Urinary cytokines correlate with acute kidney injury in critically ill COVID-19 patients

Abstract

Background: Acute kidney injury is common in COVID-19 patients admitted to the ICU. Urinary biomarkers are a non-invasive way of assaying renal damage, and so far, urinary cytokines are not fully investigated. The current study aimed to assess urinary cytokine levels in COVID-19 patients.

Methods: Urine was collected from COVID-19 patients (n = 29) in intensive care and compared to a preoperative group of patients (n = 9) with no critical illness. 92 urinary cytokines were analyzed in multiplex using the Olink Target 96 inflammation panel and compared to clinical characteristics, and urinary markers of kidney injury.

Results: There were strong correlations between proinflammatory cytokines and between urinary cytokines and urinary kidney injury markers in 29 COVID-19 patients. Several cytokines were correlated to kidney injury, 31 cytokines to AKI stage and 19 cytokines correlated to maximal creatinine.

Conclusions: Urinary inflammatory cytokines from a wide range of immune cell lineages were significantly upregulated during COVID-19 and the upregulation correlated with acute kidney injury as well as urinary markers of kidney tissue damage.

Keywords: Acute kidney injury; Biomarkers; COVID-19; Inflammation; Intensive care; Urine.

Fig. 1

Correlation between urinary cytokines detected using the proximity extension assay (black), the urinary kidney damage markers (green) albumin/creatinine-ratio (ACR), kidney injury molecule-1 (KIM-1), neutrophil gelatinase-associated lipocalin (NGAL), and acute kidney injury (AKI) in the form of maximal plasma creatinine (red) in critically ill COVID-19 patients (n = 29). Correlations were calculated using Spearman’s correlation, blue indicates positive correlation, red indicates negative correlation. Non-significant correlations are white.