Involvement of IL-26 in bronchiolitis obliterans syndrome but not in acute rejection after lung transplantation.

BACKGROUND:  The main long-term complication after lung transplantation is bronchiolitis obliterans syndrome (BOS), a deadly condition in which neutrophils may play a critical pathophysiological role. Recent studies show that the cytokine interleukin IL-26 can facilitate neutrophil recruitment in response to pro-inflammatory stimuli in the airways. In this pilot study, we characterized the local involvement of IL-26 during BOS and acute rejection (AR) in human patients. METHOD:  From a biobank containing bronchoalveolar lavage (BAL) samples from 148 lung transplant recipients (LTR), clinically-matched patient pairs were identified to minimize the influence of clinical confounders. We identified ten pairs (BOS/non-BOS) with BAL samples harvested on three occasions for our longitudinal investigation and 12 pairs of patients with and without AR. The pairs were matched for age, gender, preoperative diagnosis, type of and time after surgery. Extracellular IL-26 protein was quantified in cell-free BAL samples using an enzyme-linked immunosorbent assay. Intracellular IL-26 protein in BAL cells was determined using immunocytochemistry (ICC) and flow cytometry. RESULTS:  The median extracellular concentration of IL-26 protein was markedly increased in BAL samples from patients with BOS (p < 0.0001) but not in samples from patients with AR. Intracellular IL-26 protein was confirmed in alveolar macrophages and lymphocytes (through ICC and flow cytometry) among BAL cells obtained from BOS patients. CONCLUSIONS:  Local IL-26 seems to be involved in BOS but not AR, and macrophages as well as lymphocytes constitute cellular sources in this clinical setting. The enhancement of extracellular IL-26 protein in LTRs with BOS warrants further investigation of its potential as a target for diagnosing, monitoring, and treating BOS.

Persistent Aspergillus fumigatus infection in cystic fibrosis: impact on lung function and role of treatment of asymptomatic colonization-a registry-based case-control study.

BACKGROUND: Aspergillus fumigatus is the most common filamentous fungus isolated from the airways of people with cystic fibrosis (CF). The aim of this study was to investigate how chronic A. fumigatus colonization affects lung function in people with CF, to identify risk factors for colonization, and to evaluate antifungal treatment of asymptomatic Aspergillus colonization. METHODS: Data from 2014-2018 was collected from the Swedish CF registry and medical records. Baseline data before the start of A. fumigatus colonization was compared with the two succeeding years to evaluate how colonization and treatment affected lung function and other clinical aspects. RESULTS: A total of 437 patients were included, of which 64 (14.6%) became colonized with A. fumigatus during the study period. Inhaled antibiotics was associated with A. fumigatus colonization (adjusted OR 3.1, 95% CI 1.6-5.9, p < 0.05). Fungal colonization was not associated with a more rapid lung function decline or increased use of IV-antibiotics compared to the non-colonized group, but patients with A. fumigatus had more hospital days, a higher increase of total IgE, and higher eosinophil counts. In the Aspergillus group, 42 patients were considered to be asymptomatic. Of these, 19 patients received antifungal treatment. Over the follow up period, the treated group had a more pronounced decrease in percent predicted Forced Expiratory Volume in one second (ppFEV1) compared to untreated patients (- 8.7 vs - 1.4 percentage points, p < 0.05). CONCLUSION: Inhaled antibiotics was associated with A. fumigatus colonization, but no association was found between persistent A. fumigatus and subsequent lung function decline. No obvious benefits of treating asymptomatic A. fumigatus colonization were demonstrated.

Patient acceptance and outcome of mental health screening in Swedish adults with cystic fibrosis.

PURPOSE: Anxiety and depression are common among adults with cystic fibrosis (CF), and the International Committee on Mental Health in CF (ICMH) recommends annual screening for mental health problems. We implemented screening according to the recently published guidelines and assessed the results from the first year, as well as the patients' attitude to annual screening METHODS: Adult patients attending Gothenburg CF-center from Feb 2015 to Dec 2016 completed the GAD-7 (anxiety) and PHQ-9 (depression) forms at the time of their annual review. In addition, questions regarding the screening process and instruments used were asked. RESULTS: All invited patients (n = 100, 52% males, 2% lung transplanted), with a median age of 28 years (range 18-65), agreed to participate. In general (83%), the patients were positive to screening on an annual basis. No significant differences in total GAD-7 and PHQ-9 scores were found when comparing men and women. Patients younger than 30 years of age reported more symptoms of anxiety compared to older patients (p = 0.02). There were 21 (21%) patients with scores > 10 for GAD-7 and/or PHQ-9 indicating at least moderate anxiety or depression. Scores > 10 were reported by 15 patients on GAD-7, 15 patients on PHQ-9, and 9 patients reported scores above 10 on both measures. CONCLUSION: The patients considered annual check-ups for mental health issues important. Although the screening results are reassuring, the group is heterogenic and younger individuals should be given extra attention. Follow-up over longer time will provide more robust data.

Impact of lumacaftor/ivacaftor on the bacterial and fungal respiratory pathogens in cystic fibrosis: a prospective multicenter cohort study in Sweden.

BACKGROUND: A significant decline in pulmonary exacerbation rates has been reported in CF patients homozygous for F508del treated with lumacaftor/ivacaftor. However, it is still unclear whether this reduction reflects a diminished microbiological burden. OBJECTIVES: The aim of this study was to determine the impact of lumacaftor/ivacaftor on the bacterial and fungal burden. DESIGN: The study is a prospective multicenter cohort study including 132 CF patients homozygous for F508del treated with lumacaftor/ivacaftor. METHODS: Clinical parameters as well as bacterial and fungal outcomes 1 year after initiation of lumacaftor/ivacaftor were compared to data from 2 years prior to initiation of the treatment. Changes in the slope of the outcomes before and after the onset of treatment were assessed. RESULTS: Lung function measured as ppFEV1 (p < 0.001), body mass index (BMI) in adults (p < 0.001), and BMI z-score in children (p = 0.007) were improved after initiation of lumacaftor/ivacaftor. In addition, the slope of the prevalence of Streptococcus pneumoniae (p = 0.007) and Stenotrophomonas maltophilia (p < 0.001) shifted from positive to negative, that is, became less prevalent, 1 year after treatment, while the slope for Candida albicans (p = 0.009), Penicillium spp (p = 0.026), and Scedosporium apiospermum (p < 0.001) shifted from negative to positive. CONCLUSION: The current study showed a significant improvement in clinical parameters and a reduction of some of CF respiratory microorganisms 1 year after starting with lumacaftor/ivacaftor. However, no significant changes were observed for Pseudomonas aeruginosa, Staphylococcus aureus, or Aspergillus fumigatus, key pathogens in the CF context.

Low Levels of Exhaled Surfactant Protein A Associated With BOS After Lung Transplantation.

BACKGROUND: There is no clinically available marker for early detection or monitoring of chronic rejection in the form of bronchiolitis obliterans syndrome (BOS), the main long-term complication after lung transplantation. Sampling and analysis of particles in exhaled air is a valid, noninvasive method for monitoring surfactant protein A (SP-A) and albumin in the distal airways. METHODS: We asked whether differences in composition of exhaled particles can be detected when comparing stable lung transplant recipients (LTRs) (n = 26) with LTRs who develop BOS (n = 7). A comparison between LTRs and a matching group of healthy controls (n = 33) was also conducted. Using a system developed in-house, particles were collected from exhaled air by the principal of inertial impaction before chemical analysis by immunoassays. RESULTS: Surfactant protein A in exhaled particles and the SP-A/albumin ratio were lower (P = 0.002 and P = 0.0001 respectively) in the BOS group compared to the BOS-free group. LTRs exhaled higher amount of particles (P < 0.0001) and had lower albumin content (P < 0.0001) than healthy controls. CONCLUSIONS: We conclude that low levels of SP-A in exhaled particles are associated with increased risk of BOS in LTRs. The possibility that this noninvasive method can be used to predict BOS onset deserves further study with prospective and longitudinal approaches.

BAL levels of interleukin-18 do not change before or during acute rejection in lungtransplant recipients.

STUDY OBJECTIVE: Acute rejection (AR) of the allograft is a major clinical problem after lungtransplantation. Repeated episodes of AR increase the risk of developing obliterative bronchiolitis, the main cause of mortality in this patient group. It is believed that AR is caused by T-lymphocytes reacting to donor antigens and in turn activating antigen presenting cells (APC) such as alveolar macrophages. Hypothetically, the interferon-gamma inducing cytokine IL-18 released from activated macrophages can play a role in the development of AR by modulating cytotoxic T-lymphocytes. DESIGN: To determine whether IL-18 may serve as a marker of AR, we retrospectively analysed the concentration of soluble IL-18 protein and inflammatory cells in bronchoalveolar lavage fluid (BAL) from lungtransplant recipients. PATIENTS: To minimize confounding factors, eight pairs of patients were matched for age, gender, pre-op diagnosis, type of operation, absence of infection and time post transplant. METHODS: BAL levels of IL-18 (ELISA) and BAL cell differentials were analysed before, during and after an episode of AR and compared with the matched control group. CONCLUSION: We found no changes in IL-18 concentration in BAL associated with AR. IL-18 in BAL did not correlate with BAL lymphocyte percentage. We conclude that change in soluble IL-18 protein does not constitute a useful marker of acute rejection in lung allograft recipients.

Increased net gelatinase but not serine protease activity in bronchiolitis obliterans syndrome.

BACKGROUND: Bronchiolitis obliterans syndrome (BOS) is the main long-term complication after lung transplantation. Previous studies indicate that neutrophil mobilization causes high protease concentrations in the lung allograft during BOS. This study assessed net protease activity and the functional aspect of proteases in BOS. METHODS: The net gelatinase and net serine protease activity was assessed in bronchoalveolar lavage (BAL) fluid from 12 pairs of 24 lung allograft recipients with and without BOS, carefully selected from a larger cohort that was otherwise clinically matched. We determined the identity and total activity of gelatinases and concentrations of matrix metalloproteinases (MMP) 2 and 9, as well as the concentration of serine protease, neutrophil elastase (NE), and one major antiprotease, secretory leukocyte protease inhibitor (SLPI). RESULTS: Net gelatinase activity was substantially increased in BOS (n = 12), with total MMP-9 activity exceeding total MMP-2 activity (p < 0.01). Correspondingly, the total mean (interquartile range) concentration of MMP-9 was increased in BOS (62 [160] ng/ml) vs non-BOS (20 [24] ng/ml; p < 0.05), but not MMP-2 (BOS: 0.6 [0.7]; non-BOS: 0.6 [0.8] ng/ml, p = 0.23). Notably, net gelatinase activity correlated with MMP-9 (rho = 0.9, p < 0.01) and percentage of neutrophils (rho = 0.8, p < 0.01). Despite increased levels of NE and unaltered levels of SLPI, net serine protease levels remained unaltered, suggesting that NE does not contribute to BOS pathology. CONCLUSIONS: Our study supports that there is an unopposed increase in gelatinase activity in BOS, which in part is likely to be accounted for by MMP-9 from local neutrophils. No corresponding evidence was found for serine protease activity.