Osteoarthritis Phenotypes and Novel Therapeutic Targets.

Copyright © 2019 The Authors. Published by Elsevier Inc. All rights reserved.
Biochemical Pharmacology. 2019 Jul;37 doi: 10.1016/j.bcp.2019.02.037. Epub 2019 Mar 1.


The success of disease-modifying osteoarthritis drug (DMOAD) development is still elusive. While there have been successes in preclinical and early clinical studies, phase 3 clinical trials have failed so far and there is still no approved, widely available DMOAD on the market. The latest research suggests that, among other causes, poor trial outcomes might be explained by the fact that osteoarthritis (OA) is a heterogeneous disease with distinct phenotypes. OA trials might be more successful if they would address and target a specific phenotype. The increasing availability of advanced techniques to detect particular OA characteristics expands the possibilities to distinguish between such potential OA phenotypes. Magnetic resonance imaging is among the key imaging techniques to stratify and monitor patients with changes in bone, cartilage and inflammation. Biochemical markers have mainly used as secondary parameters and could further delineate phenotypes. Moreover, post-hoc analyses of trial data have suggested the existence of distinct pain phenotypes and their relevance in the design of clinical trials. Although ongoing work in the field supports the concept of OA heterogeneity, this has not yet resulted in more effective treatment options. This paper reviews the current knowledge about potential OA phenotypes and suggests that combining patient clinical data, quantitative imaging, biochemical markers and utilizing data-driven approaches in patient selection and efficacy assessment will allow for more successful development of effective DMOADs.

Synovial Cellular and Molecular Signatures Stratify Clinical Response to csDMARD Therapy and Predict Radiographic Progression in Early Rheumatoid Arthritis Patients

Copyright © Author(s) (or their employer(s)) 2019. Re-use permitted under CC BY. Published by BMJ.
Annals of the Rheumatic Diseases. 2019 Jun;78(6) doi: 10.1136/annrheumdis-2018-214539. Epub 2019 Mar 16.


To unravel the hierarchy of cellular/molecular pathways in the disease tissue of early, treatment-naïve rheumatoid arthritis (RA) patients and determine their relationship with clinical phenotypes and treatment response/outcomes longitudinally.
144 consecutive treatment-naïve early RA patients (<12 months symptoms duration) underwent ultrasound-guided synovial biopsy before and 6 months after disease-modifying antirheumatic drug (DMARD) initiation. Synovial biopsies were analysed for cellular (immunohistology) and molecular (NanoString) characteristics and results compared with clinical and imaging outcomes. Differential gene expression analysis and logistic regression were applied to define variables correlating with treatment response and predicting radiographic progression.
Cellular and molecular analyses of synovial tissue demonstrated for the first time in early RA the presence of three pathology groups: (1) lympho-myeloid dominated by the presence of B cells in addition to myeloid cells; (2) d iffuse-myeloid with myeloid lineage predominance but poor in B cells nd (3) pauci-immune characterised by scanty immune cells and prevalent stromal cells. Longitudinal correlation of molecular signatures demonstrated that elevation of myeloid- and lymphoid-associated gene expression strongly correlated with disease activity, acute phase reactants and DMARD response at 6 months. Furthermore, elevation of synovial lymphoid-associated genes correlated with autoantibody positivity and elevation of osteoclast-targeting genes predicting radiographic joint damage progression at 12 months. Patients with predominant pauci-immune pathology showed less severe disease activity and radiographic progression.
We demonstrate at disease presentation, prior to pathology modulation by therapy, the presence of specific cellular/molecular synovial signatures that delineate disease severity/progression and therapeutic response and may pave the way to more precise definition of RA taxonomy, therapeutic targeting and improved outcomes.

Imaging in Rheumatoid Arthritis: The Role of Magnetic Resonance Imaging and Computed Tomography.


In suspected and diagnosed rheumatoid arthritis (RA), magnetic resonance imaging (MRI) allows detection of all relevant pathologies, such as synovitis, tenosynovitis, bone marrow edema (osteitis), bone erosion and cartilage damage. MRI is more sensitive than clinical examination for monitoring disease activity (i.e., inflammation) and more sensitive than conventional radiography and ultrasonography for monitoring joint destruction. In suspected RA, MRI bone marrow edema predicts development of RA, and in early RA patients, it predicts subsequent structural damage progression. CT is the standard reference imaging modality for visualizing bone damage, including bone erosions in RA, but lacks sensitivity for soft-tissue changes, including synovitis and tenosynovitis. CT has a minimal role in RA clinical trials and practice, except in selected patients where MRI is contraindicated or not available or if crystal arthritis such as gout or pseudo-gout is suspected. MRI has documented utility in diagnosis, monitoring and prognostication of patients with RA and is increasingly used for these purposes in clinical practice and particularly clinical trials.