Non-tuberculous mycobacterial pulmonary disease (NTM-PD): Epidemiology, diagnosis and multidisciplinary management

Non-tuberculous mycobacteria (NTM) are ubiquitous environmental organisms that can cause significant disease in both immunocompromised and immunocompetent individuals. The incidence of NTM pulmonary disease (NTM-PD) is rising globally. Diagnostic challenges persist and treatment efficacy is variable. This article provides an overview of NTM-PD for clinicians. We discuss how common it is, who is at risk, how it is diagnosed and the multidisciplinary approach to its clinical management. [Abstract copyright: Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.

The role of the clinical pharmacist in the respiratory or sleep multidisciplinary team

The role of the pharmacist has evolved significantly, not least over the last 20 years. It delivers a skilled profession with a vital role in medicines optimisation and the management of patients with a respiratory or sleep disorder. While pharmacists are capable of acting as independent practitioners delivering direct patient care, this article explores their contribution to multidisciplinary teams within asthma, COPD, cystic fibrosis, tuberculosis, interstitial lung disease and sleep medicine. Having identified patient cohorts needing specialist medicines support, notably those with poor medicines adherence or specific medicines-related needs (for example during adolescence, or women who are pregnant or breastfeeding), these pharmacists work within primary, secondary and specialist tertiary care. The aim of this review is to share and inspire innovative models of working to include more pharmacists in respiratory and sleep medicine

Neutrophils with myeloid derived suppressor function deplete arginine and constrain T cell function in septic shock patients

Introduction: Impaired T cell function in sepsis is associated with poor outcome, but the mechanisms are unclear. In cancer, arginase-expressing myeloid derived suppressor cells (MDSCs) deplete arginine, impair T cell receptor CD3 zeta-chain expression and T cell function and are linked to poor clinical outcome, but their role during acute human infectious disease and in particular sepsis remains unknown. Hypoarginemia is prevalent in sepsis. This study aimed to determine whether neutrophils that co-purify with PBMC express arginase, and if arginine depletion constrains T cell CD3 zeta-chain expression and function in human sepsis. Methods: Using flow cytometry, cell culture, HPLC, arginase activity and mRNA detection, our study examined whether neutrophils, with reduced buoyant density isolated in the Ficoll interface, metabolise L-arginine and suppress T cell proliferation in sepsis. A total of 35 sepsis patients (23 with septic shock) and 12 hospital controls in a tertiary referral hospital in tropical Australia were evaluated. Results: Only sepsis patients had interphase neutrophils, neutrophils co-purifying with mononuclear cells (≤1.077 specific gravity). The percentage of interphase neutrophils in sepsis was proportional to sepsis severity and correlated with plasma IL-6 concentrations. <i>Ex vivo</i>, sepsis-derived interphase neutrophils expressed arginase, metabolised culture L-arginine and suppressed T cell proliferation and CD3 zeta-chain expression. <i>In vivo</i>, in septic shock there was a longitudinal inverse association between interphase neutrophil number and CD3 zeta-chain expression. Depletion or inhibition of interphase neutrophils in vitro restored zeta-chain expression and T cell function. Conclusions: For the first time during an acute human infection, interphase neutrophils that express arginase were found to circulate in sepsis, in proportion to disease severity. These neutrophil-MDSCs impair T cell CD3 zeta-chain expression and T cell function via L-arginine metabolism, and likely contribute to the T cell dysfunction seen in sepsis. Modulation of neutrophil-MDSC or their downstream effects warrant consideration as targets for novel adjunctive therapies in sepsis

Increased plasma arginase activity in human sepsis: association with increased circulating neutrophils

Background: The pathophysiology of sepsis is incompletely understood. Impaired bioavailability of L-arginine, the substrate for NO synthesis, is linked to sepsis severity, and plasma arginase has been linked to hypoargininemia in other disease states. Circulating neutrophils are increased in sepsis and constitutively express arginase. We investigated whether plasma arginase activity is increased in human sepsis and whether this is associated with neutrophil numbers and activation. Methods: We used HPLC and a radiometric assay to evaluate plasma amino acid concentrations and plasma arginase activity. The relationships between plasma arginase activity, neutrophil count, neutrophil activity and plasma L-arginine and arginine metabolites were evaluated in 44 sepsis patients and 25 controls. Results: Plasma arginase activity was increased in sepsis patients, correlated with neutrophil count (r=0.44; p=0.003), but was independent of sepsis severity (SOFA or APACHE II score). Plasma HNP1-3 correlated with neutrophil count (r=0.31; p=0.04), was elevated in shock (median 180 ng/mL vs. 83 ng/mL sepsis without shock, p=0.0006) and correlated with SOFA score. Sepsis patients with high neutrophil counts had significantly higher plasma HNP1-3 and arginase activity and lower plasma L-arginine concentrations than those with lower neutrophil counts and controls. Conclusions: Plasma arginase activity, potentially derived in part from neutrophil activation, is elevated in sepsis, and may contribute to impaired bioavailability of L-arginine in sepsis

Principal coordinate analysis (PCoA) of bacterial composition between internal and external body samples of <i>Anopheles coluzzii</i> mosquitoes.

Analysis was based on the Bray Curtis metric. (TIF)</p

Relative abundances of major bacterial taxa at the phylum level.

‘Other’ group represents all taxa with relative abundance below 5%. (TIFF)</p

Alpha diversity measures of the internal and external body microbiomes of <i>Anopheles coluzzii</i> mosquitoes.

(A) Observed OTUs, (B) Shannon diversity and (C) Faith’s phylogenetic diversity.</p