Imunofenotipagem e remodelamento da matriz extracelular na sarcoidose pulmonar e extrapulmonar

Plasma collagen neoepitopes are associated with multiorgan disease in the ACCESS and GRADS sarcoidosis cohorts

INTRODUCTION

The pathogenesis of sarcoidosis involves tissue remodelling mediated by the accumulation of abnormal extracellular matrix, which is partly the result of an imbalance in collagen synthesis, cross-linking and degradation. During this process, collagen fragments or neoepitopes, are released into the circulation. The significance of these circulating collagen neoepitopes in sarcoidosis remains unknown.

METHODS

We employed plasma samples from patients with sarcoidosis enrolled in A Case Control Etiologic Study of Sarcoidosis (ACCESS) and Genomic Research in Alpha-1 Antitrypsin Deficiency and Sarcoidosis (GRADS), and healthy control patients recruited from the Yale community. Plasma concentrations of type III and VI collagen degradation (C3M and C6M) and formation (PRO-C3 and PRO-C6) were quantified via neoepitope-specific competitive ELISA, and statistical associations were sought with clinical phenotypes.

RESULTS

Relative to healthy controls, the plasma of both sarcoidosis cohorts was enriched for C3M and C6M, irrespective of corticosteroid use and disease duration. While circulating collagen neoepitopes were independent of Scadding stage, there was a significant association between multiorgan disease and PRO-C3, PRO-C6 and C3M in the ACCESS cohort; PRO-C3 and C6M displayed this property in GRADS. These findings were unrelated to plasma levels of interleukin-4 (IL-4), IL-5, IL-6, IL-9, IL-10 and IL-13. Moreover, PRO-C3 was associated with dermatological disease in both cohorts.

DISCUSSION

In two well-characterised sarcoidosis cohorts, we discovered that the plasma is enriched for neoepitopes of collagen degradation (C3M and C6M). In multiorgan disease, there was an association with circulating neoepitopes of type III formation (PRO-C3), perhaps mediated by dermatological sarcoidosis. Further investigation in this arena has the potential to foster new insights into the pathogenic mechanisms of this complex disease.

The utility of neutrophil-to-lymphocyte ratio determined at initial diagnosis in predicting disease stage and discriminating between active and stable disease in patients with sarcoidosis: cross-sectional study

OBJECTIVE

To evaluate the utility of neutrophil-lymphocyte ratio (NLR) determined at initial diagnosis in predicting advanced disease stage and discriminating between active and stable disease in sarcoidosis.

METHODS

A total of 465 patients with biopsy-proven sarcoidosis (age: 47 years, 70.5% females) were included in this retrospective cross-sectional study. Data on patient demographics, sarcoidosis stage, clinical status (stable and active), anti-inflammatory treatments, complete blood count, and inflammatory markers including erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), neutrophil-to-lymphocyte ratio (NLR) and platelet/mean platelet volume (MPV) ratio were recorded. NLR values were compared by subgrouping the patients according to the stage of sarcoidosis and clinical status, while the receiver operating characteristics (ROC) curve was plotted to determine the role of NLR in the identification of disease activity with the calculation of area under the curve (AUC) and cut-off value via ROC analysis.

RESULTS

Overall, active, and stable disease was evident in 36 (7.8%) and 427 (92.2%) patients, respectively. Median NLR values were significantly higher in patients with active disease compared with stable disease (3.31 (2.34-4.31) vs. 2.29 (1.67- 3.23), p=0.005). Advanced sarcoidosis stage was associated with significantly higher NLR values at stages 0, I, II, III and IV, respectively (p=0.001). ROC analysis revealed a NLR cut-off value of ≥2.39 (AUC (95% CI): 0.70(0.62 - 0.79), p<0.001) to discriminate between active and stable clinic with a sensitivity of 72.0% and specificity of 52.0%. The significantly higher percentage of patients with active vs. stable disease had NLR values ≥ 2.39 (74.0 vs. 47.0%, p=0.002).

CONCLUSION

Our findings indicate the potential utility of on-admission NLR values to predict the risk of advanced disease stage and to discriminate between active and stable disease in sarcoidosis. Measured via a simple, readily available, and low-cost test, NLR seems to be a valuable marker for monitoring disease activity and progression.

The Th17 pathway in the peripheral lung microenvironment interacts with expression of collagen V in the late state of experimental pulmonary fibrosis

BACKGROUND

Myofibroblasts derived from fibroblasts in the pathogenesis of pulmonary fibrosis causes excessive and disordered deposition of matrix proteins, including collagen V, which can cause a Th17-mediated immune response and lead to apoptosis. However, whether the intrinsic ability of lung FBs to produce the matrix depends on their site-specific variations is not known.

AIM

To investigate the link between Th17 and collagen V that maintains pulmonary remodeling in the peripheral lung microenvironment during the late stage of experimental pulmonary fibrosis.

METHODS

Young male mice including wild Balb/c mice (BALB, n=10), wild C57 Black/6J mice (C57, n=10) and IL-17 receptor A knockout mice (KO, n=8), were sacrificed 21 days after treatment with bleomycin. Picrosirius red staining, immunohistochemistry for IL-17-related markers and "in situ" detection of apoptosis, immunofluorescence for collagen types I and V, primary cell cultures from tissue lung explants for RT-PCR and electron microscopy were used.

RESULTS

The peripheral deposition of extracellular matrix components by myofibroblasts during the late stage is maintained in C57 mice compared with that in Balb mice and is not changed in the absence of IL-17 receptor A; however, the absence of IL-17 receptor A induces overexpression of type V collagen, amplifies the peripheral expression of IL-17 and IL-17-related cytokines and reduces peripheral lung fibroblast apoptosis.

CONCLUSION

A positive feedback loop between the expression patterns of collagen V and IL-17 may coordinate the maintenance of peripheral collagen I in the absence of IL-17 receptor A in fibrosis-susceptible strains in a site-specific manner.