Using FIB-4 score as a screening tool in the assessment of significant liver fibrosis (F2) in patients with transfusion dependent beta thalassaemia: a cross sectional study

Objective To evaluated the performance of FIB-4 score as a screening tool to detect significant liver fibrosis (F2) compared to transient elastography (TE), among chronic transfusion-dependent beta-thalassemia (TDT) patients, in a resource-poor setting. Design A cross-sectional study Setting Adolescent and Adult Thalassaemia Care Center (University Medical Unit), Kiribathgoda, Sri Lanka. Participants 45 TDT patients who have undergone more than 100 blood transfusions with elevated serum ferritin >2000ng/mL, were selected for the study. Patients who were serologically positive for hepatitis C antibody were excluded. Outcome measures TE and FIB-4 score were estimated at the time of recruitment in all participants. Pre-defined cut-off values for F2, extracted from previous studies for TE and FIB-4 score, were compared. A new cut-off value for FIB-4 score was estimated using ROC curve analysis to improve the sensitivity for F2 prediction. Results Of the selected 45 TDT patients, 22(49%) were males. FIB-4 score showed a significant linear correlation with TE (r= 0.52; p < 0.0003). The FIB-4 score was improbable to lead to a false classification of TDT patients to have F2 when the FIB-4 cut-off value was 1.3. On the other hand, it had a very low diagnostic yield in missing almost all (except one) of those who had F2. Using a much-lowered cut-off point of 0.32 for FIB-4, we improved the pick-up rate of F2 to 72%. Conclusions Regardless of the cut-off point, FIB-4 score cannot be used as a good screening tool to pick-up F2 in patients with TDT, irrespective of their splenectomy status. On the contrary, at 1.3 cut off value though FIB-4 is a very poor detector for F2 fibrosis it will not erroneously diagnose F2 fibrosis in those who don’t have it. Article summary Strengths and limitations of this study There is limited information available on the applicability of FIB-4 score to assess significant liver fibrosis in patients with transfusion-dependent beta-thalassemia (TDT). The present study among a Sri Lankan TDT population had their liver fibrosis assessed by FIB-4 score biomarker compared with Transient elastography (TE). Small sample size of the study is one of the major limitations. Even though the liver biopsy is the gold standard method of assessing liver fibrosis, non-invasive TE was used as the reference standard in our study