Serum and urine free light chains measurements in patients with systemic sclerosis: novel biomarkers for disease activity.

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.

Gigante A ，Pellicano C ，Leodori G ，Napodano C ，Vantaggio L ，Gulli F ，Marino M ，Visentini M ，Rosato E ，Basile U ... -  《-》

Free light chains of immunoglobulins in patients with systemic sclerosis: correlations with lung involvement and inflammatory milieu.

Humoral immunity and B cells are thought to play an important role in the pathophysiology of the systemic sclerosis (SSc). The production of free light chains (FLC) of immunoglobulins is abnormally high in several pathological autoimmune conditions and reflects B cell activation. Furthermore, FLCs demonstrated different biological activities including their capability to modulate the immune system, proteolytic activity and complement cascade activation. The aims of this study are to determine the FLC levels in patients with SSc compared with healthy controls (HC) and to study their possible association with organ involvement and disease characteristics. Sixty-five patients with SSc and 20 HC were studied. Clinical and immunological inflammatory characteristics were assessed for all the patients with SSc. κ-FLC and λ-FLC, interleukin 6 (IL-6) and B cell activating factor levels were measured. The mean serum κ-FLC levels and FLC ratio were significantly higher in patients with SSc compared with HC, while the serum λ-FLC levels were comparable.The levels of FLC were comparable in patients with diffuse skin disease and limited skin involvement, while κ-FLC levels were increased in patients with restrictive lung (forced vital capacity (FVC) <80%) disease (26.4±7.4 mg/L) when compared with patients with FVC ≥80% (19.6±7.3 mg/L, P=0.009). In patients with SSc, the levels of serum κ-FLC level directly correlated with the IL-6 levels (R=0.3, P=0.001) and disease activity (R=0.4, P=0.003). FLC levels are elevated in SSc and high levels are associated with lung involvement and with a higher degree of inflammation, supporting a possible role of B cell activation in the pathophysiology of the disease.

Bosello S ，Basile U ，De Lorenzis E ，Gulli F ，Canestrari G ，Napodano C ，Parisi F ，Pocino K ，Di Mario C ，Tolusso B ，Ferraccioli G ，Gremese E ... -  《-》

Differences in kappa to lambda (kappa:lambda) ratios of serum and urinary free light chains.

Abe M ，Goto T ，Kosaka M ，Wolfenbarger D ，Weiss DT ，Solomon A ... -  《-》

Evaluation of Urinary Free Light Chains as a Marker of Severity of HIV Disease and Its Correlation with CD4 Count: A Pilot Study.

Melkunte Shanthaiah D ，Chitkara A ，Murthy S ，Srivastava D ... -  《-》

The significance and predictive value of free light chains in the urine of patients with chronic inflammatory rheumatic disease.

Bramlage CP ，Froelich B ，Wallbach M ，Minguet J ，Grupp C ，Deutsch C ，Bramlage P ，Koziolek M ，Müller GA ... -  《-》