Table 1.

Rheumatoid factor (RF) ELISA and anti-CCP antibodies in patients with established inflammatory diseases and with noninflammatory diagnoses.

	Female, %	Age, yrs, median (IQR)	RF ELISA Positive, %	Anti-CCP ELISA Positive, %	RF ELISA Positive and Anti-CCP ELISA Positive, %
WG, n = 10	70	62 (44.5–77)	0	0	0
SLE, n = 10	90	59 (34.5–74)	40	10	10
AS, n = 12	17	47 (37–50.5)	0	0	0
Inflammatory bowel disease, n = 10	50	62.5 (52–74.5)	30	20	10
Sarcoidosis, n = 10	30	48.5 (37.5–64)	10	0	0
OA, n = 10	60	60.5 (49–72)	10	0	0
Hyperlipidemia, n = 20	40	56 (47–60)	0	0	0
Seropositive RA, n = 22	57	70 (62.5–74)	100	86	86
Seronegative RA*, n = 20	70	62 (53.5–72)	15	25	10

^*Seronegative RA defined on the basis of RF tested by latex agglutination. WG: Wegener’s granulomatosis, SLE: systemic lupus erythematosus, AS: ankylosing spondylitis, OA: osteoarthritis; RA: rheumatoid arthritis.