The Localized Scleroderma Cutaneous Assessment Tool: responsiveness to change in a pediatric clinical population.

BACKGROUND: Lack of agreement on how to accurately capture disease outcomes in localized scleroderma (LS) has hindered the development of efficacious treatment protocols. The LS Cutaneous Assessment Tool (LoSCAT), consisting of the modified LS Skin Severity Index (mLoSSI) and the LS Damage Index, has potential for use in clinical trials. OBJECTIVE: The goal of this article is to further evaluate the clinical responsiveness of the LoSCAT. Based on the modifiable nature of disease activity versus damage, we expected the mLoSSI to be responsive to change. METHODS: At 2 study visits, a physician completed the LoSCAT and Physician Global Assessment (PGA) of Disease Activity and of Disease Damage for 29 patients with LS. Spearman correlations were used to examine the relationships between the change in the LoSCAT and the PGA scores. To evaluate contrasted group validity, patients were grouped according to disease activity classification and change scores of groups were compared. Minimal clinically important differences were calculated and compared with the standard error of measurement. RESULTS: Change in the mLoSSI score correlated strongly with change in the PGA of Disease Activity score, whereas change in the LS Damage Index score correlated weakly with change in the PGA of Disease Damage score. The mLoSSI and PGA of Disease Activity exhibited contrasted group validity. Minimal clinically important differences for the activity measures were greater than the respective standard errors of measurement. LIMITATIONS: Only 2 study visits were included in analysis. CONCLUSION: This study gives further evidence that the LoSCAT, specifically the mLoSSI, is a responsive, valid measure of activity in LS and should be used in future treatment studies.

Interferon-gamma inducible protein-10 as a potential biomarker in localized scleroderma.

INTRODUCTION: The purpose of this study was to evaluate the presence and levels of interferon-gamma inducible protein-10 (IP-10) in the plasma and skin of pediatric localized scleroderma (LS) patients compared to those of healthy pediatric controls and to determine if IP-10 levels correlate to clinical disease activity measures. METHODS: The presence of IP-10 in the plasma was analyzed using a Luminex panel in 69 pediatric patients with LS and compared to 71 healthy pediatric controls. Of these patients, five had available skin biopsy specimens with concurrent clinical and serological data during the active disease phase, which were used to analyze the presence and location of IP-10 in the skin by immunohistochemistry (IHC). RESULTS: IP-10 levels were significantly elevated in the plasma of LS patients compared to that of healthy controls and correlated to clinical disease activity measures in LS. Immunohistochemistry staining of IP-10 was present in the dermal infiltrate of LS patients and was similar to that found in psoriasis skin specimens, the positive disease control. CONCLUSIONS: Elevation of IP-10 levels in the plasma compared to those of healthy controls and the presence of IP-10 staining in the affected skin of LS patients indicates that IP-10 is a potential biomarker in LS. Furthermore, significant elevation of IP-10 in LS patients with active versus inactive disease and correlations between IP-10 levels and standardized disease outcome measures of activity in LS strongly suggest that IP-10 may be a biomarker for disease activity in LS.