Invasive and Non-Invasive Diagnosis of Pancreatic Fibrosis in Patients with Complicated Forms of Chronic Pancreatitis

The purpose of the study was to identify the patterns of changes in the state of the parenchyma of the pancreas in patients with complicated forms of chronic pancreatitis with evaluation of the diagnostic effectiveness of shear wave elastometry (graphy). Materials and methods. For the period from 2006 to 2018 58 patients with complicated forms of chronic pancreatitis were examined. The average age of patients is (47.1±3.2) years old. The medical history ranged from 3 to 15 years. The basis of morphological studies were biopsies of the pancreas obtained during surgery. Ultrasound elastometry and pancreatic parenchymal elastography were performed by transcutaneous shear wave approach in Shear Wave Elastography. Software consistency was assessed by the nature of the color mapping. Results and discussion. The morphometry of the volume parts of the structural components of the pancreas showed that with the development of complicated chronic pancreatitis there is an increase in the area of fibrous tissue and a decrease in the area of acinar components. The proof of this is the strong inverse relationship between the degree of fibrosis and the volume fraction of acinar tissue (r= -0.83; р <0.05), as well as the direct relationship between the degree of fibrosis and the volume fraction of connective tissue (r=0.61; р <0.05). If at a fibrosis of the III degree acinar tissue occupied (25.39±2.01)%, connective – (64.33±3.85)%, fatty – (6.42±4.48)%, at a fibrosis of the IV degree noted the following: the proportion of acinar tissue was only (2.86±0.76)%, connective – (74.11±4.17)%, and (20.14±4.29)% was adipose tissue. Such manifestations indicated severe irreversible changes in the external secretory function of the pancreas. When assessing changes in the stiffness of the pancreatic parenchyma with the deepening of fibrosis processes and data from transcutaneous shear wave elastography, it was found that the degree of fibrosis according to morphological data correlated with the degree of fibrosis according to shear wave elastography, r = 0.71; p <0.05. The following patterns were noted. Grade II pancreatic fibrosis was characterized by intralobular fibrosis, which covered 26-50% of the gland area, which corresponded to the shear wave elastography data in green-blue color (5.98-7.05 kPa). Grade III pancreatic fibrosis corresponded to intralobular fibrosis, which covered 51-75% of the gland area in shear wave elastography in green-yellow color (7.06-9.06 kPa). Grade IV pancreatic fibrosis was characterized by intralobular fibrosis, which covered 76-100% of the gland area, which corresponded to shear wave elastography data in yellow-red color (> 9.07 kPa). Conclusion. Thus, the objectification of shear wave elastography indicators of the pancreas based on the correlation of histological evaluation and morphometric indicators of structural changes in the pathological process allows to consider transcutaneous shear wave elastography as a promising and reliable method of non-invasive diagnosis of fibrosis in chronic pancreatitis

Histological and transcriptional characterization of the pancreatic acinar tissue in type 1 diabetes

IntroductionDespite a reduced function and volume of the exocrine pancreas in type 1 diabetes, the acinar cells remain understudied in type 1 diabetes research. The hypothesis of this study is that the acinar tissue is altered in subjects with type 1 diabetes compared with subjects without diabetes.Research design and methodsThe cell density, expression of digestive enzymes, and transcriptome of acinar tissue at varying distances from islets were analyzed using histology, immunostaining, and AmpliSeq RNA sequencing of laser capture microdissected tissue. Pancreases examined were from organ donors with or without type 1 diabetes.ResultsWe demonstrate preserved acinar nuclei density and find no support of acinar atrophy in type 1 diabetes. Staining for digestive enzymes (amylase, lipase, and trypsin) demonstrated an evenly distributed expression in the exocrine parenchyma; although occasional amylase-negative regions appeared in tissue that had been formalin-fixed and paraffin-embedded, this phenomenon was not evident in frozen tissue. Gene set enrichment analysis of whole transcriptome data identified transcriptional alterations in type 1 diabetes that were present in the acinar tissue independent of the distance from islets. Among these, the two most enriched gene sets were Myc Targets V2 and Estrogen Response Early.ConclusionTaken together, these new data emphasize the involvement of the entire pancreas in type 1 diabetes pathology. The alteration of the gene sets Myc Targets V2 and Estrogen Response Early is a possible link to the increased incidence of pancreatic cancer in type 1 diabetes.

VISTA: VIsual Semantic Tissue Analysis for pancreatic disease quantification in murine cohorts

Mechanistic disease progression studies using animal models require objective and quantifiable assessment of tissue pathology. Currently quantification relies heavily on staining methods which can be expensive, labor/time-intensive, inconsistent across laboratories and batch, and produce uneven staining that is prone to misinterpretation and investigator bias. We developed an automated semantic segmentation tool utilizing deep learning for rapid and objective quantification of histologic features relying solely on hematoxylin and eosin stained pancreatic tissue sections. The tool segments normal acinar structures, the ductal phenotype of acinar-to-ductal metaplasia (ADM), and dysplasia with Dice coefficients of 0.79, 0.70, and 0.79, respectively. To deal with inaccurate pixelwise manual annotations, prediction accuracy was also evaluated against biological truth using immunostaining mean structural similarity indexes (SSIM) of 0.925 and 0.920 for amylase and pan-keratin respectively. Our tool’s disease area quantifications were correlated to the quantifications of immunostaining markers (DAPI, amylase, and cytokeratins; Spearman correlation score = 0.86, 0.97, and 0.92) in unseen dataset (n = 25). Moreover, our tool distinguishes ADM from dysplasia, which are not reliably distinguished with immunostaining, and demonstrates generalizability across murine cohorts with pancreatic disease. We quantified the changes in histologic feature abundance for murine cohorts with oncogenic Kras-driven disease, and the predictions fit biological expectations, showing stromal expansion, a reduction of normal acinar tissue, and an increase in both ADM and dysplasia as disease progresses. Our tool promises to accelerate and improve the quantification of pancreatic disease in animal studies and become a unifying quantification tool across laboratories.

Single-cell resolution analysis of the human pancreatic ductal progenitor cell niche

We have described multipotent progenitor-like cells within the major pancreatic ducts (MPDs) of the human pancreas. They express PDX1, its surrogate surface marker P2RY1, and the bone morphogenetic protein (BMP) receptor 1A (BMPR1A)/activin-like kinase 3 (ALK3), but not carbonic anhydrase II (CAII). Here we report the single-cell RNA sequencing (scRNA-seq) of ALK3bright+-sorted ductal cells, a fraction that harbors BMP-responsive progenitor-like cells. Our analysis unveiled the existence of multiple subpopulations along two major axes, one that encompasses a gradient of ductal cell differentiation stages, and another featuring cells with transitional phenotypes toward acinar tissue. A third potential ducto-endocrine axis is revealed upon integration of the ALK3bright+ dataset with a single-cell whole-pancreas transcriptome. When transplanted into immunodeficient mice, P2RY1+/ALK3bright+ populations (enriched in PDX1+/ALK3+/CAII− cells) differentiate into all pancreatic lineages, including functional β-cells. This process is accelerated when hosts are treated systemically with an ALK3 agonist. We found PDX1+/ALK3+/CAII− progenitor-like cells in the MPDs of types 1 and 2 diabetes donors, regardless of the duration of the disease. Our findings open the door to the pharmacological activation of progenitor cells in situ.

Features of pathogenesis, progression and structure of pancreatic fibrosis in chronic pancreatitis

The article is devoted to the results of our own study of structural and fibrotic changes in the pancreatic parenchyma in patients with chronic pancreatitis. It was shown that the formation of fibrous tissue in chronic pancreatitis begins from the ducts and gradually covers the interlobar space and penetrates into the lobes of the pancreas. As fibrosis progresses, the volume fraction of exocrine tissue decreases due to the activation of apoptosis mechanisms and due to fatty degeneration. With a high degree of fibrosis, focal vacuolar dystrophy was detected in the acinar tissue of the pancreatic lobules of all patients, focal apoptosis and lobular apoptosis was observed in 45.4 %. With complete atrophy of the acinar tissue of the pancreatic lobes, hyperplasia of the epithelium of the interlobar and intralobar ducts was observed. The adaptive neoplasm of the endocrine islets (non-idiogenesis) from the epithelium of the intralobular ducts of the pancreas was revealed.

The Pancreas

The casual observer might be forgiven for assuming that the pancreas plays an insignificant role given its size, morphology, and location. Indeed, Galen and anatomists for a millennium considered the pancreas a fatty cushion on which the stomach rested. In truth, this largest digestive gland, situated in the center of the body, on either side of the transpyloric (L1) plane, is notable for its complex anatomy and the colocation of exocrine and endocrine organs. The pancreas is an organ of endless fascination, with congenital anomalies giving rise to a range of anatomic variations, anatomic relations challenging the most meticulous surgeons, and wide-ranging pathology of clinical significance. Surgical management of pancreatic disease requires a detailed understanding of the anatomy of the pancreas and its relation to adjacent vital structures, and the management of patients with diseases related to the pancreas requires a detailed understanding of the physiology of both the exocrine and the endocrine pancreas. The functional reserve of the gland is such that over 50% of its acinar tissue must be destroyed before there is marked evidence of an effect on digestion, and more than 70% of insulin secreting beta cells must be destroyed before the endocrine functions of the gland are affected. This review contains 16 figures, and 16 references. Key words: chronic pancreatitis, pancreas, pancreatic anatomy, pancreatic cancer, pancreatic pathology, pancreatic physiology, pancreatitis

Deformability-based microfluidic separation of pancreatic islets from exocrine acinar tissue for transplant applications

Tangential flows for selective deformation of acinar tissue and periodic switching of hydrodynamic resistance enables high-throughput islet enrichment in transplant samples.

Морфологічні основи розвитку хронічного інтерстиційного сіалоаденіту при патології гепатобіліарної системи

Reactive changes of different nature in salivary glands is accompanied by many diseases of internal organs. Due to the complex neurohormonal regulation, bile secretion system is functionally interconnected with all organs and systems of the digestive tract. The article presents data of structural changes of acinar tissue and bloodstream of parotid salivary gland in experimental obstructive jaundice. It was established that the degree of morphological changes in the parotid gland, angioarchitectonics state and nature of degenerative and destructive processes is directly dependent on the duration of obstructive cholestasis.