotrexate (mean dose 12.5 mg/day), six patients were receiving leflunomide (mean dose 20 mg/day) and nine patients were concomitantly receiving corticosteroids at a mean daily dose of 10 mg.

RESULTS

After 12 months of infliximab therapy, there was a significant increase in BMD in the spine (BMD, P < 0.001; T-score, P < 0.001; Z-score, P < 0.001) and the femoral neck (BMD, P < 0.001; T-score, P < 0.001; Z-score, P < 0.01). With regard to the root mean square average, there was a significant increase in BMD at the left femoral neck (11.6% for a root mean square of 6%) but only a trend towards improvement in the spine (2.7% for a root mean square of 4%) during the study period. There was a significant increase in osteocalcin serum levels between baseline and after 12 months (P < 0.01) and a significant decrease in the marker for bone resorption (P < 0.01) but no change in serum calcium was observed. However, the changes in markers of bone metabolism and BMD were not correlated.

CONCLUSION

The data support the hypothesis that anti-TNF therapy may exert beneficial effects on bone metabolism in RA patients.

The influence of strongly reducing conditions on strong metal–support interactions in Cu/ZnO catalysts used for methanol synthesis

A systematic series of binary and ternary copper catalysts was investigated using the methanol synthesis reaction at atmospheric pressure. Strong metal-support interactions between copper and zinc oxide induced by strongly reducing conditions were probed by the adsorption of carbon monoxide, which was monitored qualitatively and quantitatively by a combination of microcalorimetry, temperature-programmed desorption experiments and Fourier transform infrared spectroscopy. For the zinc oxide-containing catalysts, the pretreatment in flowing carbon monoxide at 493 K resulted in a severe decoration of the copper metal particles with ZnOx adspecies, whereas after methanol synthesis at 493 K the state of the copper was essentially identical to that seen after hydrogen reduction. Copper was always found to be present in its zero-valent state.

Association of 1.25 vitamin D3 deficiency, disease activity and low bone mass in ankylosing spondylitis

Vertebral fractures due to osteoporosis are a common but frequently unrecognized complication in established ankylosing spondylitis (AS). It is known that inflammatory activity in rheumatic diseases (i.e., proinflammatory cytokines) itself plays a possible role in the pathophysiology of bone loss. The aim of this study was to analyze whether inflammatory activity and an alteration of the vitamin D metabolism play a substantial role in the loss of bone mass in AS. In this cross-sectional study, 58 patients with established AS and an age- and sex-matched control group were examined. The vitamin D status was investigated, as was, in parallel, the relationship to disease activity (erythrocyte sedimentation rate [ESR], C-reactive protein [CRP], Bath Ankylosing Spondylitis Disease Activity Index [BASDAI]), markers of bone metabolism (parathyroid hormone [PTH], 1.25 vitamin D3, 25 vitamin D3), calcium, bone alkaline phosphatase (bone-AP), urine cross-links, and plasma tumor necrosis factor alpha (TNFalpha). Bone mineral density was measured by quantitative computed tomography (QCT) of the lumbar spine. Osteoporosis was diagnosed in early as well as in progressive stages of AS (23/58=39.6%). Furthermore, serum levels of 1.25 vitamin D3 and PTH were negatively correlated with disease activity and TNFalpha. The excretion of cross-links showed a positive correlation with disease activity and TNFalpha, and 1.25 vitamin D3 and PTH were positively correlated with bone-AP. TNFalpha also positively correlated with disease activity. AS patients with osteoporosis showed significantly increased CRP, ESR, cross-links and PTH and a significantly decreased 1.25 D3. Osteoporosis is frequent in AS and high disease activity is associated with an alteration in vitamin D metabolites and increased levels of bone resorption in active AS. Our findings propose a close association of BMD, bone metabolism and inflammatory activity, possibly related to vitamin D inflammation interactions.

Ankylosing spondylitis and bone mineral density--what is the ideal tool for measurement?

Ankylosing spondylitis (AS) is characterised by chronic inflammation and partial ossification, yet vertebral fractures due to osteoporosis, although common, are frequently unrecognised. The aim of this study was to (1) show the frequency of changes in the progress of osteopenia/osteoporosis in AS depending on duration and stage of the disease and (2) assess the ranking of two different methods of bone density measurement in this clinical pattern. We measured bone density in 84 male and female patients with both dual X-ray absorptiometry (DXA) and single energy quantitative computed tomography (SE-QCT). In the initial and advanced stages of the disease, a high decrease in axial bone density could be verified (DXA: osteopenia in 5% and osteoporosis in 9.2%; SE-QCT: osteopenia in 11.8% and osteoporosis in 30.3%). Peripheral bone density decrease as in osteopenia could be proven in 17.6% by DXA measurement. With SE-QCT, a decrease in vertebral trabecular bone density could already be observed in the initial stage and continued steadily during the course of the disease; cortical bone displayed the same trend up to stages of ankylosis. With DXA, valid conclusions are more likely to be expected in less marked ankylosing stages of AS. In stages of advanced ankyloses in the vertebral region (substantial syndesmophytes), priority should be given to SE-QCT, due to the selective measurement of trabecular and cortical bone. The DXA method often yields values that are too high, and the replacement of vertebral trabecular bone by fatty bone marrow is not usually recorded as standard. There may already be an increased risk of bone fracture in AS in osteopenia on DXA along with an osteoporosis already established on SE-QCT.

A new approach to studying angiogenesis in rheumatoid arthritis by means of power Doppler ultrasonography and measurement of serum vascular endothelial growth factor

OBJECTIVE

To evaluate angiogenesis as an essential component of pannus formation and cartilage destruction in rheumatoid arthritis (RA) using power Doppler ultrasonography (PDUS) and serum vascular endothelial growth factor (VEGF) measurement.

METHODS

Twenty-one RA patients with a painful and swollen wrist and 12 healthy controls were examined with ultrasound. By means of standard scans, vascularity near and inside the joint capsule was visualized with PDUS. Two trained investigators performed sonography. Representative video clips were stored and read by two independent investigators, under blinded conditions, with regard to the microvascular Doppler flow being either inside or outside the joint capsule and with respect to a qualitative estimate of the intensity of blood flow, according to a grading from 1 to 3. Serum levels of VEGF were measured with a standard quantitative sandwich ELISA.

RESULTS

The power Doppler mode identified increased synovial microvascular blood flow inside the joint capsule in 17 of 21 RA patients (81%) vs one of the healthy controls. We found large variation in serum VEGF levels in RA patients and in healthy controls. The degree of synovial vascularity determined by PDUS showed no correlation with the immediate serum VEGF level in the same patient.

CONCLUSION

The high correlation between intra-articular microvascular power Doppler flow and clinical synovitis in RA patients (P<0.0001) indicates that PDUS may be helpful in studying the role of synovial blood vessels in rheumatoid inflammation.

Identification and exclusion of intermediates of photocatalytic CO2 reduction on TiO2 under conditions of highest purity

On TiO₂ P25, CO is not an intermediate in photocatalytic CO₂ reduction; instead, a mechanism involving C₂ intermediates is likely.

Multi-dimensional zinc oxide (ZnO) nanoarchitectures as efficient photocatalysts: What is the fundamental factor that determines photoactivity in ZnO?

While bulk zinc oxide (ZnO) is of non-toxic in nature, ZnO nanoarchitectures could potentially induce the macroscopic characteristics of oxidative, lethality and toxicity in the water environment. Here we report a systematic study through state-of-the-art controllable synthesis of multi-dimensional ZnO nanoarchitectures (i.e. 0D-nanoparticle, 1D-nanorod, 2D-nanosheet, and 3D-nanoflowers), and subsequent in-depth understanding on the fundamental factor that determines their photoactivities. The photoactivities of resultant ZnO nanoarchitectures were interpreted in terms of the photodegradation of salicylic acid as well as inactivation of Bacillus subtilis and Escherichia coli under UV-A irradiation. Photodegradation results showed that 1D-ZnO nanorods demonstrated the highest salicylic acid photodegradation efficiency (99.4%) with a rate constant of 0.0364 min^-1. 1D-ZnO nanorods also exhibited the highest log reductions of B. subtilis and E. coli of 3.5 and 4.2, respectively. Through physicochemical properties standardisation, an intermittent higher k value for pore diameter (0.00097 min^-1 per mm), the highest k values for crystallite size (0.00171 min^-1 per nm) and specific surface area (0.00339 min^-1 per m²/g) contributed to the exceptional photodegradation performance of nanorods. Whereas, the average normalised log reduction against the physicochemical properties of nanorods (i.e. low crystallite size, high specific surface area and pore diameter) caused the strongest bactericidal effect.

Reliability of different Doppler ultrasound quantification methods and devices in the assessment of therapeutic response in arthritis

OBJECTIVE

To evaluate the metric qualities of power Doppler ultrasound (PDUS) for different quantification methods and devices in the assessment of arthritis during anti-inflammatory treatment.

METHODS

Twenty-four patients with active arthritis and first-time treatment with the TNF-alpha inhibitor adalimumab underwent sequential clinical, laboratory and US examination at baseline, weeks 2, 6 and 12. 2D and 3D PDUS was performed by two independent investigators. The images and movies were scored from 0 to 3 and the amount of colour pixels and voxels was calculated. In addition, the resistance index of a synovial artery was measured. Thirteen patients were examined with a second US machine.

RESULTS

Treatment response was already observed at week 2 with a significant reduction of 2D (P < 0.01) and 3D scores (P < 0.001). A moderate correlation to 28-joint disease activity score was found for 3D voxel count (r(s) = 0.35, P < 0.001). Interobserver agreement was kappa or ICC >or= 0.8 for all methods except the resistance index (ICC = 0.60). Intermachine agreement was kappa = 0.57 for 2D PDUS score.

CONCLUSIONS

The study demonstrates good to excellent interobserver and moderate intermachine reliability of different PDUS assessment methods in a longitudinal open-label study.