Acute Kidney Injury After Acute Viral Hepatitis A in Adults: Incidence, Predictors, and Impact on Outcomes

Acute kidney injury (AKI) is a recognized complication of severe liver disease, but data describing its incidence and determinants in adult hepatitis A are limited. We aimed to evaluate the incidence, predictors, urinary characteristics, and clinical impact of AKI in adults hospitalized with hepatitis A-related acute liver disease.

In this retrospective single-center cohort study, adults (aged ≥18 years) admitted with anti-hepatitis A virus IgM-positive acute hepatitis A between January 2022 and December 2025 were included. Patients with chronic liver disease or pre-existing kidney disease were excluded. AKI was defined using Kidney Disease: Improving Global Outcome (KDIGO) criteria. Patients were categorized as acute viral hepatitis (AVH), acute liver injury (ALI), or acute liver failure (ALF). Clinical outcomes included intensive care unit (ICU) admission, dialysis, liver transplantation, and in-hospital mortality. Logistic regression analyses were performed to identify predictors of AKI.

Among 421 patients (median age: 24 years; 70.5% male), AKI occurred in 60 (14.3%), with moderate-to-severe AKI in 11.4%. AKI incidence increased with disease severity (AVH: 6.8%, ALI: 9.7%, ALF 44%). Proteinuria and bilirubin uria were universal among AKI patients, while urinary casts were present in 68.3%. AKI was strongly associated with adverse outcomes, including ICU admission (81.7% vs 15.5%), dialysis requirement (58.3% vs 1.1%), and in-hospital mortality (5.0% vs 0%). Clinical evidence of systemic infection was markedly more frequent in patients with AKI (71.7% vs 4.7%) and demonstrated a very strong association with AKI. In the multivariable analysis, sepsis, ALF, and lower serum albumin emerged as the dominant independent predictor of AKI.

AKI is a common and clinically significant complication of adult hepatitis A, particularly in patients with severe disease. Systemic infection and worsening hepatic dysfunction were strongly associated with AKI development. Early recognition of infection and proactive renal-protective strategies may improve outcomes.