Effect of antifibrotic agents on postoperative complications after lung transplantation for idiopathic pulmonary fibrosis.

BACKGROUND: Antifibrotic agents (AFAs) are now standard-of-care for idiopathic pulmonary fibrosis (IPF). Concerns have arisen about the safety of these drugs in patients undergoing lung transplantation (LTx). METHODS: We performed a multi-centre, nationwide, retrospective, observational study of French IPF patients undergoing LTx between 2011 and 2018 to determine whether maintaining AFAs in the peri-operative period leads to increased bronchial anastomoses issues, delay in skin healing and haemorrhagic complications. We compared the incidence of post-operative complications and the survival of patients according to AFA exposure. RESULTS: Among 205 patients who underwent LTx for IPF during the study period, 58 (28%) had received AFAs within 4 weeks before LTx (AFA group): pirfenidone in 37 (18.0%) and nintedanib in 21 (10.2%). The median duration of AFA treatment before LTx was 13.8 (5.6-24) months. The AFA and control groups did not significantly differ in airway, bleeding or skin healing complications (p = 0.91, p = 0.12 and p = 0.70, respectively). Primary graft dysfunction was less frequent in the AFA than control group (26% vs. 43%, p = 0.02), and the 90-day mortality was lower (7% vs. 18%, p = 0.046). CONCLUSIONS: AFA therapy did not increase airway, bleeding or wound post-operative complications after LTx and could be associated with reduced rates of primary graft dysfunction and 90-day mortality.

[Pharmacological prevention of fibrosis in dacryosurgery]. / Medikamentoznaya profilaktika fibrotizatsii v dakriokhirurgii.

Chronic inflammatory process in the lacrimal drainage system is the main etiological factor leading to dacryostenosis and consequent obliteration - partial and total nasolacrimal duct obstruction. Prevention of this process is an urgent problem in dacryology. Currently, there is very little research on the development and use of conservative methods for treating dacryostenosis using anti-inflammatory, as well as anti-fibrotic drugs. In this regard, the main method of treating lacrimal drainage obstruction is dacryocystorhinostomy. However, the problem of recurrence after this operation has not been resolved. The causes of recurrence can be cicatricial healing of dacryocystorhinostomy ostium, canalicular obstruction, formation of granulations and synechiae in its area. Surgical methods of recurrence prevention are associated with possible complications, and there is conflicting data on the feasibility of their use. Based on this, the development of pharmacological methods for the prevention of fibrosis in dacryology is promising, among which the antitumor antibiotic Mitomycin C is the most studied. However, there are no specific scientifically substantiated recommendations for the use of this drug, and the data on its effectiveness vary. This has prompted researchers to look for and study alternative anti-fibrotic agents, such as antitumor drugs, glucocorticoids, hyaluronic acid, small molecule, biological, immunological and genetically engineered drugs, as well as nanoparticles. This review presents the current data on the efficacy and prospects of the use of these drugs in dacryology.

Geriatric Nutritional Risk Index is a predictor of tolerability of antifibrotic therapy and mortality risk in patients with idiopathic pulmonary fibrosis.

BACKGROUND AND OBJECTIVE: Idiopathic pulmonary fibrosis (IPF) is characterized by progressive lung fibrosis of unknown aetiology. Epidemiological studies have suggested that IPF progression may negatively affect nutritional status. Weight loss during antifibrotic therapy is also frequently encountered. The association of nutritional status and outcome has not been fully evaluated in IPF patients. METHODS: This retrospective multicohort study assessed nutritional status of 301 IPF patients receiving antifibrotic therapy (Hamamatsu cohort, n = 151; Seirei cohort, n = 150). Nutritional status was evaluated using the Geriatric Nutritional Risk Index (GNRI). The GNRI was calculated based on body mass index and serum albumin. The relationship between nutritional status and tolerability of antifibrotic therapy as well as mortality was explored. RESULTS: Of 301 patients, 113 (37.5%) had malnutrition-related risk (GNRI < 98). Patients with malnutrition-related risk were older, had increased exacerbations and worse pulmonary function than those without a GNRI status <98. Malnutrition-related risk was associated with a higher incidence of discontinuation of antifibrotic therapy, particulary due to gastrointestinal disturbances. IPF patients with malnutrition-related risk (GNRI < 98) had shorter survival than those without such risk (median survival: 25.9 vs. 41.1 months, p < 0.001). In multivariate analysis, malnutrition-related risk was a prognostic indicator of antifibrotic therapy discontinuation and mortality, independent of age, sex, forced vital capacity, or gender-age-physiology index. CONCLUSION: Nutritional status has significant effects on the treatment and outcome in patients with IPF. Assessment of nutritional status may provide important information for managing patients with IPF.

Observational, Multicenter Study on the Efficacy, Tolerability, and Safety of Nintedanib in Patients with Idiopathic Pulmonary Fibrosis Older than 80 Years.

BACKGROUND: Idiopathic pulmonary fibrosis (IPF) primarily affects old patients. Old age is a predictor of mortality. Nintedanib, the only antifibrotic drug approved in Italy for patients aged >80 years, can slow the progression of IPF by reducing the rate of decline in forced vital capacity (FVC) and the risk of exacerbations. OBJECTIVES: The primary aim of the study was to compare the decline of FVC after 12 months of nintedanib in patients aged >80 years versus younger patients. Differences related to other functional data, safety, tolerability, hospitalizations, exacerbations, and mortality were evaluated. METHODS: An observational, retrospective, multicenter study was carried out in Italy. RESULTS: 159 (122 [76.7%] males) patients were recruited: 106 (66.7%) aged ≤80 years and 53 (33.3%) aged >80 years. FVC decline after 12 months of therapy was not significantly different (-45 mL [-170; 75] vs. -20 mL [-138; 110] mL; p: 0.51). No differences were found for other functional data. Diarrhea was the most frequent adverse event (AE). Rate and type of any AEs, permanent/temporary dose reduction, or drug discontinuation were not significantly different between patients aged ≤80 vs. >80 years. Furthermore, acute exacerbations, hospitalization, and mortality were not significantly different. CONCLUSIONS: Nintedanib is effective and safe in patients with IPF aged >80 years, and no significant differences were found when clinical outcomes were compared with those of younger patients. Thus, older age should not be a barrier for the early prescription of antifibrotic treatment in IPF patients.

Overall drug treatment of idiopathic pulmonary fibrosis patients from national registries - a real-world study from Finland.

BACKGROUND: Currently, two disease-modifying antifibrotic drugs are indicated for the treatment of idiopathic pulmonary fibrosis. The objective of this study was to analyse antifibrotic and overall prescription medication use of IPF patients in the real world. METHODS: Data was collected from the FinnishIPF registry and the Registry of the Social Insurance Institution of Finland (SII). Purchases of all prescription medicines were assessed. The frequency, the initiation interval, the duration, and the breaks of the antifibrotic treatments were defined. The association between the prescription of antifibrotic therapy and different patient-related clinical parameters was studied. Accordingly, the relationships between the delay in starting therapy and patient-related variables were analysed. RESULTS: Of the 263 IPF patients, 132 (50.2%) had started antifibrotic treatment during the study period 2011-2018. The mean interval from the diagnosis to the first purchase was 367 (SD 429) days. The antifibrotic drug was switched in 14% of patients. Discontinuation of therapy occurred most commonly during the first year of the treatment. The one-year persistence was 77.1% for pirfenidone and 78.9% for nintedanib. A tendency of treating patients under 75 years was noticed. Low forced vital capacity predicted earlier initiation of medication. CONCLUSIONS: The initiation of antifibrotics after diagnosis was slow, probably due to reimbursement limitations. Younger age at diagnosis affected treatment initiation although it is unknown which patients benefit most from these medications. The reasons for discontinuation of the antifibrotic therapy during the first year should be a focus in clinical work and further studies.

Blood Immunophenotypes of Idiopathic Pulmonary Fibrosis: Relationship with Disease Severity and Progression.

(1) The role of the immune response in the pathogenesis of idiopathic pulmonary fibrosis (IPF) remains controversial. We hypothesized that peripheral blood immune phenotypes will be different in IPF patients and may relate to the disease severity and progression. (2) Whole blood flow cytometry staining was performed at diagnosis in 32 IPF patients, and in 32 age- and smoking-matched healthy controls. Thirty-one IPF patients were followed up for one year and categorized as stable or progressors based on lung function, deterioration and/or death. At 18-60 months, immunophenotypes were characterized again. (3) The main results showed that: (1) compared to matched controls, at diagnosis, patients with IPF showed more neutrophils, CD8+HLA-DR+ and CD8+CD28- T cells, and fewer B lymphocytes and naïve T cells; (2) in IPF, circulating neutrophils, eosinophils and naïve T cells were associated with lung function abnormalities; (3) patients whose disease progressed during the 12 months of follow-up showed evidence of cytotoxic dysregulation, with increased CD8+CD28- T cells, decreased naïve T cells and an inverted CD4/CD8 ratio at baseline; and (4) blood cell alterations were stable over time in survivors. (4) IPF is associated with abnormalities in circulating immune cells, particularly in the cytotoxic cell domain. Patients with progressive IPF, despite antifibrotic therapy, present an over-activated and exhausted immunophenotype at diagnosis, which is maintained over time.

Nintedanib modulates type III collagen turnover in viable precision-cut lung slices from bleomycin-treated rats and patients with pulmonary fibrosis.

BACKGROUND: Aberrant extracellular matrix (ECM) deposition and remodelling is important in the disease pathogenesis of pulmonary fibrosis (PF). We characterised neoepitope biomarkers released by ECM turnover in lung tissue from bleomycin-treated rats and patients with PF and analysed the effects of two antifibrotic drugs: nintedanib and pirfenidone. METHODS: Precision-cut lung slices (PCLS) were prepared from bleomycin-treated rats or patients with PF. PCLS were incubated with nintedanib or pirfenidone for 48 h, and levels of neoepitope biomarkers of type I, III and VI collagen formation or degradation (PRO-C1, PRO-C3, PRO-C6 and C3M) as well as fibronectin (FBN-C) were assessed in the culture supernatants. RESULTS: In rat PCLS, incubation with nintedanib led to a reduction in C3M, reflecting type III collagen degradation. In patient PCLS, incubation with nintedanib reduced the levels of PRO-C3 and C3M, thus showing effects on both formation and degradation of type III collagen. Incubation with pirfenidone had a marginal effect on PRO-C3. There were no other notable effects of either nintedanib or pirfenidone on the other neoepitope biomarkers studied. CONCLUSIONS: This study demonstrated that nintedanib modulates neoepitope biomarkers of type III collagen turnover and indicated that C3M is a promising translational neoepitope biomarker of PF in terms of therapy assessment.

[Pulmonary fibrosis in patients with COVID-19: A review].

The viral infectious disease pandemic caused by SARS-CoV-2 has affected over 500 million people and killed over 6 million. This is the official data provided by the WHO as of the end of May 2022. Among people who have recovered from COVID-19, post-COVID syndrome is quite common. Scattered epidemiological studies on post-COVID syndrome, however, indicate its high relevance. One of the manifestations of post-COVID syndrome is the development of pulmonary fibrosis (PF). This article is devoted to the analysis of literature data on epidemiology, immunomorphology, as well as X-ray morphological and functional characteristics of PF in patients with post-COVID syndrome. Attention is drawn to the various phenotypes of the post-COVID syndrome and the incidence of PF, which, as clinical practice shows, is most common in people who have had severe COVID-19. This article discusses in detail the molecular biological and immunological mechanisms of PF development. The fibrotic process of the lung parenchyma is not an early manifestation of the disease; as a rule, radiomorphological signs of this pathological process develop after four weeks from the onset of acute manifestations of a viral infection. The characteristic signs of PF include those that indicate the process of remodulation of the lung tissue: volumetric decrease in the lungs, "cellular" degeneration of the lung parenchyma, bronchiectasis and traction bronchiolectasis. The process of remodulating the lung tissue, in the process of fibrosis, is accompanied by a violation of the lung function; a particularly sensitive test of functional disorders is a decrease in the diffusion capacity of the lung tissue. Therefore, in the process of monitoring patients with post-COVID syndrome, a dynamic study of the ventilation function of the lungs is recommended. The main clinical manifestation of PF is dyspnea that occurs with minimal exertion. Shortness of breath also reflects another important aspect of fibrous remodulation of the lung parenchyma - oxygen dissociation is disturbed, which reflects a violation of the gas exchange function of the lungs. There are no generally accepted treatments for PF in post-COVID syndrome. The literature considers such approaches as the possibility of prescribing antifibrotic therapy, hyaluronidase, and medical gases: thermal helium, nitric oxide, and atomic hydrogen. The article draws attention to the unresolved issues of post-covid PF in people who have had COVID-19.

Clinical course of IPF in Italian patients during 12 months of observation: results from the FIBRONET observational study.

BACKGROUND: FIBRONET was an observational, multicentre, prospective cohort study investigating the baseline characteristics, clinical course of disease and use of antifibrotic treatment in Italian patients with idiopathic pulmonary fibrosis (IPF). METHODS: Patients aged ≥ 40 years diagnosed with IPF within the previous 3 months at 20 Italian centres were consecutively enrolled and followed up for 12 months, with evaluations at 3, 6, 9 and 12 months. The primary objective was to describe the clinical course of IPF over 12 months of follow-up, including changes in lung function measured by % predicted forced vital capacity (FVC% predicted). RESULTS: 209 patients (82.3% male, mean age 69.54 ± 7.43 years) were enrolled. Mean FVC% predicted was relatively preserved at baseline (80.01%). The mean time between IPF diagnosis and initiation of antifibrotic therapy was 6.38 weeks; 72.3% of patients received antifibrotic therapy within the first 3 months of follow-up, and 83.9% within 12 months of follow-up. Mean FVC% predicted was 80.0% at baseline and 82.2% at 12 months, and 47.4% of patients remained stable (i.e. had no disease progression) in terms of FVC% predicted during the study. CONCLUSIONS: FIBRONET is the first prospective, real-life, observational study of patients with IPF in Italy. The short time between diagnosis and initiation of antifibrotic therapy, and the stable lung function between baseline and 12 months, suggest that early diagnosis and prompt initiation of antifibrotic therapy may preserve lung function in patients with IPF. TRIAL REGISTRATION: NCT02803580.

Cause of mortality and sarcopenia in patients with idiopathic pulmonary fibrosis receiving antifibrotic therapy.

BACKGROUND AND OBJECTIVE: Recent research has highlighted the fundamental role of sarcopenia, characterized by loss of skeletal muscle mass and strength, with a risk of poor outcomes. AFT preserves lung function by preventing the annual decline in FVC and is associated with improved outcomes in patients with IPF. However, altered cause of death and prognostic implications of sarcopenia in patients with IPF receiving AFT remain unknown. METHODS: This study comprised two cohorts of patients with IPF receiving AFT, historical cohort of IPF patients without AFT and controls. The cause of mortality was compared with a historical cohort. Sarcopenia was assessed by measuring the ESMCSA and ESMMA via CT. RESULTS: Patients with IPF had smaller ESMCSA and lower ESMMA but similar BMI than controls, suggesting patients with IPF had skeletal muscle loss without any obvious body weight loss. The most common cause of mortality in patients receiving AFT was chronic respiratory failure, accounting for approximately 60%, and decreased proportions of LC were found. Subsequently, low ESMCSA was an independent prognostic factor associated with worse survival rates. Furthermore, combined assessment of ESMCSA , %FVC predicted and BMI values provided clear prognostic distinction. CONCLUSION: Patients with IPF receiving AFT showed skeletal muscle loss without obvious weight loss. These patients mostly died by chronic respiratory failure, and skeletal muscle wasting has prognostic significance, suggesting that preventing sarcopenia as well as preserving lung function are important for managing these patients.

Outcomes of patients with advanced idiopathic pulmonary fibrosis treated with nintedanib or pirfenidone in a real-world multicentre cohort.

BACKGROUND AND OBJECTIVE: Antifibrotic therapy with nintedanib or pirfenidone slows disease progression and reduces mortality in patients with idiopathic pulmonary fibrosis (IPF). However, patients with advanced IPF, as defined by forced vital capacity (FVC) < 50% and/or diffusion capacity for carbon monoxide (DLCO) < 30% of predicted, have not been included in randomized trials, and the outcomes of such patients who initiate treatment are not well understood. We determined lung function, disease progression and mortality outcomes following initiation of antifibrotic therapy in patients with advanced IPF at the time of treatment initiation compared to those with mild-moderate IPF. METHODS: We included 502 patients enrolled in IPF registries from four Nordic countries. Linear mixed models were used to assess change in FVC and DLCO over time. Cox proportional hazards models were used to assess transplant-free survival and progression- and transplant-free survival. RESULTS: Of 502 patients, 66 (13%) had advanced IPF. Annual change in FVC was -125 ml (95% CI -163, -87) among patients with mild-moderate IPF, and +28 ml (95% CI -96, +152) among those with advanced IPF. Advanced IPF at treatment initiation was associated with poorer transplant-free survival (hazard ratio [HR] 2.39 [95% CI 1.66, 3.43]) and progression- and transplant-free survival (HR 1.60 [95% CI 1.15, 2.23]). CONCLUSION: In a broadly representative IPF population, patients with advanced IPF at the initiation of antifibrotic therapy did not have greater lung function decline over time compared with those with mild-moderate IPF, but had substantially higher mortality. Prospective studies are needed to determine the effect of antifibrotic therapy in patients with advanced IPF.

Switching antifibrotics in patients with idiopathic pulmonary fibrosis: a multi-center retrospective cohort study.

BACKGROUND: Currently, there are two antifibrotics used to treat idiopathic pulmonary fibrosis (IPF): pirfenidone and nintedanib. Antifibrotics slow disease progression by reducing the annual decline of forced vital capacity (FVC), which possibly improves outcomes in IPF patients. During treatment, patients occasionally switch antifibrotic treatments. However, prognostic implication of changing antifibrotics has not yet been evaluated. METHODS: This multi-center retrospective cohort study examined 262 consecutive IPF patients who received antifibrotic therapy. Antifibrotic agents were switched in 37 patients (14.1%). The prognoses were compared between the patient cohort that switched antifibrotics (Switch-IPF) and those without (Non-Switch-IPF) using propensity-score matched analyses. RESULTS: The median period between the initiation of antifibrotic therapy and the drug switch was 25.8 (12.7-35.3) months. The most common reasons for the switch were disease progression (n = 17) followed by gastrointestinal disorders (n = 12). Of the 37 patients that switched antifibrotics, only eight patients disrupted switched antifibrotics by their adverse reactions. The overall prognosis of the Switch-IPF cohort was significantly better than the Non-Switch-IPF cohort (median periods: 67.2 vs. 27.1 months, p < 0.0001). In propensity-score matched analyses that were adjusted to age, sex, FVC (%), history of acute exacerbation, and usage of long-term oxygen therapy, the Switch-IPF cohort had significantly longer survival times than the Non-Switch-IPF group (median 67.2 vs. 41.3 months, p = 0.0219). The second-line antifibrotic therapy showed similar survival probabilities than those in first-line antifibrotic therapy in multistate model analyses. CONCLUSION: Switching antifibrotics is feasible and may improve prognosis in patients with IPF. A further prospective study will be required to confirm clinical implication of switching the antifibrotics.

Sorafenib reduces steatosis-induced fibrogenesis in a human 3D co-culture model of non-alcoholic fatty liver disease.

Non-alcoholic fatty liver disease (NAFLD) affects around 25% of the worldwide population. Non-alcoholic steatohepatitis (NASH), the more progressive variant of NAFLD, is characterized by steatosis, cellular ballooning, lobular inflammation, and may culminate on hepatic stellate cell (HSC) activation, thus increasing the risk for fibrosis, cirrhosis, and HCC development. Conversely, the antifibrotic effects of sorafenib, an FDA-approved drug for HCC treatment, have been demonstrated in 2D cell cultures and animal models, but its mechanisms in a NAFLD-related microenvironment in vitro requires further investigation. Thus, a human 3D co-culture model of fatty hepatocytes and HSC was established by culturing hepatoma C3A cells, pre-treated with 1.32 mM oleic acid, with HSC LX-2 cells. The fatty C3A/LX-2 spheroids showed morphological and molecular hallmarks of altered lipid metabolism and steatosis-induced fibrogenesis, similarly to the human disease. Sorafenib (15 µM) for 72 hours reduced fatty spheroid viability, and upregulated the expression of lipid oxidation- and hydrolysis-related genes, CPT1 and LIPC, respectively. Sorafenib also inhibited steatosis-induced fibrogenesis by downregulating COL1A1, TGFB1, PDGF, and TIMP1 and by decreasing protein levels of IL-6, TGF-ß1, and TNF-α in fatty spheroids. The demonstration of the antifibrotic properties of sorafenib on steatosis-induced fibrogenesis in a 3D in vitro model of NAFLD supports its clinical use as a therapeutic agent for the treatment of NAFLD/NASH patients.

[Experimental investigation of the efficacy of pirfenidone in prevention of ostium cicatricial closure after dacryocystorhinostomy]. / Eksperimental'noe obosnovanie effektivnosti pirfenidona v predotvrashchenii rubtsovogo zarashcheniya iskusstvennogo soust'ya posle dakriotsistorinostomii.

One of the main reasons of failure of dacryocystorhinostomy (DCR) is cicatricial closure of the ostium. Finding a way to prevent this outcome remains one of the leading aims of research in dacryology. The effectiveness of the most widespread methods is often considered contradictory by various researchers. Pirfenidone is a small-molecule agent that demonstrated good antifibrotic effect and low toxicity in previous in vitro research. There haven't been any in vivo studies of its intraoperative use in DCR.Purpose - to determine the in vivo efficacy of pirfenidone in prevention of ostium cicatricial closure following dacryocystorhinostomy in an animal experiment. MATERIAL AND METHODS: The study was conducted on 18 Chinchilla rabbits. They were divided into 3 groups and each animal underwent modified dacryocystorhinostomy. On the final stage of surgery rabbits of group 1 were injected 1 ml of 0.15 mg/ml pirfenidone solution, rabbits of group 2 - 0.3 mg/ml pirfenidone solution. No injections were performed in group 3. Animals were terminated on days 7 (6 rabbits), 14 (6 rabbits) and 28 (6 rabbits) following surgery. Lacrimal stoma patency was evaluated in vivo by irrigation, and morphologically postmortem. Tissue samples obtained from the stoma area were examined histologically for signs of fibrosis. RESULTS: Failure of dacryocystorhinostomy was observed in 4 out of 18 cases: all rabbits of group 3 terminated on days 14 and 28. The most pronounced morphological signs of fibrosis were also noted in group 3. No topical or systemic adverse effects of the medication were observed in groups 1 and 2. CONCLUSION: Pirfenidone demonstrated high antifibrotic efficacy and low toxicity in experimental dacrycystorhinostomy in rabbits. These results provide grounds for further research into the use of pirfenidone in dacrycystorhinostomy.

Rilpivirine attenuates liver fibrosis through selective STAT1-mediated apoptosis in hepatic stellate cells.

OBJECTIVE: Liver fibrosis constitutes a major health problem worldwide due to its rapidly increasing prevalence and the lack of specific and effective treatments. Growing evidence suggests that signalling through cytokine-activated Janus kinase (JAK)-signal transducer and activator of transcription (STAT) pathways regulates liver fibrosis and regeneration. Rilpivirine (RPV) is a widely used anti-HIV drug not reported to produce hepatotoxicity. We aimed to describe the potential hepatoprotective effects of RPV in different models of chronic liver injury, focusing on JAK-STAT signalling regulation. DESIGN: The effects of RPV on hepatic steatosis, inflammation and fibrogenesis were studied in a nutritional mouse model of non-alcoholic fatty liver disease, carbon tetrachloride-induced fibrosis and bile duct ligation-induced fibrosis. Primary human hepatic stellate cells (hHSC) and human cell lines LX-2 and Hep3B were used to investigate the underlying molecular mechanisms. RESULTS: RPV exerted a clear anti-inflammatory and antifibrotic effect in all the in vivo models of liver injury employed, and enhanced STAT3-dependent proliferation in hepatocytes and apoptosis in HSC through selective STAT1 activation. These results were reproduced in vitro; RPV undermined STAT3 activation and triggered STAT1-mediated pathways and apoptosis in HSC. Interestingly, this selective pro-apoptotic effect completely disappeared when STAT1 was silenced. Conditioned medium experiments showed that HSC apoptosis activated STAT3 in hepatocytes in an interleukin-6-dependent mechanism. CONCLUSION: RPV ameliorates liver fibrosis through selective STAT1-dependent induction of apoptosis in HSC, which exert paracrinal effects in hepatocytes, thus promoting liver regeneration. RPV's actions may represent an effective strategy to treat chronic liver diseases of different aetiologies and help identify novel therapeutic targets.

Antifibrotic therapy to normalize the tumor microenvironment.

Most tumors develop abnormal fibrotic regions consisting of fibroblasts, immune cells, and a dense extracellular matrix (ECM) immersed in a viscous interstitial fluid, and an abundant fibrotic tumor microenvironment (TME) is associated with poor outcome of treatment. It has been hypothesized that the treatment of cancer may be improved by interventions aiming to normalize this TME. The approaches used in attempts to normalize the fibrotic TME can be categorized into three strategies of targeted antifibrotic therapy: targeting of components of the ECM, targeting of the producers of the ECM components-the activated cancer-associated fibroblasts (CAFs), and targeting of the signaling pathways activating CAFs. To target the ECM, enzymes against components of the ECM have been used, including collagenase, relaxin, hyaluronidase, and lyxyl oxidase. Targeting of CAFs have been investigated by using agents aiming to eliminate or reprogram CAFs. CAFs are activated primarily by transforming growth factor-ß (TGF-ß), hedgehog, or focal adhesion kinase signaling, and several agents have been used to target these signaling pathways, including angiotensin II receptor I blockers (e.g., losartan) to inhibit the TGF-ß pathway. Taken together, these studies have revealed that antifibrotic therapy is a two-edged sword: while some studies suggest enhanced response to treatment after antifibrotic therapy, others suggest that antifibrotic therapy may lead to increased tumor growth, metastasis, and impaired outcome of treatment. There are several possible explanations of these conflicting observations. Most importantly, tumors contain different subpopulations of CAFs, and while some subpopulations may promote tumor growth and metastasis, others may inhibit malignant progression. Furthermore, the outcome of antifibrotic therapy may depend on stage of disease, duration of treatment, treatment-induced activation of alternative profibrotic signaling pathways, and treatment-induced recruitment of tumor-supporting immune cells. Nevertheless, losartan-induced suppression of TGF-ß signaling appears to be a particularly promising strategy. Losartan is a widely prescribed antihypertensive drug and highly advantageous therapeutic effects have been observed after losartan treatment of pancreatic cancer. However, improved understanding of the mechanisms governing the development of fibrosis in tumors is needed before safe antifibrotic treatments can be established.

Increased expression of the transforming growth factor ß-inducible gene HIC-5 in systemic sclerosis skin and fibroblasts: a novel antifibrotic therapeutic target.

OBJECTIVE: SSc is a systemic fibrotic disease affecting skin, numerous internal organs and the microvasculature. The molecular pathogenesis of SSc tissue fibrosis has not been fully elucidated, although TGF-ß1 plays a crucial role. The Hic-5 protein encoded by the TGF-ß1-inducible HIC-5 gene participates in numerous TGF-ß-mediated pathways, however, the role of Hic-5 in SSc fibrosis has not been investigated. The aim of this study was to examine HIC-5 involvement in SSc tissue fibrosis. METHODS: Affected skin from three patients with diffuse SSc and dermal fibroblasts cultured from affected and non-affected SSc skin were examined for HIC-5 and COL1A1 gene expression. Real-time PCR, IF microscopy, western blotting and small interfering RNA-mediated HIC-5 were performed. RESULTS: HIC-5 and COL1A1 transcripts and Hic-5, type 1 collagen (COL1) and α-smooth muscle actin (α-SMA) protein levels were increased in clinically affected SSc skin compared with normal skin and in cultured dermal fibroblasts from affected SSc skin compared with non-affected skin fibroblasts from the same patients. HIC-5 knockdown caused a marked reduction of COL1 production in SSc dermal fibroblasts. CONCLUSION: HIC-5 expression is increased in affected SSc skin compared with skin from normal individuals. Affected SSc skin fibroblasts display increased HIC-5 and COL1A1 expression compared with non-affected skin fibroblasts from the same patients. Hic-5 protein was significantly increased in cultured SSc dermal fibroblasts. HIC-5 mRNA knockdown in SSc fibroblasts caused >50% reduction of COL1 production. Although these are preliminary results owing to the small number of skin samples studied, they indicate that Hic-5 plays a role in the profibrotic activation of SSc dermal fibroblasts and may represent a novel molecular target for antifibrotic therapy in SSc.

Intercellular crosstalk of hepatic stellate cells in liver fibrosis: New insights into therapy.

Liver fibrosis is a dynamic wound-healing process characterized by the net accumulation of extracellular matrix. There is no efficient antifibrotic therapy other than liver transplantation to date. Activated hepatic stellate cells (HSCs) are the major cellular source of matrix-producing myofibroblasts, playing a central role in the initiation and progression of liver fibrosis. Paracrine signals from resident and inflammatory cells such as hepatocytes, liver sinusoidal endothelial cells, hepatic macrophages, natural killer/natural killer T cells, biliary epithelial cells, hepatic progenitor cells, and platelets can directly or indirectly regulate HSC differentiation and activation. Intercellular crosstalk between HSCs and those "responded" cells has been a critical event involved in HSC activation and fibrogenesis. This review summarizes recent advancement regarding intercellular communication between HSCs and other "responded cells" during liver fibrosis and experimental models of intercellular crosstalk systems, and provides novel ideas for potential antifibrotic therapeutic strategy.

Advances in Targeted Therapy for Progressive Fibrosing Interstitial Lung Disease.

Progressive fibrosing interstitial lung disease (PF-ILD) has been redefined as a new clinical syndrome that shares similar genetics, pathophysiology, and natural history to idiopathic pulmonary fibrosis (IPF). IPF is the most common form of idiopathic interstitial pneumonias, which is progressive in nature and is associated with significant mortality. Therapies targeting an inflammatory and/or immune response have not been consistently effective or well tolerated in patients with IPF. The two antifibrotic drugs approved for IPF treatment, nintedanib and pirfenidone, have been shown to reduce lung function decline in PF-ILD. Novel uses of antifibrotic therapy are emerging due to a paucity of evidence-based treatments for multiple ILD subtypes. In this review, we describe the current body of knowledge on antifibrotic therapy and immunomodulators in PF-ILD, drawing from experience in IPF where appropriate.

Diagnostic Likelihood Thresholds That Define a Working Diagnosis of Idiopathic Pulmonary Fibrosis.

Rationale: The level of diagnostic likelihood at which physicians prescribe antifibrotic therapy without requesting surgical lung biopsy (SLB) in patients suspected of idiopathic pulmonary fibrosis (IPF) is unknown.Objectives: To determine how often physicians advocate SLB in patient subgroups defined by IPF likelihood and risk associated with SLB, and to identify the level of diagnostic likelihood at which physicians prescribe antifibrotic therapy with requesting SLB.Methods: An international cohort of respiratory physicians evaluated 60 cases of interstitial lung disease, giving: 1) differential diagnoses with diagnostic likelihood; 2) a decision on the need for SLB; and 3) initial management. Diagnoses were stratified according to diagnostic likelihood bands described by Ryerson and colleagues.Measurements and Main Results: A total of 404 physicians evaluated the 60 cases (24,240 physician-patient evaluations). IPF was part of the differential diagnosis in 9,958/24,240 (41.1%) of all physician-patient evaluations. SLB was requested in 8.1%, 29.6%, and 48.4% of definite, provisional high-confidence and provisional low-confidence diagnoses of IPF, respectively. In 63.0% of provisional high-confidence IPF diagnoses, antifibrotic therapy was prescribed without requesting SLB. No significant mortality difference was observed between cases given a definite diagnosis of IPF (90-100% diagnostic likelihood) and cases given a provisional high-confidence IPF diagnosis (hazard ratio, 0.97; P = 0.65; 95% confidence interval, 0.90-1.04).Conclusions: Most respiratory physicians prescribe antifibrotic therapy without requesting an SLB if a provisional high-confidence diagnosis or "working diagnosis" of IPF can be made (likelihood ≥ 70%). SLB is recommended in only a minority of patients with suspected, but not definite, IPF.