Urinary Neutrophil Gelatinase-Associated Lipocalin (NGAL) and proteinuria predict severity of acute kidney injury in Puumala virus infection

Background: Nephropathia epidemica (NE) is a mild form of hemorrhagic fever with renal syndrome (HFRS) that is caused by the Puumala virus. Periodic outbreaks have been described in endemic areas, with a substantial number of previously healthy individuals developing acute kidney injury (AKI). There is a considerable diversity in the clinical course of the disease, and few patients require renal replacement therapy. Methods: We tested whether urinary neutrophil gelatinase associated lipocalin (uNGAL), urine albumin/creatinine ratio (uACR), urine protein/creatinine ratio (uPCR), urine dipstick protein, C-reactive protein, procalcitonin, leukocyte and platelet count, determined on admission to the hospital, can predict the severity of AKI. Sixty-one patients were analyzed during admission in the emergency department. Results: The variables most strongly associated with peak plasma creatinine concentration were uNGAL (beta = 0.70, p < 0.0001), uPCR (beta = 0.64, p = 0.001), uACR (beta = 0.61, p = 0.002), and dipstick proteinuria (beta = 0.34, p = 0.008). The highest AUC-ROC to predict stage 3 AKI according to the acute kidney injury network's (AKIN) classification was seen for uNGAL (0.81, p = 0.001). Conclusion: uNGAL accurately predicts the severity of AKI in NE. This could help emergency room physicians predict disease severity and allow for initial risk stratification.