ObjectivesWe investigated whether local joint swelling recurs in the same joints over time in patients with rheumatoid arthritis (RA) who are treated to target.MethodsPatients with newly diagnosed RA participating in the Behandel-Strategieën, “treatment strategies” (BeSt) study (n=508) were followed for median 10 years while receiving Disease Activity Score (DAS) ≤2.4 steered treatment. Every 3 months 68 joints were assessed for the presence of swelling. We evaluated whether baseline local joint swelling was predictive for swelling in the same joint during follow-up using a multilevel mixed-effect logistic regression model. Different strategies were used to account for missing data. A permutation test was performed to assess if joint swelling was better predicted by baseline swelling of the joint itself than by baseline swelling of randomly selected other joints.ResultsIn 46% of the joints that were swollen at baseline, joint swelling later recurred at least once during follow-up. Joint swelling at baseline was statistically significantly associated with swelling in the same joint during follow-up (OR 2.37, 95% CI 2.30 to 2.43, p<0.001), and also specifically with recurrent swelling in the same joint (OR 1.73, 95% CI 1.37 to 1.59, p<0.001). Local joint swelling was better predicted by baseline swelling of that particular joint than by baseline swelling of other joints (p<0.001).ConclusionJoint swelling tends to recur locally in the joints swollen at RA onset. This suggests that local factors influence the manifestation of joint inflammation over time.

Background: A challenge in imaging research is a diagnostic classification of study participants. We hypothesised that a structured approach would be efficient and that classification by medical students, residents, and an expert panel whenever necessary would be as valid as classification of all patients by experts. Methods: OPTIMACT is a randomised trial designed to evaluate the effectiveness of replacing chest x-ray for ultralow-dose chest computed tomography (CT) at the emergency department. We developed a handbook with diagnostic guidelines and randomly selected 240 cases from 2,418 participants enrolled in OPTIMACT. Each case was independently classified by two medical students and, if they disagreed, by the students and a resident in a consensus meeting. Cases without consensus and cases classified as complex were assessed by a panel of medical specialists. To evaluate the validity, 60 randomly selected cases not referred to the panel by the students and the residents were reassessed by the specialists. Results: Overall, the students and, if necessary, residents were able to assign a diagnosis in 183 of the 240 cases (76% concordance; 95% confidence interval [CI] 71-82%). We observed agreement between students and residents versus medical specialists in 50/60 cases (83% concordance; 95% CI 74-93%). Conclusions: A structured approach in which study participants are assigned diagnostic labels by assessors with increasing levels of medical experience was an efficient and valid classification method, limiting the workload for medical specialists. We presented a viable option for classifying study participants in large-scale imaging trials (Netherlands National Trial Register number NTR6163).

ObjectivesWe studied patterns of joint inflammation in juvenile idiopathic arthritis (JIA) to assess whether joint activity recurs locally in the same joints.MethodsJoints of 91 patients of the BeSt for Kids study, a treat-to-target trial for children with recent-onset oligoarticular, rheumatoid factor-negative polyarticular and psoriatic JIA, were clinically assessed during 2 years (10 study visits). The association between joint inflammation at baseline and later inflammation in the same joint was assessed using a multilevel mixed-effects logistic regression model at joint level. With a Poisson model, the association between baseline joint inflammation and the number of study visits at which the same joint was recurrently inflamed was tested.ResultsOf the 6097 joints studied, 15% (897) was clinically inflamed at baseline. In 42% (377/897) of those joints, inflammation recurred during follow-up. Joint inflammation at baseline was statistically significantly associated with joint inflammation during follow-up in the same joint (OR 3.9, 95% CI 3.5 to 4.4) and specifically with the number of episodes of recurrent joint inflammation (IRR 1.6, 95% CI 1.2 to 2.1).ConclusionIn JIA, joint inflammation has the tendency to recur multiple times in joints that are clinically inflamed at disease onset. This indicates that local factors might play a role in the processes contributing to the occurrence of JIA flares.

BackgroundInterstitial lung disease (ILD) is a spectrum of inflammatory and fibrotic lung diseases, and can be associated with RA (RA-ILD). The reported prevalence ranges from 1.8 to 58 percent, depending on the definition and diagnostics.ObjectivesTo investigate the incidence and prevalence of RA-ILD in different countries worldwide.MethodsPatients of 5 countries from 2 observational databases were studied. Patients from India, Mexico, South Africa (two clinics) and Colombia with a physician-based RA diagnosis were selected from the observational METEOR database. From the Leiden EAC in the Netherlands, patients with early RA (1987 ACR/ 2010 ACR/EULAR criteria) were included. A clinical diagnosis of RA-ILD was based on chest X-ray or CT. X-ray was performed at the first visit in India, South Africa and the Netherlands and on clinical indication in all countries.Prevalence of RA-ILD at the end of follow-up was calculated for each country. Incidence rates (IR) were calculated in patients with newly diagnosed RA and an available baseline visit. Patient characteristics were described, comparing patients with and without RA-ILD using appropriate statistical tests.ResultsWithin the five countries 16,667 patients with RA, both newly diagnosed and with longer RA disease duration, were evaluated. Prevalence and incidence of RA-ILD differed per country. The prevalence of RA-ILD at the end of follow-up was 0.7% (84/11,733) in India (mean follow-up 12±20 months), 2.1% (9/427) in Mexico (mean follow-up 17±27 months), 2.0% (21/1,077) in the Netherlands (mean follow-up 83±71 months), 3.0% (19/629) in South Africa (mean follow-up 20±21 months) and 0.7% (18/2,747) in Colombia (mean follow-up 14±12 months).The IR of RA-ILD in newly diagnosed RA patients in India was 1.6 (95% CI 1.0-2.5) per 1000 person years. In the Netherlands the IR was 3.8 (95% CI 1.6-9.1) per 1000 person years. In South Africa the IR was 6.6 (95% CI 2.5-17.5) per 1000 person years. For Mexico and Colombia, no IR could be calculated.Patient characteristics are described in Table 1. In India and Mexico, patients with RA-ILD were older. In 4 of 5 countries RA-ILD patients were more often male. Higher inflammatory markers and more RF positivity were seen in RA-ILD patients in India and the Netherlands. In South Africa, patients with RA-ILD more often had a history of smoking. ACPA positivity was more frequent in RA-ILD patients from India, but less frequent in RA-ILD patients from South Africa.Table 1.Patient characteristics at the first available visitIndiaMexicoSouth AfricaNetherlandsColombiaRA-ILD (n=84)no RA-ILD (n=11,703)RA-ILD (n=9)no RA-ILD (n=418)RA-ILD (n=19)no RA-ILD (n=610)RA-ILD (n=21)no RA-ILD (n=1,077)RA-ILD (n=18)no RA-ILD (n=2,729)Age (years)57.9±10.646.6±15.362.1±13.352.7±12.652.8±10.250.5±12.857.4±9.255.8±14.561.2 (15.9)59.1 (13.6)p<0.0010.0270.420.600.50Symptom duration (months)47.9(18.0-95.9)59.9(23.9-143.9)108.4(49.3-206.8)68.2(46.7-159.6)25.0(8.3-58.4)45.3(13.1-92.5)4.0(1.9-7.8)4.0(1.6-8.0)89.1(37.9-180.9)111.2(67.6-140.6)p value0.0290.320.180.980.38Sex (female)77%85%67%90%84%82%48%68%78%89%p0.0430.0270.840.0550.12Ever smoker3%1%11%13%93%28%65%62%*p0.270.89<0.0010.81DAS286.3±1.36.0±1.44.5±1.74.6±1.44.9±0.95.2±1.45.2±0.75.1±1.3*p0.110.840.540.80ESR (mm/h)91.5±29.976.7±32.830.7±16.69.0±13.345.0±22.837.1±28.844.3±23.532.0±25.3*p<0.0010.770.260.027Patient global assessment51.2±21.053.8±18.327.8±31.144.6±27.842.6±12.060.1±24.931.5±26.441.1±25.322.2±19.331.0±21.5p0.260.0750.0040.110.084ACPA positive94%81%*83%96%62%54%*p value0.0110.0080.45RF positive95%83%*94%98%86%57%*p0.0030.310.009Data are presented as mean±SD, median (IQR), %.*Insufficient data availableConclusionPrevalence and incidence of RA-ILD varied between the four countries with the highest prevalence and incidence in South Africa. These differences might be partially explained by differences in diagnostic approaches, and potentially in patient populations, used therapies and comorbidity.REFERENCES:NIL.Acknowledgements:NIL.Disclosure of InterestsSascha L Heckert Grant/research support from: Bristol-Myers Squibb (BMS), Tjardo Maarseveen: None declared, Emiel R Marges: None declared, Arvind Chopra: None declared, David Vega-Morales: None declared, Riette du Toit: None declared, Lai-Ling Winchow: None declared, Carlos Enrique Toro Gutierrez: None declared, Rachel Knevel: None declared, Annette van der Helm – van Mil: None declared, Thomas Huizinga: None declared, Cornelia Allaart: None declared, Sytske Anne Bergstra: None declared.