Autoimmune pancreatitis (AIP) is a unique subtype of chronic pancreatitis, which shares many clinical presentations with pancreatic ductal adenocarcinoma (PDA). The misdiagnosis of AIP often leads to unnecessary pancreatic resection. 18F-FDG positron emission tomography/ computed tomography (PET/CT) could provide comprehensive information on the morphology, density, and functional metabolism of the pancreas at the same time. It has been proved to be a promising modality for noninvasive differentiation between AIP and PDA. However, there is a lack of clinical analysis of PET/CT image texture features. Difficulty still remains in differentiating AIP and PDA based on commonly used diagnostic methods. Therefore, this paper studied the differentiation of AIP and PDA based on multi-modality texture features. We utilized multiple feature extraction algorithms to extract the texture features from CT and PET images at first. Then, the Fisher criterion and sequence forward floating selection algorithm (SFFS) combined with support vector machine (SVM) was employed to select the optimal multi-modality feature subset. Finally, the SVM classifier was used to differentiate AIP from PDA. The results prove that texture analysis of lesions helps to achieve accurate differentiation of AIP and PDA.
Objective To investigate the postoperative biochemical changes and the strategy of steroid treatment for autoimmune pancreatitis （AIP）. Methods Six patients with AIP from January 2007 to October 2011 in this hospital were included in this study. Four patients received pancreaticoduodenectomy or distal pancreatectomy for being preoperatively misdiagnosed as malignant tumors. Two patients avoided the unnecessary resection and received the internal drainage for obstructive jaundice and postoperative steroid medication because of a confirmation of AIP by intraoperative frozen biopsy. All the patients underwent routine examinations， including liver function， CA19-9 level， and imaging data. Measurement of serum IgG or IgG4 was performed for fewer patients after operation. Results CA19-9 levels were normal or slightly elevated in six AIP patients. For five patients with AIP in the head of pancreas， preoperative serum γ-GT levels were elevated. For these patients， whether pancreaticoduodenectomy or the internal drainage were performed， TB/DB levels were transiently elevated on day 1 or 4 after operation but dropped to below preoperative levelsor normal levels on day 7 after operation， and serum γ-GT levels among them presented a downward. Serum γ-globulin levels exhibited a downward trend among four AIP patients after resection， while a upward trend was found in another two AIP patients receiving internal drainage. From the limited data， elevated serum level of IgG in the AIP patients were found. As to IgG4， the only case was tested on month 7 after operation， the serum IgG4 level was elevated. CT showed that the swollen status of pancreas obviously reduced on month 3 after operation as compared with before operation.Conclusions Postoperative steroid therapy of AIP should be based on the serum γ-globulin level and operation method. CT or MRI imaging is used to evaluate the response to steroid treatment for the AIP patients.
ObjectiveTo analyze the R0 resection rate and survival time of pancreatic cancer with serum IgG4 elevated, and to discuss whether serum IgG4 can distinguish autoimmune pancreatitis from pancreatic cancer.MethodsThe retrospective cohort study was adopted. The clinical data of 146 patients with pancreatic cancer confirmed by histology in Affiliated Hospital of Qingdao University from January 2016 to December 2019 were analyzed retrospectively. According to the level of serum IgG4, they were divided into normal IgG4 group (<1.35 g/L, n=124) and IgG4 elevated group (≥1.35 g/L, n=22). The tumor R0 resection rate, survival time and whether complicated with AIP of the two groups were compared.ResultsOne hundred and one patients (81.5%) with normal serum IgG4 underwent radical surgery, while only 13 patients (59.1%) with elevated serum IgG4 underwent radical surgery, the difference was significant (P=0.019). The median survival time of patients with normal serum IgG4 was 18.7 months, while patients with elevated serum IgG4 was 8.1 months, there was no significant difference between the two groups (P=0.121). Subgroup analysis showed that the median survival time of patients with pancreatic ductal adenocarcinoma in the normal IgG4 group was 17.5 months, while the IgG4 elevated group was 6.8 months, the difference was significant (P=0.016). Only 1 case of pancreatic cancer with AIP in the 2 groups.ConclusionsSerum IgG4 ≥1.35 g/L indicates low radical resection rate in pancreatic cancer and poor prognosis in pancreatic ductal adenocarcinoma. Serum IgG4 can only be used as an auxiliary index to distinguish pancreatic cancer from autoimmune pancreatitis.
ObjectiveTo learn the distribution pattern and characteristics of autoimmune pancreatitis research literature, and its worldwide research trend.
MethodsPublished data between September 22, 2004 and September 21, 2014 were searched by using the keyword autoimmune pancreatitis in the database of Pubmed. Publication year, journals, authors and research topics were bibliometrically analyzed. The analysis software Bibliographic Item Co-occurrence Matrix Builder was used for cluster analysis on high-frequency keywords.
ResultsA total of 1 518 articles on autoimmune pancreatitis were acquired. The amount of published literature rose rapidly in the past 10 years, reaching its peak in the year of 2012. Most of the articles were published by several leading authors in the leading journals. There were 26 keywords with a frequency of more than 30 times, and 4 categories were classified through cluster analysis of these keywords. They were pathology and immunology, imaging, diagnosis and treatment.
ConclusionsAttention on autoimmune pancreatitis has been increasing in the recent 10 years. Japanese researchers have been taking the lead. Current research focus is the diagnosis of autoimmune pancreatitis.
