The identification of CCL18 as biomarker of disease activity in localized scleroderma.

BACKGROUND: Localized Scleroderma (LoS) encompasses a group of idiopathic skin conditions characterized by (sub)cutaneous inflammation and subsequent development of fibrosis. Currently, lack of accurate tools enabling disease activity assessment leads to suboptimal treatment approaches. OBJECTIVE: To investigate serum concentrations of cytokines and chemokines implicated in inflammation and angiogenesis in LoS and explore their potential to be utilized as biomarker of disease activity. Additionally, to investigate the implication of potential biomarkers in disease pathogenesis. METHODS: A 39-plex Luminex immuno-assay was performed in serum samples of 74 LoS and 22 Healthy Controls. The relation between a validated clinical measure of disease activity (mLoSSI) and serum analytes was investigated. Additionally, gene and protein expression were investigated in circulating cells and skin biopsies. RESULTS: From the total of 39, 10 analytes (CCL18, CXCL9, CXCL10, CXCL13, TNFRII, Galectin-9, TIE-1, sVCAM, IL-18, CCL19) were elevated in LoS serum. Cluster analysis of serum samples revealed CCL18 as most important analyte to discriminate between active and inactive disease. At individual patient level, CCL18 serum levels correlated strongest with mLoSSI-scores (rs = 0.4604, P < 0.0001) and in longitudinal measures CCL18 concentrations normalised with declining disease activity upon treatment initiation. Additionally, CCL18 was elevated in LoS serum, and not in (juvenile) dermatomyositis or spinal muscular atrophy. Importantly, CCL18 gene and protein expression was increased at the inflammatory border of cutaneous LoS lesions, with normal expression in unaffected skin and circulating immune cells. CONCLUSION: CCL18 is specific for disease activity in LoS thereby providing relevance as a biomarker for this debilitating disease.

Disease recurrence in localized scleroderma: a retrospective analysis of 344 patients with paediatric- or adult-onset disease.

BACKGROUND: Localized scleroderma (LoS) is characterized by a phase of disease activity followed by remission. However, disease recurrences occur. Knowledge concerning these recurrences can help prompt treatment, thereby preventing disease damage. OBJECTIVES: To investigate the frequency and characteristics of disease recurrences in paediatric- and adult-onset LoS, and to identify patient variables that are associated with a higher risk of disease recurrence. METHODS: Retrospective chart reviews were performed of patients with LoS. Data concerning the frequency and characteristics of the disease recurrences were collected. A multivariate analysis was performed to identify patient variables that were associated with a higher risk of disease recurrence. RESULTS: In total, 344 patients were included in the analysis, of whom 119 (35%) had paediatric-onset LoS and 225 (65%) had adult-onset LoS. Disease recurrence was present in 27% (n = 32) of the paediatric-onset group and 17% (n = 39) of the adult-onset group (P = 0·037). Multivariate analysis identified a statistically significant association between disease recurrence and the linear LoS of the limbs subtype, independent of age at disease onset. CONCLUSIONS: Recurrences in LoS occurred in almost one-quarter of the patients and were most frequent in the linear LoS of the limbs subtype, independent of age at disease onset. These disease recurrences can occur even after many years of quiescent disease. Awareness of the high recurrence rates may help treating physicians to recognize reactivation of the disease, leading to a decreased delay in treatment reinitiation.