Nuclear factor kappa B in urine sediment: a useful indicator to detect acute kidney injury in Plasmodium falciparum malaria

BACKGROUND: Acute kidney injury (AKI) is one of the major complications of Plasmodium falciparum malaria, especially among non-immune adults. It has recently been revealed that activation of transcription factor nuclear factor kappa B (NF-κB) induces pro-inflammatory gene expression involved in the development of progressive renal inflammatory diseases. The aim of this study was to determine whether urinary sediment NF-κB p65 can act as a biomarker for AKI in patients with P. falciparum malaria. METHODS: Urinary sediments from malaria patients, including Plasmodium vivax malaria, uncomplicated P. falciparum malaria, complicated P. falciparum malaria without AKI (serum creatinine-Cr <3 mg/dl) and complicated P. falciparum malaria with AKI (Cr ≥3 mg/dl) were used to determine NF-κB p65 level by sandwich enzyme-linked immunosorbent assay (ELISA). Urinary sediments obtained from healthy controls were used as a normal baseline. Correlations between levels of urinary sediment NF-κB p65 and pertinent clinical data were analysed. RESULTS: Urinary sediment NF-κB p65 levels were significantly increased on the day of admission (day 0) and on day 7 post-treatment in complicated P. falciparum malaria patients with AKI, compared with those without AKI (p = 0.001, p <0.001, respectively), P. vivax patients (all p <0.001) and healthy controls (all p <0.001). NF-κB p65 levels in urinary sediment cells showed a significant positive correlation with serum Cr (Day 0: r(s) = 0.792; p <0.001, Day 7: r(s) = 0.605; p <0.001) and blood urea nitrogen (BUN) (Day 0: r(s) = 0.839; p <0.001, Day 7: r(s) = 0.596; p <0.001). CONCLUSIONS: Urinary sediment NF-κB p65 level is a useful indicator for estimating renal tubular epithelial cell damage and subsequent development of AKI among patients with P. falciparum malaria.