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Table 5 Sensitivity, Specificity, and PPV of anti-citrullinated antibodies and RF isotypes for the overall JIA population and JIA subtypes

From: Evidence of fibrinogen as a target of citrullination in IgM rheumatoid factor-positive polyarticular juvenile idiopathic arthritis

 

Sensitivity (%)

With 95%CI

Specificity (%)

With 95% CI

PPV (%)

With 95% CI

Anti-Citrullinated Fibrinogen Antibodies (> 0.59OD)

   

   Overall

32.3 (23.3-42.7)

84.2 (59.5-95.8)

91.2 (75.2-97.7)

   Poly RF-positive

81.3 (53.7-95.0)

78.8 (69.2-86.1)

38.2 (22.7-56.4)

   Poly RF-negative

30.6 (16.9-48.3)

70.9 (59.4-80.3)

32.4 (18.0-50.6)

   Oligoarthritis

24.0 (10.2-45.5)

68.9 (58.1-78.0)

17.6 (7.4-35.0)

   Systemic-Onset

7.7 (0.4-37.9)

67.6 (57.6-76.4)

29.4 (0.1-17.1)

Anti-Citrullinated α-Enolase Antibodies (> 0.91OD)

   

   Overall

9.4 (4.6-17.5)

57.9 (34.0-78.9)

52.9 (28.5-76.1)

   Poly RF-positive

18.8 (5.0-46.3)

85.9 (77.1-91.8)

17.6 (4.6-44.2)

   Poly RF-negative

5.6 (1.0-20.0)

70.9 (59.4-80.3)

11.8 (2.1-37.7)

   Oligoarthritis

0

81.1 (71.2-88.3)

0

   Systemic-Onset

7.7 (0.4-37.9)

84.3 (75.5-90.5)

5.9 (0.3-31.0)

IgG anti-CCP antibodies (> 20U)

   

   Overall

14.6 (8.5-23.6)

94.7 (71.9-99.7)

93.3 (66.0-99.7)

   Poly RF-positive

56.3 (30.6-79.2)

93.9 (86.8-97.5)

60.0 (32.9-82.5)

   Poly RF-negative

13.9 (5.2-30.3)

87.3 (77.5-93.4)

33.3 (13.0-61.3)

   Oligoarthritis

0

83.3 (73.7-90.0)

0

   Systemic-Onset

0

85.3 (76.6-91.2)

0

IgA anti-CCP antibodies (> 0.16OD)

   

   Overall

10.4 (5.4-18.7)

84.2 (59.5-95.8)

76.9 (46.0-93.8)

   Poly RF-positive

25.0 (8.3-52.6)

90.9 (83.0-95.5)

30.8 (10.3-61.1)

   Poly RF-negative

16.7 (6.9-33.5)

91.1 (82.0-96.1)

46.2 (20.4-73.9)

   Oligoarthritis

0

85.6 (76.2-91.8)

0

   Systemic-Onset

0

87.3 (78.8-92.8)

0

IgM Anti-CCP Antibodies (> 0.45OD)

   

   Overall

16.7 (10.1-26.0)

73.7 (48.6-89.9)

76.2 (52.5-90.9)

   Poly RF-positive

31.3 (12.1-58.5)

83.8 (74.8-90.2)

23.8 (9.1-47.5)

   Poly RF-negative

16.7 (6.9-33.5)

91.1 (82.0-96.1)

46.2 (20.4-73.9)

   Oligoarthritis

0

76.7 (66.3-84.7)

0

   Systemic-Onset

7.7 (0.4-37.9)

80.4 (71.1-87.3)

4.8 (0.2-25.9)

IgA RF (> 6U)

   

   Overall

15.6 (9.3-24.8)

84.2 (59.5-95.8)

83.3 (57.7-95.6)

   Poly RF-positive

62.5 (35.9-83.7)

91.9 (84.2-96.2)

55.6 (31.3-77.6)

   Poly RF-negative

11.1 (3.6-27.0)

82.2 (71.7-89.6)

22.2 (7.4-48.1)

   Oligoarthritis

0

80.0 (70.0-87.4)

0

   Systemic-Onset

7.7 (0.4-37.9)

83.3 (74.4-89.7)

5.6 (0.3-29.4)

IgM RF (> 6U)

   

   Overall

47.9 (37.7-58.3)

63.1 (38.6-82.8)

86.8 (74.0-94.1)

   Poly RF-positive

100.0 (75.9-100.0)

62.6 (52.3-72.0)

30.2 (18.7-44.5)

   Poly RF-negative

47.2 (30.8-64.7)

54.4 (42.9-65.5)

32.1 (20.3-46.4)

   Oligoarthritis

20.0 (7.6-41.3)

46.7 (36.2-57.4)

9.4 (3.5-21.4)

   Systemic-Onset

61.5 (32.3-84.9)

55.9 (45.7-65.6)

15.1 (7.2-28.1)

  1. Anti-CCP antibodies: anti-cyclic citrullinated peptide antibodies; OD: optical density; CI: confidence interval; PPV: positive predictive value; RF: rheumatoid factor; U: units. Subtypes with small sample size were not included in the subtype analysis.