Controlled Attenuation Parameter (CAP) with the XL Probe of the Fibroscan ® : A Comparative Study with the M Probe and Liver Biopsy.

INTRODUCTION: Controlled attenuation parameter (CAP) is a new method for the diagnosis of steatosis. Until now, CAP was available only with the M probe of the Fibroscan. The aim of this study was to evaluate the diagnostic performance of CAP with the XL probe versus CAP with the M probe, using liver biopsy (LB) as gold standard.

PATIENTS AND METHODS: A total of 236 patients with chronic liver disease undergoing LB had CAP measurement with M and XL probes the same day. All LB were analyzed independently by two experienced pathologists.

RESULTS: Median CAP was 240.5 and 239.5 dB/m with the M and XL probes, respectively. For the detection of steatosis grade with the M and XL probes, AUROCs were 0.82/0.83 for S ≥ 1, 0.89/0.88 for S ≥ 2, and 0.92/0.93 for S3, respectively. Cutoffs were (M and XL probes) 246/242 for S ≥ 1, 269/267 for S ≥ 2, and 285/286 dB/m for S3, respectively. The factor significantly associated with CAP with the M and XL probes was steatosis grade. In multivariate analysis, a low CAP value with XL probe was negatively associated with waist circumference, triglycerides, albumin, and the alcohol consumption, and positively with alkaline phosphatases. In multivariate analysis, a high CAP value with the XL probe was positively associated with waist circumference and triglycerides.

CONCLUSION: CAP with the XL probe is a new tool for the diagnosis of steatosis. This parameter could be useful for the diagnosis and the follow-up of obese patients.