Pathogenesis and Management of Hepatolithiasis: A Report of Two Cases

Clinical, histopathological, and immunohistochemical spectrum of hepatolithiasis: a tertiary care center-based study from north India

Hepatolithiasis (HL), an uncommon disease among Indians, occurs due to a complex interplay of various structural and functional factors. We retrospectively evaluated the clinical and histopathological spectrum of HL (N = 19) with immunohistochemical evaluation for biliary apomucins and canalicular transporter proteins, both crucial for lithogenesis. Nineteen surgically resected cases were included. Histopathology was systematically evaluated. Immunohistochemistry for apomucins (MUC1, MUC2, MUC4, MUC5AC, and MUC6) and canalicular transporter proteins (BSEP and MDR3) was applied to all cases. The median age was 51 years with female preponderance (F:M = 1.4:1). The stone was cholesterol-rich in 71.4% and pigmented in 28.6% (n = 14). Histopathology showed variable large bile-duct thickening due to fibrosis and inflammation with peribiliary gland hyperplasia. Structural causes (Caroli disease, choledochal cyst, and post-surgical complication) were noted in 15.8% of cases (secondary HL). Expression of gel-forming apomucin MUC1, MUC2, and MUC5AC was seen in either bile duct epithelia or peribiliary glands in 84.2%, 10.5%, and 84.2% cases respectively. Loss of canalicular expression of MDR3 was noted in 42.1% of cases while BSEP was retained in all. Primary HL in the north Indian population can be associated with the loss of MDR3 expression (with retained BSEP) and/ or a shift in the phenotype of biliary apomucins to gel-forming apomucins. The former factor alters the bile acid/ phospholipid ratio while the latter parameter promulgates crystallization. In conjunction, these factors are responsible for the dominantly cholesterol-rich stones in the index population.

Distinct PD-L1/PD1 Profiles and Clinical Implications in Intrahepatic Cholangiocarcinoma Patients with Different Risk Factors

Rationale: PD1/PD-L1 immune checkpoint inhibitors have shown promising results for several malignancies. However, PD1/PD-L1 signaling and its therapeutic significance remains largely unknown in intrahepatic cholangiocarcinoma (ICC) cases with complex etiology. Methods: We investigated the expression and clinical significance of CD3 and PD1/PD-L1 in 320 ICC patients with different risk factors. In addition, we retrospectively analyzed 7 advanced ICC patients who were treated with PD1 inhibitor. Results: The cohort comprised 233 patients with HBV infection, 18 patients with hepatolithiasis, and 76 patients with undetermined risk factors. PD-L1 was mainly expressed in tumor cells, while CD3 and PD1 were expressed in infiltrating lymphocytes of tumor tissues. PD1/PD-L1 signals were activated in tumor tissues, and expression was positively correlated with HBV infection and lymph node invasion. More PD1⁺ T cells and higher PD-L1 expression were observed in tumor tissues of ICC patients with HBV infection compared to patients with hepatolithiasis or undetermined risk factors. More PD1⁺ T cells and/or high PD-L1 expression negatively impacted the prognosis of patients with HBV infection but not those with hepatolithiasis. Multivariate analysis showed PD1/PD-L1 expression was an independent indicator of ICC patient prognosis. Advanced ICC patients with HBV infection and less PD1⁺ T cells tended to have good response to anti-PD1 therapy. Conclusion: Hyperactivated PD1/PD-L1 signals in tumor tissues are a negative prognostic marker for ICCs after resection. HBV infection- and hepatolithiasis-related ICCs have distinct PD1/PD-L1 profiles. Further, PD1⁺ T cells could be used as a biomarker to predict prognosis and assay the efficiency of anti-PD1 immunotherapy in ICC patients with HBV infection.

A Case of Biliary Ascariasis in Korea

Biliary ascariasis is still the leading cause of surgical complication of ascariasis, though its incidence has been dramatically reduced. Herein, we report a case of biliary ascariasis for the purpose of enhancing awareness of parasitic infections as a possible cause. A 72-year-old male visited the emergency room of Dankook University Hospital on 12 July 2015, complaining of right-upper-quadrant pain. By endoscopic retrograde cholangiopancreatography (ERCP), a tubular filling defect in the right hepatic duct was detected. The defect was endoscopically removed and diagnosed as an adult female of Ascaris lumbricoides worm, of 30 cm length. Upon removal of the worm, the pain subsided, and the patient was discharged without any complication. When treating cases of biliary colic, physicians should not neglect biliary ascariasis as the possible cause.

Lipopolysaccharide stimulates endogenous β-glucuronidase via PKC/NF-κB/c-myc signaling cascade: a possible factor in hepatolithiasis formation

Hepatolithiasis is commonly encountered in Southeastern and Eastern Asian countries, but the pathogenesis mechanism of stone formation is still not well understood. Now, the role of endogenous β-glucuronidase in pigment stones formation is being gradually recognized. In this study, the mechanism of increased expression and secretion of endogenous β-glucuronidase during hepatolithiasis formation was investigated. We assessed the endogenous β-glucuronidase, c-myc, p-p65, and p-PKC expression in liver specimens with hepatolithiasis by immunohistochemical staining, and found that compared with that in normal liver samples, the expression of endogenous β-glucuronidase, c-myc, p-p65, and p-PKC in liver specimens with hepatolithiasis significantly increased, and their expressions were positively correlated with each other. Lipopolysaccharide (LPS) induced increased expression of endogenous β-glucuronidase and c-myc in hepatocytes and intrahepatic biliary epithelial cells in a dose- and time-dependent manner, and endogenous β-glucuronidase secretion increased, correspondingly. C-myc siRNA transfection effectively inhibited the LPS-induced expression of endogenous β-glucuronidase. Furthermore, NF-κB inhibitor pyrrolidine dithiocarbamate or PKC inhibitor chelerythrine could effectively inhibit the LPS-induced expression of c-myc and endogenous β-glucuronidase, and the expression of p-p65 was also partly inhibited by chelerythrine. Our clinical observations and experimental data indicate that LPS could induce the increased expression and secretion of endogenous β-glucuronidase via a signaling cascade of PKC/NF-κB/c-myc in hepatocytes and intrahepatic biliary epithelial cells, and endogenous β-glucuronidase might play a possible role in the formation of hepatolithiasis.