Macrolides for better resolution of community-acquired pneumonia: A global meta-analysis of clinical outcomes with focus on microbial aetiology

The Interplay between Antibiotics and the Host Immune Response in Sepsis: From Basic Mechanisms to Clinical Considerations: A Comprehensive Narrative Review

Sepsis poses a significant global health challenge due to immune system dysregulation. This narrative review explores the complex relationship between antibiotics and the immune system, aiming to clarify the involved mechanisms and their clinical impacts. From pre-clinical studies, antibiotics exhibit various immunomodulatory effects, including the regulation of pro-inflammatory cytokine production, interaction with Toll-Like Receptors, modulation of the P38/Pmk-1 Pathway, inhibition of Matrix Metalloproteinases, blockade of nitric oxide synthase, and regulation of caspase-induced apoptosis. Additionally, antibiotic-induced alterations to the microbiome are associated with changes in systemic immunity, affecting cellular and humoral responses. The adjunctive use of antibiotics in sepsis patients, particularly macrolides, has attracted attention due to their immune-regulatory effects. However, there are limited data comparing different types of macrolides. More robust evidence comes from studies on community-acquired pneumonia, especially in severe cases with a hyper-inflammatory response. While studies on septic shock have shown mixed results regarding mortality rates and immune response modulation, conflicting findings are also observed with macrolides in acute respiratory distress syndrome. In conclusion, there is a pressing need to tailor antibiotic therapy based on the patient's immune profile to optimize outcomes in sepsis management.

Clarithromycin for early anti-inflammatory responses in community-acquired pneumonia in Greece (ACCESS): a randomised, double-blind, placebo-controlled trial

BACKGROUND

Addition of macrolide antibiotics to β-lactam antibiotics for the treatment of patients in hospital with community-acquired pneumonia is based on results from observational studies and meta-analyses rather than randomised clinical trials. We investigated if addition of the macrolide clarithromycin to treatment with a β-lactam antibiotic in this population could improve early clinical response-the new regulatory endpoint for community-acquired pneumonia-and explored the possible contribution of modulation of the inflammatory host response to that outcome.

METHODS

The ACCESS trial was a phase 3 prospective, double-blind, randomised controlled trial, in which adults in hospital with community-acquired pneumonia who had systemic inflammatory response syndrome, Sequential Organ Failure Assessment (SOFA) score of 2 or more, and procalcitonin 0·25 ng/mL or more were enrolled in 18 internal medicine departments of public Greek hospitals. Patients were randomly assigned (1:1) by computer-generated block randomisation to standard of care medication (including intravenous administration of a third-generation cephalosporin or intravenous administration of β-lactam plus β-lactamase inhibitor combination) plus either oral placebo or oral clarithromycin 500 mg twice daily for 7 days. Investigators, staff, and patients were masked to group allocation. The primary composite endpoint required that patients fulfilled both of the following conditions after 72 hours (ie, day 4 of treatment): (1) decrease in respiratory symptom severity score of 50% or more as an indicator of early clinical response and (2) decrease in SOFA score of at least 30% or favourable procalcitonin kinetics (defined as ≥80% decrease from baseline or procalcitonin <0·25 ng/mL), or both, as an indicator of early inflammatory response. Participants who were randomly assigned and received allocated treatment were included in the primary analysis population. This trial is complete and is registered with the EU Clinical Trials Register (2020-004452-15) and ClinicalTrials.gov (NCT04724044).

FINDINGS

Patients were enrolled between Jan 25, 2021, and April 11, 2023, and 278 individuals were randomly allocated to receive standard of care in combination with either clarithromycin (n=139) or placebo (n=139). 134 patients in the clarithromycin group (five withdrew consent) and 133 patients in the placebo group (six withdrew consent) were included in the analysis of the primary endpoint. The primary endpoint was met in 91 (68%) patients in the clarithromycin group and 51 (38%) patients in the placebo group (difference 29·6% [95% CI 17·7-40·3]; odds ratio [OR] 3·40 [95% CI 2·06-5·63]; p<0·0001). Serious treatment-emergent adverse events (TEAEs) occurred in 58 (43%) patients in the clarithromycin group and 70 (53%) patients in the placebo group (difference 9·4% [95% CI -2·6 to 20·9]; OR 0·67 [95% CI 0·42 to 1·11]; p=0·14). None of the serious TEAEs was judged to be related to treatment assignment.

INTERPRETATION

Addition of clarithromycin to standard of care enhances early clinical response and attenuates the inflammatory burden of community-acquired pneumonia. The mechanism of benefit is associated with changes in the immune response. These findings suggest the importance of adding clarithromycin to β-lactams for treatment of patients in hospital with community-acquired pneumonia to achieve early clinical response and early decrease of the inflammatory burden.

FUNDING

Hellenic Institute for the Study of Sepsis and Abbott Products Operations.

Developing a novel magnetic organic polymer for selective extraction and determination of 16 macrolides in water and honey samples

A novel magnetic organic polymer Fe3O4@SiO2@Tb-PDAN was designed and synthesized, which was used as an adsorbent for magnetic solid-phase extraction (MSPE) of 16 macrolides (MALs) in water and honey. The synthesized adsorbent was characterized using techniques including scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR) and X-ray diffraction (XRD). Then several parameters of the extraction process were further optimized. Under the optimized conditions, an MSPE-LC-MS/MS method was established for extraction and determination of 16 MALs, which showed good linearity (r ≥ 0.999), low limits of detection (0.001-0.012 μg L-1 for water and 0.001-0.367 μg kg-1 for honey) and satisfactory recoveries (70.02-118.91%) with the relative standard deviations (RSDs) lower than 10.0%. This established method was then successfully applied to detect MALs in real samples, which suggested that Fe3O4@SiO2@Tb-PDAN was a potential magnetic adsorbent for efficient extraction and analysis of MALs.