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 evaluate the performance of the fibrosis-4 (FIB-4) score as a screening tool to detect significant liver fibrosis (F2) compared with transient elastography (TE), among chronic transfusion-dependent beta-thalassaemia (TDT) patients in a resource-poor setting. DESIGN: A cross-sectional study. SETTING: Adolescent and Adult Thalassaemia Care Centre (University Medical Unit), Kiribathgoda, Sri Lanka. PARTICIPANTS: 45 TDT patients who had undergone more than 100 blood transfusions with elevated serum ferritin >2000 ng/mL were selected for the study. Patients who were serologically positive for hepatitis C antibodies were excluded. OUTCOME MEASURES: TE and FIB-4 scores were estimated at the time of recruitment in all participants. Predefined cut-off values for F2, extracted from previous TE and FIB-4 scores studies, were compared. A new cut-off value for the FIB-4 score was estimated using receiver operating characteristics 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, the 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 a 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 do not have it.