Liver Stiffness Variability and Limited Performance of Non-Invasive Fibrosis Scores in Hemodialysis: A Prospective Study

Background: Transient elastography (TE) is widely used for noninvasive assessment of liver fibrosis. In patients undergoing hemodialysis, however, liver stiffness measurements (LSM) may be affected by rapid intradialytic changes in volume status, venous congestion, and other non-fibrotic determinants. We prospectively evaluated peridialytic variability in liver stiffness and the concordance of serum fibrosis indices with elevated LSM in patients receiving maintenance hemodialysis. Methods: In this prospective paired pilot study, 45 adults on maintenance hemodialysis underwent LSM and controlled attenuation parameter (CAP) assessments immediately before and after a dialysis session; paired data were available for 41 patients. The Fibrosis-4 index (FIB-4) and the aspartate aminotransferase-to-platelet ratio index (APRI) were calculated from routine laboratory values. Paired comparisons, correlation analyses, and receiver operating characteristic curves were used to assess within-patient changes and the ability of serum indices to identify elevated pre-dialysis liver stiffness (LSM ≥ 8 kPa). Because no histologic or imaging reference standard for fibrosis was available, these analyses were interpreted as evidence of concordance with elevated LSM rather than as diagnostic accuracy for liver fibrosis. Results: Median LSM was 7.1 kPa (interquartile range [IQR] 5.2–12.1) pre-dialysis and 7.7 kPa (IQR 5.8–12.2) post-dialysis, with no significant paired change (median ΔLSM −0.2 kPa [IQR −1.1 to 1.2]; p = 0.898). However, the proportion with LSM ≥ 8 kPa increased from 36.6% to 46.3%, with 4 of 41 patients (9.8%) newly exceeding the threshold. CAP values showed no significant paired change (p = 0.511). Intradialytic weight loss was not associated with ΔLSM (rho = −0.13, p = 0.44). FIB-4 and APRI showed poor correlation with LSM and limited concordance with elevated LSM (area under the curve 0.553 and 0.578, respectively, with wide confidence intervals). Conclusions: In this exploratory hemodialysis cohort, cohort-level median LSM did not change significantly after dialysis, but clinically relevant individual-level reclassification occurred in approximately 10% of patients. Measurement timing may alter LSM-based classification, underscoring the need for dialysis-specific validation of LSM thresholds and noninvasive assessment strategies.