BACKGROUND: The relationship between inflammation and joint destruction in rheumatoid arthritis (RA) has not been unequivocally characterised. Joint destruction may result from the cumulative inflammatory burden over time, modified by an individual constant factor. OBJECTIVE: To test the hypothesis that the relationship between radiological progression and inflammation can mathematically be expressed as: [equation: see text] where Re is a factor that varies from person to person. METHODS: Clinical data and radiographs of 76 patients with early RA receiving different disease modifying antirheumatic drugs were analysed. Radiographs were quantified using the modified Larsen score and the "X-Ray RheumaCoach" software. The cumulative inflammatory burden was estimated by the time integrated 28 joint Disease Activity Score (DAS28), calculated as the area under the curve. RESULTS: 76 patients with early RA who started treatment with methotrexate (n = 20), sulfasalazine (n = 37), or oral gold (n = 19) monotherapy were evaluated. The mean (SEM) DAS28 decreased from 4.6 (0.1) at baseline to 2.3 (0.1) after 2 years. The mean (SEM) DeltaLarsen score from baseline to year 2 was 10.3 (1.5). Correlation between cumulative inflammation and radiographic change was poor. In contrast, when calculating a person's factor Re in year 1 ( Re 1) and year 2 ( Re 2), a strong and significant correlation (r = 0.58, p<0.000001) was seen between Re 1 and Re 2. CONCLUSIONS: Joint destruction is the result of the cumulative burden of inflammation over time, modified by an individual factor Re that remains relatively constant over the first 2 years of observation. The data support a mathematical model that expresses the interrelationship between inflammation and joint destruction.
BACKGROUND: The relationship between inflammation and joint destruction in rheumatoid arthritis (RA) has not been unequivocally characterised. Joint destruction may result from the cumulative inflammatory burden over time, modified by an individual constant factor. OBJECTIVE: To test the hypothesis that the relationship between radiological progression and inflammation can mathematically be expressed as: [equation: see text] where Re is a factor that varies from person to person. METHODS: Clinical data and radiographs of 76 patients with early RA receiving different disease modifying antirheumatic drugs were analysed. Radiographs were quantified using the modified Larsen score and the "X-Ray RheumaCoach" software. The cumulative inflammatory burden was estimated by the time integrated 28 joint Disease Activity Score (DAS28), calculated as the area under the curve. RESULTS: 76 patients with early RA who started treatment with methotrexate (n = 20), sulfasalazine (n = 37), or oral gold (n = 19) monotherapy were evaluated. The mean (SEM) DAS28 decreased from 4.6 (0.1) at baseline to 2.3 (0.1) after 2 years. The mean (SEM) DeltaLarsen score from baseline to year 2 was 10.3 (1.5). Correlation between cumulative inflammation and radiographic change was poor. In contrast, when calculating a person's factor Re in year 1 ( Re 1) and year 2 ( Re 2), a strong and significant correlation (r = 0.58, p<0.000001) was seen between Re 1 and Re 2. CONCLUSIONS: Joint destruction is the result of the cumulative burden of inflammation over time, modified by an individual factor Re that remains relatively constant over the first 2 years of observation. The data support a mathematical model that expresses the interrelationship between inflammation and joint destruction.
Authors: P E Lipsky; D M van der Heijde; E W St Clair; D E Furst; F C Breedveld; J R Kalden; J S Smolen; M Weisman; P Emery; M Feldmann; G R Harriman; R N Maini Journal: N Engl J Med Date: 2000-11-30 Impact factor: 91.245
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Authors: Philip G Conaghan; Philip O'Connor; Dennis McGonagle; Paul Astin; Richard J Wakefield; Wayne W Gibbon; Mark Quinn; Zunaid Karim; Michael J Green; Susanna Proudman; John Isaacs; Paul Emery Journal: Arthritis Rheum Date: 2003-01
Authors: Else N Kop; Janik Adriaansen; Tom J M Smeets; Margriet J Vervoordeldonk; René A W van Lier; Jörg Hamann; Paul P Tak Journal: Arthritis Res Ther Date: 2006 Impact factor: 5.156
Authors: Maria L E Andersson; Björn Svensson; Ingemar F Petersson; Ingiäld Hafström; Kristina Albertsson; Kristina Forslind; Dick Heinegård; Tore Saxne Journal: BMC Musculoskelet Disord Date: 2013-08-02 Impact factor: 2.362