In recent clinical trials, fibrotic interstitial lung disease (ILD) that shares the similar physiopathologic mechanism and behavior with those of idiopathic pulmonary fibrosis (IPF) have been uniformly termed as progressive fibrosing ILD (PF-ILD). However, there is no consensus on the definition and diagnostic criteria of PF-ILD." Idiopathic Pulmonary Fibrosis (an Update) and Progressive Pulmonary Fibrosis in Adults: An Official ATS/ERS/JRS/ALAT Clinical Practice Guideline (2022 Edition)" unifies the process of ILD with progressive exacerbation of fibrosis other than idiopathic pulmonary fibrosis, and newly termed as progressive pulmonary fibrosis (PPF). They also clarify the diagnostic criteria, and anti-fibrosis treatment of PPF.This article thoroughly interprets this guideline for PPF.

Background and objective: Idiopathic pulmonary fibrosis (IPF) is an aggressive fibrotic pulmonary disease with spatially and temporally heterogeneous alveolar lesions. There are no early diagnostic biomarkers, limiting our understanding of IPF pathogenesis.Methods: Lung tissue from surgical lung biopsy of patients with early-stage IPF (n = 7), transplant-stage IPF (n = 2), and healthy controls (n = 6) were subjected to mRNA sequencing and verified by real-time quantitative PCR (RT-qPCR), immunohistochemistry, Western blot, and single-cell RNA sequencing (scRNA-Seq).Results: Three hundred eighty differentially expressed transcripts (DETs) were identified in IPF that were principally involved in extracellular matrix (ECM) remodeling, lipid metabolism, and immune effect. Of these DETs, 21 (DMD, MMP7, POSTN, ECM2, MMP13, FASN, FADS1, SDR16C5, ACAT2, ACSL1, CYP1A1, UGT1A6, CXCL13, CXCL5, CXCL14, IL5RA, TNFRSF19, CSF3R, S100A9, S100A8, and S100A12) were selected and verified by RT-qPCR. Differences in DMD, FASN, and MMP7 were also confirmed at a protein level. Analysis of scRNA-Seq was used to trace their cellular origin to determine which lung cells regulated them. The principal cell sources of DMD were ciliated cells, alveolar type I/II epithelial cells (AT cells), club cells, and alveolar macrophages (AMs); MMP7 derives from AT cells, club cells, and AMs, while FASN originates from AT cells, ciliated cells, and AMs.Conclusion: Our data revealed a comprehensive transcriptional mRNA profile of IPF and demonstrated that ECM remodeling, lipid metabolism, and immune effect were collaboratively involved in the early development of IPF.

Idiopathic pulmonary fibrosis (IPF) is an age-related disease with no cure. Mesenchymal stem cell (MSC)-based therapy has emerged as a novel strategy for IPF treatment. Nevertheless, MSCs derived from patients with IPF (IPF-MSCs) become senescent, thereby reducing their beneficial effects in IPF. MicroRNAs (miRNAs) mediate the senescence of MSCs, but the underlying mechanisms are not fully understood. We investigated the mechanisms by which miR-199a-5p regulates IPF-MSC senescence and whether its inhibition could rejuvenate IPF-MSCs and enhance their therapeutic efficacy. Control-MSCs and IPF-MSCs were isolated from the adipose tissue of age-matched healthy and IPF donors, respectively. Cell senescence was examined by senescence-associated β-galactosidase (SA-β-gal) staining. The level of miR-199a-5p was measured by RT-PCR. Autophagy was determined using a transmission electron microscope (TEM). The therapeutic efficacy of anti-miR-199a-5p-IPF-MSCs was assessed using a mouse model of bleomycin-induced lung fibrosis. Despite similar surface makers, IPF-MSCs exhibited increased cellular senescence and decreased proliferative capacity compared with control-MSCs. The expression of miR-199a-5p was significantly enhanced in the serum of IPF patients and IPF-MSCs compared with that of healthy donors and control-MSCs. The upregulation of miR-199a-5p induced senescence of control-MSCs, whereas the downregulation rescued IPF-MSC senescence. Mechanistically, miR-155-5p suppressed autophagy of MSCs via the AMPK signaling pathway by downregulating the expression of Sirtuin 1(Sirt1), resulting in cellular senescence. Accordingly, miR-155-5p inhibition promoted autophagy and ameliorated IPF-MSC senescence by activating the Sirt1/AMPK signaling pathway. Compared with IPF-MSCs, the transplantation of anti-miR-199a-5p-IPF-MSCs increased the ability to prevent progression of pulmonary fibrosis in bleomycin-treated mice. Our study shows that miR-199a-5p regulates MSC senescence in patients with IPF by regulating the Sirt1/AMPK signaling pathway and miR-199a-5p is a novel target to rejuvenate IPF-MSCs and enhance their beneficial effects.

The application of transbronchial lung cryobiopsy (TBLC) and uniportal and tubeless video-assisted thoracic surgery (UT-VATS) in the multidisciplinary diagnosis of interstitial lung disease (ILD) has not been demonstrated in real-world clinical practice. This prospective study included 137 patients with no definitive diagnosis who were the subject of two multidisciplinary discussion (MDD) sessions. As indicated in the first MDD, 67 patients underwent UT-VATS and 70 underwent TBLC. The specificity of biopsy information and its contribution to final MDD diagnosis were evaluated in the second MDD. The post-operative complications and hospitalization costs associated with the two biopsy methods were compared. UT-VATS was favored for patients initially diagnosed with idiopathic pulmonary fibrosis (IPF), bronchiolitis-associated interstitial lung disease (RB-ILD)/desquamative interstitial pneumonia (DIP) and undefined idiopathic interstitial pneumonia (UIIP), while TBLC was preferred for pulmonary lymphangioleiomyomatosis (PLAM) and pulmonary alveolar proteinosis (PAP). The spirometry parameters were better in patients who underwent UT-VATS than those who underwent TBLC. UT-VATS provided more specific pathological results than TBLC (85.7 vs 73.7%, p = 0.06). In patients initially diagnosed with UIIP, pathological information from UT-VATS was more clinically useful than that obtained from TBLC, although both tests contributed similarly to cases initially diagnosed as interstitial pneumonia with auto-immune features (IPAF)/connective tissue disease-related ILD (CTD-ILD). The safety of UT-VATS was comparable with TBLC although TBLC was cheaper during hospitalization (US$4,855.7 vs US$3,590.9, p < 0.001). multidisciplinary discussion decisions about biopsies were driven by current knowledge of sampling and diagnosis capacity as well as potential risks of different biopsy methods. The current MDD considered UT-VATS more informative than TBLC in cases initially diagnosed as UIIP although they were equally valuable in patients initially diagnosed with IPAF/CTD-ILD.

Vascular smooth muscle cells (VSMCs) senescence contributes to abdominal aortic aneurysm (AAA) formation although the underlying mechanisms remain unclear. This study aimed to investigate the role of miR‐199a‐5p in regulating VSMC senescence in AAA. VSMC senescence was determined by a senescence‐associated β‐galactosidase (SA‐β‐gal) assay. RT‐PCR and Western blotting were performed to measure miRNA and protein level, respectively. The generation of reactive oxygen species (ROS) was evaluated by H2DCFDA staining. Dual‐luciferase reporter assay was used to validate the target gene of miR‐199a‐5p. VSMCs exhibited increased senescence in AAA tissue relative to healthy aortic tissue from control donors. Compared with VSMCs isolated from control donors (control‐VSMCs), those derived from patients with AAA (AAA‐VSMCs) exhibited increased cellular senescence and ROS production. Angiotensin II (Ang II) induced VSMC senescence by promoting ROS generation. The level of miR‐199a‐5p expression was upregulated in the plasma from AAA patients and Ang II–treated VSMCs. Mechanistically, Ang II treatment significantly elevated miR‐199a‐5p level, thereby stimulating ROS generation by repressing Sirt1 and consequent VSMC senescence. Nevertheless, Ang II–induced VSMC senescence was partially attenuated by a miR‐199a‐5p inhibitor or Sirt1 activator. Our study revealed that miR‐199a‐5p aggravates Ang II–induced VSMC senescence by targeting Sirt1 and that miR‐199a‐5p is a potential therapeutic target for AAA.

BACKGROUND:Reported data on the disease spectrum of interstitial lung diseases (ILDs) of China are sparse and varied. We aimed to investigate the spectrum of ILDs and the distribution of diagnostic methods under a uniform diagnosis.METHODS:This retrospective study enrolled ILDs cases from Guangzhou Institute of Respiratory Health (GIRH). All cases were classified into specific subgroups of ILDs according to updated guidelines.RESULTS:A total of 1,945 subjects were enrolled from January 2012 to December 2017. The mean age was 57.9 years, and 1,080 (55.5%) patients were male. The most common subtype of ILDs was idiopathic pulmonary fibrosis (IPF, 20.3%), followed by interstitial pneumonia with autoimmune features (IPAF, 17.9%), connective tissue disease associated ILD (CTD-ILD, 18.3%) and unclassifiable idiopathic interstitial pneumonia (UIIP, 14.7%). A total of 818 (42.1%) patients underwent lung biopsy in order to obtain a histological diagnose. TBLB was performed in 565 (29.0%) patients, eleven of whom underwent SLB because TBLB failed to obtain lung samples. SLB was performed in 213 (11.0%) patients and TBCB was performed in 51 (2.6%) patients. Among them, histological results were considered clinically helpful in 722 (88.3%) cases, and provided definitive histopathological diagnoses in 368 cases. Surgical lung biopsy (SLB) was performed in 213 (10.9%) subjects, while 115 (54.0%) cases were performed among the idiopathic interstitial pneumonia (IIP). Among SLB cases in IIP, the highest rate of SLB was desquamative interstitial pneumonia/respiratory bronchiolitis-interstitial lung disease (DIP/RB-ILD, 10/10), lymphoid interstitial pneumonia (LIP, 9/9), followed by cryptogenic organizing (COP, 18/26), nonspecific interstitial pneumonia (NSIP, 22/53), IPF (43/395), UIIP (13/285).CONCLUSIONS:IPF was the most common ILDs in our ILD center, followed by IPAF, CTD-ILD and UIIP. Histological information may help to establish diagnostic algorithm in ILD.

Objectives: To evaluate the efficacy and safety of ultra-low dose (100 mg) rituximab (RTX) administration in anti-melanoma differentiation-associated gene 5 (MDA5) positive patients with polymyositis/dermatomyositis (PM/DM) associated interstitial lung disease. Methods: This retrospective study included anti-MDA5 antibody positive ILD subjects in the First Affiliated Hospital of Guangzhou Medical University from November 2017 to March 2019. Independent predictors for 180-day mortality were measured by Cox regression analysis. Patients were divided into 3 groups: Group 1 (non-cyclophosphamide (CTX)/RTX) (n = 10), Group 2 (CTX only) (n = 19) and Group 3 (RTX with/without CTX) (n = 11). The 180-day mortality was compared among 3 groups with Kaplan-Meier analysis. Post-RTX serological parameters as well as adverse events were evaluated. Results: Forty patients were included with the mean age of 51.3 years. Elevated IL-10 level and CD4(+)/8(+) ratio were considered as risk factors of 180-day mortality. Kaplan-Meier analysis showed a trend toward decrease, albeit non-significant, in 180-day mortality in Group 3 (P = 0.26). The administration of 100 mg RTX brought down B cell within 7 days that lasted for 180 days. There were 7 and 6 infection events observed within 2 months of CTX/RTX treatment in Group 2 and 3, with 5 and 2 fatal cases respectively. Cytomegalovirus infection accounted for half infection events in Group 3. Conclusion: We found a pronounced and prolonged B cell depletion following 100 mg RTX infusion and RTX add-on may be effective in anti-MDA5 positive ILD patients. However, infection, especially opportunistic infection, should be concerned during the treatment.

We aimed to evaluate the alteration of diagnosis of individual expert and multidisciplinary discussion (MDD) team in the longitudinal diagnostic assessment of idiopathic interstitial pneumonia (IIP). The retrospective analysis included 56 patients diagnosed as IIP by The First Affiliated Hospital of Guangzhou Medical University with follow-up visits during Jan 1st to Aug 31st 2014. Each expert was provided information in a sequential manner and was asked to assign an individual diagnosis and an MDD diagnosis after group discussion. The level of agreement among individual experts and between different visits was calculated by kappa and the agreement between individual specialist and MDD team with different consensus levels was measured by weighted-kappa coefficients. Follow-up data changed the original clinical diagnosis and MDD diagnosis in 24.1% and 10.7% of all cases, respectively, and clinician and MDD consensus level in 55.4% and 25.0%, respectively. The diagnostic performance of individual clinicians or radiologist was closer to that of the MDD compared with the pathologist, and follow-up further increased the agreement. The longitudinal evaluation of patients with IIP improved the inter-observer agreement in a multidisciplinary team. The performance of individual clinicians or radiologist was approaching the accuracy of multidisciplinary team when provided with follow-up data.

Mesenchymal stem cells (MSCs) have shown beneficial effects in the treatment of abdominal aortic aneurysm (AAA). Nonetheless, the biological properties of adipose-derived MSCs (ASCs) from patients with AAA (AAA-ASCs) remain unclear. This study is aimed at investigating the properties of cell phenotype and function of AAA-ASCs compared with ASCs from age-matched healthy donors (H-ASCs). H-ASCs and AAA-ASCs were studied for cell phenotype, differentiation capacity, senescence, and mitochondrial and autophagic functions. Cellular senescence was examined by senescence-associated β-galactosidase (SA-β-gal) staining. Mitochondrial morphology was determined by MitoTracker staining. Despite the similar surface markers of AAA-ASCs and H-ASCs, AAA-ASCs exhibited altered multidifferentiation potential. Compared with H-ASCs, AAA-ASCs displayed enhanced senescence manifested by increased SA-β-gal activity and decreased proliferation and migration ability. Furthermore, AAA-ASCs showed increased mitochondrial fusion, reactive oxygen species (ROS) production, and decreased mitochondrial membrane potential. In addition, AAA-ASCs exhibited decreased autophagy level, upregulation of IL-6 and TNF-α secretion, and downregulation of IL-10 secretion compared with H-ASCs. Nonetheless, treatment of AAA-ASCs with rapamycin (an autophagy activator) dramatically reduced secretion of IL-6 and TNF-α and enhanced secretion of IL-10. In conclusion, our study showed that AAA-ASCs exhibit senescence phenomena and decreased cell function. Understanding the specific alterations in AAA-ASCs will help explore novel strategies to restore cell function for AAA treatment.

利妥昔单抗是一种人鼠嵌合性单克隆抗体,通过特异性结合CD20抗原靶向杀伤B细胞,目前逐渐应用于特发性炎性肌病(idiopathic inflammatory myositis, IIM).抗合成酶综合征(anti?synthetase syndrome, ASS)是IIM中最常见的亚型,常合并间质性肺疾病(interstitial lung disease, ILD),大部分ASS?ILD患者对糖皮质激素和(或)免疫抑制剂治疗反应好、预后佳;但有小部分患者对治疗反应差,病情持续进展,病死率高,称难治性ASS?ILD.近年来,临床实践表明利妥昔单抗可改善此类患者临床症状及预后,具有较好的安全性;本文就利妥昔单抗的作用机制及其在ASS?ILD中的应用展开综述.