The relationship between observation interval and prognosis in pancreatic cancer concomitant with intraductal papillary mucinous neoplasia.

BACKGROUND: Intraductal papillary mucinous neoplasia (IPMN) is a risk factor for pancreatic cancer (PC). PC concomitant with IPMN shows rapid progression similar to de novo PC, therefore, the appropriate observation interval (OI) is not yet clear. PATIENTS AND METHOD: This was a multicenter retrospective observational study, and patients with PC concomitant with IPMN were analyzed. OI was defined as the interval between the date of imaging at PC diagnosis and just before the diagnosis. Clinical factors of PC and prognosis were assessed according to OI. RESULTS: From January 2010 to December 2018, 73 patients from 11 institutions were enrolled. The images performed just before PC diagnosis were contrast-enhanced CT/magnetic resonance imaging/endoscopic ultrasonography in 44/27/2 patients, respectively. The median cyst size was 14.0 mm, and the median main pancreatic duct diameter was 3.0 mm. The median OI was 6.8 months. In OI 6 months or less (OI ≤ 6 M)/OI more than 6 months (OI > 6 M), the mean tumor size, the frequencies of metastatic PC, resectable PC and early-stage PC were 20.1/21.5 mm (P = 0.91), 12.1 %/32.5 % (P = 0.05), 72.7 %/52.5 % (P = 0.09) and 27.3 %/25.0 % (P = 1.00), respectively. The median overall survival was 35.5 months in OI ≤ 6 M and 16.2 months in OI > 6 M (P = 0.05). CONCLUSION: In OI 6 months or less, the rate of resectable PC was high, however, the rate of early PC was almost the same as that of OI more than 6 months. Approximately 10 % of cases found in the advanced stage with metastasis even if OI 6 months or less.

Postoperative bleeding after percutaneous transhepatic gallbladder drainage and aspiration in patients receiving antithrombotic therapy.

This study aimed to investigate the bleeding risk associated with percutaneous transhepatic gallbladder interventions in patients with acute cholecystitis receiving antithrombotic therapy. In this retrospective study, 194 consecutive patients who underwent percutaneous transhepatic gallbladder interventions for acute cholecystitis between April 2011 and April 2021 were enrolled. Patients were sorted into four groups: no prior antithrombotic therapy, discontinued antithrombotic drugs, single antithrombotic drug continued perioperatively, and multiple antithrombotic drugs continued perioperatively. The risk of postoperative bleeding after percutaneous transhepatic gallbladder interventions was evaluated via multivariate logistic regression analysis. Of the 116 (59.8%) patients receiving antithrombotic therapy, 32 (16.5%) discontinued antithrombotic drugs before their respective procedure, 50 (25.8%) continued a single antithrombotic drug, and 34 (17.5%) continued multiple antithrombotic drugs during the perioperative period. The rates of significant and severe bleeding were 10.3% (20/194) and 3.1% (6/194), respectively. The rate of significant bleeding was significantly higher in patients who continued multiple antithrombotic drugs than in patients who received no prior antithrombotic therapy (P = 0.006). In the multivariate logistic regression analysis, the continuation of multiple antithrombotic drugs during the perioperative period was a risk factor for significant bleeding after percutaneous transhepatic gallbladder interventions. In conclusion, the perioperative continuation of multiple antithrombotic drugs is a risk factor for postoperative bleeding after percutaneous transhepatic gallbladder interventions.

Diagnostic Reference Levels for Fluoroscopy-guided Gastrointestinal Procedures in Japan from the REX-GI Study: A Nationwide Multicentre Prospective Observational Study.

BACKGROUND: Diagnostic reference levels (DRLs) are required to optimize medical exposure. However, data on DRLs for interventional fluoroscopic procedures are lacking, especially in gastroenterology. This study aimed to prospectively collect currently used radiation doses and help establish national DRLs for fluoroscopy-guided gastrointestinal procedures in Japan. METHODS: This multicentre, prospective, observational study collected actual radiation dose data from endoscopic retrograde cholangiopancreatography (ERCP), interventional endoscopic ultrasound (EUS), balloon-assisted enteroscopy (BAE), enteral metallic stent placement, and enteral tube placement from May 2019 to December 2020. The study outcomes were fluoroscopy time (FT: min), air kerma at the patient entrance reference point (Ka,r: mGy), air kerma area product (PKA: Gycm2), and radiation dose rate (RDR: mGy/min). Additionally, the basic settings of fluoroscopy equipment and the factors related to each procedure were investigated. This study was registered in the UMIN Clinical Trial Registry (UMIN 000036525). FINDINGS: Overall, 12959 fluoroscopy-guided gastrointestinal procedures were included from 23 hospitals in Japan. For 11162 ERCPs, the median/third quartile values of Ka,r (mGy), PKA (Gycm2), and FT (min) were 69/145 mGy, 16/32 Gycm2, and 11/20 min, respectively. Similarly, these values were 106/219 mGy, 23/41 Gycm2 and 17/27 min for 374 interventional EUSs; 53/104 mGy, 16/32 Gycm2 and 10/15 min for 523 metallic stents; 56/104 mGy, 28/47 Gycm2, and 12/18 min for 599 tube placements; and 35/81 mGy, 16/43 Gycm2 and 7/15 min for 301 BAEs, respectively. For the overall radiation dose rate, the median/third quartile values of RDR were 5.9/9.4 (mGy/min). The RDR values at each institution varied widely. INTERPRETATION: This study reports the current radiation doses of fluoroscopy-guided gastrointestinal procedures expressed as DRL quantities. This will serve as a valuable reference for national DRL values. FUNDING: This work was supported by a clinical research grant from the Japanese Society of Gastroenterology.

Endoscopic biliary stenting as the risk factor for cholangitis after endoscopic ultrasound in patients with biliary strictures.

BACKGROUND AND AIM: Endoscopic ultrasound (EUS) and EUS-guided fine needle aspiration (FNA) are established as efficient and safe diagnostic modalities. However, the risk of cholangitis after EUS/EUS-FNA (post-EUS cholangitis) in patients who have biliary strictures has not been fully examined. METHODS: We retrospectively reviewed 136 consecutive inpatients with biliary strictures who received EUS/EUS-FNA at our hospital from April 2012 to September 2017 and evaluated complications that occurred by the next day after EUS/EUS-FNA. Patients with percutaneous biliary drainage, those in whom it was difficult to reach the duodenum, and those receiving concurrent endoscopic retrograde cholangiopancreatography were excluded. RESULTS: We included 121 patients (147 cases); 90 patients were malignant. Endoscopic biliary stenting (EBS) with plastic stents had already been performed in 86 cases. Post-EUS cholangitis was observed in 4.1% (6/147). No other EUS-related complications were observed. The incidence of cholangitis with EBS was significantly higher than that in the cases without EBS (7.0% [6/86] vs 0% [0/61], P = 0.042). Biliary enzyme elevation was also identified as a risk factor of cholangitis. CONCLUSION: Endoscopic biliary stenting was identified as a risk factor associated with post-EUS cholangitis in patients with biliary strictures. Endoscopists should pay attention to post-EUS cholangitis, especially in cases with EBS and biliary enzyme elevation.

Risk Factors for Pancreatic Cancer and the Necessity of Long-Term Surveillance in Patients With Pancreatic Cystic Lesions.

OBJECTIVES: Pancreatic cystic lesions (PCLs) are a risk factor for pancreatic cancer (PC). Which PCLs should be surveilled and necessity of long-term observation are still controversial. METHODS: From January 2000 to March 2016, we enrolled 1137 patients with PCLs observed for 1 year. We defined PCLs with cyst size of greater than 30 mm, main pancreatic duct (MPD) of greater than 5 mm or mural nodule as high-risk group, and others as low-risk group (LRG). Kaplan-Meier method and Cox proportional hazard model were applied to assess incidence and risk factors of PC. RESULTS: In 107 high-risk group and 1030 LRG patients, mean observation period was 4.3 years and 5.0 years, respectively, and 5-year PC incidence was 12.0% and 2.8%, respectively. In LRG, MPD of greater than 3 mm, diabetes mellitus, and presumed branch-duct intraductal papillary mucinous neoplasia (BD-IPMN), defined as PCLs fulfilling any of multilocular formation, multiplicity, or MPD communication, were independent risk factors for PC. In 450 LRG observed for 5 years, 10-year PC incidence was higher in PCLs with our identified risk factors. There was no PC occurrence in PCLs not presumed BD-IPMN after 5-year observation. CONCLUSIONS: Continuous surveillance is needed after 5-year observation, especially in LRG with our identified risk factors. For discontinuing surveillance, PCLs not presumed BD-IPMN at fifth year could be candidates.

Soluble UL16-binding protein 2 is associated with a poor prognosis in pancreatic cancer patients.

The immune system plays important roles in pancreatic cancer. MHC class I-chain-related proteins A and B (MICA/B) and UL16-binding proteins (ULBPs) are known natural killer group 2D (NKG2D) ligands. Soluble NKG2D ligands can inhibit the activation of Natural killer (NK) cells. In pancreatic cancer, soluble ULBPs are relatively unstudied in contrast to soluble MICA/B. We examined the significance of soluble ULBPs, especially ULBP2, in pancreatic cancer. Soluble ULBP2 but neither soluble ULBP1 nor soluble ULBP3, was etected in the supernatants of pancreatic cancer cells. Soluble ULBP2 derived from pancreatic cancer cells could reduce the cytotoxicity of NK cells. Multivariate analysis demonstrated that serum soluble ULBP2 was a significant independent factor associated with poor overall survival (OS) in all pancreatic cancer patients, specifically in stage IV patients. In conclusion, pancreatic cancer-derived soluble ULBP2 might affect the prognosis in pancreatic cancer.

CEACAM1 Is Associated With the Suppression of Natural Killer Cell Function in Patients With Chronic Hepatitis C.

Natural killer cells (NK cells) play an essential role in the immunological mechanism underlying chronic hepatitis C (CHC). Impairment of NK cell function facilitates persistent infection with hepatitis C virus (HCV) and hepatocellular carcinogenesis. However, the mechanism by which NK cell activity is suppressed in CHC is not completely understood. In this study, we focused on carcinoembryonic antigen-related cell-adhesion molecule 1 (CEACAM1). CEACAM1 is thought to suppress NK cell function. We examined the effect of CEACAM1 on NK cell function in CHC. We investigated the function of CEACAM1 in vitro using Huh7.5.1 cells and the HCV-Japanese fulminant hepatitis (JFH)-1 strain. We analyzed serum CEACAM1 level, NK cell function, and CEACAM1 messenger RNA (mRNA) level in human liver samples. Levels of CEACAM1 on the cell surface, CEACAM1 mRNA levels, and soluble CEACAM1 levels in supernatants were significantly higher in Huh7.5.1 cells infected with JFH-1 (Huh7.5.1/JFH-1 cells) than in Huh7.5.1 cells. Significantly higher NK cell cytotoxicity was observed toward K562 cells after coculture with CEACAM1 knockout Huh7.5.1/JFH-1 cells than after coculture with Huh7.5.1/JFH-1 cells. CEACAM1 expression was induced by the HCV E2 glycoprotein in HCV infection. Significantly higher serum CEACAM1 levels were detected in patients with CHC compared with healthy subjects and patients who achieved sustained virological responses. The expression of CD107a on NK cells from patients with CHC was negatively correlated with serum CEACAM1 levels. Significantly higher levels of CEACAM1 mRNA were detected in HCV-infected livers compared with uninfected livers. Conclusion: CEACAM1 expression was induced in hepatocytes following HCV infection and decreased NK cell cytotoxicity. These results demonstrate a possible role for CEACAM1 in the pathogenesis of CHC and hepatocellular carcinoma progression.

Characterization of miR-122-independent propagation of HCV.

miR-122, a liver-specific microRNA, is one of the determinants for liver tropism of hepatitis C virus (HCV) infection. Although miR-122 is required for efficient propagation of HCV, we have previously shown that HCV replicates at a low rate in miR-122-deficient cells, suggesting that HCV-RNA is capable of propagating in an miR-122-independent manner. We herein investigated the roles of miR-122 in both the replication of HCV-RNA and the production of infectious particles by using miR-122-knockout Huh7 (Huh7-122KO) cells. A slight increase of intracellular HCV-RNA levels and infectious titers in the culture supernatants was observed in Huh7-122KO cells upon infection with HCV. Moreover, after serial passages of HCV in miR-122-knockout Huh7.5.1 cells, we obtained an adaptive mutant, HCV122KO, possessing G28A substitution in the 5'UTR of the HCV genotype 2a JFH1 genome, and this mutant may help to enhance replication complex formation, a possibility supported by polysome analysis. We also found the introduction of adaptive mutation around miR-122 binding site in the genotype 1b/2a chimeric virus, which originally had an adenine at the nucleotide position 29. HCV122KO exhibited efficient RNA replication in miR-122-knockout cells and non-hepatic cells without exogenous expression of miR-122. Competition assay revealed that the G28A mutant was dominant in the absence of miR-122, but its effects were equivalent to those of the wild type in the presence of miR-122, suggesting that the G28A mutation does not confer an advantage for propagation in miR-122-rich hepatocytes. These observations may explain the clinical finding that the positive rate of G28A mutation was higher in miR-122-deficient PBMCs than in the patient serum, which mainly included the hepatocyte-derived virus from HCV-genotype-2a patients. These results suggest that the emergence of HCV mutants that can propagate in non-hepatic cells in an miR-122-independent manner may participate in the induction of extrahepatic manifestations in chronic hepatitis C patients.

Frequency and role of NKp46 and NKG2A in hepatitis B virus infection.

BACKGROUND AND AIM: Natural Killer (NK) cells are involved in the control of viral infection. However, the role of NK cells in chronic hepatitis B (CHB) remains unclear. This study investigated the frequencies and roles of NK cells in CHB, with a focus on activating receptor NKp46 and inhibitory receptor NKG2A. PATIENTS/METHOD: Peripheral blood lymphocytes were obtained from 71 CHB patients and 37 healthy subjects (HS). The expressions of NKp46 and NKG2A were analyzed using flow cytometry. The role of NKp46-ligand was assessed using an in vitro co-culture system. Cytotoxicity and IFN-γ production in NK cells were evaluated using RT-PCR and flow cytometry. RESULTS: CHB patients were classified into treatment-naïve patients with low HBV DNA titer (CHB-L; n = 28), high HBV DNA titer (CHB-H; n = 24) by the cut-off level of serum HBV DNA 4 log copies/ml, and patients receiving nucleos(t)ide analogue (CHB-NA; n = 19). The expressions of NKp46 and NKG2A were higher in CHB-H than in HS/CHB-L/CHB-NA. HepG2.2.15 had higher NKp46-ligand expression than HepG2. When NK cells from HS were co-cultured with HepG2.2.15, inhibition of the NKp46 and NKp46-ligand interaction by anti-NKp46 antibody significantly reduced cytolysis of HepG2.2.15 and IFN-γ production. However, those reductions were not observed in co-culture with HepG2. Additionally, NK cells that highly expressed NKp46 also highly expressed NKG2A (NKp46highNKG2Ahigh subset). The frequencies of NKp46highNKG2Ahigh subset in CHB-H were higher than those in HS/CHB-L/CHB-NA. Among treatment-naïve CHB patients, the frequencies of NKp46highNKG2Ahigh subset were positively correlated with serum ALT (P<0.01, r = 0.45) and HBV DNA (P<0.01, r = 0.59) levels. The expressions of Fas-L, STAT1, TRAIL and CD107a were higher and IFN-γ expression was lower in the NKp46highNKG2Ahigh subset than in the other subsets. CONCLUSION: The NKp46 and NKp46-ligand interaction contributes to NK cell activation. A novel NK cell subset, the NKp46highNKG2Ahigh subset, may be associated with liver injury and HBV replication.

CD14+ monocyte-derived galectin-9 induces natural killer cell cytotoxicity in chronic hepatitis C.

Natural killer (NK) cell activation is associated with both liver injury and persistent infection in chronic hepatitis C (CHC); however, the detailed mechanism of this activation has not yet been fully elucidated. Because galectin-9 (Gal-9) has been reported to be increased in the serum and liver tissue of CHC patients, we investigated the function of Gal-9 in NK cell activation in CHC. First, we evaluated the function of Gal-9 on NK cytotoxicity in vitro. Gal-9 treatment resulted in increased cytotoxicity of naïve NK cells, and the Gal-9-activated NK cells demonstrated cytotoxicity toward hepatoma cells and T cells. Additionally, coculturing peripheral blood mononuclear cells (PBMCs) with JFH-1/Huh7.5.1 cells increased both Gal-9 production and NK cell cytotoxicity. Next, we investigated the source of Gal-9 and the mechanism of Gal-9 production. Deletion of CD14+ monocytes from PBMCs resulted in reduced Gal-9 production in the coculture with JFH-1/Huh7.5.1 cells. Gal-9 production was driven by coculturing of PBMCs with apoptotic hepatocytes. Blocking integrin αv ß3 , a receptor for phosphatidylserine expressed on apoptotic cells, also resulted in decreased Gal-9 production. Finally, we found that serum Gal-9 levels were significantly higher in CHC patients than in healthy donors and patients who achieved sustained virologic response. Among CHC patients, serum Gal-9 levels were significantly higher in patients with elevated alanine aminotransferase (ALT) than in those with normal ALT. CONCLUSION: These results demonstrate that CD14+ monocyte-derived Gal-9 increases NK cell cytotoxicity in HCV infection, which might be associated with liver injury and persistent infection. (Hepatology 2017;65:18-31).

A case report of pancreatic metastasis from synovial sarcoma successfully treated by metastasectomy with adjuvant chemotherapy.

INTRODUCTION: Synovial sarcoma is a malignant soft tissue sarcoma which arises near joints. The most frequent metastasis sites of synovial sarcoma are the lungs, lymph nodes, and bone. Pancreatic metastasis is quite rare; only 3 cases have been reported worldwide to date. We herein present the 4th case of pancreatic metastasis from synovial sarcoma. METHODS AND RESULTS: A 32-year-old man underwent extended excision of synovial sarcoma in the left pelvis and femur in 2009. In 2013, follow-up contrast-enhanced computed tomography revealed a 35-mm heterogeneously enhanced mass in the pancreas body. Endoscopic ultrasound-guided fine needle aspiration of the mass revealed a diffuse proliferation of atypical spindle cells in a fascicular arrangement. Because the histology was quite similar to the resected specimen of synovial sarcoma in 2009, the mass was suspected to be a metastasis from synovial sarcoma. Laparoscopic distal pancreatectomy with adjuvant adriamycin/ifosfamide chemotherapy was subsequently performed. Synovial sarcoma-specific SS18-SSX1 (synovial sarcoma translocation, chromosome 18-synovial sarcoma X1) or SS18-SSX2 chimera mRNA was detected in the resected specimen, confirming the diagnosis of metastasis from synovial sarcoma. The patient did well for 30 months without recurrence. CONCLUSION: This case suggests that pancreatic metastasis from synovial sarcoma can be successfully treated by metastasectomy with adjuvant chemotherapy.

The safety and benefit of pancreatic juice cytology under ERCP in IPMN patients.

BACKGROUND: International consensus guidelines 2012 for intraductal papillary mucinous neoplasia (IPMN), defined two characteristics: high-risk stigmata (HRS) and worrisome features (WF). Patients with WF require detailed examination including cytology. However, routine endoscopic retrograde cholangiopancreatography (ERCP) for cytology is not recommended in the guidelines due to risk of post-ERCP pancreatitis (PEP). Our aim was to clarify what types of IPMN were susceptible for PEP and gain benefit of ERCP. PATIENTS/METHODS: We examined 138 consecutive IPMN patients who underwent ERCP in our hospital, retrospectively. Patients were classified into HRS, WF and the others (N) based on imaging findings before ERCP. We assessed pancreatic juice cytology, PEP frequency and rate of malignant IPMN at 12 months after ERCP. RESULTS: The rates of cytological malignancy were 0% (N), 4.8% (WF) and 19.5% (HRS). The PEP frequency was 14.5%, and these risk factors were branch duct (BD)-IPMN, body/tail cysts and brush cytology by multivariate logistic analysis. The rates of malignant IPMN were 0% (N), 16.4% (WF) and 48.8% (HRS). Furthermore, we examined patients with WF in detail. The PEP frequency/rate of malignancy were 3.6%/23.1% in patients with main pancreatic duct (MPD) dilatation (5-9 mm), and the sensitivity of cytology was 33.3%. On the other hand, the PEP frequency/rate of malignancy were 17.2%/0% in patients with BD-IPMN fulfilling only cyst size over 30 mm. CONCLUSIONS: Routine ERCP for IPMN, especially for BD-IPMN, is not recommended. ERCP may be beneficial for WF patients with MPD dilatation based on a balance between PEP risk and presence of malignancy.