THE ROLE OF THE NEUTROPHIL-TO-LYMPHOCYTE RATIO (NLR) AND THE PLATELET-TO-LYMPHOCYTE RATIO (PLR) AS PROGNOSTIC BIOMARKERS IN SEPSIS: AN INTEGRATIVE REVIEW

Abstract

This article aims to analyze the role of the neutrophil-to-lymphocyte ratio (NLR) and the platelet-to-lymphocyte ratio (PLR) as prognostic biomarkers in adult patients with sepsis, considering their associations with clinical severity and mortality, as well as their performance compared with biomarkers traditionally used in clinical practice. This is an integrative literature review conducted using the PubMed/MEDLINE, Scopus, Web of Science, and SciELO databases, with searches performed between November 2025 and February 2026, covering publications from 2020 to 2026. After applying the eligibility criteria, 31 studies were included, and their findings were descriptively synthesized. The NLR was investigated in 28 studies and frequently showed associations with mortality and greater clinical severity, although its prognostic performance varied across populations, and some studies did not identify an independent association after statistical adjustment. The PLR, evaluated in 12 studies, showed more heterogeneous results. Serial measurements of these ratios and their combination with other biomarkers demonstrated potential complementary value in specific studies. It is concluded that the NLR and PLR may contribute to prognostic stratification in sepsis; however, the evidence does not support their isolated use or demonstrate consistent superiority over traditional biomarkers.