Immune factors are crucial in the pathogenesis of rheumatoid arthritis (RA), and immune cells play a key role in the development of RA. However, there is still disagreement regarding the specific roles of each type of immune cell in the pathological process of RA.

Takayasu arteritis (TA) and tuberculosis (TB) share similar histopathological and immunological characteristics. Studies comparing patients with TA with or without active or latent TB infection (LTBI) have revealed some differences in clinical and angiographic profiles. Patient with TA and history of TB exhibited more constitutional symptoms and structural damage to the aorta. This study compared the clinical and radiological features of patients with TA with and without active TB or LTBI.

Sarcopenia is a muscle disease characterized by reduction of muscle strength and muscle mass. In RA, 25.9 to 43.3% of the patients present sarcopenia. The loss of muscle mass observed in RA patients occurs either by activation of catabolic pathways or by inhibition of anabolic pathways. Despite having a list of drugs capable of treating RA inflammation, their effect on muscle is unclear. Our objective was to evaluate the tofacitinib effect on the muscle mass of collagen-induced arthritis (CIA) mice.

SARS-CoV-2 infection has become a major international issue, not only from a medical point of view, but also social, economic and political. Most of the available information comes from the United States, Europe, and China, where the population and the socioeconomic status are very different from Latin American countries. This study evaluates the effect of regional socioeconomic characteristics on mortality due SARS-CoV-2 infection in patients with immune-mediated rheumatic diseases (IMRD) from Argentina, Mexico and Brazil.

Systemic vasculitis is a group of rare diseases that share an essential characteristic: inflammation of blood vessel walls. This injury occurs during the disease course, but specific features vary for each entity. In this paper, we will address relevant aspects of the newest monogenic mutation vasculitis, such as deficiency of adenosine deaminase 2 (ADA2) and VEXAS syndrome (UBA1), and other relevant vasculitis, such as Cogan syndrome and Susac syndrome that may share some similarities with them.

Today, the prescription of tramadol in patients with osteoarthritis (OA) has increased significantly, which can be associated with serious consequences. Contradictory results have been reported regarding the association of tramadol versus codeine with the risk of all-cause mortality (ACM) and cardiovascular diseases (CVD).

Fibromyalgia is a non-inflammatory syndrome characterized by generalized muscle pain, with other symptoms. Numerous forms of physical training for this population have been studied through high-quality randomized clinical trials involving strength, flexibility, aerobic conditioning and multicomponent exercise interventions. This research evaluated the effectiveness of a functional exercise program at reducing pain, improving functional capacity, increasing muscle strength as well as improving flexibility, balance and quality of life in individuals with fibromyalgia.

Hand osteoarthritis (HOA) is a highly prevalent disease that may be impacted by social inequalities. Few studies in HOA are from underdeveloped regions. We intend to contribute to fill this gap presenting clinical characteristics of our low-income HOA cohort (LIHOA).

To evaluate the tuberculin skin test (TST) conversion in chronic inflammatory arthropathies (CIA) patients on TNFα inhibitors (TNFi) and without previous latent tuberculosis infection (LTBI) treatment.

Spondyloarthritis (SpA) encompasses a spectrum of immune-mediated inflammatory conditions primarily affecting the axial skeleton, including sacroiliitis and spondylitis, each with distinct features. This study aimed to investigate imaging disparities, focusing on sacroiliac magnetic resonance and spine radiography, across phenotypes and between males and females in axial SpA.

Amyloidosis is a localized or systemic disease caused by deposition of proteins in the extracellular space of various organs and tissues. As part of the disease, proteins that were originally soluble misfold and acquire a fibrillar conformation that renders them insoluble and resistant to proteolysis. Systemic amyloidosis is a rare, often underdiagnosed condition. In recent years, the incidence of newly diagnosed cases of amyloidosis has been increasing in association with the aging of the population and greater access to diagnostic tests. From a clinical perspective, systemic amyloidosis is frequently associated with involvement of the kidneys (causing nephrotic syndrome), heart (cardiac failure and arrhythmia), and peripheral nervous system (sensorimotor polyneuropathy and autonomic dysfunction). This condition is important to the rheumatologist for several reasons, such as its systemic involvement that mimics autoimmune rheumatic diseases, its musculoskeletal manifestations, which when recognized can allow the diagnosis of amyloidosis, and also because reactive or secondary AA amyloidosis is a complication of rheumatic inflammatory diseases. The treatment of amyloidosis depends on the type of amyloid protein involved. Early recognition of this rare disease is fundamental for improved clinical outcomes.

Ankylosing spondylitis (AS) has been known to have auto-inflammatory nature; hence, the efficacy of autoantibodies is low. However, studies on autoantibodies are ongoing, with some studies showing associations. Previous studies showed that anti-protein phosphatase magnesium-dependent 1A (PPM1A) IgG was increased in patients with AS and associated with radiographic progression. However, the diagnostic usefulness was limited due to relatively low sensitivity and specificity. This pilot study evaluated the diagnostic utility of anti-PPM1A-IgM and anti-PPM1A-IgG in patients with active AS.

Limited data exist on psoriatic arthritis (PsA) treatment in lower-income regions, particularly from the patient perspective. This study explores the challenges faced by socioeconomically vulnerable PsA patients and the reasons for non-adherence to treatment guidelines. The main objective of the study is to develop a questionnaire to identify the primary challenges in PsA treatment adherence and to analyze its feasibility while simultaneously understanding the target population's unique characteristics.

Gout is associated with several comorbidities. This study aimed to evaluate the prevalence of comorbidities in the Korean adult population with gout and investigated the association of gout with these comorbidities.

Psoriatic arthritis can involve several domains. Due to its multifaceted nature and its frequent comorbidities such as depression, obesity, osteoarthritis and fibromyalgia, it is difficult to monitor these patients because the clinical scores involve subjective data. High-resolution ultrasound probes allowed the evaluation of more superficial structures, such as the nails and their synovio-entheseal framework, in close relationship with the enthesis of the distal extensor digitorum tendon. Nail ultrasound studies vary in terms of the parameters and fingers studied and in their findings.

Exploring the effect of resilience and self-efficacy in mediating the chain between fatigue and quality of life(QOL) in patients with rheumatoid arthritis (RA).

Progranulin (PGRN) is a growth factor-like molecule with diverse roles in homeostatic and pathogenic processes including the control of immune and inflammatory responses. Pathogenic inflammation is a hallmark of systemic lupus erythematosus (SLE) and elevated serum levels of PGRN has been evaluated as a biomarker of disease activity in SLE. However, the role of PGRN in SLE has not been fully investigated. This study is aimed to determine the potential involvements of PGRN in SLE.

Although the terms "rare diseases" (RD) and "orphan diseases" (OD) are often used interchangeably, specific nuances in definitions should be noted to avoid misconception. RD are characterized by a low prevalence within the population, whereas OD are those inadequately recognized or even neglected by the medical community and drug companies. Despite their rarity, as our ability on discovering novel clinical phenotypes and improving diagnostic tools expand, RD will continue posing a real challenge for rheumatologists. Over the last decade, there has been a growing interest on elucidating mechanisms of rare autoimmune and autoinflammatory rheumatic diseases, allowing a better understanding of the role played by immune dysregulation on granulomatous, histiocytic, and hypereosinophilic disorders, just to name a few. This initiative enabled the rise of innovative targeted therapies for rheumatic RD. In this review, we explore the state-of-the art of rare RD and the critical role played by rheumatologists in healthcare. We also describe the challenges rheumatologists may face in the coming decades.