Optimal use of red cell volume distribution width-to-platelet ratio to exclude cirrhosis in patients with chronic hepatitis B

Abstract

Background and aims

Hepatitis B virus (HBV) infection is a major public health issue worldwide as it may cause serious liver diseases such as cirrhosis and hepatocellular carcinoma (HCC). Ruling out cirrhosis is important when treating chronic hepatitis B (CHB). The aim of this study was to compare the performance of the aspartate aminotransferase-to-platelet ratio index (APRI), fibrosis score based on four factors (FIB-4), and red cell volume distribution width-to-platelet ratio (RPR) in diagnosing liver fibrosis stages and to identify new cut-off values to rule out cirrhosis.

Methods

Between 2005 and 2020, 2182 eligible individuals who underwent liver biopsy were randomly assigned to derivation and validation cohorts in a 6:4 ratio. A grid search was applied to identify optimal cut-off values with a sensitivity of >90% and a negative predictive value (NPV) of at least 95%.

Results

Overall, 1309 individuals (175 patients with cirrhosis) were included in the derivation dataset, and 873 (117 patients with cirrhosis) were included in the validation cohort. The area under the receiver operating characteristic curve of RPR for diagnosing cirrhosis was 0.821, which was comparable to that of APRI (0.818, P = 0.7905) and FIB-4 (0.803, P = 0.2395). When applying an RPR of 0.06, cirrhosis was correctly identified with a sensitivity of 93.1% and an NPV of 97.1%, while it misclassified 12 of 175 (6.9%) patients in the derivation cohort. In the validation cohort, RPR had a sensitivity and NPV of 97.4% and 99.0%, respectively, and only misclassified 3 of 117 (2.6%) patients. Subgroup analysis indicated that the new RPR cut-off value performed more consistently than that of APRI and FIB-4 in all subgroups.

Conclusion

A recently established cut-off value for RPR (≤0.06) was validated and was more effective than APRI and FIB-4 in excluding patients with cirrhosis due to a higher sensitivity and NPV and a lower misclassification rate. This simple and dependable test could have significant clinical implications in identifying patients who require monitoring for portal hypertension-associated complications and screening for HCC, particularly in middle and primary healthcare settings.