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NCT Number: NCT06594133

Longitudinal and Cross-sectional Analysis of Pulmonary Microbiota in Lung Transplant Recipients Infected With Nocardia

This retrospective observational study aims to explore the impact of Nocardia infection on the pulmonary microbiota of lung transplant recipients (LTRs). The study will analyze both cross-sectional and longitudinal data from patients diagnosed with Nocardia pneumonia, comparing microbial composition and diversity between infected and non-infected groups. This research seeks to provide insights into the relationship between pulmonary microbiota alterations and clinical outcomes in LTRs.

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Key information

Conditions

Nocardia Infections Actinomycetales Infections Bacterial Infections Bacterial Infections and Mycoses Gram-Positive Bacterial Infections Infections Lung Transplantation

Age range

18 year and older

Sex eligibility

All sexes

Study type

Observational

Primary location

Guangzhou Institute of Respiratory Diseases, the First Affiliated Hospital of Guangzhou Medical University

Guangzhou, Guangdong, 510120, China

About this study

This study is a single-center, retrospective, observational study designed to investigate the impact of Nocardia infection on the pulmonary microbiota of lung transplant recipients (LTRs). The study will include both cross-sectional and longitudinal analyses. In the cross-sectional study, 17 LTRs diagnosed with Nocardia pneumonia (Nocardia pneumonia group, NPG) will be compared with 51 non-infected LTRs (non-Nocardia infection group, NNIG) matched for age, sex, and underlying conditions.

The longitudinal study will follow LTRs over a 4-month period, collecting samples before, during, and after treatment. Patients in this group will be categorized into the Recovered group (RG) or Not Recovered group (NRG) based on treatment outcomes. The study will also include a subgroup analysis of patients with disseminated Nocardia infection, comparing pulmonary and systemic microbiota changes.

Microbial diversity and composition will be assessed using high-throughput sequencing of bronchoalveolar lavage fluid (BALF) samples. Statistical analyses will include the Kolmogorov-Smirnov test, ANOVA, and Kruskal-Wallis test for group comparisons, with linear mixed-effects models used to analyze changes over time.

The goal of this study is to provide a deeper understanding of how Nocardia infection affects the pulmonary microbiota in LTRs and to identify key microbial species associated with clinical outcomes.

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Lung transplant recipients
  • Diagnosed with Nocardia pneumonia (for the study group)
  • Age ≥ 18 years

Exclusion criteria

  • Patients with incomplete medical records
  • Patients who survived ≤ 3 days after transplantation
  • Patients lost to follow-up

Treatment and study plan

Antibiotic treatment

Drug

For lung transplant recipients with Nocardia infection, the treatment regimen could include:

Sulfamethoxazole/Trimethoprim (Bactrim): 800 mg/160 mg orally or intravenously twice daily for at least 6 months.

Imipenem: 500 mg intravenously every 6 hours for severe cases. Monitoring: Regular monitoring of blood levels of the drug to avoid toxicity and adjust doses accordingly.

Primary outcomes

  1. Pulmonary Microbiota Diversity in Nocardia-infected Lung Transplant Recipients

    Time frame: January 2023 to August 2024

    Measurement of alpha and beta diversity of the pulmonary microbiota in BALF samples from lung transplant recipients with and without Nocardia infection. Alpha diversity will be quantified using Shannon diversity index and observed species richness, while beta diversity will be analyzed using Bray-Curtis dissimilarity. Microbial composition and relative abundance will be compared between the Nocardia pneumonia group and the non-Nocardia infection group. Changes in diversity metrics will be analyzed over time to assess the impact of Nocardia infection on pulmonary microbiota.

Secondary outcomes

  1. Correlation Between Pulmonary Microbiota and Clinical Outcomes

    Time frame: January 2023 to August 2024

    Correlation between pulmonary microbiota diversity and clinical factors such as age, kidney function, nutritional status, and immunosuppressive therapy in lung transplant recipients. The analysis includes changes in pulmonary microbiota before and after treatment in patients with Nocardia infection and the number of participants showing significant correlations between microbiota diversity and clinical outcomes.

Sponsors and collaborators

Lead sponsor

Zhibin Xu

Other

Registry information

Official study title

Longitudinal and Cross-sectional Analysis of Pulmonary Microbiota in Lung Transplant Recipients Infected With Nocardia: A Single-center Retrospective Study

Acronym: NocardiaLM

Important dates

Study start
2023
Primary completion
2024
Study completion
2024
First posted
Sep 19, 2024
Registry last updated
Nov 12, 2024

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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