The Macrophage Activation Marker Soluble CD163 Predicts the Response to Atezolizumab and Bevacizumab in Advanced Hepatocellular Carcinoma

Background/Aim: This study aimed to identify predictors of therapeutic response to atezolizumab plus bevacizumab (Atez/Bev) in patients with advanced hepatocellular carcinoma (aHCC). Patients and Methods: Of the 39 patients included in the study, 28 underwent a lactulose-mannitol test. Intestinal permeability (IP) was evaluated using the lactulose-to-mannitol ratio (LMR), serum soluble CD163 (sCD163), and soluble mannose receptor (sMR). The therapeutic response and its correlation with IP were evaluated. Results: The median progression-free survival (PFS) and overall survival (OS) were 208 and 489 days, respectively. Regarding the best achieved treatment response, the objective response rate and disease control rate (DCR) were 39.2% and 67.8%, respectively, based on the Response Evaluation Criteria in Solid Tumors 1.1. The LMR was significantly higher in those with progressive disease (PD group) than in those achieving complete response, partial response, and stable disease [disease control (DC) group]. The optimal LMR cutoff was 5.24 for predicting ORR and PD. The low-LMR group showed significantly longer PFS than the high-LMR group. sCD163 and sMR were significantly higher in the PD group than in the DC group. sCD163 was found to be significantly associated with the DCR [odds ratio (OR)=14.3, 95%CI=1.47–138, p=0.022]. The patients were divided into two groups according to their median CD163 levels. The low-CD163 group showed significantly longer PFS and OS than the high-CD163 group. Conclusion: IP was associated with Atez/Bev response in HCC. sCD163 could be a predictive marker of Atez/Bev response in patients with aHCC.