Interleukin-17 and interleukin-23: importance in the pathogenesis of lung impairment in patients with systemic sclerosis.

T cell abnormalities with a focus on Th17 cells have been associated with the pathogenesis of systemic sclerosis (SSc) and interstitial lung disease (ILD). The aim of this study was to evaluate serum levels of interleukin (IL)-17, IL-21 and IL-23 in SSc patients and to assess their relationship with ILD-SSc. Thirty-eight patients with SSc and 39 healthy controls were recruited. Serum IL-17, IL-21 and IL-23 levels were examined using enzyme-linked immunosorbent assay (ELISA). Lung involvement of SSc patients was assessed functionally (diffusing capacity of the lung for carbon monoxide [DLCO], body plethysmography) and radiologically (using average disease extent on high resolution computed tomography [HRCT] of the lungs according to the percentage of interstitial changes and quantified with a 30-point Warrick score) in 29 SSc patients. Serum IL-17 and IL-23 levels were significantly decreased and IL-21 levels were elevated in SSc patients when compared with controls (P < 0.001, P < 0.001, P < 0.01, respectively). The level of IL-17 was negatively associated with disease duration (P = 0.01) and positively with HRCT Warrick score (P = 0.03). IL-23 concentration negatively correlated with DLCO (P = 0.04), total lung capacity (TLC) (P = 0.01) and the 6-min walk test distance (P = 0.03). No associations were found between the cytokine levels and the average extent of the disease on HRCT. While the relationship between Th17-associated cytokines and ILD-SSc needs to be verified in a larger cohort of patients, the changes in concentrations of IL-17, IL-21 and IL-23 support the hypothesis that these cytokines may play a role in the pathogenesis of SSc.

Olewicz-Gawlik A ，Danczak-Pazdrowska A ，Kuznar-Kaminska B ，Gornowicz-Porowska J ，Katulska K ，Trzybulska D ，Batura-Gabryel H ，Silny W ，Poplawski D ，Hrycaj P ... -  《-》

Determinants of impairment in lung diffusing capacity in patients with systemic sclerosis.

Guarnieri G ，Zanatta E ，Mason P ，Scarpa MC ，Pigatto E ，Maestrelli P ，Cozzi F ... -  《CLINICAL AND EXPERIMENTAL RHEUMATOLOGY》

KL6 and IL-18 levels are negatively correlated with respiratory function tests and ILD extent assessed on HRCT in patients with systemic sclerosis-related interstitial lung disease (SSc-ILD).

Interstitial lung disease (ILD) is one of the leading causes of mortality in patients with systemic sclerosis (SSc). Serum biomarkers have been suggested as indicators for pulmonary damage with clinical value in the diagnosis and prognosis of SSc-ILD. To investigate the role of serum biomarkers (Krebs von den Lungen-6 KL-6, IL-18 and IL-18BP) as a potential biomarker reflecting the severity of SSc-ILD as assessed through high-resolution computed tomography (HRCT) and pulmonary function tests (PFT), including forced vital capacity (%FVC) and diffusing capacity of the lung for carbon monoxide (%DLCO). A cross-sectional study including patients with SSc fulfilling the 2013 ACR/EULAR criteria was performed. Patients were classified according to disease duration and pulmonary involvement (presence of ILD). All SSc patients underwent chest HRCT scans and pulmonary function test at baseline. Serum concentration of KL-6, IL8 and IL18BP were determined using the quantitative ELISA technique, sandwich type (solid phase sandwich Enzyme Linked-Immuno-Sorbent Assay), with kits from MyBiosource for KL-6 and from Invitrogen for IL18 and IL18BP. A semiquantitative grade of ILD extent was evaluated through HRCT scan (grade 1, 0-20%; grade 2, >20%). Extensive disease was defined as >20% lung involvement on HRCT, and FVC <70% predicted and limited lung involvement as ≤20% ILD involvement on HRCT, and an FVC ≥70% predicted. 74 patients were included, 27% were male. The mean age at diagnosis was 57.5±15 years and the mean time since diagnosis was 7.67±8 years. 28 patients had ILD (38%). 64% of patients had <20% ILD extent classified through HRCT scan. SSc-ILD patients had elevated serum KL-6 and IL-18 levels compared to patients without ILD (p=0.003 and p=0.04), and those findings were preserved after adjusting for age and sex. Negative correlation between KL-6 levels and%FVC (β=-0.25, p 0.037) and% DLCO (β=-0.28, p 0.02) and between IL-18 levels and%FVC (β=-0.38, p 0.001) and%DLCO (β=-0.27, p 0.03) were found. Serum KL-6 and IL-18 levels successfully differentiated grades 1 and 2 of the semiquantitative grades of ILD extent (p = 0.028 and p = 0.022). Semiquantitative grades of ILD on the HRCT scan were significantly proportional to the KL-6 (p = 0.01) and IL-18 (p = 0.03). A positive correlation between extensive lung disease and KL-6 (β=0.42, p = 0.007) but not with IL-18 was found. Serum KL-6 levels and IL-18 were increased in patients with SSc-ILD and showed a positive correlation with ILD severity as measured using a semiquantitative CT grading scale and negative correlation with PFT parameters. Serum KL-6 and IL-18 could be a clinically useful biomarker in screening and evaluating SSc-ILD.

Sieiro Santos C ，Antolín SC ，Lorenzo JC ，Garay CL ，Morales CM ，de Miguel EB ，Guerrero MR ，Herránz LS ，Álvarez ED ... -  《-》

Elevated serum Krebs von den Lungen-6 in systemic sclerosis: a marker of lung fibrosis and severity of the disease.

Benyamine A ，Heim X ，Resseguier N ，Bertin D ，Gomez C ，Ebbo M ，Harlé JR ，Kaplanski G ，Rossi P ，Bardin N ，Granel B ... -  《-》

Performance of Candidate Serum Biomarkers for Systemic Sclerosis-Associated Interstitial Lung Disease.

Interstitial lung disease (ILD) in systemic sclerosis (SSc) runs a highly variable course, and prediction tools are highly desired. The aim of this study was to assess the diagnostic and prognostic performance of 4 candidate serum biomarkers for SSc-associated ILD. Serum samples from a combined cohort of SSc patients (from Paris, France and Oslo, Norway; n = 427) were analyzed by enzyme-linked immunosorbent assay for concentrations of lung epithelial-derived surfactant protein D (SP-D), Krebs von den Lungen 6 glycoprotein (KL-6), CCL18, and OX40 ligand (OX40L). Lung fibrosis was measured by high-resolution computed tomography and pulmonary function tests. Associations of these candidate biomarkers with baseline disease involvement and prediction of disease progression over time (mean ± SD follow-up 3.2 ± 4.4 years) were investigated. In SSc patients at baseline, serum levels of KL-6 correlated with the forced vital capacity (FVC) (r = -0.317, P < 0.001), diffusing capacity for carbon monoxide (r = -0.335, P < 0.001), and extent of lung fibrosis (r = 0.551, P < 0.001). In multivariate analyses, serum levels of KL-6 and SP-D, but not CCL18 and OX40L, were associated with lung fibrosis (odds ratio [OR] 2.41, 95% confidence interval [95% CI] 1.43-4.07 [P = 0.001] and OR 3.15, 95% CI 1.81-5.48 [P < 0.001], respectively). In SSc patients with ILD at baseline, longitudinal, multivariate analyses showed that CCL18 serum levels were an independent predictor of a >10% decrease in the FVC (hazard ratio [HR] 2.90, 95% CI 1.25-6.73; P = 0.014) and de novo development of extensive disease (HR 3.71, 95% CI 1.02-13.52; P = 0.048). Matrix-based logistic regression models for the diagnosis and prognosis of SSc-associated ILD were constructed, and these models discriminated 3 groups of risk (mild, moderate, or high) for the diagnosis or worsening of lung fibrosis according to the serum levels of SP-D (for diagnosis) and serum levels of CCL18 (for progression of disease). These results show that SP-D is a relevant diagnostic biomarker for SSc-associated ILD, whereas KL-6 could be used to assess the severity of lung fibrosis. CCL18 appears to be a potential predictive marker for progression of ILD in SSc.

Elhai M ，Hoffmann-Vold AM ，Avouac J ，Pezet S ，Cauvet A ，Leblond A ，Fretheim H ，Garen T ，Kuwana M ，Molberg Ø ，Allanore Y ... -  《-》