ACR Meeting Abstracts

ACR Meeting Abstracts

Abstract Number: 1628

Is Axial Psoriatic Arthritis Distinct from Ankylosing Spondylitis with and without Concomitant Psoriasis?

Joy Feld1, Justine Y. Ye2, Vinod Chandran2, Robert D Inman3, Nigil Haroon4, Richard J. Cook5 and Dafna D Gladman1, 1Toronto Psoriatic Arthritis Research Program, University of Toronto, Toronto Western Hospital, Toronto, ON, Canada, 2Rheumatology, University of Toronto, Toronto Western Hospital, Toronto, ON, Canada, 3Toronto Western Hospital, University of Toronto, Spondylitis Clinic, Toronto, ON, Canada, 4Rheumatology, Toronto Western Hospital, Toronto, ON, Canada, Toronto, ON, Canada, 5Statistics and Actuarial Science, University of Waterloo, Waterloo, ON, Canada

Meeting: 2018 ACR/ARHP Annual Meeting

Keywords: ,

Session Information

Date: Monday, October 22, 2018

Title: Spondyloarthritis Including Psoriatic Arthritis – Clinical Poster II: Clinical/Epidemiology Studies

Session Type: ACR Poster Session B

Session Time: 9:00AM-11:00AM

Background/Purpose:

Spondyloarthritis include two major phenotypes: ankylosing spondylitis (AS) and psoriatic arthritis (PsA). 10% of AS patients have concomitant psoriasis, while 25% – 70% of PsA patients have axial disease. The question arises whether AS with concomitant psoriasis and axial PsA are essentially the same disease?

The aim of this study was to compare the demographic, genetic, clinical and radiographic characteristics of patients with AS, with and without psoriasis, to axial PsA patients.

Methods:

A retrospective analysis of prospective observational cohorts was performed. Four cohorts of patients were recruited from AS and PsA clinics at one center: 1. AS without psoriasis, 2. AS patients with psoriasis (ASPs), 3. Axial PsA patients (radiographic sacroiliitis: ≥ bilateral grade 2 or unilateral grade 3), 4. Peripheral PsA patients. All patients were 18 years old and were followed prospectively according to the same protocol. The four groups were compared using ANOVA and Pearson chi-square tests. Axial PsA was subsequently compared specifically to the ASP group using the appropriate tests. Adjusted means (AM) were used for variables that change over time. They were calculated by plotting the values of the variables over time and calculating the area under the curve. AM more accurately account for the varying time intervals between visits that are common in the usual clinic setting. A logistic regression was performed to assess the differences in clinical and radiographic features between ASP vs. axial PsA adjusting for demographic and genetic variables and follow-up duration. When p<0.05 the results were considered statistically significant.

Results:

Table number 1: Four group comparison

Ankylosing spondylitis

Psoriatic arthritis

Variable

Without psoriasis (N=675)

With psoriasis (N=91)

Axial (N=477)

Peripheral (N=826)

P Value

Age at diagnosis

30.4

(12.0)

28.7

(11.0)

35.6

(13.3)

39.3

(13.7)

<0.001

Male gender

n (%)

489

(72%)

69

(76%)

3

03

(64%)

414

(50%)

<0.001

HLA-B*27

n (%)

509

(75%)

75

(82%)

91

(19%)

77

(9%)

<0.001

Adjusted mean active arthritis (tender + swollen joints)

(SD)

0.9

(2.2)

1.5

(3.5)

5.4

(6.2)

5.6

(6.6)

<0.001

Back pain at presentation n (%)

82

(90%)

618

(92%)

89

(19%)

253

(31%)

<0.001

Adjusted mean ASDAS ESR –

(SD)

2.2

(0.9)

2.3

(0.9)

2.2

(1.0)

2.1

(0.8)

0.58

Adjusted mean BASDAI –

(SD)

3.9

(2.1)

4.1

(2.0)

3.5

(2.2)

3.6

(2.0)

0.017

Adjusted mean BASMI – (SD)

2.2

(2.1)

2.9

(2.2)

1.8

(1.4)

1.4

(1.2)

<0.001

Adjusted mean patient global assessment –

(SD) (range 0-10)

4.1

(2.2)

4.3

(2.2)

4.0

(2.3)

3.9

(2.0)

0.34

Adjusted mean physician global assessment –

(SD) (range 0-10)

2.2

(0.8)

2.4

(0.9)

2.1

(0.6)

2.0

(0.7)

<0.001

Biologic treatment n (%) at baseline

145

(21%)

26

(29%)

34

(7%)

56

(7%)

<0.001

Sacroiliitis grade 3,4 (unilateral or bilateral) at baseline

576

(79%)

82

(87%)

282

(51%)

_

<0.001

ASDAS=ankylosing spondylitis disease activity score; BASDAI=Bath ankylosing spondylitis disease activity index; BASMI=Bath ankylosing spondylitis metrology index.

Table number 2: The Comparison of ASPs and axial PsA

Variable

ASPs
(N=91)

Axial PsA
(N=477)

P Value

Age of diagnosis

28.7 (11.0)

35.6 (13.3)

<.001

Male, n (%)

69 (76%)

303 (64%)

0.024

HLA B27, n (%)

75 (82%)

91 (19%)

<.001

Adjusted mean active arthritis (tender and swollen joints)

1.5 (3.5)

5.2 (6.5)

<.001

Presence of back pain at presentation, n (%)

82 (90%)

100 (21%)

<.001

Adjusted mean ASDAS ESR

2.3 (0.9)

2.2 (1.0)

0.47

Adjusted mean BASDAI

4.1 (2.0)

3.5 (2.2)

0.028

Adjusted mean BASMI

2.9 (2.2)

1.8 (1.4)

<.001

Adjusted mean physician global assessment

2.4 (0.9)

2.1 (0.6)

<.001

Adjusted mean patient global assessment

4.3 (2.2)

4.0 (2.3)

0.27

Biologic treatment at baseline, n (%)

26 (29%)

70 (15%)

0.001

ASDAS=ankylosing spondylitis disease activity score; BASDAI=Bath ankylosing spondylitis disease activity index; BASMI=Bath ankylosing spondylitis metrology index

Table number 3: Logistic regression, outcome: ankylosing spondylitis with psoriasis compared to axial PsA (axial PsA reference group)

Univariate

Multivariate

Variable

OR

95% CI

P value

OR

95% CI

P value

Adjusted mean active arthritis (tender and swollen joints)

0.68

0.61 – 0.76

<.0001

0.75

0.64- 0.86

<.0001

Adjusted mean ASDAS – ESR

1.1

0.83- 1.45

0.51

Adjusted mean BASMI

1.41

1.21- 1.63

<.0001

1.44

1.02- 2.03

0.04

Sacroiliitis (grade 3,4) at diagnosis

7.58

3.68- 15.59

<.0001

3.24

1.10- 9.49

0.03

Adjusted variables: follow-up duration, age of diagnosis, sex, HLA-B*27, biologic/NSAIDS treatment.

ASDAS-ESR=ankylosing spondylitis disease activity score; BASMI=Bath ankylosing spondylitis metrology index; NSAIDS=non-steroidal anti-inflammatory drugs

Conclusion:

AS patients, with or without psoriasis, are different demographically, genetically, clinically and radiographically to axial PsA patients. AS patients are younger, male predominant with higher HLA-B*27 rates. They have worse axial disease, while axial PsA have worse peripheral arthritis.

Disclosure: J. Feld, None; J. Y. Ye, None; V. Chandran, AbbVie Inc., 2,AbbVie Inc., amgen, celgene, eli lilly, Janssen, Novartis, Pfizer and UCB, 5,Eli Lilly and Co., 9; R. D. Inman, None; N. Haroon, AbbVie Inc., Amgen, Janssen, Novartis, UCB, 5; R. J. Cook, None; D. D. Gladman, Abbvie, Amgen, BMS, Celgene, Eli Lilly and Company, Janssen, Novartis, Pfizer, UCB, 5,Abbvie, Amgen, Celgene, Janssen, Novartis, Pfizer and UCB, 2.

To cite this abstract in AMA style:

Feld J, Ye JY, Chandran V, Inman RD, Haroon N, Cook RJ, Gladman DD. Is Axial Psoriatic Arthritis Distinct from Ankylosing Spondylitis with and without Concomitant Psoriasis? [abstract]. Arthritis Rheumatol. 2018; 70 (suppl 9). https://acrabstracts.org/abstract/is-axial-psoriatic-arthritis-distinct-from-ankylosing-spondylitis-with-and-without-concomitant-psoriasis/. Accessed .

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