Abstract
KEY POINTS: IL-17A was higher in patients with AKI versus without AKI during hospitalization and up to 1-year postdischarge. IL-17A was higher in patients with progression of kidney disease but not independently associated with subsequent progression of kidney disease. BACKGROUND: AKI is associated with increased mortality and new or progressive CKD. Inflammatory cells play an important role in acute organ injury. We previously demonstrated that serum IL-17A levels were significantly elevated in critically ill patients with AKI and independently associated with hospital mortality. We hypothesize that IL-17A levels are elevated in hospitalized patients with AKI at diagnosis, and sustained elevation after discharge is associated with subsequent CKD incidence or progression. METHODS: This was an observational convenience sampling study of hospital survivors of stage 2 or 3 AKI and controls without AKI from the Assessment, Serial Evaluation, and Subsequent Sequelae of AKI study. Patients were classified as progression or nonprogression on the basis of a composite of CKD incidence, progression, or ESKD. IL-17A levels were evaluated with S-Plex assay (Meso Scale Discovery) at 0 (during hospitalization), 3, and 12 months postdischarge and analyzed along with clinical and biomarker data up to 84 months after discharge. RESULTS: Among 171 AKI and 175 non-AKI participants, IL-17A levels were elevated in AKI versus non-AKI patients at 0-, 3-, and 12-month time points (P < 0.05 for all comparisons). Furthermore, IL-17A levels were elevated in the progression versus nonprogression group at the 3- and 12-month time points for outcomes occurring at 3–6 and 12–84 months, respectively (P < 0.05 for both). In adjusted multivariable models, IL-17A levels were not independently associated with progression of kidney disease. IL-17A levels were positively correlated with kidney disease and immune activation biomarkers at all time points (P < 0.001). CONCLUSIONS: IL-17A was higher in patients with AKI versus without AKI during hospitalization and up to 1-year postdischarge. IL-17A was higher in patients with progression of kidney disease after hospitalization, but not independently associated with subsequent progression of kidney disease in fully adjusted models.