Clinical Usefulness of Serum Autotaxin for Early Prediction of Relapse in Male Patients with Type 1 Autoimmune Pancreatitis.

BACKGROUND: Serum IgG4 level is a useful diagnostic marker for autoimmune pancreatitis (AIP), but it is difficult to use to predict relapse. AIMS: We investigated whether serum autotaxin (ATX) level is predictive of AIP relapse after steroid therapy. METHODS: Fifty-six patients with type 1 AIP were investigated. We measured serum ATX at the time of diagnosis. We selected 24 males for whom serum samples during steroid therapy had been obtained and measured serum ATX at steroid therapy for induction of remission and at maintenance therapy. In the relapse group, we also measured ATX at the time of relapse. RESULTS: ATX was significantly higher in female patients than in male patients. In order to clarify changes in ATX during steroid therapy, we focused on 24 male patients. We found that ATX decreased significantly during steroid therapy for induction of remission and at the time of maintenance therapy. In half of all patients who relapsed during maintenance therapy, ATX was significantly elevated at the time of relapse compared with that of induction therapy (P = 0.039). When we compared ATX at the time of maintenance therapy between patients with relapse and without, we observed significantly higher ATX in the former (P = 0.024). We found that the combination of ATX and elastase-1 could predict relapse with high accuracy (95%). CONCLUSIONS: Preliminary evidence suggests that serum ATX might serve as a candidate biomarker to predict relapse of AIP as well as to monitor the effect of steroid therapy.

Usefulness of peroral cholangioscopy in the differential diagnosis of IgG4-related sclerosing cholangitis and extrahepatic cholangiocarcinoma: a single-center retrospective study.

BACKGROUND: In the diagnosis of IgG4-related sclerosing cholangitis (IgG4-SC), differentiation from extrahepatic cholangiocarcinoma (ECC) is extremely important but is still a clinical challenge. This study aimed to elucidate the usefulness of peroral cholangioscopy (POCS) for the differential diagnosis between IgG4-SC and ECC. METHODS: POCS findings for bile duct stricture were retrospectively evaluated in 17 patients with IgG4-SC diagnosed at the Hiroshima University Hospital and 53 patients with surgically resected infiltrating ECC. Mucosal surface, dilated vessels (tortuosity, caliber alteration, and disruption), and easily bleeding were compared between the groups. RESULTS: The stricture sites of IgG4-SC evaluated by POCS were 10 extrapancreatic bile ducts and 9 intrapancreatic bile ducts. In patients with IgG4-SC, smooth mucosal surface was observed in 89% (17/19), dilated vessels in 58% (11/19) [tortuosity 82% (9/11), caliber alteration 18% (2/11), and disruption 9% (1/11)], and easily bleeding in 0%. Irregular mucosal surface and easily bleeding were observed significantly more frequently in ECC (both P <  0.001). The frequency of caliber alteration and disruption of dilated vessels was significantly less in IgG4-SC (P <  0.001 and 0.005, respectively). The sensitivity and specificity of POCS in the diagnosis of ECC were 96 and 89%, respectively. Dilated vessels in IgG4-SC were observed significantly more frequently in the extrapancreatic bile duct, especially the hilar bile duct (P = 0.006). Concerning image evaluation, the interobserver agreement was κ = 0.719, and the intraobserver agreement was κ = 0.768 and 0.754. CONCLUSIONS: Characteristic POCS findings of the stricture sites in IgG4-SC were smooth mucosal surface, dilated vessels without caliber alteration and disruption, and lack of easily bleeding. These POCS findings are extremely useful for distinguishing between IgG4-SC and ECC.

The role of apparent diffusion coefficient value in the diagnosis of localized type 1 autoimmune pancreatitis: differentiation from pancreatic ductal adenocarcinoma and evaluation of response to steroids.

PURPOSE: The aim of this study was to clarify the usefulness of the apparent diffusion coefficient (ADC) value in the differential diagnosis of localized autoimmune pancreatitis (AIP) and pancreatic ductal adenocarcinoma (PDAC) and the evaluation of response to steroids. METHODS: This study retrospectively analyzed 40 patients with localized AIP and 71 patients with PDAC who underwent abdominal MRI with DWI (b = 0 and 1000 s/mm2). Their ADC values at the lesion sites and five MRI findings useful for diagnosing AIP were evaluated. In addition, ADC values before and after steroid therapy were compared in 28 patients with localized AIP. RESULTS: The median ADC value was significantly lower for localized AIP than for PDAC (1.057 × 10-3 vs 1.376 × 10-3 mm2/s, P < 0.001). In the ROC curve analysis, the area under the curve was 0.957 and optimal cut-off value of ADC for differentiating localized AIP from PDAC was 1.188 × 10-3 mm2/s. ADC value ≤ 1.188 × 10-3 mm2/s showed the highest sensitivity and accuracy among the MRI findings (92.6% and 90.7%, respectively), and when combined with one or more other MRI findings, showed 96.3% specificity. The median ADC values before and after steroid therapy (mean 7.9 days) were 1.061 × 10-3 and 1.340 × 10-3 mm2/s, respectively, and ADC values were significantly elevated after steroid induction (P < 0.001). CONCLUSION: The measurement of ADC values was useful for the differential diagnosis of localized AIP and PDAC and for the early determination of the effect of steroid therapy.

Role of Endoscopic Ultrasonography and Endoscopic Retrograde Cholangiopancreatography in the Diagnosis of Pancreatic Cancer.

Pancreatic cancer has the poorest prognosis among all cancers, and early diagnosis is essential for improving the prognosis. Along with radiologic modalities, such as computed tomography (CT) and magnetic resonance imaging (MRI), endoscopic modalities play an important role in the diagnosis of pancreatic cancer. This review evaluates the roles of two of those modalities, endoscopic ultrasonography (EUS) and endoscopic retrograde cholangiopancreatography (ERCP), in the diagnosis of pancreatic cancer. EUS can detect pancreatic cancer with higher sensitivity and has excellent sensitivity for the diagnosis of small pancreatic cancer that cannot be detected by other imaging modalities. EUS may be useful for the surveillance of pancreatic cancer in high-risk individuals. Contrast-enhanced EUS and EUS elastography are also useful for differentiating solid pancreatic tumors. In addition, EUS-guided fine needle aspiration shows excellent sensitivity and specificity, even for small pancreatic cancer, and is an essential examination method for the definitive pathological diagnosis and treatment decision strategy. On the other hand, ERCP is invasive and performed less frequently for the purpose of diagnosing pancreatic cancer. However, ERCP is essential in cases that require evaluation of pancreatic duct stricture that may be early pancreatic cancer or those that require differentiation from focal autoimmune pancreatitis.