Characterization of the Microbiome and Host's Metabolites of the Lower Respiratory Tract During Acute Community-Acquired Pneumonia Identifies Potential Novel Markers.

Purpose: Community-acquired pneumonia (CAP) is one of the most frequently encountered infectious diseases worldwide. Few studies have explored the microbial composition of the lower respiratory tract (LRT) and host metabolites of CAP. We analyzed the microbial composition of the LRT and levels of host metabolites to explore new biomarkers for CAP. Patients and Methods: Bronchoalveolar lavage fluid (BALF) was collected from 28 CAP patients and 20 healthy individuals. Following centrifugation, BALF pellets were used for amplicon sequencing of a variable region of the bacterial 16S rDNA gene to characterize the microbial composition. Non-targeted metabolomics was used to detect host's metabolites in the supernatant. Results: Compared with healthy individuals, the bacterial alpha diversity in the LRT of CAP patients was significantly lower in CAP patients (p<0.05). On the bacterial genus level, over 20 genera were detected with lower relative abundance (p<0.05), while the relative abundance of Ruminiclostridium-6 was significantly higher in CAP patients. The levels of the host metabolites dimethyldisulfide, choline, pyrimidine, oleic acid and N-acetyl-neuraminic acid were all increased in BALF of CAP patients (p<0.05), while concentrations of lysophosphatidylcholines (LPC (12:0/0:0)) and phosphatidic acid (PA (20:4/2:0)) were decreased (p<0.05). Furthermore, the relative abundance of Parvimonas, Treponema-2, Moraxella, Aggregatibacter, Filifactor, Fusobacterium, Lautropia and Neisseria negatively correlated with concentrations of oleic acid (p<0.05). A negative correlation between the relative abundance of Treponema-2, Moraxella, Filifactor, Fusobacterium and dimethyldisulfide concentrations was also observed (p<0.05). In contrast, the relative abundance of Treponema-2, Moraxella, Filifactor, and Fusobacterium was found to be positively associated with concentrations of LPC (12:0/0:0) and PA (20:4/2:0) (p<0.05). Conclusion: The composition of the LRT microbiome differed between healthy individuals and CAP patients. We propose that some respiratory microbial components and host metabolites are potentially novel diagnostic markers of CAP.

Efficacy and Safety of Rivaroxaban versus Warfarin for the Treatment of Acute Pulmonary Embolism: A Real-World Study.

BACKGROUND: Pulmonary embolism (PE) is a life-threatening disease. Target-specific anticoagulant rivaroxaban is a direct factor Xa inhibitor that can be safely used without laboratory monitoring. OBJECTIVE: To investigate the efficacy and safety of rivaroxaban versus warfarin for the treatment of acute pulmonary thromboembolism in real-world clinical practice. METHOD: This was a semiretrospective, semiprospective, and real-world trial involving 128 patients with acute symptomatic pulmonary embolism with or without active tumor or frailty. We compared rivaroxaban to the standard therapy consisting of low-molecular-weight heparin combined with warfarin. The primary efficacy outcome was absorption of thrombus. The principal safety outcome was bleeding episode. RESULTS: There was no significant difference in thrombus absorption between rivaroxaban and standard therapy after 3-month treatment (P = 0.798, 95% confidence interval (CI) 0.686 to 1.336) or more than 6-month treatment (P = 0.534, 95% confidence interval (CI) 0.795 to 1.556). There was no decline in efficacy (including computed tomographic pulmonary angiography and recurrence) when the rivaroxaban dose was reduced to 10 mg once daily after 3 months of administration. The ratio of patients without bleeding was 48.84% for rivaroxaban and 19.05% for standard therapy (P = 0.001). There was no significant difference in rivaroxaban monotherapy subgroups (including frail patients, tumor patients, and thrombolysis or nonthrombolysis at intermediate-high-risk patients). CONCLUSION: In this real-world study, the efficacy and safety of rivaroxaban alone was not different to standard therapy for pulmonary emboli absorption. With an extension in treatment duration, the rivaroxaban regimen had a higher efficacy and safety than standard therapy and there was no decline in treatment efficacy when the rivaroxaban dose was reduced to 10 mg once daily.

Comparison of rivaroxaban mono-therapy and standard-therapy adjusted by CYP2C9 and VKORC1 genotypes in symptomatic pulmonary embolism.

RATIONALE: Pulmonary embolism (PE) is a life-threatening manifestation of venous thromboembolism. Rivaroxaban is an oral anticoagulant, which directly inhibits Factor Xa. The objective of the current study was, in comparison to the standard-therapy method, to investigate the potential of rivaroxaban to improve the treatment of patients with PE, and to reduce hemorrhage in the standard-therapy group through adjusting the dose of warfarin by CYP2C9 and VKORC1 genotypes. METHODS: Sixty-two PE patients with or without deep venous thrombosis (DVT) was randomized to rivaroxaban mono-therapy or standard-therapy with enoxaparin followed by vitamin K antagonist (VKA). Concentration of the anticoagulants was adjusted according to the results of CYP2C9 and VKORC1 genotypes in order to stabilize the international normalized rate (INR) at 2.0-3.0 range. Length of hospital stay at initial hospitalization was compared, therapeutic efficacy was examined by computed tomographic pulmonary angiography (CTPA) and ventilation/perfusion (V/Q) scan, and side-effect of anti-coagulants was monitored at 1-month, and 3- or 6-months follow-up check points. RESULTS: We found that, overall, patients who received rivaroxaban mono-therapy had a significantly shorter length of hospital stay compared with patients who received standard-therapy of enoxaparin followed by VKA (9.29±3.70 versus 11.38±3.12days, P=0.021). The therapeutic efficacy was of no marked difference between these two groups. However, after one month treatment, 50% (16/32) of the standard-therapy group had mild hemorrhage, which was significantly higher than that of rivaroxaban mono-therapy group (16.7%, 5/30, P=0.006). Moreover, a significantly higher rate in the standard-therapy group (22.2% versus 3.4%, P=0.032) was found after 3 or 6months therapy. Major bleeding was slightly but not significantly higher in the standard-therapy group than that in the rivaroxaban therapy group. In addition, 2 (6.3%) patients died from Life-threatening bleeding in the standard-therapy group. CONCLUSION: Findings of the current study suggested that rivaroxaban mono-therapy result in shorter hospital stay compared to the standard-therapy. Implication of CYP2C9 and VKORC1 genotypes in determining dose of warfarin, however, remains to be further examined in larger cohort studies.