Table 1.

Patient characteristics of synovial fluid samples. Control samples were obtained from orthopedic procedures.

Characteristic	Oligo (n=33)	Poly (n=14)	Systemic (n=11)	Control (n=10)
Age, years	9.6 + 4.4 *	13.1 + 5.6	12.5 + 4.1	N/A
Sex, no (%)
Male	6 (18)	5 (36)**	6 (54)	8 (80)
Female	27 (82)	9 (64)**	5 (45)	2 (20) #
Disease Duration, years	4.1 + 4.7	7.7 + 3.5	6.9 + 5.7	N/A
ANA status, no (%)
positive	17 (52)	5 (36)	1 (9)	N/A
negative	14 (42)	8 (57)	8 (73)	N/A
unknown	1 (3)	1 (7)	2 (18)
Rf status, no (%)
positive	0	1 (7)	1 (9)	N/A
negative	20 (61)	7 (50)	5 (45)	N/A
unknown	13 (39)	6 (43)	5 (45)
Treatment at time of procedure, no (%)				N/A
None	2 (6)	3 (21)	1 (9)
Non-steroidals	31 (94)	7 (50)	4 (36)
Methotrexate	1 (3)	2 (14)	4 (36)
Sulfasalazine	1 (3)	4 (28)	0
Plaquenil	2 (6)	3 (21)	0
Prednisone	0	0	1 (9)
Leflunomide	0	1 (7)	0
Gold	0	1 (7)	0
Biologics	0	2 (14)	1 (9)

Each subtype was pooled into a single sample for the analyses. Student’s T-test used for comparison between individual groups. No significant differences between the groups except as indicated:

^*P<.05 for comparison between oligoarticular vs polyarticular,

^**P<.05 for comparison between systemic versus oligoarticular,

^#P<.05 for comparison between oligoarticular versus control.

JIA = Juvenile Idiopathic Arthritis, N/A = data not available.