Noninvasive ratio indexes to evaluate fibrosis staging in chronic hepatitis C: Role of platelet count/spleen diameter ratio index

Abstract

Objectives. Noninvasive evaluation of fibrosis is an on-going effort in the management of chronic hepatitis C. This study was planned to noninvasively evaluate fibrosis staging. Design. We evaluated the biochemical, functional [aminopyrine breath test (ABT)] and ultrasonographic variables of 75 chronic hepatitis C patients. Results. Clinical [body mass index (BMI)], biochemical [aspartate aminotransferase (AST), alanine aminotransferase (ALT) and platelets (PLT)] and ratio indexes, together with the ABT, showed a higher relationship with fibrosis: initial (score ≤ 2) versus evident (score > 2) fibrosis: BMI (24 ± 2 vs. 26 ± 2, P = 0.0007), AST (56 ± 36 vs. 88 ± 65, P = 0.0159), ALT (92 ± 54 vs. 139 ± 108, P = 0.0290), PLT (220 ± 64 vs. 173 ± 61, P = 0.0007), PLT/spleen diameter ratio (PLT/SPD) (2133 ± 786 vs. 1540 ± 681, P = 0.0003), AST/platelet count ratio index (APRI) (0.80 ± 0.87 vs. 1.51 ± 1.47, P = 0.0010), ABT%d/h30 min (10.8 ± 4.5 vs. 7.6 ± 3.8, P = 0.0007), ABT%d/cum120 min (8.9 ± 3.3 vs. 6.5 ± 3.1, P = 0.0007). Considering the differences between fibrosis score 2 and 3 patients, BMI, ABT and PLT/SPD ratio proved to be statistically significant. Multivariate stepwise analysis (with and without BMI) identified two models for distinguishing between initial and evident fibrosis: Model 1: -0.569 +(BMI x 0.107) + (APRI x 0.169)-(PLT/SPD x 0.304), and Model 2: 2.376 + (APRI x 0.152)-(ABTd/h30 x 0.043)-(PLT/SPD x 0.249). These models showed concordance in identifying or ruling out evident fibrosis in 76% and 78.7% of the patients respectively. The PLT/SPD ratio also showed 78.7% concordance with the histological score. Conclusion. These results suggest that noninvasive evaluation of fibrosis in chronic hepatitis C may be considered an effective tool thanks to the use of an inexpensive, reproducible ratio index. © 2006 Blackwell Publishing Ltd.