Table 2.

Diagnostic immunology markers in RA and non-RA patients and healthy controls.

Variables	Mean SD or frequency (%) of RA (n = 41)	Mean SD or frequency (%) of non-RA (n = 31)	Mean SD or frequency (%) of healthy controls (n = 29)
C-reactive protein
Negative	8 19.5	18 58.1	22 75.9
Positive	33 80.5	13 41.9	7 24.1
Rheumatoid factor
Negative	20 48.8	23 74.2	28 96.6
Positive	21 51.2	8 25.8	1 3.4
Anti-CCP antibody
Negative	15 36.6	27 87.1	28 96.55
Positive	26 63.4	4 12.9	1 3.4
Anti-RA33 antibody
Negative	38 92.7	30 96.7	28 96.6
Positive	3 7.3	1 3.2	1 3.4