Antonia Valenzuela1, Kathryn Stevens2, Melody P Chung3, Tatiana S Rodriguez-Reyna4, Susanna Proudman5, Murray Baron6, Flavia V Castelino7, Vivien Hsu8, Lorraine Green9, Francesco Del Galdo9, Shufeng Li10, David Fiorentino10, Lorinda Chung11. 1. Pontificia Universidad Católica de Chile, Department of Immunology and Rheumatology. 2. Stanford University, Division of Radiology. 3. John Hopkins University, Division of Rheumatology. 4. Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, Department of Immunology and Rheumatology. 5. Royal Adelaide Hospital North Terrace, Rheumatology Unit, Discipline of Medicine, University of Adelaide. 6. Division of Rheumatology, Jewish General Hospital, McGill University. 7. Harvard Medical School, Division of Rheumatology. 8. Rutgers-RWJ Medical School, Rheumatology Division. 9. Leeds University, Division of Rheumatology. 10. Stanford University School of Medicine, Department of Dermatology. 11. Stanford University School of Medicine and Palo Alto VA Health Care System, Department of Immunology and Rheumatology and Dermatology (by courtesy). Electronic address: shauwei@stanford.edu.
Abstract
INTRODUCTION: Calcinosis cutis is a debilitating complication of systemic sclerosis (SSc). We previously developed a radiographic scoring system to assess severity of calcinosis affecting the hands in patients with SSc. We sought to further validate our radiographic scoring system to assess for change over 1 year and to identify factors associated with improvement or progression. MATERIALS AND METHODS: Baseline and 1-year antero-posterior hand radiographs were obtained in 39 SSc patients with calcinosis prospectively enrolled at 6 centers within the US, Canada, Mexico and Australia. Two readers (one radiologist and one rheumatologist) scored all radiographs using the calcinosis scoring system and a 5-point Likert scale (1 = A lot better, 2 = A little better, 3=No change, 4 = A little worse, 5 = A lot worse) on follow-up. By maximizing the Kappa coefficient of agreement between grouped Likert scale (better/no change/worse) and the percentage of change of calcinosis in the radiographic scoring system, we defined progressive calcinosis as >25% increase in score from baseline at 1-year, stable calcinosis as change in score between -25% to 25%, and improvement of calcinosis as decrease in score by >25%. Nineteen SSc patients from an independent cohort were used for validation. RESULTS: Inter-rater reliability of the calcinosis scoring system was high with intra-class correlation coefficient of 0.93 (0.89-0.95). The median percentage of change from baseline to 1 year was 12.8% (range -89.3 to 290.2%). Sixteen patients (41%) experienced progression of calcinosis over 1 year; 18 (46%) remained stable; and 5 (13%) had improvement. Patients with progressive calcinosis had lower T-score on bone densitometry (-3.3 vs -1.7, p = 0.044) and higher prevalence of loss of digital pulp on physical exam (56% vs 22%, p = 0.027), with a trend towards lower baseline modified Rodnan skin score (mRSS) (3.8 vs. 5.9, p = 0.057), than patients who did not progress. Patients who experienced improvement in calcinosis had lower prevalence of digital pitting scars (20% vs 71%, p = 0.047) than patients whose calcinosis did not improve. In multivariable analysis, loss of digital pulp remained a predictor of calcinosis progression (OR 5.8, p = 0.023, CI 1.27 - 26.36). In the validation cohort, 2 (11%) patients improved, 10 (53%) remained stable, and 7 (37%) progressed. CONCLUSIONS: We confirmed the excellent inter-rater reliability of our radiographic calcinosis scoring system and demonstrated its usefulness to detect change over time. Approximately 40% of patients experienced progression of calcinosis over 1 year. Loss of digital pulp was predictive of progressive calcinosis providing further evidence that digital ischemia contributes to the progression of calcinosis. Published by Elsevier Inc.
INTRODUCTION: Calcinosis cutis is a debilitating complication of systemic sclerosis (SSc). We previously developed a radiographic scoring system to assess severity of calcinosis affecting the hands in patients with SSc. We sought to further validate our radiographic scoring system to assess for change over 1 year and to identify factors associated with improvement or progression. MATERIALS AND METHODS: Baseline and 1-year antero-posterior hand radiographs were obtained in 39 SSc patients with calcinosis prospectively enrolled at 6 centers within the US, Canada, Mexico and Australia. Two readers (one radiologist and one rheumatologist) scored all radiographs using the calcinosis scoring system and a 5-point Likert scale (1 = A lot better, 2 = A little better, 3=No change, 4 = A little worse, 5 = A lot worse) on follow-up. By maximizing the Kappa coefficient of agreement between grouped Likert scale (better/no change/worse) and the percentage of change of calcinosis in the radiographic scoring system, we defined progressive calcinosis as >25% increase in score from baseline at 1-year, stable calcinosis as change in score between -25% to 25%, and improvement of calcinosis as decrease in score by >25%. Nineteen SSc patients from an independent cohort were used for validation. RESULTS: Inter-rater reliability of the calcinosis scoring system was high with intra-class correlation coefficient of 0.93 (0.89-0.95). The median percentage of change from baseline to 1 year was 12.8% (range -89.3 to 290.2%). Sixteen patients (41%) experienced progression of calcinosis over 1 year; 18 (46%) remained stable; and 5 (13%) had improvement. Patients with progressive calcinosis had lower T-score on bone densitometry (-3.3 vs -1.7, p = 0.044) and higher prevalence of loss of digital pulp on physical exam (56% vs 22%, p = 0.027), with a trend towards lower baseline modified Rodnan skin score (mRSS) (3.8 vs. 5.9, p = 0.057), than patients who did not progress. Patients who experienced improvement in calcinosis had lower prevalence of digital pitting scars (20% vs 71%, p = 0.047) than patients whose calcinosis did not improve. In multivariable analysis, loss of digital pulp remained a predictor of calcinosis progression (OR 5.8, p = 0.023, CI 1.27 - 26.36). In the validation cohort, 2 (11%) patients improved, 10 (53%) remained stable, and 7 (37%) progressed. CONCLUSIONS: We confirmed the excellent inter-rater reliability of our radiographic calcinosis scoring system and demonstrated its usefulness to detect change over time. Approximately 40% of patients experienced progression of calcinosis over 1 year. Loss of digital pulp was predictive of progressive calcinosis providing further evidence that digital ischemia contributes to the progression of calcinosis. Published by Elsevier Inc.