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.