Arthritis & Rheumatism, Volume 63,
November 2011 Abstract Supplement
Abstracts of the American College of
Rheumatology/Association of Rheumatology Health Professionals
Annual Scientific Meeting
Chicago, Illinois November 4-9, 2011.
Clinical Predictors Associated with Severe Radiographic Sacroilitis in Axial Spondyloarthritis.
Yoon1, Grace, Learch2, Thomas J., Davis3, John C., Gensler4, Lianne S.
UCSF, San Franciscao, CA
Cedars-Sinai, Los Angeles, CA
Genentech Inc, South San Francisco, CA
UCSF, San Francisco, CA
Background/Purpose:
Sacroilitis is the hallmark radiographic feature of Axial Spondyloarthritis (ASpA). To date, there has been little published on the predictors of radiographic severity of sacroilitis. The objective of this study was to determine if there were clinical predictors of severe sacroilitis, as defined by completely fused sacroiliac joints (grade 4 according to the New York classification scale).
Methods:
We studied 151 consecutive ASpA subjects who met Assessment of SpondyloArthritis (ASAS) criteria for axial SpA. All subjects underwent radiographic imaging using the anterior-posterior pelvis view. Right and left sacroiliac joints were scored by 2 of the investigators (LG, TL). The average of the scores was then calculated and used in the analysis. Forty two patients were found to have bilateral grade 4 sacroilitis and 109 patients were calculated to have less than grade 4 sacroilitis. Demographics and clinical variables were collected at the time the radiograph was obtained. Statistical analysis was performed using the student t-test and wilcoxan ranksum for continuous variables and a chi-square analysis for dichotomous variables. A multivariate logistic regression was performed adjusting for age and gender.
Results:
Severe sacroilitis was significantly associated with non-Caucasian ethnicity, disease duration and a history of total hip arthroplasty. Having a first degree relative with Ankylosing Spondylitis (AS) was also a predictor of severe sacroilitis as was smoking tobacco as measured by pack years (Table 2).
Table 1. Univariate Analysis
| Predictor | Sacroilitis < grade 4 (n = 109) | Sacroilitis = grade 4 (n = 42) | P value |
|---|---|---|---|
| Age (years) | 37.7 ± 10.0 | 41.9 ± 13.2 | .16 |
| Gender (% male) | 64 | 79 | .09 |
| Ethnicity (% non-Caucasian) | 34 | 57 | .009 |
| % Modified NY criteria | 64 | 100 | <.0001 |
| Disease duration (years) | 13.3 ± 9.8 | 20.1 ± 11.4 | .0007 |
| HLA B27 positivity (%) | 81 | 89 | .25 |
| Age at onset | 24.4 ± 9.3 | 21.8 ± 8.5 | .05 |
| History of Uveitis (%) | 47 | 40.5 | .46 |
| History of peripheral symptoms (%) | 58 | 49 | .32 |
| Total hip arthroplasty (%) | 3 | 14 | .008 |
| Family history of AS in a first degree relative (FDR) (%) | 10 | 32 | .002 |
| On biologic (%) | 31 | 41 | .28 |
| Smoking (pack years) | 1.4 ± 4.3 | 6.2 ± 12.8 | .04 |
| Employed (%) | 83 | 73 | .19 |
| Education (years) | 16.6 ± 2.5 | 15.2 ± 3.9 | .1 |
| BASDAI (0–100) | 37.3 ± 24.6 | 38.3 ± 20.5 | .67 |
| Inflammation score (0–100) | 41.3 ± 31 | 33.1 ± 24.5 | .2 |
| ASDAS (ESR) | 15 ± 10.3 | 14 ± 8.1 | .85 |
| ASDAS (CRP) | 14.1 ± 9.52 | 13.8 ± 8.4 | .99 |
| BASFI (0–100) | 23.3 ± 24.3 | 33.4 ± 26 | .02 |
| ESR (mm/hour) | 15.9 ± 20.9 | 17.3 ± 16.6 | .29 |
| CRP (g/dL) | 6.7 ± 12.3 | 9.9 ± 11.4 | .006 |
Table 2. Multivariate Logistic Regression (after adjustment for age and gender)
| Predictor | Odds ratio | P value | 95% Confidence Interval |
|---|---|---|---|
| Non-Caucasian ethnicity | 3.3 | .02 | 1.26; 8.79 |
| Disease duration | 1.07 | .05 | 1; 1.13 |
| Total hip arthroplasty | 27.9 | .0004 | 2.84; 274.3 |
| Family history of AS (in a FDR) | 4.65 | .01 | 1.44; 15 |
| Smoking (pack years) | 1.13 | .006 | 1.04; 1.23 |
Conclusion:
Severe radiographic sacroilitis appears to be associated with predictable characteristics like disease duration and total hip arthroplasty, but also appears to be associated with less reported characteristics such as familial AS and tobacco use. Smoking may be a modifiable risk factor for the development of severe radiographic AS.
To cite this abstract, please use the following information:
Yoon, Grace, Learch, Thomas J., Davis, John C., Gensler, Lianne S.; Clinical Predictors Associated with Severe Radiographic Sacroilitis in Axial Spondyloarthritis. [abstract]. Arthritis Rheum 2011;63 Suppl 10 :512
DOI:
