Microbial etiology of pneumonia in patients with decreased renal function

PLoS One. 2019 May 9;14(5):e0216367. doi: 10.1371/journal.pone.0216367. eCollection 2019.

Abstract

Background: Patients with renal impairment have altered immunity, which might cause vulnerability to specific pathogens and worsen pneumonia-related outcomes. Nonetheless, the microbiological features of pneumonia in patients with decreased renal function remain unknown.

Methods: Therefore, we conducted a retrospective cohort study enrolling adult patients hospitalized with pneumonia to assess this knowledge gap. The baseline estimated glomerular filtration rate (eGFR) and first sputum microbiology during hospitalization were used for statistical analyses.

Results: Overall, 1554 patients hospitalized with pneumonia (mean age, 76.1 ± 16.7) were included, and 162 patients had died at the end of hospitalization. The cutoff eGFR value predicting mortality was <55 mL/min/1.73 m2, which defined decreased renal function in this study. Patients with decreased renal function demonstrated a significantly higher risk of fungi and Staphylococcus aureus (S. aureus) infection. On the other hand, this group of patients showed significantly higher neutrophil-to-lymphocyte ratio (NLR), which associated with higher mortality. Additionally, patients with S. aureus had a significantly lower eGFR, lymphocyte count and a higher NLR.

Conclusions: These findings suggested the altered immunity and vulnerability to S. aureus infection in patients with decreased renal function, which may be the underlying cause of worse outcomes of pneumonia in this group of patients.

Publication types

  • Clinical Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Aged, 80 and over
  • Female
  • Glomerular Filtration Rate*
  • Hospital Mortality*
  • Hospitalization*
  • Humans
  • Male
  • Middle Aged
  • Pneumonia, Staphylococcal* / microbiology
  • Pneumonia, Staphylococcal* / mortality
  • Renal Insufficiency* / microbiology
  • Renal Insufficiency* / mortality
  • Renal Insufficiency* / physiopathology
  • Retrospective Studies

Grants and funding

This work was supported, in part, by the research grants from the Taipei Medical University [TMU 106-AE1-B22], the Ministry of Science and Technology of Taiwan [MOST 104-2314-B-075-047], the Novel Bioengineering and Technological Approaches to Solve Two Major Health Problems in Taiwan sponsored by the Taiwan Ministry of Science and Technology Academic Excellence Program [MOST 106-2633-B-009-001], the Ministry of Health and Welfare [MOHW106-TDU-B-211-113001], and Taipei Veterans General Hospital [V105C-0207,V106C-045]. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.