Circulating metabolic profile in idiopathic pulmonary fibrosis: data from the IPF-PRO Registry.

BACKGROUND: The circulating metabolome, reflecting underlying cellular processes and disease biology, has not been fully characterized in patients with idiopathic pulmonary fibrosis (IPF). We evaluated whether circulating levels of metabolites correlate with the presence of IPF, with the severity of IPF, or with the risk of clinically relevant outcomes among patients with IPF. METHODS: We analyzed enrollment plasma samples from 300 patients with IPF in the IPF-PRO Registry and 100 individuals without known lung disease using a set of targeted metabolomics and clinical analyte modules. Linear regression was used to compare metabolite and clinical analyte levels between patients with IPF and controls and to determine associations between metabolite levels and measures of disease severity in patients with IPF. Unadjusted and adjusted univariable Cox regression models were used to evaluate associations between circulating metabolites and the risk of mortality or disease progression among patients with IPF. RESULTS: Levels of 64 metabolites and 5 clinical analytes were significantly different between patients with IPF and controls. Among analytes with greatest differences were non-esterified fatty acids, multiple long-chain acylcarnitines, and select ceramides, levels of which were higher among patients with IPF versus controls. Levels of the branched-chain amino acids valine and leucine/isoleucine were inversely correlated with measures of disease severity. After adjusting for clinical factors known to influence outcomes, higher levels of the acylcarnitine C:16-OH/C:14-DC were associated with all-cause mortality, lower levels of the acylcarnitine C16:1-OH/C14:1DC were associated with all-cause mortality, respiratory death, and respiratory death or lung transplant, and higher levels of the sphingomyelin d43:2 were associated with the risk of respiratory death or lung transplantation. CONCLUSIONS: IPF has a distinct circulating metabolic profile characterized by increased levels of non-esterified fatty acids, long-chain acylcarnitines, and ceramides, which may suggest a more catabolic environment that enhances lipid mobilization and metabolism. We identified select metabolites that were highly correlated with measures of disease severity or the risk of disease progression and that may be developed further as biomarkers. TRIAL REGISTRATION: ClinicalTrials.gov; No: NCT01915511; URL: www. CLINICALTRIALS: gov .

Poor tolerability of cystic fibrosis transmembrane conductance regulator modulator therapy in lung transplant recipients.

Elexacaftor/tezacaftor/ivacaftor (ELX/TEZ/IVA) is a highly effective therapy for patients with cystic fibrosis (CF) with potential benefits in lung transplant recipients (LTRs) for extrapulmonary CF manifestations; however, tolerability and efficacy in this population are largely unknown. We report our experience with ELX/TEZ/IVA in LTRs for extrapulmonary complications of CF including tolerability, drug-drug interactions, and therapeutic benefit. All LTRs at a single center initiated on ELX/TEZ/IVA were reviewed. Adverse events and patient-reported outcomes attributed to ELX/TEZ/IVA were documented. Pulmonary function, tacrolimus requirements in mg/kg/dl, body mass index (BMI), and reason for initiation were assessed at the initiation of ELX/TEZ/IVA, and at 12 months post-initiation or at the time of discontinuation for those in whom therapy was discontinued. Thirteen LTRs were initiated on ELX/TEZ/IVA at a mean of 115 ± 92 months post-transplant. All were initiated on ELX/TEZ/IVA for sinus or sinus and gastrointestinal CF manifestations. Five (38.4%) patients discontinued therapy due to declining pulmonary function (2/5, 40%), mood disturbances (2/5, 40%), or lack of benefit (1/5, 20%). Of the eight patients who remain on ELX/TEZ/IVA, four reported adverse effects and three LTRs temporarily held therapy. Six (46.2%) LTRs reported improvement in sinus symptoms, while four (30.7%) reported improved gastrointestinal symptoms. Weight declined in the cohort overall. Tacrolimus dose requirements decreased following initiation of ELX/TEZ/IVA therapy, with a 50% decline in dose requirements observed. In our experience, ELX/TEZ/IVA in LTRs is poorly tolerated with modest perceived extrapulmonary benefit and a significant effect on tacrolimus dose requirements. More data are needed to determine the benefits of ELX/TEZ/IVA therapy in LTRs.

Expanded clinical presentation of community-acquired methicillin-resistant Staphylococcus aureus pneumonia.

BACKGROUND: Community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) has been documented to cause community-acquired pneumonias (CAP), notable for necrotizing features. The frequency of occurrence, risk factors, and optimal treatment of CA-MRSA CAP are unclear. METHODS: This was a retrospective analysis of patients admitted to Northwestern Memorial Hospital from January 2005 to April 2007 with initial clinical presentation of pneumonia and respiratory or blood culture positive for CA-MRSA. Definition of CA-MRSA was based on sensitivity to trimethoprim/sulfamethoxazole and clindamycin. RESULTS: Fifteen patients with CA-MRSA CAP were identified during the 28-month period. Only one of the 14 patients tested had evidence of preceding influenza, and no seasonal pattern was seen. Seven patients were never admitted to the ICU. Eight of 14 with chest CT scans had evidence of lung necrosis. Nine of 15 had evidence of pleural effusions early in their hospital course, and five of nine required at least one pleural drainage procedure. Seven of 15 were immunocompromised (three HIV, one acute lymphocytic leukemia [ALL], one high-dose steroids, and two immunoglobulin deficiency) with an additional three patients with diabetes. Mortality was only 13% (two of 15); both deaths occurred in patients with severe immunocompromise (ALL post chemotherapy and AIDS). Fourteen of 15 patients were treated with antimicrobials that inhibit exotoxin production (clindamycin or linezolid). CONCLUSIONS: CA-MRSA pneumonia is not necessarily a post-influenza infection. Despite necrotizing features in many, the mortality of CA-MRSA pneumonia in our series is lower than previously reported, and patients do not routinely require ICU care. Treatment with antibiotics that inhibit exotoxin production and/or nontoxigenic strains may explain this improved outcome.