Comparative analysis of the clinical characteristics of elderly onset rheumatoid arthritis and elderly onset rheumatoid arthritis with osteoarthritis

Abstract

Objective To compare the clinical features, ultrasonic imaging manifestations and therapeutic evaluations between elderly onset rheumatoid arthritis (EORA) and EORA with osteoarthritis (OA). Methods Eighty-eight patients with rheumatoid arthritis were divided into two groups: group EORA (n=36) and group EORA+OA (n=52). The onset age of all patients was 60 years or older. General conditions, joint involvement distribution, ultrasonic manifestations and disease activity scores (DAS28-3) of patients in the two groups were analyzed. The χ2 test/Fisher's exact probability test and the Student's t test/Mann-Whitney U test were used to analyze data. Results There was no significant difference in the proportion of male and female patients and erythrocyte sedimentation rate (ESR) between the two groups (P>0.05). The onset age of patients in group EORA+OA [(68±4) years old] was higher than that in group EORA [(65±4) years old], and the difference was statistically significant (t=-3.465, P=0.001). Duration of the disease and body mass index in group EORA+OA were significantly higher respectively than those in group EORA. Joint involvement in the two groups was mainly found in shoulder, wrist, Metacarpophalangeal joint (MCP)2, MCP3, proximal inter-phalangeal joint (PIP)2, PIP3, PIP4, and knee joint (34.7%-86.5%). The percentage of MCP2[36.5%(38/104), 70.8%(51/72); χ2=20.02, P<0.01], MCP3[33.7%(35/104), 59.7%(43/72); χ2=11.72, P=0.001], MCP4[4.8%(5/104), 22.2%(16/72); χ2=12.28, P<0.01], PIP2[69.2%(72/104), 83.3%(60/72); χ2=4.51, P=0.034] and PIP3[53.8%(56/104), 70.8%(51/72); χ2=5.15, P=0.023] in the EORA+OA group was lower while the percentage of MCP1, DIP 2, DIP3, DIP4 and knee joints were higher than that in the EORA group (P<0.05). In group EORA+OA, the synovial thickness of the wrist joints [(4.2±0.5) mm] and knee joints [(7.7±0.8) mm] were significantly thicker than those in group EORA [(3.2±0.9) mm; (6.3±0.8) mm, t=-5.82, P<0.01; t=-7.22, P<0.01]; The proportion (70.0%) of level 2 and 3 of patients' wrist joint synovium pannus blood flow and knee joint synovium pannus in group EORA+OA were increased than group EORA (51.9%; 52.3%), the difference between the two groups was statistically significant (χ2=4.64, P=0.031; χ2=4.43, P=0.035). There was no significant difference in DAS28-3 scores between the two groups before patients received treatment. After 2 weeks and 12 weeks of glucocorticoid treatment, DAS28-3 scores in group EORA [3.62(2.88, 4.03); 2.35(2.26, 2.62) points] were significantly lower than group EORA+OA [5.01(4.68, 5.26); 3.38(2.28, 3.83) points] (Z=-7.766, P<0.01; Z=-3.461, P<0.01). Conclusion Compared with patients of EORA alone, patients of EORA with OA have more obvious joint symptoms, MCP1, DIP and knee joint are susceptible to the co-involvement among them, longer duration of disease, and were prone to synovial hyperplasia and pannus flow formation. The therapeutic effects of glucocorticoid on joint inflammation in patients of EORA alone are superior to those patients of EORA with OA. Key words: Aged; Arthritis, rheumatoid; Osteoarthritis; Symptoms and signs