Background: Both a probable usual interstitial pneumonia (UIP) pattern (p-UIP) and a definite UIP pattern (d-UIP) on high-resolution computed tomography (HRCT) are sufficient to establish a diagnosis of idiopathic pulmonary fibrosis (IPF) without the need for a surgical lung biopsy, according to the 2022 IPF guidelines. However, it remains unknown whether patients with p-UIP and d-UIP have similar disease behaviors and clinical courses. Material and Methods: We retrospectively collected clinical data of patients with IPF and divided the patients into two groups according to their HRCT patterns: a p-UIP group and a d-UIP group. The baseline characteristics, survival rates, and pulmonary function tests were compared between the two groups. The risk factors for mortality were determined by Cox regression in p-UIP and d-UIP separately. Results: There were 304 patients in the p-UIP group and 480 patients in the d-UIP group. Patients in the d-UIP group were more likely to have smoking histories (p < 0.001) and had lower baseline FVC% (74% vs. 77%, p = 0.021) and DLCO% (50% vs. 58%, p < 0.001). Survival rates were higher in p-UIP compared with d-UIP (p = 0.004). There were no differences in changes in FVC% or DLCO% between the two groups. Baseline DLCO% was the only independent risk factor for mortality in p-UIP. Baseline FVC% was independently associated with mortality in d-UIP. Symptom of cough was a risk factor for disease progression (OR = 1.2, p = 0.002) in p-UIP, while symptom of dyspnea might be associated with disease progression in d-UIP (OR = 2.7, p = 0.065). Male patients (OR = 1.88, p = 0.002) with a smoking history (OR = 1.16, p = 0.002) were at higher risk of developing d-UIP. Conclusions: We observed the different disease trajectories between p-UIP and d-UIP. P-UIP on HRCT might identify a subgroup of IPF patients who are in the early stage with a better prognosis.

Idiopathic pulmonary fibrosis (IPF) is a heterogeneous group of lung diseases with different etiologies and characterized by progressive fibrosis. This disease usually causes pulmonary structural remodeling and decreased pulmonary function. The median survival of IPF patients is 2-5 years. Predominantly accumulation of type II innate immune cells accelerates fibrosis progression by secreting multiple pro-fibrotic cytokines. Group 2 innate lymphoid cells (ILC2) and monocytes/macrophages play key roles in innate immunity and aggravate the formation of pro-fibrotic environment. As a potent immunosuppressant, tacrolimus has shown efficacy in alleviating the progression of pulmonary fibrosis. In this study, we found that tacrolimus is capable of suppressing ILC2 activation, monocyte differentiation and the interaction of these two cells. This effect further reduced activation of monocyte-derived macrophages (Mo-M), thus resulting in a decline of myofibroblast activation and collagen deposition. The combination of tacrolimus and nintedanib was more effective than either drug alone. This study will reveal the specific process of tacrolimus alleviating pulmonary fibrosis by regulating type II immunity, and explore the potential feasibility of tacrolimus combined with nintedanib in the treatment of pulmonary fibrosis. This project will provide new ideas for clinical optimization of anti-pulmonary fibrosis drug strategies.

Background: Respiratory involvement is common in immunoglobulin G4-related disease (IgG4-RD). However, severe asthma as the initial clinical manifestation of IgG4-RD is rare and might be neglected by respiratory clinicians. We aimed to explore the clinical characteristics and prognoses of patients with immunoglobulin G4-related disease (IgG4-RD) manifesting as severe asthma. Methods: A retrospective analysis of the clinical characteristics and prognoses of patients with severe asthma who were eventually diagnosed with IgG4-RD was performed in the Peking Union Medical College Hospital from 2013 to 2019. Results: Twelve patients (5males, 7 females) were included. The mean age at enrollment and age of asthma onset were 59.4 ± 10.1 and 53.8 ± 10.4 years, respectively. The mean duration of asthma symptoms was 5.7 ± 2.0 years. In all patients, the proportion (25.1 ± 10.3%) and count (2.0 ± 1.1) × 10⁹/L of eosinophils in peripheral blood increased. Additionally, all patients exhibited elevated total immunoglobulin E [IgE, (1279.3 ± 1257.9) KU/L] and IgG4 (9155.8 ± 9247.6) mg/dL. Bronchial wall thickening (n = 11) and mediastinal/hilar lymphadenopathy (n = 11) were major chest CT manifestations. All were pathologically diagnosed through surgical biopsy; submandibular gland (n = 8), supraclavicular lymph node (n = 2), stomach (n = 1), rashes (n = 1), lacrimal gland (n = 1) and thoracoscopic lung (n = 1) biopsies were performed. Asthma was well controlled by oral glucocorticoids (GCs), but some patients relapsed during tapering (n = 11). The refractory condition was controlled after increasing the dosage of GCs and add-on immunosuppressants. Conclusions: For patients with middle age-onset severe asthma with elevated eosinophils, total IgE and IgG4 levels and available salivary gland ultrasound imaging, ruling out IgG4-RD is recommended. GCs used in combination with immunosuppressants is recommended to prevent relapse.

Introduction: Pneumocystis jirovecii pneumonia (PJP) is a common opportunistic infection. With the wide application of glucocorticosteroids and immunosuppressants, the incidence and mortality rates of PJP in connective tissue disease (CTD) patients with interstitial lung disease (ILD) are increasing. Methods: We retrospectively enrolled consecutive CTD-ILD patients with PJP in our center between January 2014 and December 2022. Cox regression models were constructed to explore prognostic factors in CTD-ILD-PJP patients. Results: There were 159 CTD-ILD patients [60 (51, 68) years, 61.0% female] with PJP, 78 (49.1%) of whom died. Compared with those in the CTD-non-ILD-PJP group, there were more pneumomediastinum cases (16.4% vs. 6.7%, p = 0.030) and significantly higher all-cause mortality rates (49.1% vs. 33.7%, p = 0.019) in the CTD-ILD-PJP group. Multivariate analysis indicated that IIM (HR = 2.635, 95% CI: 1.383–5.019), pneumomediastinum (HR = 2.877, 95% CI: 1.483–5.582), oral candidiasis infection (HR = 2.596, 95% CI: 1.229–5.483), aspergilli infection (HR = 2.886, 95% CI: 1.412–5.900), and lower minimal albumin (Alb) (HR = 0.872, 95% CI: 0.819–0.927) were independent risk factors associated with poor survival in CTD-ILD-PJP patients. Conclusions: CTD-ILD-PJP patients were mainly middle-aged females and had higher mortality rates than CTD-PJP patients without ILD. IIM, pneumomediastinum, oral candidiasis infection, aspergilli infection, and lower minimal Alb were independent risk factors associated with poor survival in CTD-ILD-PJP patients. Key Points• CTD-ILD-PJP patients had higher mortality rates than CTD-PJP patients without ILD.• IIM, pneumomediastinum, oral candidiasis infection, aspergilli infection, and lower minimal Alb were independent survival risk factors in CTD-ILD-PJP patients.• The study explored susceptibility and prognostic risk factors of CTD-ILD-PJP patients, to reduce the incidence and mortality.

(1) Background: The clinical characteristics and the prognostic factors of HIV-negative Pneumocystis jirovecii pneumonia (PJP) patients (non-HIV-PJP) with interstitial lung disease (ILD) remain unclear. Our objectives were to describe the clinical characteristics and to explore the prognostic factors of non-HIV-ILD-PJP patients. (2) Methods: The enrolled patients in this retrospective study were stratified based on the presence or absence of ILD and fibrotic ILD (FILD). The log-rank test and Cox regression models were used to analyze the prognostic factors. (3) Results: Among 378 non-HIV-PJP patients, there were 133 patients with ILD-PJP, and 70 patients were classified as having FILD-PJP. The all-cause mortality rate for the ILD-PJP group is higher than that of the ILD-PJP group (57.9% vs. 38.4%, p < 0.001). However, the all-cause mortality is similar between the FILD-PJP group and non-FILD-PJP group. Preexisting ILD (HR: 2.156, p = 0.003) and honeycomb appearance on the chest HRCT (HR = 16.3, p < 0.001) are independent survival risk factors for ILD-PJP. Non-invasive ventilation is an independent survival risk factor for ILD-PJP patients (HR = 928.56, p < 0.01) and FILD-PJP patients (HR = 33.86, p < 0.001). (4) Conclusions: Pre-existing ILD and honeycomb appearance on the chest HRCT are independent survival risk factors for PJP patients. Non-invasive ventilation is associated with poor survival for both ILD-PJP and FILD-PJP patients.

Immune-related adverse events (irAEs) of immunotherapy would lead to the temporary or permanent discontinuation of immune checkpoint inhibitors (ICIs). Among them, checkpoint inhibitor pneumonitis (CIP) is a potentially life-threatening irAE. This study aimed to identify the differences between patients with low-grade CIPs (grades 1–2) and high-grade CIPs (grades 3–5) and to explore the prognostic factors. We retrospectively reviewed the medical records of 916 lung cancer patients who were treated with ICIs. Patients with CIPs were identified after multidisciplinary discussion, and their clinical, laboratory, radiological, and follow-up data were analyzed. Among the 74 enrolled CIP patients, there were 31 low-grade CIPs and 43 high-grade CIPs. Compared with low-grade CIP patients, patients with high-grade CIPs were older (65.8 years vs. 61.5 years) and had lower serum albumin (35.2 g/L vs. 37.9 g/L), higher D-dimer (5.1 mg/L vs. 1.7 mg/L), and more pulmonary infectious diseases (32.6% vs. 6.5%) during follow-up. In addition, complication with pulmonary infectious diseases, management with intravenous immunoglobulin, tocilizumab, and longer duration of large dosage corticosteroids might be associated with worse outcomes for patients with CIPs. This study highlights potential risk factors for high-grade CIP and poor prognosis among lung cancer patients who were treated with anti-cancer ICIs.