Background Rapid radiographic progression (RRP) leads to severe bone destruction in small joints. Meanwhile, there have been no reports about medium and large (M-L) sized joint destruction in patients with RRP.
Objectives To compare M-L sized joint destruction in RRP group with non-RRP group RA patients who have been treated with tocilizumab (TCZ) for 1 year.
Methods All patients took radiographs of both small and M-L sized joints. The modified total sharp score (mTSS) were assessed to find RRP (ΔmTSS/year>3). Twelve M-L sized joints (bilateral elbow, shoulder, hip, knee, ankle, and subtalar joints) per patients were radiographically assessed by the Larsen method (Grade 0–5). Eight RRP patients(96 joints) were compared with 17 non- RRP patients(204 joints) to estimate the amount of M-L sized joints destruction. The chi-squared test and the Wilcoxon test were used for the statistical analysis.
Results In 25 RA patients, the baseline characteristics (mean values) were: age: 58.8 years, disease duration: 84.4 months, pretrial biological treatment: 60%, concomitant MTX use: 72%, DAS28- ESR: 6.24, HAQ-DI: 1.78, mTSS: 65.7, mTSS/y before TCZ treatment: 10.1, M-L sized joint Larsen grade/joint: 1.36, M-L sized joint Larsen grade increased/y/joint: 0.34, RF: 100.7 IU/ml (72% positive), MMP-3: 513ng/ml and CRP: 6.42mg/dl. DAS28-ESR, HAQ-DI, ΔmTSS/year 1 year after TCZ treatment were 3.79, 1.22 and 2.91, respectively. Eight patients were in RRP group (ΔmTSS/y: 9.7) and 17 patients were in non-RRP group (ΔmTSS/y: -0.75). Between two groups, no statistically significant difference was observed in baseline M-L sized joint Larsen grade/joint. Among baseline clinical factors, only serum CRP (9.5mg/dl vs 5.0 mg/dl, p<0.05) and mTSS/year (14.9 vs 7.9, p<0.01) were significantly increased in RRP group. Out of t 204 M-L sized joints examined in non-RRP group, there was progression in 2 joints, 3 grades (knee, subtalar), and improvement in 4 joints, 4 grades (subtalar, elbow, shoulder, knee). Percentages of progression and improvement of joint destruction in patients with Larsen grade 0-2 was as same as 1.1% (2/178) for each and in patients with Larsen grade 3-4 was 0% (0/21) and 9.5% (2/21), respectively. Out of 96 M-L sized joints examined in RRP group, there was bone destruction progression in 7 joints as 9 grades (elbow, 2 subtalar, knee, 3 hip joints), and improvement in 5 joints as 5 grades (elbow, 2 ankle, 2subtalar ). The percentages of progression and improvement of joint destruction in patients with Larsen grade 0-2 were 5% (4/80) and 3.8% (3/80), respectively, while in patients with Larsen grade 3-4 were18.8% (3/16) and 12.5% (2/16), respectively. Progression of Larsen grades was statistically significant in RRP group (total, Larsen 3-4) in contrast with non-RRP group (p<0.05) and no statistically significant difference was observed for improvement of Larsen grade between both groups.
Conclusions RRP RA patients during 1 year TCZ treatment had high risk for joint damage, because of high serum CRP and mTSS/year at baseline. Progression of joint destruction was significantly observed in RRP groups compared with non-RRP group and mainly observed in large joints (knee, hip) in lower extremity.
Disclosure of Interest: None Declared