Correlation of Serological Status with Disease Activity Score 28-Erythrocyte Sedimentation Rate Score in Elderly Patients with Rheumatoid Arthritis: A Cross-sectional Study

Abstract Background: Rheumatoid arthritis (RA) in the elderly is a clinically distinct entity with unique presenting features, serological profiles, and high disease burden. Elderly-onset RA (EORA), defined as RA with onset at or after 65 years, remains understudied in the Indian population despite its growing prevalence. Objective: To characterize the clinical profile of elderly RA patients and to evaluate the correlation between serological status and disease activity as measured by disease activity score 28-erythrocyte sedimentation rate (DAS28-ESR). Methodology: A cross-sectional observational study was conducted at a tertiary care centre enrolling 120 elderly patients (aged ≥60 years) diagnosed with RA by ACR/EULAR 2010 criteria. Clinical, laboratory, serological, and disease activity parameters were systematically recorded. Results: The mean age was 67.53 ± 6.047 years; 66.7% were female. Classical RA was the most common clinical form (70%), followed by polymyalgia rheumatica-like (25%) and remitting seronegative symmetrical synovitis with pitting edema (RS3PE)-like (5%), with a significant association between the RS3PE-like form and advancing age ( P = 0.005). Acute onset was observed in 70%. The shoulder was the most commonly involved joint (43.3%). Proximal interphalangeal joint involvement was significantly higher in YORA (37.9% vs. 14.8%; P = 0.007), whereas ankle joint involvement was significantly higher in EORA (27.8% vs. 7.6%; P = 0.006). Asymmetric joint involvement was significantly more common in EORA (66.7% vs. 42.4%; P = 0.010). RF positivity was 71.7%, anti-cyclic citrullinated peptide (CCP) 69.2%, and overall seropositivity 78.3%. Anti-CCP positivity was significantly associated with high disease activity ( P = 0.020), and overall seropositivity was significantly associated with disease activity category ( P = 0.033). Mean ESR was 56.41 ± 20.369 mm/h, C-reactive protein was 38.97 ± 19.467 mg/L, and hemoglobin was 11.86 ± 1.246 g/dL. The mean DAS28-ESR was 5.28 ± 0.857; 63.3% had high, and 34.2% had moderate disease activity. Hypertension (30%) and diabetes mellitus (18.3%) were the most prevalent comorbidities. Only 34.2% were on disease-modifying antirheumatic drugs (DMARDs) at enrollment. Conclusion: RA in the Indian elderly population is characterized by acute onset, large joint involvement, high serological positivity, elevated inflammatory markers, and predominantly high disease activity. Anti-CCP positivity is a significant predictor of high disease activity. The high comorbidity burden and suboptimal DMARD utilization underscore the need for early diagnosis and comprehensive multidisciplinary management.