Four Janus kinases (JAKs) (JAK1, JAK2, JAK3, TYK2) and seven signal transducers and activators of transcription (STATs) (STAT1, STAT2, STAT3, STAT4, STAT5A, STAT5B, STAT6) mediate the signal transduction of more than 50 cytokines and growth factors in many different cell types. Located intracellularly and downstream of cytokine receptors, JAKs integrate and balance the actions of various signaling pathways. With distinct panels of STAT-sensitive genes in different tissues, this highly heterogeneous system has broad in vivo functions playing a crucial role in the immune system. Thus, the JAK/STAT pathway is critical for resisting infection, maintaining immune tolerance, and enforcing barrier functions and immune surveillance against cancer. Breakdowns of this system and/or increased signal transduction may lead to autoimmunity and other diseases. Accordingly, the recent development and approval of the first small synthetic molecules targeting JAK molecules have opened new therapeutic avenues of potentially broad therapeutic relevance. Extensive data are now available regarding the JAK/STAT pathway in rheumatoid arthritis. Dysregulation of the cytokines is also a hallmark of systemic lupus erythematosus (SLE), and targeting the JAK/STAT proteins allows simultaneous suppression of multiple cytokines. Evidence from in vitro studies and animal models supports a pivotal role also in the pathogenesis of cutaneous lupus and SLE. This has important therapeutic implications, given the current paucity of targeted therapies especially in the latter. Herein, we summarize the currently available literature in experimental SLE, which has led to the recent promising Phase II clinical trial of a JAK inhibitor.
1 October 2017 in Seminars in Arthritis and Rheumatism
Rheumatoid arthritis (RA) is an immune-mediated chronic and long-term condition that can lead to severe joint damage and disability. It has been shown that doctor–patient interaction and communication can have a significant impact on faster patient diagnosis and treatment outcomes. Primary care (PC) is the first level of patient contact with doctors and the health system. Communication between them is often ineffective, leading to delays in diagnosis, care, and the use of disease-modifying antirheumatic drugs (DMARDs). The protocols and standards for the treatment of RA are well established by all rheumatology organizations. All of them recommend early initiation of DMARDs, which leads to better long-term outcomes. There are some recommendations that would lead to better optimization of recognition, management, and referral practices. Early diagnosis, effective communication between general practitioners and specialists, and patient education about possible targeted therapies and biological products, as well as subsequent monitoring of therapies and screening for risk factors and comorbidities, will improve patient health and optimize costs. We aimed to offer strategies and possibilities for integrating and optimizing primary care and specialized therapies in RA because proper management will reduce the severity of the disease and even reduce mortality from chronic diseases such as RA.