Late Onset Rheumatoid Arthritis

Late-onset rheumatoid arthritis (LORA) refers to rheumatoid arthritis (RA) with initial symptoms and signs appearing after the age of 60 or 65. A higher frequency of HLA-DRB1*01:01, *04:03, and *14:02 alleles and a lower frequency of HLA-DRB1*04 are observed in patients with LORA compared to young-onset RA (YORA). Due to immunosenescence, the immune response in LORA differs from that in YORA. Specifically, in LORA, there is an increase in M1 macrophages and CD56^dim NK cells, whereas the numbers of M2 macrophages, Mer proto-oncogene tyrosine kinase, and CD56^bright NK cells are reduced. Elevated levels of age-related B cells in older individuals may contribute to more swollen and tender joints, as well as higher disease severity scores in LORA than in YORA. Additionally, impaired DNA repair mechanisms, an increased ratio of CD4⁺/CD8⁺ T cells, and elevated CD28^- T cells may contribute to a higher risk of both articular and extra-articular complications in LORA. Conventional disease-modifying antirheumatic drugs (DMARDs) used in LORA are similar to those used in YORA. Methotrexate is often the first choice for LORA; however, the dosage should be adjusted according to renal function. Biologic DMARDs is used less frequently in LORA than in YORA, as patients with LORA may be at a higher risk for serious infections. Furthermore, patients with LORA are at an increased risk of cardiovascular disease, fragility fractures, and malignancy compared to those with YORA; they also exhibit a higher prevalence of geriatric syndrome features. Furthermore, the use of antirheumatoid drugs can influence geriatric syndromes.