Search

Summary: Circulating free light chains (FLCs), considered biomarkers of B cell activity, are frequently elevated in patients affected by systemic inflammatory autoimmune diseases. As the systemic sclerosis (SSc) clinical course can be variable, this study is aimed at evaluating FLCs levels in affected individuals as biomarkers of disease activity. We assessed FLC levels in serum and urine of 72 SSc patients and 30 healthy controls (HC). Results were analyzed in comparison with overall clinical and laboratory findings, disease activity index (DAI) and disease severity scale (DSS). SSc patients displayed increased levels of κ and λ FLC in serum significantly higher than HC (p = 0.0001) alongside the mean values of free κ/λ ratio and κ + λ sum (p = 0.0001). SSc patients showed increased free κ in urine with a κ/λ higher than HC (p = 0.0001). SSc patients with increased κ + λ in serum showed that erythro‐sedimentation rate (p = 0.034), C‐reactive protein (p = 0.003), DAI (p = 0.024) and DSS (p = 0.015) were higher if compared to SSc patients with normal levels of FLC. A positive linear correlation was found between serum levels of free κ and DAI (r = 0.29, p = 0.014). In addition, SSc patients with increased free κ in urine had higher DAI (p = 0.048) than SSc patients with normal κ levels. Our results strengthen the role of serum FLC as useful biomarker in clinical practice to early diagnosis and monitor disease activity, showing for the first time that also urine FLC levels correlated with disease activity in SSc patients. [ABSTRACT FROM AUTHOR]

Summary: The objective of this study was to evaluate the predictive role of CD21low B cells as markers of new digital ulcers in systemic sclerosis patients. Peripheral blood B cell subpopulations and clinical assessments have been evaluated in 74 systemic sclerosis patients at baseline and after a 12‐month follow‐up. After a 12‐month follow‐up, 23 (31.1%) systemic sclerosis patients developed new digital ulcers. The median percentage of CD21low B cells was significantly higher in patients with than without new digital ulcers [10.1 (4.3–13.6) versus 4.8 (3.5–7.4); p < 0.01]. The 10% cut‐off shows good diagnostic accuracy [area under the curve (AUC) = 0.732, confidence interval (CI) = 0.587–0.878; P = 0.01]. Kaplan–Meier curves show a significantly reduced free survival from new digital ulcers in systemic sclerosis patients with CD21low B cells ≥ 10% (p < 0.0001). In multivariate analysis, CD21low B cells ≥ 10%, modified Rodnan skin score (mRSS) and systolic pulmonary arterial pressure (sPAP) are associated with the development of new digital ulcers. We hypothesize that CD21low B cells are a predictive marker of new digital ulcers in systemic sclerosis patients. [ABSTRACT FROM AUTHOR]