Table 1 Patient characteristics of investigated cases

Female, no (%)

143/181 patients (79.0%)

27/37 patients (73.0%)

Age at diagnosis (median, range)

4.8 years (1.1 -16.3)

4.61 years (1.06 -15.47)

Antinuclear antibodies

134/181 patients (74.0%)

22/37 patients (59.4%)

Disease duration at time of testing

14 months (0–170)

n/a

Diagnosis

  oligoarthritis, persistent

75/181 (41.4%)

9/37 (24.3%)

  oligoarthritis, extended

31/181 (17.2%)

10/37 (27.0%)

  rheumatoid factor negative polyarthritis

75/181 (41.4%)

18/37 (48.6%)

Total active joint count (TAJC) (mean, standard deviation)

  oligoarthritis, persistent

1.17 ± 1,66^a

0.86 ± 1,17^a

  oligoarthritis, extended

1.98 ± 3.41^a

1,44 ± 1.88^a

  rheumatoid factor negative polyarthritis

4.53 ± 7.65^a

3.09 ± 7.22^a

cJADAS27 (mean, standard deviation)

  oligoarthritis, persistent

0.93 ± 1.19^a

3.47 ± 4.02^a

  oligoarthritis, extended

1.50 ± 2.60^a

5,37 ± 4.81^a

  rheumatoid factor negative polyarthritis

2.79 ± 4.35^a

5.42 ± 7.01^a