Hepato-Gastroenterology Outpatient Unit, Ospedale San Camillo, Brescia, Italy.
Institute of Endocrine and Metabolic Sciences, Università Vita-Salute San Raffaele, IRCCS Ospedale San Raffaele, Milan, Italy.
Endocrine. 2022 Nov;78(2):262-269. doi: 10.1007/s12020-022-03157-x. Epub 2022 Aug 18.
Controlled attenuation parameter (CAP) has been suggested as a new non-invasive measurement performed during transient elastography (TE) to assess liver steatosis. The aim of this study was to evaluate CAP values head to head with ultrasound (US) as reference standard.
A consecutive cohort of patients attending abdominal US in an outpatient liver unit was included in this study with simultaneous CAP determination using the FibroScan M probe and fibrosis scored by TE. Patients were subdivided in four groups on the basis of risk factors for Metabolically Associated Fatty Liver Disease (MAFLD).
Four hundred thirty-five patients were included in the analysis: 221 (51%) were male; 117 (26.9%) were in control group, 144 (33.1%) in group 2 with inactive HCV or HBV infection and at low-risk for MAFLD, 134 (30.8%) in group 3 at high-risk of MAFLD, 40 (9.2%) in group 4 at high-risk of MAFLD and concomitant inactive HCV or HBV infection. Liver steatosis detected with US evaluation was observed in the 41% of the entire cohort; in particular in the 3.4%, 20.1%, 83.6% and 87.4% of the group 1, 2, 3 and 4, respectively (p < 0.001). In patients at high-risk factor for MAFLD (group 3 and 4), CAP median levels were found statistically different among the severity-grading groups for US steatosis (S0 [n.27], ≥S1 [n.59], ≥S2 + S3 [n.89]), observing higher CAP levels in patients with a higher steatosis grade (≥S2 + S3 327.5 [±40.6] vs ≥S1 277.7 [±45.6] vs S0 245.1 [±47.4]; p < 0.001 for the whole cohort analysis) (p < 0.001 between ≥S2 + S3 and ≥S1) (p < 0.001 between ≥S2 + S3 and S0) (p = 0.004 between ≥S1 and S0). ROC analysis showed that the global performance of the CAP median level ≥ 258 to predict liver steatosis (S0 vs S1-3), was excellent with an Area Under the Curve (AUC) value of 0.87 [CI 95% 0. 835-0.904] with an 84% of sensitivity and a 78% of specificity, and a positive predictive value (PPV) of 73% and negative predictive value (NPV) of 88%. A TE-kPa median value <8.0 was detected in the 100%, 84%, 83.6% and 60% of patients in group 1, 2, 3 and 4, respectively. A TE-kPa median value >13.0 was detected in the 0%, 4.2%, 5.2% and 17.5% of patients in group 1, 2, 3 and 4, respectively.
CAP values are strongly associated with the standard US criteria for different degree of steatosis. Integrating TE up to 5% of patients may be identified at risk for advanced fibrosis.
控制衰减参数 (CAP) 已被提议作为一种新的非侵入性测量方法，在瞬时弹性成像 (TE) 期间用于评估肝脂肪变性。本研究的目的是评估 CAP 值与超声 (US) 作为参考标准的一致性。
本研究纳入了在门诊肝脏单位进行腹部 US 检查的连续队列患者，并同时使用 FibroScan M 探头进行 CAP 测定和 TE 纤维化评分。根据代谢相关脂肪性肝病 (MAFLD) 的危险因素，将患者分为四组。
共纳入 435 例患者：221 例（51%）为男性；117 例（26.9%）为对照组，144 例（33.1%）为 HCV 或 HBV 感染不活动且 MAFLD 低危组，134 例（30.8%）为 MAFLD 高危组，40 例（9.2%）为 MAFLD 高危且同时伴有 HCV 或 HBV 感染不活动组。通过 US 评估，整个队列中有 41%的患者存在肝脂肪变性；具体而言，分别在组 1、2、3 和 4 中，这一比例分别为 3.4%、20.1%、83.6%和 87.4%（p<0.001）。在 MAFLD 高危因素患者（组 3 和 4）中，CAP 中位数水平在 US 脂肪变性严重程度分级组之间存在统计学差异（S0 [n.27]、≥S1 [n.59]、≥S2+S3 [n.89]），观察到脂肪变性程度较高的患者 CAP 水平较高（≥S2+S3 327.5 [±40.6] vs ≥S1 277.7 [±45.6] vs S0 245.1 [±47.4]；p<0.001 对于整个队列分析）（p<0.001 在≥S2+S3 与≥S1 之间）（p<0.001 在≥S2+S3 与 S0 之间）（p=0.004 在≥S1 与 S0 之间）。ROC 分析显示，CAP 中位数水平≥258 预测肝脂肪变性（S0 与 S1-3）的整体性能非常出色，曲线下面积（AUC）值为 0.87 [95%CI 0.835-0.904]，灵敏度为 84%，特异性为 78%，阳性预测值（PPV）为 73%，阴性预测值（NPV）为 88%。组 1、2、3 和 4 中的患者分别有 100%、84%、83.6%和 60%的患者检测到 TE-kPa 中位数<8.0，而 0%、4.2%、5.2%和 17.5%的患者检测到 TE-kPa 中位数>13.0。
CAP 值与不同程度脂肪变性的标准 US 标准密切相关。整合 TE 可识别多达 5%的患者存在进展性纤维化风险。
