Combining Calcitonin and Procalcitonin and Rheumatoid Arthritis-Related Biomarkers Improve Diagnostic Outcomes in Early Rheumatoid Arthritis
Table 7
Evaluation of the diagnostic performance using single tests and test combinations.
Variable
Without PCT and CT
With PCT and CT
value
Sn/Sp
LR+/LR-
Sn/Sp
LR+/LR-
Early RA vs. all controls
RF
64.58/61.24
1.67/0.58
89.58/58.99
2.18/0.18
<0.01
Anti-CCP
81.58/76.97
3.54/0.24
92.11/62.92
2.48/0.13
>0.05
Anti-RA33
58.33/74.72
2.31/0.56
91.67/59.55
2.27/0.14
<0.05
RF and anti-CCP
86.84/50.56
1.76/0.26
92.11/62.36
2.45/0.13
<0.05
RF and anti-RA33
47.92/84.27
3.05/0.62
87.5/64.04
2.43/0.20
<0.01
Anti-CCP and anti-RA33
76.32/82.02
4.25/0.29
97.37/58.99
2.37/0.05
>0.05
Early RA vs. disease controls
RF
64.58/60.20
1.62/0.59
81.25/58.16
1.94/0.32
<0.01
Anti-CCP
81.58/96.94
26.65/0.19
89.47/54.08
1.95/0.19
<0.01
Anti-RA33
58.33/74.79
2.29/0.56
87.50/54.08
1.91/0.23
>0.05
RF and anti-CCP
92.11/66.33
2.74/0.12
89.47/54.08
1.95/0.19
>0.05
RF and anti-RA33
66.67/62.24
1.77/0.54
83.33/58.16
1.99/0.29
<0.01
Anti-CCP and anti-RA33
81.58/91.84
9.99/0.20
86.84/58.16
2.08/0.23
<0.05
Early RA vs. healthy
RF
33.33/100.00
—/0.67
83.33/100.00
—/0.17
<0.01
Anti-CCP
44.74/92.50
5.96/0.60
92.11/93.75
14.74/0.08
<0.01
Anti-RA33
58.33/75.00
2.33/0.56
87.50/91.25
10.00/0.14
<0.01
RF and anti-CCP
57.89/86.25
4.21/0.49
92.11/93.75
14.74/0.08
<0.01
RF and anti-RA33
50.00/96.25
13.33/0.52
83.33/100.00
—/0.17
<0.01
Anti-CCP and anti-RA33
63.16/78.75
2.97/0.47
92.11/95.00
18.42/0.08
<0.01
Could not be calculated because the specificity was 100.00. AUC: area under the receiver operating characteristic curve; LR: likelihood ratios; PPV/NPV: positive/negative predictive value; PCT: procalcitonin; CT: calcitonin; RF: rheumatoid factor; anti-CCP: anti-cyclic citrullinated peptide; anti-RA33: anti-RA33 antibodies.
