Patients with hepatitis B virus (HBV)-related cirrhosis and a higher fibrosis burden have worse renal outcomes compared with patients without significant fibrosis, according to findings published in 2017. Journal of Infectious Diseases.
A growing body of research suggests that adverse renal outcomes may be associated with fibrotic burden in patients with cirrhosis. Antiviral treatment of hepatitis B-related cirrhosis is associated with regression of liver fibrosis; however, tenofovir disoproxil fumarate (TDF), two commonly used antiviral drugs used to treat chronic hepatitis B infection and adefovir—show increased nephrotoxicity. Therefore, before initiating antiviral therapy, it is critical to risk stratify patients with HBV-related cirrhosis to determine who is likely to experience adverse renal outcomes.
To assess whether higher fibrosis burden in this patient population is independently associated with adverse renal outcomes, we retrospectively reviewed 1,691 patients (mean age, 53.4 years; 60.9% male) with radiologically diagnosed HBV-related cirrhosis. Longitudinal cohort study of patients who did not show baseline chronic kidney disease (CKD).
All patients underwent transient elastography (TE) to evaluate liver stiffness, reflecting fibrosis, at 2 tertiary care centers.
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Cirrhosis is diagnosed by ultrasound or computed tomography combined with laboratory studies, medical history, and clinical findings. TE uses mechanical waves and ultrasound to determine the elasticity of liver tissue that reflects liver fibrosis. A liver stiffness of 11.7 kilopascals (kPa) or higher indicates that liver fibrosis has reached the cirrhosis range, while a liver stiffness between 7.9 and 11.7 kPa indicates that liver fibrosis has entered an advanced stage. Fractions below 7.9 kPa indicate the absence of significant fibrosis.
At baseline and follow-up appointments, investigators confirmed the presence of hypertension, diabetes, and acute kidney injury (AKI). AKI is defined as a change in serum creatinine of 0.3 mg/dL or more within 48 hours or less, or a 50% increase in serum creatinine from baseline.
Follow-up visits were conducted every 3 to 6 months for a median of 5.2 years to collect blood samples, perform urinalysis, and assess kidney function. To assess kidney function, researchers calculated estimated glomerular filtration rate (eGFR). CKD event is defined as eGFR less than 60 mL/min/1.73 m2 or proteinuria on two or more consecutive outpatient visits (separated by at least 3 months). Other adverse renal outcomes assessed by the researchers included a decrease in eGFR of 50% or more from baseline, the development of end-stage kidney disease (ESKD) requiring dialysis, or death from any cause.
As TE-confirmed fibrosis burden increases, hypertension and diabetes increase (ask <.001). Approximately 60 of 1691 patients (3.5%) experienced adverse renal outcomes.
The researchers observed that higher fibrosis burden, as evidenced by cirrhosis-range liver stiffness (≥11.9 kPa), was associated with a 2.77-fold increased risk of worse renal outcomes (95% CI, 1.16-6.63; ask <.001), compared with patients without significant liver fibrosis (<7.9 kPa). This relationship between liver stiffness and adverse renal outcomes remained significant even after adjusting for potential confounders.
“In patients with HBV-related cirrhosis but no baseline CKD, higher fibrosis burden assessed using TE was independently associated with worse renal outcomes,” the study authors wrote. “The results of this study were assessed by assessing hepatitis B “The burden of fibrosis in patients with the same disease category as related cirrhosis provides a rationale for detailed risk stratification of long-term renal outcomes.”
Study limitations include a retrospective design, potential selection bias and confounding factors, lack of renal biopsy to determine the mechanistic link between cirrhosis and adverse renal outcomes, and lack of generalizability of the findings beyond the Korean population. Additionally, the researchers were unable to determine a cause-and-effect relationship between liver fibrosis and kidney disease, nor did they examine the ability of antiviral drugs to improve kidney outcomes through follow-up measurements of liver stiffness.
Disclosure: One study author declares affiliations with biotechnology, pharmaceutical and/or device companies. Please see original references for a complete list of author disclosures.
This article was originally published on Gastroenterology Consultant