Lung cancer is an important complication of combined pulmonary fibrosis and emphysema (CPFE). Whether the risk of lung cancer is higher in CPFE patients with usual interstitial pneumonia (UIP) than those with idiopathic pulmonary fibrosis (IPF) alone, remains controversial. We conducted this systematic review and meta-analysis to evaluate the prevalence of lung cancer in CPFE patients with UIP compared with IPF patients.
We searched the PubMed, Embase, and Cochrane databases for studies that focused on the incidence of lung cancer in CPFE/UIP and IPF groups. We used a fixed-effects model to analyze the odds ratios (ORs) with 95% confidence intervals (CIs) according to data heterogeneity. The cumulative effects based on the publication year and sample size were assessed by cumulative meta-analysis.
A total of nine studies with 933 patients, including 374 CPFE patients with UIP, fulfilled the inclusion criteria. Overall, CPFE patients with UIP have a higher risk of lung cancer than those with IPF alone (OR = 2.69; 95% CI: 1.78-4.05). There were increased risks of lung cancer in CPFE/UIP patients with the presence of emphysema (OR = 2.93; 95% CI: 1.79-4.79) or emphysema in ⩾10% of the lung volume (OR = 2.22; 95% CI: 1.06-4.68).
Our systematic review and meta-analysis indicated a significantly higher prevalence of lung cancer in CPFE patients with UIP than in patients with IPF alone.The reviews of this paper are available via the supplemental material section.

Riociguat in Patients with Symptomatic Pulmonary Hypertension associated with Idiopathic Interstitial Pneumonias (RISE-IIP), a randomized, controlled, phase 2b trial of riociguat for pulmonary hypertension associated with idiopathic interstitial pneumonia, was terminated early due to increased mortality in riociguat-treated patients. Baseline characteristics of enrolled patients demonstrated a low diffusing capacity of the lung for carbon monoxide (DLCO) with preserved lung volumes at baseline, suggesting the presence of combined pulmonary fibrosis and emphysema (CPFE) in some patients. This post hoc analysis of RISE-IIP was undertaken to explore lung morphology, assessed by high-resolution computed tomography, and associated clinical outcomes.
Available baseline/pre-baseline high-resolution computed tomography scans were reviewed centrally by 2 radiologists. The extent of emphysema and fibrosis was retrospectively scored and combined to provide the total CPFE score.
Data were available for 65/147 patients (44%), including 15/27 fatal cases (56%). Of these, 41/65 patients (63%) had CPFE. Mortality was higher in patients with CPFE (12/41; 29%) than those without (3/24; 13%). Fourteen patients with CPFE had emphysema > fibrosis (4 died). No relationship was observed between CPFE score, survival status, and treatment assignment. A low DLCO, short 6-min walking distance, and high forced vital capacity:DLCO ratio at baseline also appeared to be risk factors for mortality.
High parenchymal lung disease burden and the presence of more emphysema than fibrosis might have predisposed patients with pulmonary hypertension associated with idiopathic interstitial pneumonia to poor outcomes in RISE-IIP. Future studies of therapy for group 3 pulmonary hypertension should include centrally adjudicated imaging for morphologic phenotyping and disease burden evaluation during screening.

Mucins have long been regarded to play a role as a barrier to prevent mucosal infections; however, some studies report that overexpression of mucins induces obstruction and inflammation of airways. We investigated whether the secretion of overexpressed mucin, mucin5ac (MUC5AC), could improve protection against pathogens. To examine the possible roles of mucin hypersecretion in augmenting host defense against disease-promoting muco-obstructive lung disease, a mouse model that overexpressed MUC5AC was generated. We had previously proved that murine gammaherpesvirus-68 (MHV-68) infection could induce emphysema in mice, which later developed into combined pulmonary fibrosis and emphysema (CPFE). We further explored whether increased MUC5AC secretion could provide benefits against MHV-68 induced fibrosis. We initially developed a pcDNA3.1-MUC5AC mouse model. Next, the experimental mice were randomly divided into five groups: normal control, pcDNA3.1 control, pcDNA3.1-MUC5AC, CPFE, and pcDNA3.1- MUC5AC + CPFE. Morphometric analysis of each group was performed by hematoxylin and eosin staining and Masson trichrome staining. MUC5AC levels in lung tissues were analyzed by immunohistochemical staining, real-time polymerase chain reaction, and Western blot analysis. The airway inflammation was determined by differential cell counts of bronchoalveolar lavage fluid (BALF) and measurement of cytokines and chemokines in BALF by enzyme-linked immunosorbent assay. MUC5AC hypersecretion alone was not sufficient to drive goblet cell metaplasia to induce obvious mucus plugging and airway inflammation. However, MUC5AC overexpression served as a protective barrier against MHV-68 virus infection in vivo. Infectivity of MHV-68 was decreased in the pcDNA3.1-MUC5AC + CPFE group compared with that in CPFE group. Meanwhile, a reduction of MHV-68 virus attenuated the expressions of chemokine (C-C motif) ligand 2 (CCL2), chemokine (C-X-C motif) ligand 5 (CXCL5), interleukin-13 (IL-13), and transforming growth factor-β1 (TGF-β1), and weakened airway inflammation and fibrosis in the pcDNA3.1-MUC5AC + CPFE group. Overexpression of MUC5AC appears to exhibit a protective role against MHV-68 infection in mice with emphysema that subsequently developed into CPFE and to further decrease airway inflammation and fibrosis induced by MHV-68 by decreasing the expressions of CCL2, CXCL5, IL-13, and TGF-β1.

Combined pulmonary fibrosis and emphysema (CPFE) is a syndrome characterized by the coexistence of upper lobe emphysema and lower lobe fibrosis. However, whether CPFE has a higher or lower mortality than idiopathic pulmonary fibrosis (IPF) alone is still not clear. In this study we conducted a meta-analysis to assess the survival rate (SR) of CPFE versus IPF alone in clinical trials.
We performed a systematic search of PubMed, Embase, and the Cochrane Central Register of Controlled Trials for trials published prior to 31 March 2018. Extracts from the literature were analyzed with Review Manager version 5.3.
Thirteen eligible trials were included in this analysis (involving 1710 participants). Overall, the pooled results revealed that no statistically significant difference was detected in the 1-year [relative risk (RR) = 0.98, 95% confidence interval (CI): 0.94-1.03, p = 0.47], 3-year (RR = 0.83, 95% CI: 0.68-1.01, p = 0.06), and 5-year (RR = 0.80, 95% CI: 0.59-1.07, p = 0.14) SRs of CPFE versus IPF alone.
CPFE exhibits a very poor prognosis, similar to IPF alone. Additional studies are needed to provide more convincing data to investigate the natural history and outcome of patients with CPFE in comparison to IPF. The reviews of this paper are available via the supplemental material section.

Combined pulmonary fibrosis and emphysema (CPFE) is an \"umbrella term\" encompassing emphysema and pulmonary fibrosis, but its pathogenesis is not known. We established two models of CPFE in mice using tracheal instillation with bleomycin (BLM) or murine gammaherpesvirus 68 (MHV-68). Experimental mice were divided randomly into four groups: A (normal control, n=6), B (emphysema, n=6), C (emphysema+MHV-68, n=24), D (emphysema+BLM, n=6). Group C was subdivided into four groups: C1 (sacrificed on day 367, 7 days after tracheal instillation of MHV-68); C2 (day 374; 14days); C3 (day 381; 21days); C4 (day 388; 28days). Conspicuous emphysema and interstitial fibrosis were observed in BLM and MHV-68 CPFE mouse models. However, BLM induced diffuse pulmonary interstitial fibrosis with severely diffuse pulmonary inflammation; MHV-68 induced relatively modest inflammation and fibrosis, and the inflammation and fibrosis were not diffuse, but instead around bronchioles. Inflammation and fibrosis were detectable in the day-7 subgroup and reached a peak in the day-28 subgroup in the emphysema + MHV-68 group. Levels of macrophage chemoattractant protein-1, macrophage inflammatory protein-1α, interleukin-13, and transforming growth factor-β1 in bronchoalveolar lavage fluid were increased significantly in both models. Percentage of apoptotic type-2 lung epithelial cells was significantly higher; however, all four types of cytokine and number of macrophages were significantly lower in the emphysema+MHV-68 group compared with the emphysema +BLM group. The different changes in pathology between BLM and MHV-68 mice models demonstrated different pathology subtypes of CPFE: macrophage infiltration and apoptosis of type-II lung epithelial cells increased with increasing pathology score for pulmonary fibrosis.

Combined pulmonary fibrosis and emphysema (CPFE) is increasingly acknowledged as a separate syndrome with distinct clinical, physiological and radiological characteristics. We sought to identify physiologic and radiographic indices that predict mortality in CPFE.
Data on clinical characteristics, pulmonary function, high-resolution computed tomography (HRCT) and treatment were compared between patients with usual interstitial pneumonia (UIP) plus emphysema (CPFE group) and those with IPF alone (IPF group). Composite physiologic index (CPI) and HRCT scores at diagnosis and during follow-up were assessed.
CPFE group (N = 87) was characterized by the predominance of males and smokers, who were less likely to have viral infection prior to the diagnosis, and display basal crackles, finger clubbing and wheeze, as compared to that in the IPF group (N = 105). HRCT and CPI scores increased over time in both groups. Moreover, CPFE group had a poorer prognosis, lower 5-year survival rate (43.42 % vs. 65.56 %; P < 0.05), and higher mortality (39.47 % vs. 23.33 %; P < 0.05) as compared to that in the IPF group. All CPFE patients received oxygen therapy, antibiotics and oral N-acetylcysteine; > 50 % received bronchodilators, 40 % received corticosteroids and 14 % needed noninvasive mechanical ventilation. On survival analyses, pulmonary arterial hypertension (PAH) and ≥ 5-point increase in CPI score per year were predictors of mortality in the CPFE group (hazard ratio [HR]: 10.29, 95 % Confidence Interval [CI]: 2.69-39.42 and HR: 21.60, 95 % CI: 7.28-64.16, respectively).
Patients with CPFE were predominantly male and smokers and exhibited distinct clinical, physiological and radiographic characteristics. They had a poorer prognosis than IPF. PAH and ≥ 5-point increase in CPI score per year were predictors of mortality in these patients. Future studies are needed to identify the optimal treatment approach to CPFE.