Clinical and Sonographic Pattern of Late-Onset and Early-Onset Rheumatoid Arthritis: Comparative Study

Late-onset rheumatoid arthritis (LORA) poses a great challenge for physicians regarding diagnosis and treatment. The prognosis for LORA was better in some early research but worse in more recent trials.

The study aim was to compare the clinical, laboratory, and radiological characteristics assessed by musculoskeletal ultrasound (MSUS) of patients with LORA and early-onset rheumatoid arthritis (EORA) and to examine their associations with inflammation and treatment outcomes.

The study included 64 RA with EORA and 64 RA patients with LORA, fulfilling the American College of Rheumatology/European League Against Rheumatism (ACR/EULAR) 2010 criteria for RA.

Medical history, Health Assessment Questionnaire Disability Index (HAQ-DI), DAS 28 score, laboratory investigations, and MSUS of both hands and wrist joints were done.

Female patients with EORA were more compared with those with LORA (89% vs 78.1%). Comorbidities were significantly more prevalent in the LORA group (28.12%) compared with the EORA group (10.9%) (P = .0143). A significant difference was also observed between the 2 groups regarding higher ESR values in LORA, with no significant difference detected in C-reactive protein (CRP) levels. Regarding joint involvement, shoulder, metatarsophalangeal (MTP), and knee joints were more frequently affected in LORA, with statistically significant differences (P < .0001, .0119, and .0285, respectively). The MSUS findings revealed higher gray-scale grades in patients with LORA, with significantly increased Doppler signal activity (P < .052), and a greater frequency of erosions compared with those with EORA. The mean HAQ-DI score was significantly higher in LORA than in EORA (P = .0004). Regarding treatment patterns, methotrexate (MTX) was more commonly prescribed in the EORA group (67.1%) compared with the LORA group (37.5%), whereas leflunomide was used more in LORA (68.75%) compared with EORA (46.8%), with statistically significant difference.

Patients with LORA demonstrated more active synovitis and a higher frequency of erosions compared with those with EORA, despite the non-significant difference in DAS 28 scores. Moreover, patients with LORA exhibited a greater burden of comorbidities than those with EORA. Therefore, regular evaluation of inflammatory activity using MSUS, along with assessment of associated comorbid conditions, is recommended in patients with LORA.