Effects of one-year tofacitinib therapy on bone metabolism in rheumatoid arthritis

Janus kinase (JAK) inhibitors are used to treat rheumatoid arthritis (RA). We assessed the effects of tofacitinib on bone density and bone markers in association with clinical and laboratory parameters in RA. Tofacitinib stabilized bone density and resulted in a positive balance of bone turnover.

INTRODUCTION

Janus kinase (JAK) inhibitors emerged as new therapeutic options in rheumatoid arthritis (RA). We have little information on how it affects areal and volumetric bone mineral density (BMD) and bone turnover markers. The aim of this study was to assess the effects of 1-year tofacitinib therapy on bone metabolism in RA.

METHODS

Thirty RA patients with active disease were treated with either 5 mg bid or 10 mg bid tofacitinib for 12 months. We determined DAS28, CRP, IgM rheumatoid factor (RF), and anti-cyclic citrullinated peptide (CCP) levels, as well as serum levels of sclerostin, osteocalcin (OC), P1NP, DKK-1, OPG, RANKL, and 25-hydroxy-vitamin D3. Areal and volumetric BMD were assessed by DXA and peripheral quantitative CT (QCT), respectively.

RESULTS

Twenty-six patients (13 on each arm) completed the study. Tofacitinib was clinically effective by suppressing DAS28, CRP, and HAQ. This was accompanied by the attenuation of further bone loss. Tofacitinib therapy significantly increased OC, OPG, and vitamin D3, while decreased CTX levels (p < 0.05). Age and multiple bone markers (OC, CTX, P1NP, RANKL) inversely correlated with L2-4 and femoral neck BMD by DXA. CRP, DAS28, and RANKL inversely determined volumetric BMD by QCT. Age, CRP, anti-CCP, and DKK-1 influenced the effects of tofacitinib therapy on BMD changes.

CONCLUSIONS

One-year tofacitinib treatment stabilized BMD in RA patients and resulted in a positive balance of bone turnover as indicated by bone biomarkers. Further studies are needed to evaluate the potential beneficial effects of JAK inhibitors on inflammatory bone loss.

Comparison of peripheral quantitative computed tomography forearm bone density versus DXA in rheumatoid arthritis patients and controls

Rheumatoid arthritis (RA) has been associated with osteoporosis. Quantitative computed tomography (QCT) is capable of assessing bone density and composition. We found lower bone density in RA compared to controls. Age and RA duration influenced bone density. QCT may be useful to assess bone metabolism in RA.

INTRODUCTION

RA is associated with generalized and periarticular osteoporosis. In addition to DXA that determines areal bone mineral density (BMD), peripheral QCT also detects volumetric BMD. QCT differentiates between total, trabecular, and cortical BMD. Here, we compared DXA and QCT in RA patients and healthy controls.

METHODS

BMD of 57 female RA patients and 32 age-matched healthy female controls were assessed by DXA. QCT of the forearm ultradistal region was also performed. Densitometry data were correlated with age, disease duration, disease activity, serum CRP, and anti-CCP levels.

RESULTS

Total bone density (310.4 ± 79.7 versus 354.0 ± 54.1 mg/cm³; p = 0.007) and attenuation (0.37 ± 0.05 versus 0.40 ± 0.03 1/cm; p = 0.001), trabecular density (157.6 ± 57.0 versus 193.8 ± 48.7 mg/cm³; p = 0.005) and attenuation (0.28 ± 0.03 versus 0.32 ± 0.04 1/cm; p < 0.0001), and cortical density (434.3 ± 115.8 versus 492.5 ± 64.0 mg/cm³; p = 0.006) and attenuation (0.44 ± 0.07 versus 0.47 ± 0.04 1/cm; p = 0.004) were significantly lower in RA. Both lumbar and femoral neck BMD, as well as T-scores, were significantly lower in RA versus controls (p < 0.001 in all cases). In RA, total and cortical QCT attenuation and density were associated with age, the presence of RA, and their combination. In contrast, trabecular density and attenuation were only affected by the presence of the disease but not by age. Also in RA, total trabecular and cortical density as determined by QCT significantly correlated with lumbar and/or femoral neck BMD as measured by DXA. Finally, anti-CCP seropositivity was associated with lower trabecular density and attenuation.

CONCLUSIONS

Both DXA and QCT may be suitable to study bone metabolism in RA. Areal BMD determined by DXA may correlate with volumetric bone density measured by QCT. Moreover, trabecular osteoporosis may be associated by the underlying autoimmune-inflammatory disease, while cortical osteoporosis may rather be age-related.

[Systemic sclerosis and pregnancy. A review of the current literature]

Pregnancy in women diagnosed with systemic sclerosis generally has a favorable outcome according to most recent studies. Women with systemic sclerosis who wish to become pregnant should achieve low disease activity for at least 6 months prior to conception. Regular follow-up of pregnant scleroderma patients by an interdisciplinary medical team including gynaecologists and rheumatologists is necessary to control disease activity and avoid possible complications. Severe organ involvement, early diffuse systemic sclerosis with rapid onset, and pulmonary hypertension ought to discourage patients from pregnancy, as these situations are at high risk of complications for both mother and fetus during pregnancy.

Genogroup I picobirnaviruses in pigs: evidence for genetic diversity and relatedness to human strains

Picobirnaviruses (PBVs) are small, non-enveloped viruses with a bisegmented double-stranded RNA genome. Their pathogenic potential, ecology, and evolutionary features are largely unexplored. Here, we describe the molecular analysis of porcine PBVs identified in the intestinal content of dead pigs. Six of 13 positive samples were cloned and then subjected to single-strand conformation polymorphism analysis and nucleotide sequencing. All clones belonged to genogroup I PBVs and almost all clones clustered on separate branches from human strains. A single strain shared a notably close genetic relationship with a Hungarian human PBV strain (89.9 nt and 96.4 % aa identity). Genetic diversity was also observed among strains identified in mixed infections. Single point mutations and deleterious mutations within highly related strains suggested that PBVs exist as quasispecies in the swine alimentary tract. Clones with complete sequence identities originating from different animals suggested effective animal-to-animal transmission of the virus. Our findings indicate that infection with genogroup I PBVs is common in pigs.