Late Onset Rheumatoid Arthritis.

Area of Science:

• Rheumatology and Immunology

Background:

• Late-onset rheumatoid arthritis (LORA) is defined as rheumatoid arthritis (RA) with onset after age 60/65.
• LORA exhibits distinct immunological profiles and clinical characteristics compared to young-onset RA (YORA).

Purpose of the Study:

• To delineate the immunological, clinical, and management differences between LORA and YORA.
• To highlight the increased risks of complications and comorbidities in LORA patients.

Main Methods:

• Comparative analysis of immune cell populations (macrophages, NK cells, T cells) and genetic factors (HLA alleles) in LORA versus YORA.
• Review of treatment strategies and associated risks, including infections and comorbidities.

Main Results:

• LORA shows altered frequencies of specific HLA alleles, increased M1 macrophages and CD56dim NK cells, and reduced M2 macrophages and CD56bright NK cells.
• Elevated age-related B cells, impaired DNA repair, altered T cell ratios (CD4+/CD8+), and increased CD28- T cells are noted in LORA.
• LORA patients face higher risks of articular/extra-articular complications, cardiovascular disease, fractures, malignancy, and geriatric syndromes.

Conclusions:

• Immunosenescence significantly influences the immune response in LORA, contributing to disease severity and complications.
• Treatment with disease-modifying antirheumatic drugs (DMARDs) in LORA requires careful dosage adjustment, particularly methotrexate, due to renal function.
• Biologic DMARDs are used cautiously in LORA due to heightened infection risks, and comprehensive management of comorbidities is crucial.