Prognostic value of platelet-to-lymphocyte ratios among critically ill patients with acute kidney injury
Zheng et al. Critical Care
Prognostic value of platelet-to-lymphocyte ratios among critically ill patients with acute kidney injury
Chen-Fei Zheng 3
Wen-Yue Liu 2
Fang-Fang Zeng 1 7
Ming-Hua Zheng 6
Hong-Ying Shi 5
Ying Zhou 4
Jing-Ye Pan 0
0 Department of Intensive Care, The First Affiliated Hospital of Wenzhou Medical University , Wenzhou 325000 , China
1 Department of Epidemiology, School of Basic Medical Sciences, Jinan University , Guangzhou 510632 , China
2 School of the First Clinical Medical Sciences, Wenzhou Medical University , Wenzhou 325000 , China
3 Department of Nephrology, the First Affiliated Hospital of Wenzhou Medical University , Wenzhou 325000 , China
4 Department of Nephrology, The First Affiliated Hospital, Sun Yat-sen University, Key Laboratory of Nephrology, Ministry of Health and Guangdong Province , Guangzhou 510000 , China
5 Department of Preventive Medicine, Wenzhou Medical University , Wenzhou 325000 , China
6 Department of Infection and Liver Diseases, Liver Research Center, The First Affiliated Hospital of Wenzhou Medical University , Wenzhou 325000 , China
7 Guangdong Provincial Key Laboratory of Food , Nutrition, and Health , School of Public Health, Sun Yat-sen University , Guangzhou 510000 , China
Background: Inflammation plays an important role in the initiation and progression of acute kidney injury (AKI). However, evidence regarding the prognostic effect of the platelet-to-lymphocyte ratio (PLR), a novel systemic inflammation marker, among patients with AKI is scarce. In this study, we investigated the value of the PLR in predicting the outcomes of critically ill patients with AKI. Methods: Patient data were extracted from the Multiparameter Intelligent Monitoring in Intensive Care Database III version 1.3. PLR cutoff values were determined using smooth curve fitting or quintiles and were used to categorize the subjects into groups. The clinical outcomes were 30-day and 90-day mortality in the intensive care unit (ICU). Cox proportional hazards models were used to evaluate the association between the PLR and survival. Results: A total of 10,859 ICU patients with AKI were enrolled. A total of 2277 thirty-day and 3112 ninety-day deaths occurred. A U-shaped relationship was observed between the PLR and both 90-day and 30-day mortality, with the lowest risk being at values ranging from 90 to 311. The adjusted HR (95% CI) values for 90-day mortality given risk values < 90 and > 311 were 1.25 (1.12-1.39) and 1.19 (1.08-1.31), respectively. Similar trends were observed for 30-day mortality or when quintiles were used to group patients according to the PLR. Statistically significant interactions were found between the PLR and both age and heart rate. Younger patients (aged < 65 years) and those with more rapid heart rates (≥89.4 beats per minute) tended to have poorer prognoses only when the PLR was < 90, whereas older patients (aged ≥ 65 years) and those with slower heart rates (<89.4 beats per minute) had higher risk only when the PLR was > 311 (P < 0.001 for age and P < 0.001 for heart rate). Conclusions: The preoperative PLR was associated in a U-shaped pattern with survival among patients with AKI. The PLR appears to be a novel, independent prognostic marker of outcomes in critically ill patients with AKI.
Platelet-to-lymphocyte ratio; Acute kidney injury; Prognosis; Intensive care unit
Background
More than 5 million patients are admitted to intensive care
units (ICUs) each year in America [
1, 2
], and 6–24% of
these patients have acute kidney injury (AKI) [3]. In the
presence of AKI, patient mortality increases to as high as
60–70%, especially within 1 year after ICU admission [
4–6
].
Considering the high incidence of AKI in the ICU and its
poor prognosis, an increasing number of observational
studies over the past 2 decades have been devoted to
identifying the clinical predictors of mortality in AKI.
Systemic inflammation is an integral part of disease
progression in critical illness and is commonly
associated with sepsis, leading to an increased risk of mortality
[
7, 8
]. Inflammation plays an important role in the
initiation and progression of AKI [
9–11
], and morphological
and/or functional changes in vascular endothelial cells
and/or in the tubular epithelium are observed in patients
with AKI. Leukocytes, including lymphocytes, infiltrate
the injured kidneys and the entire body via the
circulatory system and induce the generation of inflammatory
mediators such as cytokines and chemokines, which
damage the kidney and other organs [12]. The
antithrombotic effects of platelets can evolve into
atherogenesis via the secretion of proinflammatory cytokines [
13
],
whereas the binding of platelets to endothelial cells can
trigger leukocyte transmigration and adhesion, especially
in the presence of shear stress [
14
]. The
platelet-tolymphocyte ratio (PLR) has been introduced as a
potential marker of inflammation in cardiovascular disease
(CVD) and tumo (...truncated)