New Provisional Classification of Juvenile Idiopathic Arthritis Applying Rheumatoid Factor and Antinuclear Antibody

Hyuck Jin Kwon; Myung Hoon Bang; Kwang Nam Kim

doi:10.4078/jrd.2018.25.1.34

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Kwon, Bang, and Kim: New Provisional Classification of Juvenile Idiopathic Arthritis Applying Rheumatoid Factor and Antinuclear Antibody

Original Article

J Rheum Dis 2018;25(1):34-46.

Published online: 31 October 2018

DOI: https://doi.org/10.4078/jrd.2018.25.1.34

New Provisional Classification of Juvenile Idiopathic Arthritis Applying Rheumatoid Factor and Antinuclear Antibody

Hyuck Jin Kwon, Myung Hoon Bang, Kwang Nam Kim

Department of Pediatrics, Hallym University Sacred Heart Hospital, Anyang, Korea

Corresponding to: Kwang Nam Kim, Department of Pediatrics, Hallym University Sacred Heart Hospital, 22 Gwanpyeong-ro 170beon-gil, Dongan-gu, Anyang 14068, Korea. E-mail: kwangnamkim@naver.com

Received 25 August 2017 Revised 28 September 2017 Accepted 16 October 2017

This is a Open Access article, which permits unrestricted non-commerical use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Objective

Previous classification systems for juvenile idiopathic arthritis (JIA) were based on the number of joints involved and did not categorize homogenous disease entities. Therefore, JIA patients were reclassified retrospectively by applying rheumatoid factor (RF) and antinuclear antibody (ANA), which have been proven to constitute a homogenous disease entity.

Methods

The medical records of JIA patients were investigated retrospectively and reclassified into six categories using the new provisional classification. The nomenclature was based on Dr. Martini's proposal in the 23rd European Paediatric Rheumatology Congress (2016) at Genoa, Italy. New categories included systemic JIA (sJIA), RF-positive JIA (RF-JIA), early-onset ANA-positive JIA (eoANA-JIA), enthesitis/spondylitis-related JIA (ESR-JIA), “other JIA”, and “unclassified JIA”.

Results

Of a total of 262 JIA patients, 71 (27.1%) were reclassified as sJIA, 31 (11.8%) as RF-JIA, 22 (8.4%) as eoANA-JIA, 63 (24.0%) as ESR-JIA, 65 (24.8%) as “other JIA”, and 10 (3.8%) as “unclassified JIA”. A comparison of RF-JIA, eoANA-JIA, and ESR-JIA revealed significant differences in the gender ratio, age of disease onset, and the cumulative number and type of joints involved among the three groups. “Other JIA” comprised a significant proportion (24.8%) and warrants the need for further classification. The characteristics of the RF-positive patients were comparable to those of the anti-cyclic citrullinated peptide antibody-positive patients. The ANA positivity was lower (28.2%) than that in Western studies but showed similar clinical features.

Conclusion

This is the first study applying RF and ANA to classify JIA without considering the joint counts. The six new categories include sJIA, RF-JIA, eoANA-JIA, ESR-JIA, “other JIA,” and “unclassified JIA”.

Keywords: Juvenile idiopathic arthritis, Classification, Rheumatoid factor, Antinuclear antibody

REFERENCES

1. Fink CW. Proposal for the development of classification criteria for idiopathic arthritides of childhood. J Rheumatol. 1995; 22:1566–9.

2. Petty RE, Southwood TR, Baum J, Bhettay E, Glass DN, Manners P, et al. Revision of the proposed classification criteria for juvenile idiopathic arthritis: Durban, 1997. J Rheumatol. 1998; 25:1991–4.

3. Petty RE, Southwood TR, Manners P, Baum J, Glass DN, Goldenberg J, et al. International League of Associations for Rheumatology classification of juvenile idiopathic arthritis: second revision, Edmonton, 2001. J Rheumatol. 2004; 31:390–2.

4. Ravelli A, Martini A. Juvenile idiopathic arthritis. Lancet. 2007; 369:767–78.

5. Criteria for the classification of juvenile rheumatoid arthritis. Bull Rheum Dis. 1972; 23:712–9.

6. Brewer EJ Jr, Bass J, Baum J, Cassidy JT, Fink C, Jacobs J, et al. Current proposed revision of JRA Criteria. JRA Criteria subcommittee of the diagnostic and therapeutic criteria committee of the American rheumatism section of the arthritis foundation. Arthritis Rheum. 1977; 20(2 Suppl):195–9.

7. European League Against Rheumatism. EULAR Bulletin No. 4: Nomenclature and classification of arthritis in children. Basel: National Zeitung AG;1977.

8. Ravelli A, Varnier GC, Oliveira S, Castell E, Arguedas O, Magnani A, et al. Antinuclear antibody-positive patients should be grouped as a separate category in the classification of juvenile idiopathic arthritis. Arthritis Rheum. 2011; 63:267–75.

9. Martini A. Are the number of joints involved or the presence of psoriasis still useful tools to identify homogeneous disease entities in juvenile idiopathic arthritis? J Rheumatol. 2003; 30:1900–3.

10. Ravelli A, Felici E, Magni-Manzoni S, Pistorio A, Novarini C, Bozzola E, et al. Patients with antinuclear antibody-positive juvenile idiopathic arthritis constitute a homogeneous subgroup irrespective of the course of joint disease. Arthritis Rheum. 2005; 52:826–32.

11. Stoll ML, Zurakowski D, Nigrovic LE, Nichols DP, Sundel RP, Nigrovic PA. Patients with juvenile psoriatic arthritis comprise two distinct populations. Arthritis Rheum. 2006; 54:3564–72.

12. Martini A. It is time to rethink juvenile idiopathic arthritis classification and nomenclature. Ann Rheum Dis. 2012; 71:1437–9.

13. Hofer MF, Mouy R, Prieur AM. Juvenile idiopathic arthritides evaluated prospectively in a single center according to the Durban criteria. J Rheumatol. 2001; 28:1083–90.

14. Petty RE. Growing pains: the ILAR classification of juvenile idiopathic arthritis. J Rheumatol. 2001; 28:927–8.

15. Tsitsami E, Bozzola E, Magni-Manzoni S, Viola S, Pistorio A, Ruperto N, et al. Positive family history of psoriasis does not affect the clinical expression and course of juvenile idiopathic arthritis patients with oligoarthritis. Arthritis Rheum. 2003; 49:488–93.

16. Griffin TA, Barnes MG, Ilowite NT, Olson JC, Sherry DD, Gottlieb BS, et al. Gene expression signatures in polyarticular juvenile idiopathic arthritis demonstrate disease heterogeneity and offer a molecular classification of disease subsets. Arthritis Rheum. 2009; 60:2113–23.

17. Magni-Manzoni S, Epis O, Ravelli A, Klersy C, Veisconti C, Lanni S, et al. Comparison of clinical versus ultrasound-determined synovitis in juvenile idiopathic arthritis. Arthritis Rheum. 2009; 61:1497–504.

18. Stoll ML, Lio P, Sundel RP, Nigrovic PA. Comparison of Vancouver and international league of associations for rheumatology classification criteria for juvenile psoriatic arthritis. Arthritis Rheum. 2008; 59:51–8.

19. Barnes MG, Thompson SD, Griffin TA, Grom AA, Glass DN, Colbert RA. B-cell signature in patients with JIA is associated with age of onset suggesting biologically relevant classification criteria. Arthritis Rheum. 2009; 60(Suppl 10):620.

20. Prakken B, Albani S, Martini A. Juvenile idiopathic arthritis. Lancet. 2011; 377:2138–49.

21. Barnes MG, Grom AA, Thompson SD, Griffin TA, Luyrink LK, Colbert RA, et al. Biologic similarities based on age at onset in oligoarticular and polyarticular subtypes of juvenile idiopathic arthritis. Arthritis Rheum. 2010; 62:3249–58.

22. Borchers AT, Selmi C, Cheema G, Keen CL, Shoenfeld Y, Gershwin ME. Juvenile idiopathic arthritis. Autoimmun Rev. 2006; 5:279–98.

23. Aletaha D, Neogi T, Silman AJ, Funovits J, Felson DT, Bingham CO 3rd, et al. 2010 Rheumatoid arthritis classification criteria: an American College of Rheumatology/ European League Against Rheumatism collaborative initiative. Arthritis Rheum. 2010; 62:2569–81.

24. Rantapää-Dahlqvist S, de Jong BA, Berglin E, Hallmans G, Wadell G, Stenlund H, et al. Antibodies against cyclic citrullinated peptide and IgA rheumatoid factor predict the development of rheumatoid arthritis. Arthritis Rheum. 2003; 48:2741–9.

25. Kang M, Sohn TY, Kim SH, Lee HR, Kang HJ, Kim KN. The clinical significance of anti-cyclic citrullinated peptide anti-bodies in juvenile rheumatoid arthritis. J Rheum Dis. 2014; 21:236–40.

26. Omar A, Abo-Elyoun I, Hussein H, Nabih M, Atwa H, Gad S, et al. Anti-cyclic citrullinated peptide (anti-CCP) anti-body in juvenile idiopathic arthritis (JIA): correlations with disease activity and severity of joint damage (a multicenter trial). Joint Bone Spine. 2013; 80:38–43.

27. Ferucci ED, Majka DS, Parrish LA, Moroldo MB, Ryan M, Passo M, et al. Antibodies against cyclic citrullinated peptide are associated with HLA-DR4 in simplex and multiplex polyarticular-onset juvenile rheumatoid arthritis. Arthritis Rheum. 2005; 52:239–46.

28. Burgos-Vargas R. The assessment of the spondyloarthritis international society concept and criteria for the classification of axial spondyloarthritis and peripheral spondyloarthritis: A critical appraisal for the pediatric rheumatologist. Pediatr Rheumatol Online J. 2012; 10:14.

29. Helliwell PS, Hetthen J, Sokoll K, Green M, Marchesoni A, Lubrano E, et al. Joint symmetry in early and late rheumatoid and psoriatic arthritis: comparison with a mathematical model. Arthritis Rheum. 2000; 43:865–71.

30. Shin JI, Kim KH, Chun JK, Lee TJ, Kim KJ, Kim HS, et al. Prevalence and patterns of anti-nuclear antibodies in Korean children with juvenile idiopathic arthritis according to ILAR criteria. Scand J Rheumatol. 2008; 37:348–51.

31. Lee JH, Ryu JM, Park YS. Clinical observations of juvenile rheumatoid arthritis. Korean J Pediatr. 2006; 49:424–30.

32. Saurenmann RK, Rose JB, Tyrrell P, Feldman BM, Laxer RM, Schneider R, et al. Epidemiology of juvenile idiopathic arthritis in a multiethnic cohort: ethnicity as a risk factor. Arthritis Rheum. 2007; 56:1974–84.

33. Arguedas O, Fasth A, Andersson-Gäre B, Porras O. Juvenile chronic arthritis in urban San José, Costa Rica: a 2 year prospective study. J Rheumatol. 1998; 25:1844–50.

34. Aggarwal A, Misra R. Juvenile chronic arthritis in India: is it different from that seen in Western countries? Rheumatol Int. 1994; 14:53–6.

35. Colbert RA. Classification of juvenile spondyloarthritis: Enthesitis-related arthritis and beyond. Nat Rev Rheumatol. 2010; 6:477–85.

36. van Rossum M, van Soesbergen R, de Kort S, ten Cate R, Zwinderman AH, de Jong B, et al. Anti-cyclic citrullinated peptide (anti-CCP) antibodies in children with juvenile idiopathic arthritis. J Rheumatol. 2003; 30:825–8.

37. Guzmán J, Burgos-Vargas R, Duarte-Salazar C, Gómez-Mora P. Reliability of the articular examination in children with juvenile rheumatoid arthritis: interobserver agreement and sources of disagreement. J Rheumatol. 1995; 22:2331–6.

38. Nielen MM, van Schaardenburg D, Reesink HW, van de Stadt RJ, van der Horst-Bruinsma IE, de Koning MH, et al. Specific autoantibodies precede the symptoms of rheumatoid arthritis: a study of serial measurements in blood donors. Arthritis Rheum. 2004; 50:380–6.

39. Kroot EJ, de Jong BA, van Leeuwen MA, Swinkels H, van den Hoogen FH, van't Hof M, et al. The prognostic value of anticyclic citrullinated peptide antibody in patients with recent-onset rheumatoid arthritis. Arthritis Rheum. 2000; 43:1831–5.

40. Bracaglia C, de Graaf K, Pires Marafon D, et al. Elevated circulating levels of interferon-γ and interferon-γ-induced chemokines characterise patients with macrophage activation syndrome complicating systemic juvenile idiopathic arthritis. Ann Rheum Dis. 2017; 76:166–72.

Figure 1.

Comparison of sub-types between the ILAR classification and the new provisional classification. ILAR: International League of Associations for Rheumatology, RF: rheumatoid factor, ESR: enthesitis/ spondylitis-related, JIA: juvenile idiopathic arthritis, ANA: anti-nuclear antibody.

Table 1.

Demographic and patient characteristics of JIA patients classified by the ILAR classification

Variable	Systemic arthritis	Oligoarthritis		RF-negative polyarthritis	RF-positive polyarthritis	Psoriatic arthritis	ERA	Undifferentiated arthritis	Total
Variable	Systemic arthritis	PE	EX	RF-negative polyarthritis	RF-positive polyarthritis	Psoriatic arthritis	ERA	Undifferentiated arthritis	Total
Patient	73 (27.9)	39 (14.9)	16 (6.1)	37 (14.1)	15 (5.7)	1 (0.4)	63 (24.0)	18 (6.9)	262 (100)
Male: Female (female, %)	38:35 (47.9)	11:28 (71.8)	5:11 (68.8)	11:26 (70.3)	4:11 (73.3)	0:1 (100)	57:6 (9.5)	6:12 (66.7)	132:130 (49.6)
Disease onset, median (IQR) (yr)	6.0 (3.8∼9.4)	3.5 (2.3∼5.4	) 3.5 (2.1∼11.3	) 7.3 (3.3∼10.9	9) 7.7 (5.9∼11.9	9) 11.8	9.8 (7.8∼11.8	8) 6.7 (4.5∼9.5)	7.3 (3.9∼10.5)
RF	0 (0)	0 (0)	0 (0)	0 (0)	15 (100)	0 (0)	0 (0)	14 (77.8)	29 (11.1)
Anti-CCP Ab	2 (2.7)	0 (0)	2 (12.5)	3 (8.1)	13 (86.7)	0 (0)	1 (1.6)	10 (55.6)	31 (11.8)
ANA	12 (16.4)	15 (38.5)	4 (25.0)	15 (40.5)	11 (73.3)	0 (0)	8 (12.7)	9 (50.0)	74 (28.2)
HLA-B27	5 (6.8)	4 (10.3)	2 (12.5)	8 (21.6)	1 (6.7)	0 (0)	58 (92.1)	6 (33.3)	84 (32.1)
Uveitis	7 (9.6)	8 (20.5)	4 (25.0)	2 (5.4)	1 (6.7)	0 (0)	9 (14.3)	1 (5.6)	32 (12.2)
Enthesitis	1 (1.4)	1 (2.6)	0 (0)	2 (5.4)	0 (0)	0 (0)	32 (50.8)	1 (5.6)	37 (14.1)
Symmetricity	35 (47.9)	7 (17.9)	8 (50.0)	30 (81.1)	13 (86.7)	0 (0)	15 (23.8)	9 (50.0)	117 (44.7)
Cumulative number of joints involved, mean±SD	7.3±9.2	2.1±1.1	9.4±3.9	13.4±7.4	15.5±8.4	4	6.0±6.2	11.4±8.9	8.0±8.0
Upper large joint	36 (49.3)	7 (17.9)	15 (93.8)	29 (78.4)	14 (93.3)	0 (0)	17 (27.0)	16 (88.9)	134 (51.1)
Upper small joint	21 (28.8)	3 (7.7)	7 (43.8)	29 (78.4)	15 (100.0)	1 (100)	17 (27.0)	9 (50.0)	102 (38.9)
Lower large joint	60 (82.2)	35 (89.7)	15 (93.8)	33 (89.2)	11 (73.3)	0 (0)	59 (93.7)	17 (94.4)	230 (87.8)
Lower small joint	13 (17.8)	2 (5.1)	3 (18.8)	18 (48.6)	11 (73.3)	0 (0)	26 (41.3)	5 (27.8)	78 (29.8)
Axial joint	20 (27.4)	4 (10.3)	8 (50.0)	21 (56.8)	9 (60.0)	1 (100)	34 (54.0)	8 (44.4)	105 (40.1)

Except where indicated otherwise, values are the number (%). JIA: juvenile idiopathic arthritis, ILAR: International League of Associations for Rheumatology, PE: persistent, EX: extended, RF: rheumatoid factor, ERA: enthesitis-related arthritis, IQR: interquartile range, Anti-CCP Ab: anti-cyclic citrullinated peptide antibody, ANA: antinuclear antibody, HLA: human leukocyte antigen, SD: standard deviation.

Table 2.

Demographic and patient characteristics of subtypes in new provisional classification

Variable	sJIA	RF-JIA	eoANA-JIA	ESR-JIA	Other JIA	Unclassified JIA	Total	p-value^∗	Comparisons significant on post-hoc tests^†
Patient ILAR subtypes (n)	71 (27.1)	31 (11.8)	22 (8.4)	63 (24.0)	65 (24.8)	10 (3.8)	262 (100)
Systemic arthritis	71	0	0	0	0	2	73
Oligoarthritis PE	0	0	12	0	27	0	39
Oligoarthritis EX	0	2	3	0	11	0	16
Polyarthritis RF (−)	0	3	7	0	27	0	37
Polyarthritis RF (+) Psoriatic arthritis	0 0	15 0	0 0	0 1	0 0	0 0	15 1
ERA	0	0	0	62	0	1	63
Undifferentiated	0	11	0	0	0	7	18
Male: Female (female, %)	38:33 (46.5)	7:24 (77.4)	5:17 (77.3)	56:7 (11.1)	20:45 (69.2)	6:4 (40.0)	132:130 (49.6)	＜0.00001	RF vs. ESR ANA vs. ESR
Disease onset, median (IQR) (yr)	6.0 (3.8∼9.3)	7.0 (4.0∼9.6)	2.4 (2.1∼4.2)	) 9.8 (7.8∼11.8)	5.6 (3.0∼10.9)	9.0 (5.2∼12.2)	7.3 (3.9∼10.5)	＜0.00001	ANA vs. RF RF vs. ESR
									ANA vs. ESR
RF	0 (0)	26 (83.9)	0 (0)	0 (0)	0 (0)	3 (30.0)	29 (11.1)
Anti-CCP Ab	0 (0)	27 (87.1)	0 (0)	0 (0)	0 (0)	4 (40.0)	31 (12.7)
ANA	12 (16.9)	19 (61.3)	22 (100)	8 (12.7)	11 (16.9)	2 (20.0)	74 (28.2)
HLA-B27	5 (7.4)	5 (17.2)	4 (20.0)	57 (90.5)	7 (10.8)	6 (60.0)	84 (32.9)	＜0.00001	RF vs. ESR
									ANA vs. ESR
Uveitis	7 (9.9)	2 (6.5)	7 (31.8)	9 (14.3)	7 (10.8)	0 (0)	32 (12.2)	0.039
Enthesitis	1 (1.4)	0 (0)	0 (0)	31 (49.2)	3 (4.6)	2 (20.0)	37 (14.1)	＜0.00001	RF vs. ESR
Symmetricity	34 (47.9)	19 (61.3)	5 (22.7)	14 (22.2)	38 (58.5)	7 (70.0)	117 (44.7)	0.0004	ANA vs. ERA RF vs. ESR
Cumulative no. of joints involved, mean±SD	7.4±9.3	14.2±7.9	6.0±6.3	6.1±6.2	8.0±7.2	8.8±9.4	8.0±8.0	＜0.00001	ANA vs. RF ANA vs. RF RF vs. ERA
Upper large joint	35 (49.3)	29 (93.5)	12 (54.5)	17 (27.0)	35 (53.8)	6 (60.0)	134 (51.1)	＜0.00001	RF vs. ESR
Upper small joint	20 (28.2)	25 (80.6)	9 (40.9)	18 (28.6)	26 (40.0)	4 (40.0)	102 (38.9)	0.00001	ANA vs. RF RF vs. ESR
Lower large joint	59 (83.1)	27 (87.1)	19 (86.4)	58 (92.1)	59 (90.8)	8 (80.0)	230 (87.8)	0.647	ANA vs. RF
Lower small joint	12 (16.9)	16 (51.6)	9 (27.3)	26 (41.3)	15 (23.1)	3 (30.0)	78 (29.8)	0.208
Axial joint	20 (28.2)	16 (51.6)	3 (13.6)	35 (55.6)	27 (41.5)	4 (40.0)	105 (40.1)	0.003	ANA vs. ESR
									ANA vs. RF
ASAS criteria	9 (12.7)	6 (19.4)	10 (45.5)	62 (98.4)	14 (21.5)	6 (60.0)	107 (40.8)	＜0.00001	RF vs. ESR
									ANA vs. ESR
Axial SpA (n)	0	0	0	9	1	1	11
Peripheral SpA (n)	9	6	10	53	13	5	96

Except where indicated otherwise, values are the number (%). JIA: juvenile idiopathic arthritis, sJIA: systemic JIA, RF-JIA: Rheumatoid factor-positive JIA, eoANA-JIA: early-onset antinuclear antibody-positive JIA, ESR-JIA: enthesitis/spondylitis-related JIA, ILAR: International League of Associations for Rheumatology, PE: persistent, EX: extended, ERA: enthesitis-related arthritis, IQR: interquartile range, Anti-CCP Ab: anti-cyclic citrullinated peptide antibody, ANA: antinuclear antibody, HLA: human leukocyte antigen, SD: standard deviation, ASAS: Assessment of SpondyloArthritis International Society, SpA: spondyloarthritis.

^* For overall comparisons. Following three subtypes were compared statistically—RF positive arthritis, ANA positive arthritis, and ERA/SpA. Comparisons of quantitative data were made by Mann-Whitney U test; comparisons of frequencies were made by chi-square test (or by Fishers exact test if expected frequencies were <5).

^† Pairs of comparisons that were statistically significant on post-hoc tests (Bonferroni adjustment). RF: RF-JIA, ANA: eoANA-JIA, ESR: ESR-JIA.

Table 3.

Joint involvement of RF-positive juvenile idiopathic arthritis (RF-JIA), early-onset ANA-positive JIA (eoANA-JIA) and Enthesitis/spondylitis related JIA (ESR-JIA)

Variable	RF-JIA	eoANA-JIA	ESR-JIA	p-value^∗	Comparisons significant on post-hoc test^†
Lower limbs Knee	23 (74.2)	18 (81.8)	51 (81.0)	0.711
Ankle	25 (80.6)	11 (50.0)	37 (58.7)	0.045
MTP joint	15 (48.4)	4 (18.2)	18 (28.6)	0.047
Toe	8 (25.8)	3 (13.6)	16 (25.4)	0.493
Upper limbs
Elbow	14 (45.2)	8 (36.4)	7 (11.1)	0.001	RF vs. ESR
Wrist	28 (93.3)	7 (31.8)	13 (20.6)	＜0.00001	ANA vs. RF
MCP joint	14 (45.2)	5 (22.7)	13 (20.6)	0.037	RF vs. ESR RF vs. ESR
Finger	21 (67.7)	8 (36.4)	8 (12.7)	＜0.00001	RF vs. ESR
Axial joints
TMJ	4 (12.9)	2 (9.1)	4 (6.3)	0.565
Neck	1 (3.2)	1 (3.0)	8 (12.7)	0.087
Shoulder	11 (35.5)	0 (0)	11 (17.5)	0.005	ANA vs. RF
Back	0 (0)	0 (0)	10 (15.9)	0.010
Sacroiliac joint	1 (3.2)	0 (0)	9 (14.3)	0.055
Hip	12 (38.7)	2 (9.1)	26 (41.3)	0.020	ANA vs. RF
					ANA vs. ESR

Except where indicated otherwise, values are the number (%). Comparisons of frequencies were made by chi-square test (or by Fisher's exact test if expected frequencies were ＜5). RF: rheumatoid factor, ANA: antinuclear antibody, MTP: metatarsophalangeal, MCP: metacarpophalangeal, TMJ: temporomandibular joint, ERA: enthesitis-related arthritis, SpA: spondyloarthritis.

^* For overall comparisons. Following three subtypes were compared statistically― RF positive arthritis, ANA positive arthritis, and ERA/SpA. Comparisons of quantitative data were made by Mann-Whitney U test; comparisons of frequencies were made by chi-square test (or by Fisher's exact test if expected frequencies were ＜5).

^† Pairs of comparisons that were statistically significant on post-hoc tests (Bonferroni adjustment). RF: RF-JIA, ANA: eoANA-JIA, ESR: ESR-JIA

Table 4.

Univariate logistic regression analysis on rheumatoid factor (RF) and anti-cyclic citrullinated peptide antibody (anti-CCP Ab)

Variable	RF		Anti-CCP Ab
Variable	p-value	Exp(β) (95% CI)	p-value	Exp(β) (95% CI)
Female	0.002	4.514 (1.773∼11.495)	0.005	3.332 (1.431∼7.757)
Age (＞6 yr)	0.743	0.879 (0.406∼1.903)	0.662	1.183 (0.557∼2.512)
Uveitis	0.363	0.501 (0.113∼2.216)	0.137	0.215 (0.028∼1.634)
Enthesitis	0.998	0.000 (not available)	0.104	0.187 (0.025∼1.414)
ANA	0.000	7.366 (3.169∼17.123)	0.000	4.327 (1.995∼9.385)
HLA-B27	0.018	0.227 (0.066∼0.776)	0.238	0.585 (0.240∼1.424)
Number of Joints involved (≥5)	0.001	5.885 (1.986∼17.440)	0.001	6.464 (2.192∼19.059)
Symmetricity	0.020	2.617 (1.166∼5.876)	0.051	2.149 (0.997∼4.633)

CI: confidence interval, ANA: antinuclear antibody, HLA: human leukocyte antigen.

Table 5.

Comparison of ANA-positive patients and ANA-negative patients

Variable	ANA-positive patients	ANA-negative patients	p-value
Patient	35 (36.8)	60 (63.2)
Male: Female	7:28 (80.0)	24:36 (60.0)	0.045
(female, %)
Disease onset, median (IQR) (yr)	4.1 (2.3∼8.0)	5.1 (2.8∼11.3)	0.104
Uveitis	9 (25.7)	5 (8.3)	0.021
Enthesitis	1 (2.9)	4 (6.7)	0.649
HLA-B27	5 (15.2)	12 (20.0)	0.563
Symmetricity	14 (40.0)	35 (58.3)	0.085
Cumulative number of joints involved, mean±SD	8.9±9.1	7.0±5.9	0.623
Upper large joint	21 (60.0)	31 (51.7)	0.431
Upper small joint	18 (51.4)	20 (33.3)	0.082
Lower large joint	30 (85.7)	55 (91.7)	0.490
Lower small joint	10 (28.6)	13 (21.7)	0.449
Axial joint	11 (31.4)	23 (38.3)	0.498

Except where indicated otherwise, values are the number (%). Comparisons of quantitative data were made by Mann-Whitney U test; comparisons of frequencies were made by chi-square test (or by Fisher's exact test if expected frequencies were ＜5). ANA: antinuclear antibody, IQR: interquartile range, HLA: human leukocyte antigen, SD: standard deviation.

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