Inflammation and rheumatoid arthritis

TLDR: Patients with RA are at increased risk for acute cardiovascular events, such as myocardial infarction, compared with the general population, and anti-citrullinated protein antibodies (ACPAs) are a valuable diagnostic test early in the course of the disease.

Abstract: Arthritis may be defined as inflammation of joints causing pain, swelling, and stiffness. Arthritis includes more than 100 types of conditions that affect joints and the surrounding tissues, as well as the connective tissue of the skin, bones, and muscles. The broad category of arthritis includes diseases that can be categorized as inflammatory, degenerative, metabolic, or infectious. Rheumatoid arthritis (RA) is the commonest form of chronic inflammatory arthritis, characterized by synovial inflammation and subsequent tissue damage. It affects approximately 1 % of the world’s population [19]. Hypertrophy and inflammation of the soft tissues around synovial joints are the common phenomenon occurring in RA. The etiology of RA is not known, but it is classified as one of the autoimmune diseases [10]. Abnormal cellular and humoral immune responses represent one of the hallmarks of RA. Autoantibodies, particularly rheumatoid factors (RFs) and antibodies directed against collagen type II are often present [31]. Anti-citrullinated protein antibodies (ACPAs) have recently emerged as sensitive and specific serological markers of RA, providing superior alternative of the RFs test in the laboratory diagnostics of RA. Since ACPAs are present before the onset of RA symptoms and are predictive of RA development, they are a valuable diagnostic test early in the course of the disease [2]. RA can strike at any age but the prevalence increase with age and peaking between the third and fifth decades [24, 73]. RA is much more common in women and affects women two to three times more frequently than men, and during pregnancy 70 % of women suffering from RA experience remission, with flare-ups after birth [55, 97]. Female sex, a positive family history, older age, and smoking are associated with an increased risk for developing RA. It has long been suggested that patients with RA, especially the more severe cases, have a shortened life expectancy compared with the general population [72]. Many studies have shown that deaths from infections, cardiovascular diseases (CVDs) and renal failure occur more frequently in patients with RA than in controls [44, 71]. It is now recognized that patients with RA are at increased risk for acute cardiovascular events, such as myocardial infarction, compared with the general population [43]. Indeed, the most common cause of death in RA is CVDs, accounting for more than 50 % of the mortality. Patients with RA also have a higher prevalence of acute cardiovascular events than patients with osteoarthritis, a joint disease not characterized by systemic inflammation [21]. The actual cause of RA is unknown. It has been suspected through various studies that RA is caused by genetic, environmental, and hormonal factors [100]. J Physiol Biochem (2013) 69:335–347 DOI 10.1007/s13105-012-0216-5