Evaluation of cytokines in the tumor microenvironment of lung cancer using bronchoalveolar lavage fluid analysis.

INTRODUCTION: Lung cancer is the leading cause of death by cancer. In recent years, immunotherapy with checkpoint inhibitors (ICI) emerged as a promising new therapeutic approach. However, a deeper understanding of the immunologic responses adjacent to the tumor known as tumor microenvironment (TME) is needed. Our study investigated TME of lung cancer by analyzing cytokines in bronchoalveolar lavage fluid (BALF). MATERIALS AND METHODS: Between January 2018 and June 2019, 119 patients were prospectively enrolled in this study. For each cancer patient, levels of 16 cytokines (fractalkine, granulocyte-macrophage colony-stimulating factor (GM-CSF), interferon gamma (IFN-γ), tumor necrosis factor alpha (TNF-α), and interleukins (IL): IL-1b, IL-2, IL-4, IL-5, IL-6, IL-7, IL-8, IL-10, IL-12p70, IL-13, IL-17A, and IL-23) were measured in BALF and serum and compared to healthy individuals and patients with other lung diseases. RESULTS: There were several significant differences of cytokine levels of patients with lung cancer compared to healthy individuals. However, none of them remained in the multivariate analysis compared to other lung diseases in either BALF or serum. Furthermore, there were no significant differences between the groups in cell differentiation of either BALF or serum. Cytokine levels in BALF were generally near the lower detection limit and showed almost no correlation with their respective levels measured in serum of the same individual. CONCLUSIONS: Cytokines in BALF and serum of lung cancer patients may indicate unspecific inflammation. BAL is not recommendable as a tool to investigate TME of lung cancer. Therefore, cytokines measured in BALF are probably not appropriate as predictors in patients treated with ICIs.

Obstructive sleep apnea and quality of life in Fabry disease: a prospective parallel cohort study.

STUDY OBJECTIVES: Patients with Fabry disease (FD) report impaired quality of life and excessive daytime sleepiness. Obstructive sleep apnea (OSA) is frequently reported among patients with FD; however, its prevalence and its influence on quality of life and daytime sleepiness in this population are unclear. METHODS: Patients with FD in a cohort from the University Hospital Zurich (n = 52) were one-to-two matched to healthy adult controls (n = 104) according to age, sex, and body mass index. Participants underwent structured interviews (including Short Form-36) and level-3 respiratory polygraphy. An apnea-hypopnea index of ≥ 5/h was defined as OSA and the severity of FD was quantified with the Mainz Severity Score Index (MSSI). Conditional logistic regression was used to compare the outcomes. RESULTS: In patients with FD the mean MSSI was 13.3 ± 10.5 points and OSA prevalence was 19.2% vs. 9.0% in the matched control group (p = 0.09). The apnea-hypopnea index was significantly higher in patients with FD than in the control group (0.5/h [0.2-3.0] vs. 0.2/h [0.1-1.8], p = 0.026). OSA severity was associated with impaired quality of life in four dimensions for the whole study population. Furthermore, patients with FD did report significantly higher daytime sleepiness (Epworth Sleepiness Scale 7.6 points vs. 6.3 points; p = 0.01) than healthy controls. CONCLUSION: Patients with mild FD do not have a higher OSA prevalence than matched control subjects. Differences in OSA severity did not reach clinical significance. Further studies are warranted to determine the impact of OSA in patients with moderate-to-severe FD.

Variability of cytokine concentration in whole blood serum and bronchoalveolar lavage over time.

Measurement of cytokines in peripheral blood and bronchoalveolar lavage fluid (BALF) is a useful method to assess human immune responses in a large range of pulmonary diseases. One of the major pre-analytical challenges of cytokine analysis is the quality and stability of cytokines in the timeframe between sample collection and the separation of supernatant from cells. To evaluate if the method of storage may affect cytokine quantification, whole blood and BALF were collected, aliquoted, and left at room temperature (RT) to be processed at different time points. In addition, sera and BALF were left either at RT or at 4 °C for 24 h after cell separation to test cytokine variations in the absence of cells. Samples were analysed by a multiple array containing ten cytokines. Most of the cytokines analysed (interleukin (IL)-4, IL-5, IL-6, IL-12p70, IL-13, IL-17A, IL-23, interferon (IFN)-γ, and tumour necrosis factor (TNF)-α) did not show significant variations in whole blood and BALF. Levels of IL-8 however, increased after storage of whole blood and BALF for 24 h at RT. Ex vivo IL-8 production seems to correlate with higher numbers of macrophages in collected BALF. These data demonstrate that many cytokines are stable for a brief time after sample collection. For IL-8, freshly collected whole blood and BALF should be quickly processed and frozen to avoid false positive results.

Ipilimumab and early signs of pulmonary toxicity in patients with metastastic melanoma: a prospective observational study.

Ipilimumab, an immune checkpoint inhibitor, is approved for treatment metastastic melanoma and is a promising agent against other malignancies. There is some preliminary evidence from case reports that ipilimumab treatment may be associated with pulmonary side effects. However, data from prospective studies on ipilimumab-related pulmonary toxicity are still scarce. Serial spirometries and measurements of CO-diffusion capacity (DLCO) in patients with metastatic melanoma before and during treatment with ipilimumab were performed. A reduction from baseline of forced vital capacity (FVC) of ≥ 10%, or ≥ 15% of DLCO was defined as clinically meaningful and indicative for pulmonary toxicity. Of 71 patients included in this study, a clinically meaningful lung function decline was registered in 6/65 (9%), 5/44 (11%), and 9/38 (24%) patients after 3, 6, and 9 weeks of treatment initiation, respectively. Even after adjusting for age, concomitant melanoma treatment, progressive pulmonary metastases, and baseline pulmonary function values, mean ± SD DLCO decreased significantly during follow-up (-4.3% ± 13.6% from baseline, p = 0.033). Only 7% of patients reported respiratory symptoms. Clinically manifest ipilimumab-related pneumonitis was diagnosed only in one patient (1.4%). DLCO decline maybe an early indicator of subclinical pulmonary drug toxicity. Therefore, routine pulmonary function testing including DLCO measurement during treatment might help for risk stratification to screen for ipilimumab-related pneumonitis.

Obstructive sleep apnoea and quality of life in Ehlers-Danlos syndrome: a parallel cohort study.

BACKGROUND: Patients with the connective tissue disorder Ehlers-Danlos syndrome (EDS) often suffer from fatigue, excessive daytime sleepiness and impaired quality of life. Obstructive sleep apnoea (OSA) may be an underlying cause for these symptoms but its prevalence in this population is unclear. METHODS: In this prospective parallel-cohort study, we included 100 adult patients with EDS (46% hypermobile-type, 35% classical-type and 19% other), which were one-to-one matched to 100 healthy adult controls according to sex, age, weight and height. Participants underwent structured interviews (including short-form 36) and level-3 respiratory polygraphy. OSA was defined as apnoea-hypopnea index ≥5/hour. Photographic craniofacial phenotyping was conducted in a subgroup. Conditional logistic regression was used to compare the prevalence of OSA. RESULTS: In patients with EDS, OSA prevalence was 32% versus 6% in the matched control group (OR 5.3 (95% CI 2.5 to 11.2); p<0.001). The EDS group reported impaired quality of life in all dimensions (p<0.05) and significantly higher excessive daytime sleepiness measured by the Epworth Sleepiness Scale (median (quartiles) 11 (7-14) vs 7 (5-10); p<0.001). OSA severity was positively associated with daytime sleepiness and lower quality of life in the EDS group. There was no evidence of a difference between the two study groups in terms of craniofacial phenotypes. CONCLUSIONS: The prevalence of OSA is higher in patients with EDS than in a matched control group. This is of clinical relevance as it is associated with fatigue, excessive daytime sleepiness and impaired quality of life. Further studies are needed to assess the clinical benefit of OSA treatment in patients with EDS. TRIAL REGISTRATION NUMBER: NCT02435745.

Low tissue levels of miR-125b predict malignancy in solitary fibrous tumors of the pleura.

BACKGROUND: Solitary fibrous tumors of the pleura (SFTP) are rare neoplasia of the chest. A subset of SFTP follows a malignant course, sometimes several years after complete resection. Traditional scoring systems based on clinical and histological features are poor predictors of biological behavior. This study aimed to investigate tumor-associated miRNAs expression as novel biomarkers to predict the clinical behavior of SFTP. METHODS: Formalin-fixed and paraffin-embedded SFTP tissues blocks from patients surgically resected between 1992 and 2013 at two tertiary care teaching hospitals were included. SFTP tumors were categorized as either malignant or benign variants according to the WHO classification. Following miRNAs levels were measured: let-7a, miR-16b, miR-17, miR-21, miR-31, miR-34a, miR-92a, miR-125a, miR-125b, miR-195-5b, miR-203a, and miR-223. Differential gene expressions which were calculated with the threshold cycle (Ct) method were compared among the two variants. RESULTS: Thirty-eight patients (40% male, mean age 62.2 (±10.9) years) were included. Expression levels of miR-125b showed a significant difference between benign compared to malignant variants (-3.08 ± 0.93 vs. -2.22 ± 1.36, p = 0.0068). Furthermore, lower levels of miR-125b were found to be associated with increased tumor size (p = 0.0414). Thus, downregulation of miR-125b indicates malignant transformation. All other investigated miRNAs were not associated with grading of SFTP. CONCLUSIONS: Our data suggest a potential role of miR-125b in the pathogenesis of tumor growth and malignant transformation of SFTP, respectively. Further studies have to address the potential use of miRNA-125b as a biomarker or therapeutic target in SFTP.

Prognostic value of MIB-1 proliferation index in solitary fibrous tumors of the pleura implemented in a new score - a multicenter study.

BACKGROUND: Although the majority of solitary fibrous tumors of the pleura (SFTP) follow a benign course, 10-25% of patients suffer from recurrence or metastatic disease. Several scoring models have been proposed to predict the outcome. However, none of these included immunohistochemical (IHC) markers as possible prognosticators. METHODS: In this multicenter study, we collected clinical data and formalin-fixed and paraffin-embedded (FFPE) tissue blocks of patients with histologically proven SFTP which had been surgically resected between 2000 und 2015. After systematic and extensive IHC staining on tissue microarrays, the results were analyzed and compared to histomorphological and clinical data for their possible prognostic value. RESULTS: In total, 78 patients (mean age 61 ± 11 years) were included. Of these, 9 patients (11%) had an adverse outcome including SFTP recurrence (n = 6) or SFTP-related death (n = 3). Mean overall survival was 172 ± 13 months. 1 and 10-year event-free survival rates were 99% and 93%. In the multivariable analysis only MIB-1 proliferation index (Ki-67) ≥10% (HR 12.3, CI 1.1-139.5, p = 0.043), ≥4 mitoses per 10 high power fields (HR 36.5, CI 1.2-1103.7, p = 0.039) and tumor size larger than 10 cm (HR 81.8, CI 1.7-4016.8, p = 0.027) were independently associated with adverse outcome. CONCLUSION: A high proliferation rate by MIB-1 IHC was associated with impaired outcome. Upon this, we established a new score using mitosis, necrosis, size of the tumor and MIB-1, which performed better than the traditional scores in our data set. This prognostic score could help to better evaluate outcome of SFTP, but requires external validation.

Evaluation of Nickel Release from Endobronchial Valves as a Possible Cause of Hypersensitivity Pneumonitis in a Patient Treated with Bronchoscopic Lung Volume Reduction.

BACKGROUND: Endobronchial valve (EBV) placement is an established lung volume reduction procedure aiming to improve lung function and exercise capacity in patients with severe emphysema. As EBVs consist of silicone and nitinol (a metal alloy of nickel and titanium), there are concerns that nickel ions might be released and could have a clinical impact in patients with a contact allergy to nickel. Based on a case with hypersensitivity pneumonitis (HP) after treatment with EBVs, we aimed to evaluate the in vitro nickel release from EBVs using inductively coupled plasma mass spectrometry (ICP-MS) and scanning electron microscopy (SEM). METHODS: Six EBVs were immersed in artificial saliva for a period of 7 days. At 24-h intervals, the nickel ion concentration was measured using ICP-MS. RESULTS: There was evidence of a significant nickel release from EBV during the first 48 h, which is possibly due to an incomplete silicone layer detected by SEM. The concentration of released nickel was below the toxic limit. CONCLUSIONS: To the best of our knowledge, we report the first case of HP after EBV treatment. Our finding of in vitro release of nickel ions from EBVs may contribute to the current understanding on hypersensitivity reactions after nitinol implants in patients with nickel contact allergy. However, it did not confirm a causative relationship.

The use of life-saving extracorporeal membrane oxygenation (ECMO) for pregnant woman with status asthmaticus.

INTRODUCTION: Status asthmaticus can develop into a life-threatening disorder that requires mechanical ventilation. Severe respiratory failure during pregnancy can worsen maternal and fetal outcomes. Previous case studies have demonstrated extracorporeal membrane oxygenation (ECMO) as a life-saving measure for pregnant women with acute respiratory distress syndrome (ARDS) as well as non-pregnant patients with status asthmaticus. CASE STUDY: A 25-year-old woman, who was 5 weeks pregnant, was admitted with status asthmaticus and severe hypercapnic respiratory failure. Despite rescue therapies such as pressure control ventilation with high inspiratory pressures, inhaled beta2 agonists and antimuscarinic drugs, intravenous salbutamol, methylprednisolone and magnesium sulfate, her condition gradually deteriorated. Veno-venous ECMO was initiated for respiratory support and the patient's clinical condition as well as the gas exchange improved within the next few days. ECMO was removed and the patient was extubated after 2 days. Sonography, however, revealed a retrochorial hematoma; the patient was diagnosed with abortus imminens and successfully treated with magnesium substitution and bed rest. Finally, she gave birth to a healthy boy at 38 weeks of gestation. CONCLUSIONS: This is the first case report on the successful use of ECMO in a pregnant woman with severe respiratory insufficiency due to status asthmaticus, who failed to respond to invasive mechanical ventilation and maximum pharmacological treatment. Despite this life-threatening condition, the use of ECMO in our patient has greatly improved the chance of survival for the mother and the baby, who was born without any complications.

Takayasu's Arteritis with Isolated Pulmonary Artery Involvement in a Middle-Aged Asian Woman with Hepatitis B and Latent Tuberculosis Infection.

We report a rare case of Takayasu's arteritis with isolated pulmonary artery stenosis in the presence of active hepatitis B and latent Mycobacterium tuberculosis infection in a middle-aged Asian woman who initially presented with severe dyspnea on exertion and recurrent syncope, occasional burning chest pains, and fatigue. Therapy of the active hepatitis B and latent M. tuberculosis infection together with a course of methotrexate led to a slight reversal of the symptoms, as angioplasty with or without stenting was not an option. The constellation described here hints at the possible link between hepatitis B and M. tuberculosis infection and the development of Takayasu's arteritis. The case also supports the little evidence available indicating that treatment of active hepatitis B infection could positively influence the course of Takayasu's arteritis.

Towards Individualized Tracheobronchial Stents: Technical, Practical and Legal Considerations.

Stent placement has been established as a standard procedure for treating airway obstructions. Other indications are localized malacias and fistulas. Though many different stents with various diameters and lengths are available, the shapes are hardly ever ideal because of the distorted anatomy in patients with diseased airways. There are technical and legal limitations for customizing purchased airway stents. Individually tailored stents would be preferable. New techniques of additive manufacturing such as 3D printing make it possible to produce optimized stents for a particular patient. Using CT data and bronchoscopic images, stents can be constructed that match a particular anatomical situation and apply the optimized expansion force. We give an overview of the currently available manufacturing techniques for polymeric stents and report about our own experience. Direct on-site printing of polyurethane stents in a hospital and printing individual extrusion molds for silicone stents in a certified cleanroom are both feasible. Furthermore, there are promising attempts of combining mechanically customized stents with surface modifications, drug-eluting features, biodegradability, and time-dependent adaptation (4D printing). Truly optimized airway stents with the potential of solving the well-known stent problems such as granulation tissue formation, remodeling, mucostasis, and infections are in reach. The technical hurdles are probably easier to overcome than the legal constraints. The legal situations are discussed from a physician's and a manufacturer's perspective.

Effect of rituximab on pulmonary function in patients with rheumatoid arthritis.

BACKGROUND: Rituximab (RTX), a B-cell depleting monoclonal antibody is increasingly used in several antibody-mediated diseases. It has been reported to cause pulmonary toxicity, though mainly during polychemotherapy of malignant lymphoma. Prospective data on RTX-induced pulmonary complications in patients with rheumatoid arthritis (RA) are lacking. METHODS AND METHODS: Serial spirometries and measurements of diffusion capacity of the lung for carbon monoxide (DLCO) in patients with RA before and 2, 4, 8, and 26 weeks after treatment with RTX were performed. A reduction from baseline of forced vital capacity (FVC) of ≥10%, or ≥15% of DLCO was defined as indicative for pulmonary toxicity. RESULTS: Thirty-three patients (mean (SD) age 59 (12) years, 27% males) were included. Mean (SD) FVC predicted and DLCO predicted at baseline were 108% (18%) and 88% (18%), respectively. In contrast to FVC, DLCO showed a progressive decline during follow-up with a maximum reduction of 6.1% (95%CI 2.5%, 9.7%; p = 0.001) at 26 weeks compared with baseline. After 26 weeks, 22% of the patients had a ≥15% DLCO decline. None of the patients reported increased dyspnea during follow-up. Risk factors for pulmonary function changes after treatment with RTX were cigarette smoking, repeated administration of the drug, and co-medication with Prednisone. CONCLUSION: Although no cases of symptomatic lung injury were observed, the progressive DLCO decline seems to indicate the presence of subclinical RTX-induced pulmonary toxicity.

Target-controlled versus fractionated propofol sedation in flexible bronchoscopy: A randomized noninferiority trial.

BACKGROUND AND OBJECTIVE: Fractionated propofol administration (FPA) in flexible bronchoscopy (FB) may lead to oversedation and an increased risk of adverse events, because a stable plasma concentration of propofol is not maintainable. The purpose of this randomized noninferiority trial was to evaluate whether target-controlled infusion (TCI) of propofol is noninferior to FPA in terms of safety in FB. METHODS: Coprimary outcomes were the mean lowest arterial oxygen saturation (SpO2 ) during FB and the number of propofol dose adjustments in relation to procedure duration. Secondary outcomes were the number of occasions with SpO2 < 90% and/or oxygen desaturations of >4% from baseline, number of occasions with systolic blood pressure < 90 mm Hg, cough frequency, cumulative propofol dose, recovery time, maximum transcutaneous CO2 , mean SpO2 and O2 delivery during FB. RESULTS: Seventy-seven patients were included. TCI was noninferior to FPA in terms of mean (standard deviation) lowest SpO2 during the procedure (88.3% (5.4%) vs 86.9% (7.3%)) and required fewer dose adjustments (0.04/min vs 0.28/min, P < 0.001) but a higher cumulative propofol dose (264 vs 194 mg, P = 0.003). All other secondary outcomes were comparable between the groups. CONCLUSION: We suggest that TCI of propofol is a favourable sedation technique for FB with equal safety issues and fewer dose adjustments compared with FPA.

The Roles of the Charlson Comorbidity Index and Time to First Antibiotic Dose as Predictors of Outcome in Pneumococcal Community-Acquired Pneumonia.

PURPOSE: In this retrospective study, we aimed to investigate the role of comorbidities using the Charlson comorbidity index (CCI) and time to first antibiotic dose (TFAD) in patients with pneumococcal community-acquired pneumonia (PCAP). METHODS: All consecutive ER admissions with PCAP who were hospitalized in the University Hospital, Zurich between 2006 and 2012 were included. The primary outcome was to determine possible determinants of all-cause in-hospital mortality (ACIHM). The second endpoint was to detect risk factors for adverse events (AEs) and determinants of length of stay (LOS). RESULTS: 108 subjects (mean age 57.6 years) were included. The median (IQR) CCI was 4 (1, 8). The median (IQR) TFAD was 210 (150, 280) min. ACIHM was 6.5 % (7/108), and median (IQR) LOS was 9 (6, 14) days. PCAP-related AEs were observed in 57 cases (52.8 %). In the multivariable analysis, neither CCI nor TFAD was associated with the outcome measures. Pneumonia severity index (PSI) was the only statistically significant predictor of ACIHM (HR 1.31/10 point increase, 95 % CI 1.12-1.53, p = 0.001) and AE rate (OR 1.31, 95 % CI 1.15-1.50, p < 0.001). CONCLUSIONS: In this study including comparatively young patients with rather mild disease severity, we found no strong evidence supporting that CCI or TFAD influenced short-term outcome measures of PCAP. Yet, pneumonia severity appears to be the most important factor for the outcome.

Ultrathin bronchoscopy for solitary pulmonary lesions in a region endemic for tuberculosis: a randomised pilot trial.

BACKGROUND: The evaluation of solitary pulmonary lesions (SPL) requires a balance between procedure-related morbidity and diagnostic yield, particularly in areas where tuberculosis (TB) is endemic. Data on ultrathin bronchoscopy (UB) for this purpose is limited. To evaluate feasibility and safety of UB compared to SB for diagnosis of SPL in a TB endemic region. METHODS: In this prospective randomised trial we compared diagnostic yield and adverse events of UB with standard-size bronchoscopy (SB), both combined with fluoroscopy, in a cohort of patients with SPL located beyond the visible range of SB. RESULTS: We included 40 patients (mean age 55.2 years, 45 % male) with malignant SPL (n = 16; 40 %), tuberculous SPL (n = 11; 27.5 %) and other benign SPL (n = 13; 32.5 %). Mean procedure time in UB and SB was 30.6 and 26.0 min, respectively (p = 0.15). By trend, adverse events were recorded more often with UB than with SB (30.0 vs. 5.0 %, p = 0.091), including extensive coughing (n = 2), blocked working channel (n = 2), and arterial hypertension requiring therapeutic intervention (n = 1), all with UB. The overall diagnostic yield of UB compared to SB was 55.0 % vs. 80.0 %, respectively (p = 0.18). Sensitivity for the diagnosis of malignancy of UB and SB was 50.0 % and 62.5 %, respectively (p = 0.95). CONCLUSION: UB is not superior to SB for the evaluation of SPL in a region endemic with tuberculosis, when combined with fluoroscopic guidance only. TRIAL REGISTRATION: ClinicalTrials.gov (Identifier: NCT02490059 ).

Sedation during bronchoscopy: data from a nationwide sedation and monitoring survey.

BACKGROUND: There is limited knowledge on practice patterns in procedural sedation and analgesia (PSA), the use of propofol, and monitoring during flexible bronchoscopy (FB). The purpose of this study was to assess the current practice patterns of FBs and to focus on the use of propofol, the education of the proceduralist, and the involvement of anaesthesiologists during FB. METHODS: An anonymous questionnaire was sent to 299 pulmonologists. Only respondents who were active physicians in adult respiratory medicine performing FB were subsequently analysed. RESULTS: The response rate was 78 % and 27,149 FB in the previous 12 months were analysed. The overall sedation-related morbidity rate was 0.02 % and mortality was 7/100'000 FB. Sedation was used in 95 % of bronchoscopies. The main drugs used for PSA were propofol (77 %) and midazolam (46 %). In 84 % of PSAs propofol was used without the attendance of an anaesthesiologist. The use of propofol was associated with high volume bronchoscopists (p < 0.010) and career-young pulmonologists (p < 0.001). While monitoring vital parameters has become standard practice, pulmonologists reported a very low rate of systematic basic education and training in the field of PSA (50 %). CONCLUSIONS: In Switzerland, PSA during FB is mostly performed with propofol without the attendance of an anaesthesiologist and the use of this drug is expected to increase in the future. While monitoring standards are very high there is need for policies to improve education, systematic training, and support for pulmonologists for PSA during FB.

Impact of comorbidities on physical activity in COPD.

BACKGROUND AND OBJECTIVE: Both comorbidities and physical inactivity have been shown to impair quality of life and contribute to hospital admissions and mortality in chronic obstructive pulmonary disease (COPD) patients. We hypothesized that the comorbid status predicts the level of daily physical activity (PA) in COPD. METHODS: In 228 patients with COPD (76% men; median (quartiles) age: 64 (59/69) years; percentage of predicted forced expiratory volume in 1 s (FEV1 % pred): 44 (31/63)), comorbidities were assessed by medical history, clinical interviews, examination and blood analysis. PA level (PAL) was measured by an activity monitor (SenseWear Pro, Bodymedia Inc., Pittsburgh, PA, USA). The association between PAL and comorbidities was investigated by univariate and multivariate regression analysis. RESULTS: Seventy-nine percent of the COPD patients had at least one additional chronic comorbidity, 56% had two or more comorbidities and 35% had three or more comorbidities. In univariate analysis body mass index, the number of pack years and having at least one additional comorbidity was negatively associated with PAL while there was a positive nonlinear association between FEV1 and PAL. The presence of at least one additional comorbidity was independently associated with PAL irrespective of airflow limitation. CONCLUSIONS: In this cohort, almost 80% of COPD patients had at least one additional chronic comorbidity. The level of daily PA seems to be significantly impaired by the presence of comorbidities irrespective of the type of comorbidity and independent of the degree of airflow limitation. CLINICAL TRIAL REGISTRATION: NCT01527773 at http://www.clinicalTrials.gov.

Kinetics of microRNA Expression in Bronchoalveolar Lavage Fluid Samples.

Levels of microRNAs (miRNAs) are increasingly assessed in biological fluids, for example, in samples obtained by bronchoalveolar lavage (BAL). "Post-collection kinetics" of miRNA expression levels, however, have not been investigated to date. In these experiments, we analyzed the dynamic expression profile of 5 different miRNAs (miR-17, miR-19b, miR-20b, miR-125a, and miR-223-3p) in BAL within the first 24 h following collection by routine bronchoscopy. miRNAs were quantified 0, 1, 4, 8, and 24 h after collection in samples that were kept at 4 °C or at room temperature. The expression of all five miRNAs was found to remain stable between the first 8 h after collection. 24 h after collection miRNAs faced substantial alterations in their expression profile. These data emphasize that BAL samples intended for further miRNA analysis can be handled at room temperature within the first 8 h after bronchoscopy.