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.

Frequency, mutual exclusivity and clinical associations of myositis autoantibodies in a combined European cohort of idiopathic inflammatory myopathy patients.

OBJECTIVES: To determine prevalence and co-existence of myositis specific autoantibodies (MSAs) and myositis associated autoantibodies (MAAs) and associated clinical characteristics in a large cohort of idiopathic inflammatory myopathy (IIM) patients. METHODS: Adult patients with confirmed IIM recruited to the EuroMyositis registry (n = 1637) from four centres were investigated for the presence of MSAs/MAAs by radiolabelled-immunoprecipitation, with confirmation of anti-MDA5 and anti-NXP2 by ELISA. Clinical associations for each autoantibody were calculated for 1483 patients with a single or no known autoantibody by global linear regression modelling. RESULTS: MSAs/MAAs were found in 61.5% of patients, with 84.7% of autoantibody positive patients having a sole specificity, and only three cases (0.2%) having more than one MSA. The most frequently detected autoantibody was anti-Jo-1 (18.7%), with a further 21 specificities each found in 0.2-7.9% of patients. Autoantibodies to Mi-2, SAE, TIF1, NXP2, MDA5, PMScl and the non-Jo-1 tRNA-synthetases were strongly associated (p < 0.001) with cutaneous involvement. Anti-TIF1 and anti-Mi-2 positive patients had an increased risk of malignancy (OR 4.67 and 2.50 respectively), and anti-SRP patients had a greater likelihood of cardiac involvement (OR 4.15). Interstitial lung disease was strongly associated with the anti-tRNA synthetases, anti-MDA5, and anti-U1RNP/Sm. Overlap disease was strongly associated with anti-PMScl, anti-Ku, anti-U1RNP/Sm and anti-Ro60. Absence of MSA/MAA was negatively associated with extra-muscular manifestations. CONCLUSIONS: Myositis autoantibodies are present in the majority of patients with IIM and identify distinct clinical subsets. Furthermore, MSAs are nearly always mutually exclusive endorsing their credentials as valuable disease biomarkers.

[Dermatomyositis-specific antibodies]. / Dermatomyositisspezifische Antikörper.

BACKGROUND: Idiopathic inflammatory myopathies are chronic systemic autoimmune diseases characterized by symmetrical proximal muscle weakness. The clinicopathological subdivision nowadays appears to be obsolete which is why the immunoserological classification has been developed. OBJECTIVES: Dermatomyositis represents one the most important subsets of idiopathic inflammatory myopathy and dermatomyositis-specific autoantibodies play a significant role in this subset. The aim of this article was to present these autoantibodies with the help of the literature. METHODS: This article presents the most important information about dermatomyositis including not only the classical anti-Mi-2 autoantibody but also the recently detected anti-TIF1γ, anti-NXP2, anti-SAE and anti-MDA5 autoantibodies. The focus is on the frequency of these autoantibodies, the associated symptoms in adult and juvenile dermatomyositis cases and some special aspects from the literature. RESULTS: All of the studies confirmed that these autoantibodies are particularly detectable in dermatomyositis. The results from the literature have recently shown that the frequency of the autoantibodies detected in juvenile cases is higher than the frequency of traditional autoantibodies (e.g. anti-Jo-1, anti-Mi-2 and anti-SRP). CONCLUSION: It is useful to detect these autoantibodies in order to be able to make a better assessment of the clinical symptoms and prognosis during the course of the disease.

Rare myositis-specific autoantibody associations among Hungarian patients with idiopathic inflammatory myopathy.

Idiopathic inflammatory myopathies are systemic, chronic autoimmune diseases characterized by symmetrical, proximal muscle weakness. Homogeneous groups present with similar symptoms. The response to therapy and prognosis could be facilitated by myositis-specific autoantibodies, and in this way, give rise to immunoserological classification. The myositis-specific autoantibodies are directed against specific proteins found in the cytoplasm or in the nucleus of the cells. To date, literature suggests the rarity of the co-existence of two myositis-specific autoantibodies. In this study the authors highlight rare associations of myositis-specific autoantibodies. Three hundred and thirty-seven Hungarian patients with polymyositis or dermatomyositis were studied. Their clinical findings were noted retrospectively. Specific blood tests identified six patients with the rare co-existence of myositis-specific autoantibodies, anti-Jo-1 and anti-SRP, anti-Jo-1 and anti-Mi-2, anti-Mi-2 and anti-PL-12, anti-Mi-2 and anti-SRP, and anti-SRP and anti-PL-7, respectively. This case review aims to identify the clinical importance of these rare associations and their place within the immunoserological classification.