Background: Exposure to air pollution is associated with chronic obstructive pulmonary disease (COPD). However, findings on the effects of air pollution on lung function and systemic inflammation in Chinese COPD patients are inconsistent and scarce. This study aims to evaluate the effects of ambient air pollution on lung function parameters and serum cytokine levels in a COPD cohort in Beijing, China. Methods: We enrolled COPD participants on a rolling basis from December 2015 to September 2017 in Beijing, China. Follow-ups were performed every 3 months for each participant. Serum levels of 20 cytokines were detected every 6 months. Hourly ambient pollutant levels over the same periods were obtained from 35 monitoring stations across Beijing. Geocoded residential addresses of the participants were used to estimate daily mean pollution exposures. A linear mixed-effect model was applied to explore the effects of air pollutants on health in the first-year of follow-up. Results: A total of 84 COPD patients were enrolled at baseline. Of those, 75 COPD patients completed the first-year of follow-up. We found adverse cumulative effects of particulate matter less than 2.5 μm in aerodynamic diameter (PM_2.5), nitrogen dioxide (NO₂), sulfur dioxide (SO₂) and carbon monoxide (CO) on the forced vital capacity % predicted (FVC % pred) in patients with COPD. Further analyses illustrated that among COPD patients, air pollution exposure was associated with reduced levels of serum eotaxin, interleukin 4 (IL-4) and IL-13 and was correlated with increased serum IL-2, IL-12, IL-17A, interferon γ (IFNγ), monocyte displacing protein 1 (MCP-1) and soluble CD40 ligand (sCD40L). Conclusion: Acute exposures to PM_2.5, NO₂, SO₂ and CO were associated with a reduction in FVC % pred in COPD patients. Furthermore, short-term exposure to air pollutants increased systemic inflammation in COPD patients; this may be attributed to increased Th1 and Th17 cytokines and decreased Th2 cytokines.

Birt-Hogg-Dubé syndrome (BHD) is an autosomal dominant disorder, the main manifestations of which are fibrofolliculomas, renal tumors, pulmonary cysts and recurrent pneumothorax. The known causative gene for BHD syndrome is the folliculin (FLCN) gene on chromosome 17p11.2. Studies of the FLCN mutation for BHD syndrome are less prevalent in Chinese populations than in Caucasian populations. Our study aims to investigate the genotype spectrum in a group of Chinese patients with BHD. We enrolled 51 patients with symptoms highly suggestive of BHD from January 2014 to February 2017. The FLCN gene was examined using PCR and Sanger sequencing in every patient, for those whose Sanger sequencing showed negative mutation results, multiplex ligation-dependent probe amplification (MLPA) testing was conducted to detect any losses of large segments. Among the 51 patients, 27 had FLCN germline mutations. In total, 20 mutations were identified: 14 were novel mutations, including 3 splice acceptor site mutations, 2 different deletions, 6 nonsense mutations, 1 missense mutation, 1 small insertion, and 1 deletion of the whole exon 8. We found a similar genotype spectrum but different mutant loci in Chinese patients with BHD compared with European and American patients, thus providing stronger evidence for the clinical molecular diagnosis of BHD in China. It suggests that mutation analysis of the FLCN gene should be systematically conducted in patients with cystic lung diseases.

Sirolimus has been shown to be effective in patients with lymphangioleiomyomatosis (LAM). We wish to summarize our experience using sirolimus and its effectiveness in LAM patients. We analyzed data from 98 patients who were diagnosed with definite or probable sporadic LAM based on the European Respiratory Society diagnosis criteria for LAM in 2010 at Peking Union Medical College Hospital and who had received sirolimus during January 2007 to June 2015. The data before and after the initiation of sirolimus therapy included pulmonary function tests, arterial blood gas analysis, 6-min walking distance (6MWD), size of chylous effusion and renal angiomyolipomas (AML), St. George’s Respiratory Questionnaires (SGRQ) and vascular endothelial growth factor-D (VEGF-D) levels. Serum levels of sirolimus and adverse events were collected. Median follow-up was 2.5 years. Most patients had forced expiratory volume in 1 s (FEV1) values less than 70% predicted or symptomatic chylothorax. The mean changes before and after the initiation of sirolimus were − 31.12 ± 30.78 mL/month and 16.11 ± 36.00 mL/month (n = 18,p = 0.002) for FEV1 change, and − 0.55 ± 0.60 mmHg/month and 0.30 ± 1.19 mmHg/month (n = 17, p = 0.018) for PaO2 change. 6MWD improved from 358.8 ± 114.4 m to 415.6 ± 118.6 m (n = 46, p = 0.004) and SGRQ total score from 57.2 ± 21.0 to 47.5 ± 22.8 (n = 50, p < 0.001). The median VEGF-D concentration decreased to 1609.4 pg/mL from 3075.6 pg/mL after sirolimus therapy (n = 41, p < 0.001). Patients with sirolimus trough levels of 5–9.9 ng/mL had an increase in FEV1 (p < 0.05). Sixty-five percent of patients (13/20) had almost complete resolution of chylous effusions. The most frequent adverse events were mouth ulcers, menstrual disorder, hyperlipidemia and acneiform rash, all were mild. Long-term use of sirolimus is safe in patients with LAM. LAM patients with FEV1 less than 70% predicted and symptomatic chylothorax are suitable for receiving sirolimus therapy. The maintaining serum trough levels of sirolimus are recommended between 5 to 9.99 ng/mL.

(1) Background: The implication of type 2 (T2) inflammatory response in COVID-19 remains controversial. This study aimed to evaluate the association of eosinophils, neutrophils expressing eosinophilic surface markers and T2 cytokines with the severity and outcome of COVID-19. (2) Methods: Patients who were admitted to hospital due to COVID-19 from 18 December 2022 to 31 January 2023 were enrolled. Peripheral blood WBC and differentials, T2 cellular markers (subsets of eosinophils and neutrophils expressing eosinophilic surface markers) and cytokines at admission were measured and compared between subjects with different disease severities and outcomes. (3) Results: Ten mild-to-moderate and 22 severe-to-very severe cases were enrolled for analysis. Of these patients, seven died of severe-to-very severe disease. The severe-to-very severe patients showed a higher number of neutrophils, but lower numbers of eosinophils, lymphocytes cells and neutrophils expressing eosinophilic surface markers. Similarly, deceased cases were also characterized by increased neutrophils, but decreased eosinophils and neutrophils expressing eosinophilic surface markers. The levels of T2 cytokines failed to demonstrate a significant correlation with the severity or outcome of COVID-19. (4) Conclusions: Eosinophils and neutrophils expressing eosinophilic surface markers were associated with milder disease and better outcomes of COVID-19, suggesting that a T2 inflammatory response may confer a potential protective effect against the disease.