Apolipoprotein A2 isoforms associated with exocrine pancreatic insufficiency in early chronic pancreatitis

BACKGROUND AND AIM

Apolipoprotein A2 (apoA2) isoforms have been reported to undergo the aberrant processing in pancreatic cancer and pancreatic risk populations compared with that in healthy subjects. This study aimed to clarify whether apoA2 isoforms were as useful as N-benzoyl-p-aminobenzoic acid (BT-PABA) test for exocrine pancreatic dysfunction markers in patients with early chronic pancreatitis (ECP).

METHODS

Fifty consecutive patients with functional dyspepsia with pancreatic enzyme abnormalities (FD-P) (n = 18), with ECP (n = 20), and asymptomatic patients with pancreatic enzyme abnormalities (AP-P) (n = 12) based on the Rome IV classification and the Japan Pancreatic Association were enrolled in this study. The enrolled patients were evaluated using endoscopic ultrasonography and endoscopic ultrasonography elastography. Five pancreatic enzymes were estimated. Pancreatic exocrine function was analyzed using the BT-PABA test. Lighter and heavier apoA2 isoforms, AT and ATQ levels were measured by enzyme-linked immunosorbent assay methods.

RESULTS

There were no significant differences in clinical characteristics such as age, gender, body mass index, alcohol consumption and smoking among patients with AP-P, FD-P, and ECP. The BT-PABA test and lighter apoA2 isoform, AT level in the enrolled patients had a significant correlation (P < 0.01). The BT-PABA test in patients with ECP was significantly lower (P = 0.04) than that in AP-P. ApoA2-AT level in patients with ECP was lower than that in AP-P, albeit, insignificantly. Interestingly, apo A2-AT level was significantly (P = 0.041) associated with exocrine pancreatic insufficiency by multiple logistic regression analysis.

CONCLUSIONS

ApoA2-AT level is a useful tool to evaluate exocrine pancreatic insufficiency in the early stage of chronic pancreatitis.

Proposal and Validation of New Diagnostic Criteria for Diagnostic Weights of Endoultrasonographic Findings for Early Chronic Pancreatitis

[Background and study aim] A commonly applied method for diagnosing chronic pancreatitis (CP) uses endoscopic ultrasonography (EUS), assigning weights to each EUS diagnostic finding. It is the Rosemont classification (RC). In 2019, to improve EUS diagnostic specificity, Japanese diagnostic criteria for early chronic pancreatitis (ECP) were revised. Nevertheless, the criteria use no weighting of EUS diagnostic findings, as the RC does. This study was undertaken to propose diagnostic criteria that would weight each EUS finding of ECP and that would be more specific than the RC. [Methods] By EUS of the pancreas, 773 patients underwent detailed observation from January 2018 to March 2019 at our institution. An expert finalized all cases when patients were diagnosed. Using data from the medical records, 97 consecutive patients with EUS diagnostic findings of ECP based on the Japanese diagnostic criteria of ECP2009 (JDCECP2009) were selected. The definition under the RC of "Indeterminate for CP" was equivalent to ECP. Each case was diagnosed using (1) JDCECP2009 and (2) the Japanese diagnostic criteria of ECP2019 (JDCECP2019). Moreover, the four diagnostic EUS findings in JDCECP2019 were applied to the RC, weighted (modified-JDCECP2019), and subsequently compared with the earlier diagnostic criteria. As Modified-JDCECP2019, we suggested (3) RC-A-the current four items scored related to the RC, and (4) RC-B-the five items scored by dividing lobularity with and without honeycombing. [Results] Diagnoses produced based on each criterion were normal: ECP = (1) 20:77, (2) 46:51, (3) 52:42, and (4) 60:35. [Conclusions] Modified-JDCECP2019 may provide EUS diagnoses for ECP with higher specificity.

Measuring optimal ultrasound speed using endoscopic ultrasound in patients with chronic pancreatitis, including early stage

OBJECTIVES

Ultrasound speed (USS) correction improves image quality by estimating the optimal USS correcting the deviation from a predetermined USS. This study assessed USS differences between chronic pancreatitis (CP), early CP (ECP), and normal pancreas when using endoscopic ultrasound (EUS). The usefulness of measuring optimal USS was evaluated for patients with CP, including early stage patients.

METHODS

This study enrolled 116 consecutive patients for whom USS was measured using an EUS system. The USS correction principle is generation of a B-mode image by changing the USS in all ranges while correcting the delay in the received data. Final diagnoses were made according to the Japanese diagnostic criteria for CP in 2019. They were classified as CP, ECP, or normal. We compared USS applied for these three groups.

RESULTS

The medians and ranges of USS values for patients in the normal, ECP, and CP groups were 1506.0 (1407-1600) m/s, 1580.0 (1520-1630) m/s, and 1574.0 (1537-1610) m/s, respectively. The USS values of the ECP and CP groups were significantly higher than those of the normal group (P < 0.001). Analyses of the receiver operating characteristic curve in the normal pancreas, ECP, and CP revealed the area as 0.957, with specificity and sensitivity of 95.9% and 87.5%, respectively, using the USS of 1535 m/s as a cut-off.

CONCLUSION

Measurement of USS might be particularly useful for distinguishing between normal and ECP imaging.

Comparison of clinical characteristics, eating behaviors, and clinical symptoms following fat intake in functional dyspepsia with functional dyspepsia with pancreatic enzyme abnormalities between Singapore and Japan

BACKGROUND AND AIM

To clarify whether there were any significant differences in clinical symptoms and eating patterns between functional dyspepsia (FD) patients and FD with pancreatic enzyme abnormalities (FD-P) patients as refractory FD, we compared these factors in multicenter studies in Singapore and Japan.

METHODS

One hundred ninety-eight consecutive patients presenting with FD (n = 88), FD-P patients (n = 81) based on Rome III classification and controlled group (n = 39) recruited from six institutions in Singapore and Japan. Clinical characteristics, clinical symptoms for dietary fat intake, and eating behaviors were estimated using questionnaires. Anxiety and health-related quality of life were determined by STAI-state/-trait and SF-8, respectively.

RESULTS

There were no significant differences in age, sex, BMI, smoking, alcohol intake, past medical history, and history of allergy in FD and FD-P patients between Singapore and Japan. There were no significant differences in FD subtypes, gastrointestinal symptom rating scale score, severity of FD symptoms, and eating pattern in Singapore and Japan. Moreover, there were significant differences in certain eating behaviors between FD and FD-P patients in Singapore and Japan. Interestingly, epigastric pain and early satiety following fat meals in FD-P patients were significantly (P = 0.003 and P = 0.008, respectively) higher compared with those in FD patients in Japan. Physical component score in FD-P patients was significantly (P = 0.019) disturbed compared with those in FD patients in Japan.

CONCLUSIONS

Epigastric pain and early satiety following fat meals in FD-P patients may be useful tools to differentiate FD-P patients from FD patients in Japan.

A Comparative Study of Endoscopic Ultrasonography and Histopathology Images for the Diagnosis of Early Chronic Pancreatitis

OBJECTIVE

The concept of early chronic pancreatitis (ECP) and its diagnostic criteria were first proposed by Japan, using endoscopic ultrasonography (EUS) findings for diagnosis. However, these findings have not been supported by pathological findings. We aimed to examine the association between the EUS and pathological findings of the same area of the pancreas.

METHODS

In 12 patients who underwent pancreaticoduodenectomy for distal bile duct cancer without accompanying pancreatitis, a comparative analysis between preoperative EUS and pathological findings was performed. The part of the pancreas adjoining the portal vein was evaluated.

RESULTS

In 7 cases, abnormal EUS findings included in the diagnostic criteria for ECP were seen; the correlation of the accuracy of lobularity seen on EUS compared with the pathological findings of the pancreatic parenchyma (inflammatory cell infiltration, atrophy of acinar cells, and fibrosis) was high (83.3%-91.7%). Pancreatic duct findings revealed that the accuracy of the hyperechoic margin of the pancreatic duct on EUS compared with pathological findings (wall thickness of pancreatic duct) was high (83.3%).

CONCLUSIONS

Endoscopic ultrasonography findings for ECP, according to Japan's 2019 revised criteria, lobularity, and the hyperechoic margin of the pancreatic duct may highly correspond to the pathological findings of chronic inflammation.

Pancreatic Fibrosis (Early Chronic Pancreatitis) as Emerging Diagnosis in Structural Causes of Dyspepsia: Evidence from Endoscopic Ultrasonography and Shear Wave Elastography

A new concept for the diagnosis and management of non-functional dyspepsia in guidelines was lacking in the past decade. Medical advancement has proven pancreatic fibrosis (essential image evidence of early chronic pancreatitis) to be a cause of dyspepsia and related to pancreatic exocrine dysfunction. This study aimed to analyze the clinical picture, biomarker, and percentage of pancreatic fibrosis in the dyspeptic population. A total of 141 consecutive patients were retrospectively enrolled. They were diagnosed with peptic ulcer disease, 9.2% (n = 13); pancreatic fibrosis, 17% (n = 24); pure Helicobacter pylori infection, 19.9% (n = 28); functional dyspepsia, 53.2% (n = 75); and chronic pancreatitis, 0.7% (n = 1). Among those with pancreatic fibrosis, (n = 24), 11 were diagnosed on the basis of a pancreatic acoustic radiation force impulse exceeding 1.4 m/s, and the remaining 13 were diagnosed with early chronic pancreatitis with at least three of the Japanese endoscopic ultrasonography criteria. The anatomic distribution of parenchymal criteria of early chronic pancreatitis was head, 53%; body, 38%; and tail, 9%. There were 17 cases (71%, 17/24) without Helicobacter pylori and whose dyspepsia improved after pancreatic enzyme replacement with a ratio of 82.3% (14/17). Of the 141 cases, 19 received gastric emptying scintigraphy and Western blot analysis of chromogranin-A in duodenal mucosa. Delayed gastric emptying was more common in functional dyspepsia and chromogranin-A was expressed more in pancreatic fibrosis. In conclusion, pancreatic fibrosis (including early chronic pancreatitis) outnumbered peptic ulcer disease in the dyspeptic population and pancreatic enzyme therapy was effective for 82% of cases. In early chronic pancreatitis, pancreatic fibrosis is dominant in the head location, and duodenum mucosa chromogranin-A is a potential biomarker with increased expression in an age-matched manner.

Interobserver Reliability of the Endoscopic Ultrasound Criteria for the Diagnosis of Early Chronic Pancreatitis: Comparison between the 2009 and 2019 Japanese Diagnostic Criteria

In 2009, diagnostic criteria for early chronic pancreatitis (DCECP2009) were proposed by the Japan Pancreas Society. This study aimed to evaluate the interobserver reliability (IOR) of endoscopic ultrasound (EUS) criteria for diagnosis of early chronic pancreatitis (ECP) between DCECP2009 and 2019 diagnostic criteria for ECP (DCECP2019) to assess the validity of the revision from the perspective of EUS findings. Among patients who underwent a detailed observation of the pancreas by EUS at our institution between January 2018 and March 2019, EUS images of 97 patients were extracted. Images were reviewed by 12 gastrointestinal endoscopy experts (eight pancreatologists, group A and four nonpancreatologists, group B). The overall kappa (K)-values for the IOR of the DCECP2009 EUS criteria were 0.424 and 0.563:0.231 for groups A:B, whereas the overall K-values for the DCECP2019 criteria were 0.618, and 0.733:0.442 for groups A:B. Regarding changes in the final diagnosis of ECP based on clinical features and EUS findings, 20 cases were definite ECP, 53 were probable ECP, and 24 were normal according to DCECP2009. In contrast, seven were definite ECP, 19 were probable ECP, and 71 were normal according to DECEP2019. IOR of DCECP2019 was higher than that of DCECP2009, which indicates an improvement in precision.

Endosonographic features in patients with non-alcoholic early chronic pancreatitis improved with treatment at one year follow up

Since the prevention of early chronic pancreatitis (ECP) into chronic pancreatitis might be critical for the reduction of pancreatic cancer, we tried to clarify the pathophysiology of ECP patients, focusing on ECP patients without alcoholic chronic pancreatitis. 27 ECP patients without alcoholic chronic pancreatitis and 33 patients with functional dyspepsia with pancreatic enzyme abnormalities (FD-P) were enrolled in this study. Diagnosis of ECP was made when imaging findings showed the presence of more than 2 out of 7 endoscopic ultrasound features. Duodenal degranulated eosinophils and glucagon-like peptide 1 producing cells were estimated by immunostaining. There were no significant differences in characteristics and psychogenic factors between ECP and FD-P patients. Interestingly, endoscopic ultrasound score in ECP patients significantly improved, albeit clinical symptoms in ECP patients showed no improvement at one year follow up. The extent of migration of duodenal degranulated eosinophils in FD-P patients was significantly higher compared to that in ECP patients. The levels of elastase-1 and trypsin in ECP patients with improved endoscopic ultrasound features were significantly reduced by the treatment. Further studies will be needed to clarify whether clinical symptoms and endoscopic ultrasound features in ECP patients without alcoholic chronic pancreatitis were improved in longer follow up study.

Intravoxel incoherent motion magnetic resonance imaging for assessment of chronic pancreatitis with special focus on its early stage

Background

It is clinically necessary to validate a new non-invasive and reliable imaging method to detect early chronic pancreatitis. Intravoxel incoherent motion magnetic resonance imaging (MRI) is useful for quantitative assessment in abdominal solid organs.

Purpose

To investigate the usefulness of intravoxel incoherent motion MRI parameters in the diagnosis of chronic pancreatitis.

Material and Methods

Sixty patients with early chronic pancreatitis (n = 44) and chronic pancreatitis (n = 16) were assessed with intravoxel incoherent motion imaging. For comparison, a control group of 71 individuals without chronic pancreatitis was also enrolled. The perfusion fraction (f), pseudo-diffusion coefficient (D*), true diffusion coefficient (D), and apparent diffusion coefficient of pancreatic parenchyma were calculated. These measurements were compared between the three groups. The diagnostic accuracy of imaging parameters was assessed.

Results

The f values of the early chronic pancreatitis group and the chronic pancreatitis group were significantly lower than those of the control group ( P < 0.001 and P < 0.001, respectively). The D* value of the chronic pancreatitis group was significantly lower than that of the early chronic pancreatitis group ( P = 0.0025). The D values of the early chronic pancreatitis group and the chronic pancreatitis group were significantly higher than those of the control group ( P = 0.001 and P = 0.001, respectively). The perfusion fraction showed the highest diagnostic performance with an Az value of 0.76 for discriminating the control group from the early chronic pancreatitis and chronic pancreatitis groups.

Conclusion

Intravoxel incoherent motion MRI parameters may reflect the minimal histological changes in early chronic pancreatitis.

Pancreatic Fibrosis and Chronic Pancreatitis: Mini-Review of Non-Histologic Diagnosis for Clinical Applications

Pancreatic fibrosis is the dominant reversible pathological change and diagnostic factor in early chronic pancreatitis, defined by a mechanistic approach proposed in 2016. Main guidelines for chronic pancreatitis were published by the American Pancreas Association in 2014, the Japanese Society of Gastroenterology in 2015, and United European Gastroenterology in 2017. All three sets of guidelines mentioned that the staging of chronic pancreatitis is important but challenging. There are various image modalities for the non-histologic diagnosis of pancreatic fibrosis: (1) shear wave elastography, such as an acoustic radiation force impulse with a cut-off value of 1.4 m/s; (2) strain elastography using grades of strain; (3) endoscopic ultrasonography using the Rosemont criteria or endoscopic ultrasound criteria for early chronic pancreatitis proposed by the Japan Pancreas Society; (4) computed tomography using the Hounsfield scale or number of micro-calcifications; and (5) magnetic resonance imaging using the apparent diffusion coefficient and the T1w flash and T2w HASTE sequences. The clinical applications are to (1) evaluate pancreatic tumors and inflammatory disease; (2) monitor dyspepsia with early chronic pancreatitis; (3) monitor individuals with a high risk of pancreatic cancer; (4) analyze a fatty pancreas with fibrosis; (5) predict a fistula after pancreatic surgery; and (6) predict outcomes for chronic pancreatitis or pancreatic cancer. The selection of tools will be dependent on the clinical scenario. Conclusion: There are various modalities for the non-histologic diagnosis of pancreatic fibrosis. The selection of the optimal device will be dependent on the clinical scenario.

A New Insight into Chronic Pancreatitis

Chronic pancreatitis (CP) is a pancreatic disease with poor prognosis characterized clinically by abdominal pain, morphologically by pancreatic stones/calcification, duct dilatation and atrophy, and functionally by pancreatic exocrine and endocrine insufficiency. CP is also known as a risk factor for the development of pancreatic cancer. CP has long been understood based on a fixed disease concept deduced from the clinical and morphological features of the end-stage disease. However, identification of causal genes for hereditary pancreatitis and success in the isolation and culture of pancreatic stellate cells have advanced the understanding of the underlying pathological mechanisms, the early-stage pathophysiology, and the mechanisms behind pancreatic fibrosis. These advances have led to moves aimed at improving patient prognosis through prevention of disease progression by early diagnosis and early therapeutic intervention. The strategy for preventing disease progression has included a proposal for diagnostic criteria for early CP and introduction of a new definition of CP in consideration of the pathological mechanisms. Our group has been committed deeply to these studies and has provided a large amount of information to the world.

Epigastric pain syndrome accompanying pancreatic enzyme abnormalities was overlapped with early chronic pancreatitis using endosonography

There was not available data about the overlap between functional dyspepsia (FD) and pancreatic diseases. We aimed to determine whether epigastric pain syndrome (EPS) accompanying with pancreatic enzyme abnormalities were associated with early chronic pancreatitis proposed by Japan Pancreas Society (JPS) using endosonography. We enrolled 99 consecutive patients presenting with typical symptoms of FD, including patients with postprandial distress syndrome (PDS) (n = 59), EPS with pancreatic enzyme abnormalities (n = 41) and EPS without pancreatic enzyme abnormalities (n = 42) based on Rome III criteria. Gastric motility was evaluated using the ¹³C-acetate breath test. Early chronic pancreatitis was detected by endosonography and graded from 0 to 7. The ratio of female patients among EPS patients (34/41) with pancreatic enzyme abnormalities was significantly (p = 0.0018) higher than the ratio of female EPS patients (20/42) without it. Postprandial abdominal distention and physical component summary (PCS) scores in EPS patients with pancreatic enzyme abnormalities were significantly disturbed compared to those in EPS patients without it. Interestingly, AUC₅ and AUC₁₅ values (24.85 ± 1.31 and 56.11 ± 2.51, respectively) in EPS patients with pancreatic enzyme abnormalities were also significantly (p = 0.002 and p = 0.001, respectively) increased compared to those (19.75 ± 1.01 and 47.02 ± 1.99, respectively) in EPS patients without it. Overall, 64% of EPS patients with pancreatic enzyme abnormalities were diagnosed by endosonography as having concomitant early chronic pancreatitis proposed by JPS. Further studies are warranted to clarify how EPS patients with pancreatic enzyme abnormalities were associated with early chronic pancreatitis proposed by JPS.

New developments in diagnosis and non-surgical treatment of chronic pancreatitis

Chronic pancreatitis is progressive and irreversible, leading to digestive and absorptive disorders by destruction of the exocrine pancreas and to diabetes mellitus by destruction of the endocrine pancreas. When complications such as pancreatolithiasis and pseudocyst occur, elevated pancreatic ductal pressure exacerbates pain and induces other complications, worsening the patient's general condition. Combined treatment with extracorporeal shock-wave lithotripsy and endoscopic lithotripsy is a useful, minimally invasive, first-line treatment approach that can preserve pancreatic exocrine function. Pancreatic duct stenosis elevates intraductal pressure and favor both pancreatolithiasis and pseudocyst formation, making effective treatment vitally important. Endoscopic treatment of benign pancreatic duct stenosis stenting frequently decreases pain in chronic pancreatitis. Importantly, stenosis of the main pancreatic duct increases risk of stone recurrence after treatment of pancreatolithiasis. Recently, good results were reported in treating pancreatic duct stricture with a fully covered self-expandable metallic stent, which shows promise for preventing stone recurrence after lithotripsy in patients with pancreatic stricture. Chronic pancreatitis has many complications including pancreatic carcinoma, pancreatic atrophy, and loss of exocrine and endocrine function, as well as frequent recurrence of stones after treatment of pancreatolithiasis. As early treatment of chronic pancreatitis is essential, the new concept of early chronic pancreatitis, including characteristics findings in endoscopic ultrasonograms, is presented.